I know it. I tried that with my pontoon boat, and had good success - however, at the time, it was the only pontoon boat refurbish video on TH-cam. I really enjoy Fireball Tools' build videos, where they are short, enjoyable, and to the point. When my skills develop more, I hope to be on his level of clarity and editing. After watching any of Matt's Off-Road Recovery build videos, I have sworn off build series.
I saw this video and literally looked further back in your video's looking for the "part 1" and all the rest.... nothin. That's when I realized how awesome it was to only have to deal with part 1 of 1.
That is a really impressive project. I enjoyed how violet it operated but understand it's different for you. For the bearing issue, would it be possible to create a semicircular track (rainbow) around the front of the chassis, with either greased skids or wheels that create a sandwich between the upper platform. Most support is required to counteract a downward force at the front. It would add loads of stability and relegate the slew bearing to a simple pivot point. For the hydraulic cylinder, if it's not air, maybe a simple reducer valve would stop it from moving so violently. Super impressed by your DIY skills.
Came over from Tractorbynet. Congrats on getting it done. The slew base is THE key reason that trading over a month of free time for the ~$1500 you saved over a pre-engineered HF digger, was worth it. It would be silly to back off of that at this point, in my opinion. What i think the digger needs is simply to be supported at a larger radius from the center. I don't remember what you said the dimensions of the 5/8" plate was, but whatever the shortest side of that is, a circle of perhaps 1" smaller diameter, will fit on that plate. That circle would be the contact points where your additional support will contact between the two plates. Those things should be adjustable and sacrificial but don't have to be complicated, just 4+ evenly spaced wheels or rollers of some kind. Kind of hard to cut pockets in the 5/8" plate at this point so they will probably protrude upward through the blue plate and be able to be preloaded down onto the 5/8" plate and take the brunt of the digging forces off the one big, hard to replace bearing which which still support radial loads and probably live forever doing that. The over-fast cylinders is just too much hydraulic flow. I would suggest using an adjustable flow control valve vs changing the pump, because it removes the possibility of more 'error spending' on pump sizing, plus i think you will find it's just as bad to have the thing be too slow as too fast, so having the adjustability for ~$100 is the 'safe' option in my mind. The one downside is you still pump the full ~15gpm or whatever, and bypassing some of it means slightly worse fuel economy and heat buildup, but i doubt you care about the marginal fuel economy cost and your reservoir is so oversize that you have a lot of thermal mass in fluid, and surface area on the tank, to control heat. I would guess it will be a total non-issue. You can also adjust your 'transition' valve in the pump (forget the exact term) to transition to the low-flow pump section at like 300psi which is basically anything over just moving the empty boom up and down. So you could make it 'basically always 3gpm' with a pump adjustment if you wanted to. Posting this on TBN too, just wanted to put the stuff out there for the TH-cam audience who may not be on any forums.
Yup. At this point even a couple bonded sheets of 3/4 ply cut into a disc (maybe with a final steel sheet for a bearing surface) and some fixed casters mounted under the plate would help. Tho if you could find a junked mini excavator with an intact ring, that'd be great.
You need a flow control valve. It gos in-line after the spool valve to control the cycle time of the cylinder’s. Should help to make it more controllable.
or... he could put his pump on a sprocket instead of directly on the engine shaft to change the rpm ratio... maybe 6/1? wouldn't that also reduce the strain on the motor? i'm a noob tho.
Brandon these multi spool valves don’t always have the same type of spool in all valves. You may want to switch the bucket hoses and the lift hoses around to see if you get more control.
I am very impressed with your work ! I have the Harbor Freight trencher , I have done several mods to it & I like using it . The restricter in the boom lines will take care of your jerking . Just reduce the ID of the lines at the fittings . I look forward to your mods to the machine .
Brandon you need some weld-on teeth for your bucket. That stuff you're digging looks pretty hard. Also, maybe you could install a small valve block for the purpose of reducing flow to that jumpy cylinder. I really admire your determination in making this thing- great job!
Make some nylon or uhmw pucks to go between the upper and lower plates where the slue bearing is. Set then at as large a diameter as you can. That will help remove the bounce and load on that bearing. The pucks will change the load from an angular load to a straight up and down load. Thanks for the video
When considering the transverse loads on the slew bearing, remember to factor in that your digging forces are a long way from it, causing a huge lever arm/torque. Couple that with jerky hydraulics and impact loads... It won't take much force to end up being destructive
If you buy a second bearing, make a column for your slewing with a bearing top and bottom. This will remove the twisting forces from the bearings. Keep the slewing feature. It is the main advantage of an excavator over a backhoe. hugely superior. If you want your main boom to move slower, go with a larger diameter cylinder which takes more oil to fill so it moves slower or install a flow rate limiter on the lines to restrict the flow. For your first try at this, I think you have done a superior job. Nice work.
A single bearing isn't made to withstand huge bending forces. You need *two* bearings for the swivel, about 5 to 10 inches from each other. My suggestion: The easiest (and cheapest?) way would be to use a hub from a wheel axle of a scrapped heavy truck or trailer. Just make a hole in the frame plate so the tube of the shaft fits into it and weld it from both sides. And take the center of a rim, weld it to the rotating plate and bolt it onto the hub. This will last "forever" - at least as long as that excavator does :)
Awesome build. I know nothing about welding myself but been thinking I really want to build my own "heavy" machinery, as I have a homestead property and buying or renting is just so expensive. One thing I'd love to build is a tracked backhoe excavator. I think it would be the most versatile machine that can do a bit of everything. The slew bearing definitely sounds like a challenging part to deal with so I think for my design I would just design it in a way that I just have to move the whole machine itself to move boom sideways. Either that or set it up like a backhoe where the boom can move sideways without the whole machine moving, but that's still a tricky mechanism to build I would imagine. That's a lot of force sitting on a small area.
The cheap hydraulic mono spools in valves have no fine area (they are just machined round)....if you machine a small pocket on the shoulder, it gives you a small flow before you get full flow...takes the jerkyness away....also the boom up would normally have a little ball and spring in the feed ,which means nothing happens before the cylinder pressure is overcome (ie when you move down at the moment,gravity is driving it first,then hydraulics),but this would mean another purchase.....if it digs it works,well done.
Idk what type of valve block you bought, but you can probably adjust it with a little screw on the spool to shave off the peak. However, you need a proportinal valve in order to be able to finesse the lever and make more controlled movements. There should also be relief valves on all of these except the hydraulic motor used to turn. You can also install flow control valves in-line on the boom cylinder like some other comment here said to, but it will only restrict the peak, it will still be uncontrollable. I recommend you swap the hydralic lines between bucket and boom - If it makes the boom smooth and the bucket hard, then you'll know that the boom valve isn't proportinal OR it could be damaged. Another thing to consider is whether you might have your inlet and return lines mixed up. T = return, P = inlet.
Your “problem” cylinder needs flow control valves at each end. You want unrestricted flow of oil going into each end of the cylinder and adjustable flow rate for the oil leaving the cylinder. This should be a simple fix. Do a little research on this. You’re closer than you think to a well behaved machine.
Really impressive build! You do really nice work! I realize that you may have already modified it but I hope not sacrificed the 360 degree slew. All I think you need to do is put a double roller bearing with a few inches between them and a heavy shaft running through them. Or a double tapered bearing like a trailer axle shaft , bearing and hub. Good luck!
It's taken me two days to finish your video, not because it's long, BUT I didn't want to miss anything. You are completely right we watch so us mortals can build the impossible.😊
Awesome build. While watching the video there was quite a bit of flex in the area between your hydraulic tank, and the support structure for the boom on the base. It looks like your hydraulic tank is bolted in. I would maybe just add some bolt in diagonals from the top of the tank to the front of the base.
That is a awesome project that you took on. The boom up and down is terrifying. If you put on tracks are you going to make it a walk behind or keep the seated controller?
Remove both pins from your boom cylinder leaving both hoses connected. Lay the cylinder with ports facing up and actuate the cylinder through full stoke a few times. This will allow all the air to escape. Reinstall the pins and see if that helps.
Pull out your paperwork for your spool valve and it will explain how to adjust your flow rate. That boom cylinder is faster than the rest because that how the valve was adjusted from the factory for whatever it was intended for. Each output on that valve going to each cylinder should have a flow adjustment. You have to get that flow rate down so you can run your engine at high rpm's without the boom going 1,000 mph. The swing is always going to be loose with that chain drive setup. Where that bearing is needs a large plate bolted to the inner race and a large plate boltted to the outer race. The two plates need to touch each other with a method of applying grease between them. Instead of that chain motor, you'd probably be better off with a hydraulic cylinder to rotate the machine.
Pretty cool. Looks like you need a needle valve to sort out the speed of the boom up and down. Also teeth on your bucket would be helpful. On mini diggers the smaller ones are often more jerky, not because of over powered hydraulics, but usually under powered motor.
Part of the problem with the main cylinder movement might be that when the entire boom moves The rest of the machine including the controls are jerked in the opposite direction. Because of the way that the lever is set up this causes the lever to move even further in that direction making the boom move even faster causing a feedback loop. This isn't guaranteed to be the problem but I would be interested to see what happened if you just swapped the lines on that and tried it with the lever going the opposite directions so that the feedback loop would be a negative feedback instead of a positive one.
I think you should change the pump gear ratio to half the rotational speed of the current one. This way you not only "lose" the flow rate (so it become more smooth) but, per the laws of hydraulics, you should also get roughly twice the actual force (if the hose can withstand it - I figure it should).
I bought one used for three point hitch for only $400 and it was bigger with downriggers. You need cushion valves to regulate the movement. You need to be alot heavier to apply down force.
you could make your own slewing ring with steel casters. you kinda need a big diameter to resist the moment forces better. flanged caster wheels would be great and you can grease the crap out of the whole ring and channel to keep it quiet.
Just add an adjustable flow control valve on the boom. Also add some rollers on your rotating swing plate, that will spread the forces out and provide much more support to the plate.
Add a one way flow restrictor to both hoses of the boom cylinder. Add a ring of UHMW around the swing bearing to take the forces and save the bearing. Cool project… great job!
I made a bobcat with digger on front....and its not till you start digging that you understand what you need....you have plenty of power (can bend things easy)...but what you need is 1)either weight to keep you still,or 2) a hydraulic blade to stop you being pulled forward.....building it is great experience,just keep modifiying.
Very awesome build I have really wanna build one myself but looking For a use one for $500 if somebody needs gone out of their yard because they never use it .1 thing I would have considered is doubled thickness around your pins or bushings for all your pin holes you're gonna get Wallowed out holes. that quarter inch is gonna wear fast once you get some grit in it.
They are flow valves on some of those that you have to put in line to make the flow smoother on your bottom. It raises the arm up check into theat. I think on original on bigger hydraulic excavators. They have those flow Wells that you can adjust until you get the smoothness the way you want it.
Good thoughts on your build. I've been debating building my own mini digger or buying a 1 ton mini ex. I need it for work, so I think the answer is clear to buy a professional unit. Thanks for your video
I bought a mini Vote VTW-18 with cab and thumb for under $17,000.00 U.S. including all the import fees and shipping costs. The purchase price from Vote was $11,800.00 and it is 3,900# fits through a 40" wide gate with tracks that expand to 48", It has a 17" wide bucket and digs really well. It certainly is not as nice as a Case or other U.S. made brands, but it is half the price. It has a Kubota engine and rubber tracks. Runs all day on 3 gallons of diesel.
you can get restrictor valves so you could put them on the main cylinder and slow it down and it would make it usebal, would a lorry hub work for a slue bearing might be able to get one cheep, cool job you did on it though!!
The slew bearing needs to be much bigger. Saying that. You could use a standard heavy bearing in the middle then make a sort of larger roller bearing on a wider diameter as big as possible. The force on that center bearing just from digging/pulling and pushing down will destroy that small diameter bearing. You'll also want to weld bushes where all the pins go through the box beam sections. The pins will quickly tear through the steel. Also need solid steel pins. You'll regret not having the slew function. Not sure, but most valve bodies have adjustments on them to restrict the speed although I couldn't spot them on yours. Again you'll need a much bigger supporting ring bearing for slewing. Killer first attempt though. I'd be peeing my pants attempting that
You need to add a flow restrictor to each hose on the main boom hydraulic cylinder. Lower the volume to the ram and it will move more slowly and it will drastically reduce the impact.
For the flex on center support / pivot. Maybe mount a rail or 4 separate, around edge lower than moving platform. With large rubber outer castor wheels, to provide extra support for the platform... Other than that idea, shocking spectacular job pal !!
IMO this machine is way nicer than the Harbor Freight machines in overall quality despite the small negatives you state i don’t see those as very big problems and it sounds like those could be easy to rectify and from what i’ve found even the Commercially available Backhoes and machines there are always some Hydraulic changes you might prefer you generally get used to them or “massage” the controls and RPms to adjust the Machines to your preference i’m not a Hydraulics expert but just a guy that spent 35 years in Commercial and ResidentialConstruction and i used a lot of different Equipment that was available i spent a lot of time in a Backhoe and Telehandler our Company actually owned and i became their Operator
Mmm, there are lots of problems already with a build like this, at home, with limited tools and resources. You did it, no doubt about it. It works, it digs, but man, that slew ring bearing is waaaaay undersized. It should be at least 3 to 4 times it's size. 6 times recommended. 😏 You will fix the issues one by one. Jerky hidraulics is to be expected, since you're using simple spool valves with no regulation. I'm planning to build something similar but... ...different, one day, which will be a franken-thing of modular multi-purpose fusion, but I will use different cyllinder sizes like 80mm shoulder, 60 elbow and 50 wrist, so you accomodate some of the regulation problems. Other than that you have to regulate flow with some valves for individual loops. 6mm sheet is not strong enough for supporting structures, also the arm is a lot of weight by itself. Combined with digging forces is "bendy" and metal fatigue will show soon. At least 8mm shoud be used for supporting plane/arm structure. I advice you to scrap the slew ring (use it for something else) and build instead a vertical pillar with bearings system. It won't be a problem since you don't have underlying hydraulics.. ..or switch to tracks and slewing arm only, as you said. Anyway, cheers and a lot of success for the future. 😉👍 Keep on!
A swing boom would be best , less stress on the boom i believe your running to much pressure to the valves , we had that problem with a front loader until we inserted an adjustable pressure valve on the main line and purchased a log splitter control valves much less flow and i believe id use an electric motor not gas . your also getting deflection from those tires , try it without them once and you only need 1 actuator for your swing like on a snowplow . they have been using swing arms on backhoes for many years and outriggers would help a lot .
I haven’t read through all the comments so this may be a waste of time but if bleeding that cylinder didn’t fix your problem you could try installing an orifice into the supply and return connections. I’m assuming it’s double acting, that makes sense. I’ve seen drilled grub screws threaded into the fittings to restrict flow and slow things down. Been a few years 30, but thought I’d toss in my two cents. Good job with limited resources!!
Watching this I think you need a flow control valve on your boom, to stop the jerking .Otherwise a very nice build. for your bearing they using a front wheel hub.
If you added spacers to that 1 inch hole saw guide, it would have given the chips somewhere to go. On a positive note, you're improvising and innovating, nice to see.
Instead of all the bearing and gears you plan to use,get a slow speed axle stub,these aremeant for building farm utility trailers,but also make a good mount for a boom or your turn table for your homemade mini digger.
Brandon, nice build, I would recommend not using a two stage pump, use a regular pump, sounds like you have a splitter pump on now, hence two stage. I built a homemade backhoe tow behind and i used a continious flow pump.Check your suppliers and check it out.
You could help your slew bearing by putting rollers at the outer edges of the plate. Second adding electric hub wheels on the front would assist with your moving around. And the boom cylinder needs an adjustable flow valve to smooth it's action.
Sorry if you already covered it but how did the build cost compare to the harbor freight unit cost? All those grinding discs and fittings add up don't they! Great project!
@@BrandonsGarage I know you’ve move on but for your ring and pinion issue that you discussed early in the video, check out cement mixer ring and pinions (job site unit, not the trucks).They look about the size you would need.
Hi great job! I'm doing something similar too! I wanted to ask you two things: 1) the pump you use is similar to mine, what is its flow rate? 2) what ratio does the orbital motor have flow per revolution? Thank you ! P.S. I'm using a 400 mm steering wheel let's see if I can make it more stable!
I hate to say it it won't last long with the play in the deck with the hard work and money I would have put tracks on it it'll give you the weight and stability nice job
Instead of a bearing try using 2 different sized pipes to give you the stability you need and you could also reinforce the plate to handle the torque of the arm.
OK, Lets not write it all off as a lose just yet...LOL I'm no expert but I can see that you have a nice robust system in place and that's a great foundation to build upon. If your interested in getting the system sorted out, well then I believe i can get ya moving in that direction pretty quick. Along with the other experienced hands here in the comments, I bet you can get it dialed in without much trouble. I wont go into much detail , just in case I'm sticking my nose where it need not be found. "it happens when offering unsolicited help/advice" well here we go.. -Needs a Pressure Gauge -Need to add a Pressure relief/bypass valve -Manual throttle for the engine "its tryn to run on-demand like a pressure washer, that's not what we want" -Larger reserve tank -longer control sticks (not required) -We need the flow, but maybe not as much pressure depending on the model pf the valve and the working psi of the pump -Your Boom Cylinder is fast/quick because the hoses are short compared to the other functions -Remember those cylinders have a piston with a flat face (extend) and a reduced face (retract) due to the area take up by the rod. F=PxA more surface area requires less pressure to get the same force. Speed comes into play also with port size and how the valve can be throttled... But that's putting t he cart before the horse at this point. -so you will have more fluid in the system when extending or have the cylinders extended, and more fluid in the tank when retracted. and we need extra area in the tank to allow it to "breathe" rather than becoming pressurized if undersized. Well I hope you can use some of that to get you going again. I think you have done a excellent job designing and building a very useful tool and I'm sure you"ll get it where you want/need it to be sooner than you might think. Unless I'm late to the game and the kinks have already been well ironed out. maybe i should check your other videos before posting this? nahh I can always run back a delete it if I'm found to be a fool again! haha
I'm thinking if you add 3 to 4 foot circular track(greased or with heavy plastic) around rotating bearing to stop it from adding as much tilt when swinging around. Not sure exactly how to do it though.
Shovels just aren't as fun though! And there's People like me out there, when it comes to lifting anything heavy I'm a one armed Person, my left arm can only handle regular daily activities so something like this would be great for me.
Does the piston rod on the boom cylinder have a larger diameter than the stick and bucket cylinders? It's hard to tell but if so there is your speed difference. A quick test for the valve would be to simply swap the boom and bucket curl hoses at the valve and see if the problem moves with the hose position or remains. Use adapters to reduce the flow, 3/8" to 1/4" then 14" back to 3/8" cost you less than $20 bucks. Best of luck. 👍
Hydraulic In-Line Adjustable Variable Flow Control Valve will give you more control and adjustability. This way you won't need to buy multiple hydraulic restrictors to see which one works the best.
Add some length to ure boom stick the travel time will make boom /dipper arm more controllable less jerk an not as fast also you need counter wt on back of machine
Next time you attempt the project a good donor piece of equipment is a log splitter get all your hydraulic stuff off the log splitter for the most part the back frame with the wheels
I'd suggest a bit more investment into educating yourself on metal work and tooling/setup could help tremendously. Annular cutters, calipers, and a drill press would be ideal and save you so much time and material it's ridiculous, and cost less than you imagine if you buy used. Fab tricks like welding two tabs together to machine identically matching parts can raise the quality of your efforts simply and no added tools. I've learned tons just by watching fabbers on YT, I'm sure you could benefit as well!
looking at your project fantastic but there seems to be a lot of flex in the plate that the arm sits on ,, you ort to strengthen this i a lot or the base plate will bend with the pulling of the bucket hydraulics and the arm hydraulics
Surly you can see the bracing for the boom and the flat form bearing has a gap creating a diving board effect you have nothing supporting the boom no bearing surface when rotating nothing holding it stiff when moving the boom that’s why it’s nodding so badly
That was an AWESOME build! You did a great job! I'm no expert at all, but from my experience on heavy equipment, I think the problem with the boom cylinder is it's location.. I I've never seen it on the bottom of the boom. I've only seen it mounted on the top of the boom. I truly believe that it's boom problem is because the boom cylinder is below the boom instead of being on top of the boom. Also, you should get a bigger engine to be able to run at the rpm you need without it bogging down.
Many mini excavators have the cylinder on the bottom of the boom. It may be attached at too slight of an angle, but seems to have a sufficient amount of strength, just needs to be slowed down with a flow restrictor.
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Props to you for not milking this out into a 12 Part series over the course of a year like every other TH-camr would have.
I know it. I tried that with my pontoon boat, and had good success - however, at the time, it was the only pontoon boat refurbish video on TH-cam.
I really enjoy Fireball Tools' build videos, where they are short, enjoyable, and to the point.
When my skills develop more, I hope to be on his level of clarity and editing.
After watching any of Matt's Off-Road Recovery build videos, I have sworn off build series.
I saw this video and literally looked further back in your video's looking for the "part 1" and all the rest.... nothin. That's when I realized how awesome it was to only have to deal with part 1 of 1.
you know why people make shorter videos? Attention span.
The mrbeast of diyers
This comment👆🏼
That is a really impressive project. I enjoyed how violet it operated but understand it's different for you. For the bearing issue, would it be possible to create a semicircular track (rainbow) around the front of the chassis, with either greased skids or wheels that create a sandwich between the upper platform. Most support is required to counteract a downward force at the front. It would add loads of stability and relegate the slew bearing to a simple pivot point. For the hydraulic cylinder, if it's not air, maybe a simple reducer valve would stop it from moving so violently.
Super impressed by your DIY skills.
Came over from Tractorbynet. Congrats on getting it done.
The slew base is THE key reason that trading over a month of free time for the ~$1500 you saved over a pre-engineered HF digger, was worth it. It would be silly to back off of that at this point, in my opinion. What i think the digger needs is simply to be supported at a larger radius from the center. I don't remember what you said the dimensions of the 5/8" plate was, but whatever the shortest side of that is, a circle of perhaps 1" smaller diameter, will fit on that plate. That circle would be the contact points where your additional support will contact between the two plates. Those things should be adjustable and sacrificial but don't have to be complicated, just 4+ evenly spaced wheels or rollers of some kind. Kind of hard to cut pockets in the 5/8" plate at this point so they will probably protrude upward through the blue plate and be able to be preloaded down onto the 5/8" plate and take the brunt of the digging forces off the one big, hard to replace bearing which which still support radial loads and probably live forever doing that.
The over-fast cylinders is just too much hydraulic flow. I would suggest using an adjustable flow control valve vs changing the pump, because it removes the possibility of more 'error spending' on pump sizing, plus i think you will find it's just as bad to have the thing be too slow as too fast, so having the adjustability for ~$100 is the 'safe' option in my mind. The one downside is you still pump the full ~15gpm or whatever, and bypassing some of it means slightly worse fuel economy and heat buildup, but i doubt you care about the marginal fuel economy cost and your reservoir is so oversize that you have a lot of thermal mass in fluid, and surface area on the tank, to control heat. I would guess it will be a total non-issue. You can also adjust your 'transition' valve in the pump (forget the exact term) to transition to the low-flow pump section at like 300psi which is basically anything over just moving the empty boom up and down. So you could make it 'basically always 3gpm' with a pump adjustment if you wanted to.
Posting this on TBN too, just wanted to put the stuff out there for the TH-cam audience who may not be on any forums.
Yup. At this point even a couple bonded sheets of 3/4 ply cut into a disc (maybe with a final steel sheet for a bearing surface) and some fixed casters mounted under the plate would help. Tho if you could find a junked mini excavator with an intact ring, that'd be great.
You need a flow control valve. It gos in-line after the spool valve to control the cycle time of the cylinder’s. Should help to make it more controllable.
or... he could put his pump on a sprocket instead of directly on the engine shaft to change the rpm ratio... maybe 6/1? wouldn't that also reduce the strain on the motor? i'm a noob tho.
That was my first thought as well. Dial the flow down so the cyl isn't filling as fast.
Brandon these multi spool valves don’t always have the same type of spool in all valves. You may want to switch the bucket hoses and the lift hoses around to see if you get more control.
I am very impressed with your work ! I have the Harbor Freight trencher , I have done several mods to it & I like using it . The restricter in the boom lines will take care of your jerking . Just reduce the ID of the lines at the fittings . I look forward to your mods to the machine .
awesome project. Before you go change the cylinder or try hard stuff, see what happens when you attach it to one of the valves that gives smooth flow.
Brandon you need some weld-on teeth for your bucket. That stuff you're digging looks pretty hard. Also, maybe you could install a small valve block for the purpose of reducing flow to that jumpy cylinder. I really admire your determination in making this thing- great job!
I was looking for this comment, I had the exact same thought- some teeth on the bucket would help a lot.
Make some nylon or uhmw pucks to go between the upper and lower plates where the slue bearing is. Set then at as large a diameter as you can. That will help remove the bounce and load on that bearing. The pucks will change the load from an angular load to a straight up and down load. Thanks for the video
Very impressive. Might try a trailer tongue to tow it! Definitely a great project that eventually your son will enjoy using (playing)!
When considering the transverse loads on the slew bearing, remember to factor in that your digging forces are a long way from it, causing a huge lever arm/torque. Couple that with jerky hydraulics and impact loads... It won't take much force to end up being destructive
@@CoatTailShow they use a much larger bearing
If you buy a second bearing, make a column for your slewing with a bearing top and bottom. This will remove the twisting forces from the bearings. Keep the slewing feature. It is the main advantage of an excavator over a backhoe. hugely superior. If you want your main boom to move slower, go with a larger diameter cylinder which takes more oil to fill so it moves slower or install a flow rate limiter on the lines to restrict the flow. For your first try at this, I think you have done a superior job. Nice work.
A single bearing isn't made to withstand huge bending forces. You need *two* bearings for the swivel, about 5 to 10 inches from each other.
My suggestion: The easiest (and cheapest?) way would be to use a hub from a wheel axle of a scrapped heavy truck or trailer. Just make a hole in the frame plate so the tube of the shaft fits into it and weld it from both sides. And take the center of a rim, weld it to the rotating plate and bolt it onto the hub. This will last "forever" - at least as long as that excavator does :)
Awesome build. I know nothing about welding myself but been thinking I really want to build my own "heavy" machinery, as I have a homestead property and buying or renting is just so expensive. One thing I'd love to build is a tracked backhoe excavator. I think it would be the most versatile machine that can do a bit of everything. The slew bearing definitely sounds like a challenging part to deal with so I think for my design I would just design it in a way that I just have to move the whole machine itself to move boom sideways. Either that or set it up like a backhoe where the boom can move sideways without the whole machine moving, but that's still a tricky mechanism to build I would imagine. That's a lot of force sitting on a small area.
Awesome Barndon, this is how we learn real engineering.
I will show my excavator build when I get the video made soon.
The cheap hydraulic mono spools in valves have no fine area (they are just machined round)....if you machine a small pocket on the shoulder, it gives you a small flow before you get full flow...takes the jerkyness away....also the boom up would normally have a little ball and spring in the feed ,which means nothing happens before the cylinder pressure is overcome (ie when you move down at the moment,gravity is driving it first,then hydraulics),but this would mean another purchase.....if it digs it works,well done.
Idk what type of valve block you bought, but you can probably adjust it with a little screw on the spool to shave off the peak. However, you need a proportinal valve in order to be able to finesse the lever and make more controlled movements. There should also be relief valves on all of these except the hydraulic motor used to turn. You can also install flow control valves in-line on the boom cylinder like some other comment here said to, but it will only restrict the peak, it will still be uncontrollable.
I recommend you swap the hydralic lines between bucket and boom - If it makes the boom smooth and the bucket hard, then you'll know that the boom valve isn't proportinal OR it could be damaged. Another thing to consider is whether you might have your inlet and return lines mixed up. T = return, P = inlet.
Your “problem” cylinder needs flow control valves at each end. You want unrestricted flow of oil going into each end of the cylinder and adjustable flow rate for the oil leaving the cylinder. This should be a simple fix. Do a little research on this. You’re closer than you think to a well behaved machine.
Really impressive build! You do really nice work! I realize that you may have already modified it but I hope not sacrificed the 360 degree slew. All I think you need to do is put a double roller bearing with a few inches between them and a heavy shaft running through them. Or a double tapered bearing like a trailer axle shaft , bearing and hub. Good luck!
It's taken me two days to finish your video, not because it's long, BUT I didn't want to miss anything. You are completely right we watch so us mortals can build the impossible.😊
Coolest project ever!
That boom up-down is almost scary violent!
You have the best adult child toys. I'm a bit jealous
Awesome build. While watching the video there was quite a bit of flex in the area between your hydraulic tank, and the support structure for the boom on the base. It looks like your hydraulic tank is bolted in. I would maybe just add some bolt in diagonals from the top of the tank to the front of the base.
Nice build over all. I like the method done by the Green Machines build using a steel pole for pivot and turning with feet.
Cheers
Epic build/project, i love it.
You did a great job it looks great I like the combination of paint the adjustment that needs is easy you got it my friend ❤
When the first pin dropped through the hole and clanged on the floor I about pissed! 😂 You’re the man for leaving that in. Great content, like always.
That is a awesome project that you took on. The boom up and down is terrifying. If you put on tracks are you going to make it a walk behind or keep the seated controller?
Wow nice project. I'm impressed with your fabrication skills.
Remove both pins from your boom cylinder leaving both hoses connected. Lay the cylinder with ports facing up and actuate the cylinder through full stoke a few times. This will allow all the air to escape.
Reinstall the pins and see if that helps.
Pull out your paperwork for your spool valve and it will explain how to adjust your flow rate. That boom cylinder is faster than the rest because that how the valve was adjusted from the factory for whatever it was intended for. Each output on that valve going to each cylinder should have a flow adjustment. You have to get that flow rate down so you can run your engine at high rpm's without the boom going 1,000 mph. The swing is always going to be loose with that chain drive setup. Where that bearing is needs a large plate bolted to the inner race and a large plate boltted to the outer race. The two plates need to touch each other with a method of applying grease between them. Instead of that chain motor, you'd probably be better off with a hydraulic cylinder to rotate the machine.
Pretty cool. Looks like you need a needle valve to sort out the speed of the boom up and down.
Also teeth on your bucket would be helpful.
On mini diggers the smaller ones are often more jerky, not because of over powered hydraulics, but usually under powered motor.
yes, a needle valve or a orphis that limits the flow of oil.
@@gregreinhardt1293 Or a restriction fitting or larger cylinder, even the small JD 3pt mount hoe is fast, Great build
Part of the problem with the main cylinder movement might be that when the entire boom moves The rest of the machine including the controls are jerked in the opposite direction. Because of the way that the lever is set up this causes the lever to move even further in that direction making the boom move even faster causing a feedback loop. This isn't guaranteed to be the problem but I would be interested to see what happened if you just swapped the lines on that and tried it with the lever going the opposite directions so that the feedback loop would be a negative feedback instead of a positive one.
I think you should change the pump gear ratio to half the rotational speed of the current one.
This way you not only "lose" the flow rate (so it become more smooth) but, per the laws of hydraulics, you should also get roughly twice the actual force (if the hose can withstand it - I figure it should).
But that would need a gear box? You can't just change the gears in a gear pump. Wouldn't it be easier to just use a smaller pump?
I bought one used for three point hitch for only $400 and it was bigger with downriggers. You need cushion valves to regulate the movement. You need to be alot heavier to apply down force.
you could make your own slewing ring with steel casters. you kinda need a big diameter to resist the moment forces better. flanged caster wheels would be great and you can grease the crap out of the whole ring and channel to keep it quiet.
Just add an adjustable flow control valve on the boom. Also add some rollers on your rotating swing plate, that will spread the forces out and provide much more support to the plate.
Add a one way flow restrictor to both hoses of the boom cylinder. Add a ring of UHMW around the swing bearing to take the forces and save the bearing. Cool project… great job!
I made a bobcat with digger on front....and its not till you start digging that you understand what you need....you have plenty of power (can bend things easy)...but what you need is 1)either weight to keep you still,or 2) a hydraulic blade to stop you being pulled forward.....building it is great experience,just keep modifiying.
Very awesome build I have really wanna build one myself but looking For a use one for $500 if somebody needs gone out of their yard because they never use it .1 thing I would have considered is doubled thickness around your pins or bushings for all your pin holes you're gonna get Wallowed out holes. that quarter inch is gonna wear fast once you get some grit in it.
They are flow valves on some of those that you have to put in line to make the flow smoother on your bottom. It raises the arm up check into theat. I think on original on bigger hydraulic excavators. They have those flow Wells that you can adjust until you get the smoothness the way you want it.
Good thoughts on your build. I've been debating building my own mini digger or buying a 1 ton mini ex. I need it for work, so I think the answer is clear to buy a professional unit. Thanks for your video
I bought a mini Vote VTW-18 with cab and thumb for under $17,000.00 U.S. including all the import fees and shipping costs. The purchase price from Vote was $11,800.00 and it is 3,900# fits through a 40" wide gate with tracks that expand to 48", It has a 17" wide bucket and digs really well. It certainly is not as nice as a Case or other U.S. made brands, but it is half the price. It has a Kubota engine and rubber tracks. Runs all day on 3 gallons of diesel.
you can get restrictor valves so you could put them on the main cylinder and slow it down and it would make it usebal, would a lorry hub work for a slue bearing might be able to get one cheep, cool job you did on it though!!
The slew bearing needs to be much bigger. Saying that. You could use a standard heavy bearing in the middle then make a sort of larger roller bearing on a wider diameter as big as possible. The force on that center bearing just from digging/pulling and pushing down will destroy that small diameter bearing. You'll also want to weld bushes where all the pins go through the box beam sections. The pins will quickly tear through the steel. Also need solid steel pins. You'll regret not having the slew function. Not sure, but most valve bodies have adjustments on them to restrict the speed although I couldn't spot them on yours. Again you'll need a much bigger supporting ring bearing for slewing. Killer first attempt though. I'd be peeing my pants attempting that
You need to add a flow restrictor to each hose on the main boom hydraulic cylinder. Lower the volume to the ram and it will move more slowly and it will drastically reduce the impact.
Хороший мини экскаватор но надо сделать плавнее гидравлику и добавить жёсткость поворотной платформы
For the flex on center support / pivot. Maybe mount a rail or 4 separate, around edge lower than moving platform. With large rubber outer castor wheels, to provide extra support for the platform...
Other than that idea, shocking spectacular job pal !!
If you swapped out the boom cylinder for one with a larger bore, it would slow it down (and capable of more force).
IMO this machine is way nicer than the Harbor Freight machines in overall quality despite the small negatives you state i don’t see those as very big problems and it sounds like those could be easy to rectify and from what i’ve found even the Commercially available Backhoes and machines there are always some Hydraulic changes you might prefer you generally get used to them or “massage” the controls and RPms to adjust the Machines to your preference i’m not a Hydraulics expert but just a guy that spent 35 years in Commercial and ResidentialConstruction and i used a lot of different Equipment that was available i spent a lot of time in a Backhoe and Telehandler our Company actually owned and i became their Operator
Mmm, there are lots of problems already with a build like this, at home, with limited tools and resources. You did it, no doubt about it. It works, it digs, but man, that slew ring bearing is waaaaay undersized. It should be at least 3 to 4 times it's size. 6 times recommended. 😏 You will fix the issues one by one. Jerky hidraulics is to be expected, since you're using simple spool valves with no regulation. I'm planning to build something similar but... ...different, one day, which will be a franken-thing of modular multi-purpose fusion, but I will use different cyllinder sizes like 80mm shoulder, 60 elbow and 50 wrist, so you accomodate some of the regulation problems. Other than that you have to regulate flow with some valves for individual loops. 6mm sheet is not strong enough for supporting structures, also the arm is a lot of weight by itself. Combined with digging forces is "bendy" and metal fatigue will show soon. At least 8mm shoud be used for supporting plane/arm structure. I advice you to scrap the slew ring (use it for something else) and build instead a vertical pillar with bearings system. It won't be a problem since you don't have underlying hydraulics.. ..or switch to tracks and slewing arm only, as you said.
Anyway, cheers and a lot of success for the future. 😉👍 Keep on!
A swing boom would be best , less stress on the boom i believe your running to much pressure to the valves , we had that problem with a front loader until we inserted an adjustable pressure valve on the main line and purchased a log splitter control valves much less flow and i believe id use an electric motor not gas . your also getting deflection from those tires , try it without them once and you only need 1 actuator for your swing like on a snowplow . they have been using swing arms on backhoes for many years and outriggers would help a lot .
I haven’t read through all the comments so this may be a waste of time but if bleeding that cylinder didn’t fix your problem you could try installing an orifice into the supply and return connections. I’m assuming it’s double acting, that makes sense. I’ve seen drilled grub screws threaded into the fittings to restrict flow and slow things down. Been a few years 30, but thought I’d toss in my two cents. Good job with limited resources!!
Watching this I think you need a flow control valve on your boom, to stop the jerking .Otherwise a very nice build. for your bearing they using a front wheel hub.
If you added spacers to that 1 inch hole saw guide, it would have given the chips somewhere to go. On a positive note, you're improvising and innovating, nice to see.
Instead of all the bearing and gears you plan to use,get a slow speed axle stub,these aremeant for building farm utility trailers,but also make a good mount for a boom or your turn table for your homemade mini digger.
Brandon, nice build, I would recommend not using a two stage pump, use a regular pump, sounds like you have a splitter pump on now, hence two stage. I built a homemade backhoe tow behind and i used a continious flow pump.Check your suppliers and check it out.
" the squarest of squared that I've ever squared " now that's one to remember 🤔👍👍
You could help your slew bearing by putting rollers at the outer edges of the plate.
Second adding electric hub wheels on the front would assist with your moving around. And the boom cylinder needs an adjustable flow valve to smooth it's action.
move the center of gravity for the boom directly over the slew pivot. also try restrictors for the oil flow on the boom cylinder.
Cool projekt! Are you going to make it self powered movement?
Sorry if you already covered it but how did the build cost compare to the harbor freight unit cost? All those grinding discs and fittings add up don't they! Great project!
About $1000 was spent
@@BrandonsGarage I know you’ve move on but for your ring and pinion issue that you discussed early in the video, check out cement mixer ring and pinions (job site unit, not the trucks).They look about the size you would need.
Hi great job!
I'm doing something similar too! I wanted to ask you two things:
1) the pump you use is similar to mine, what is its flow rate?
2) what ratio does the orbital motor have flow per revolution?
Thank you !
P.S.
I'm using a 400 mm steering wheel let's see if I can make it more stable!
I hate to say it it won't last long with the play in the deck with the hard work and money I would have put tracks on it it'll give you the weight and stability nice job
Can’t wait to watch this!
Brendon does that boom cylinder have too much flow? Can you restrict the flow a bit smaller line or something?
You can put a restrictor in the lines so that it smooths out.
Never having built anything hydraulic before, you did great, ironing out the bugs is part of the build, you'll figure it out.
Instead of a bearing try using 2 different sized pipes to give you the stability you need and you could also reinforce the plate to handle the torque of the arm.
Ok , Great first try . Why did you not use a weld on trailer axel hub for the center pivot??
Maybe a flow restrictor for the main boom will stop the jerkyness, lol if that's even a word, just a thought I've had to do it on some projects!
Power will remain the same just slower!
OK, Lets not write it all off as a lose just yet...LOL I'm no expert but I can see that you have a nice robust system in place and that's a great foundation to build upon. If your interested in getting the system sorted out, well then I believe i can get ya moving in that direction pretty quick. Along with the other experienced hands here in the comments, I bet you can get it dialed in without much trouble. I wont go into much detail , just in case I'm sticking my nose where it need not be found. "it happens when offering unsolicited help/advice" well here we go..
-Needs a Pressure Gauge
-Need to add a Pressure relief/bypass valve
-Manual throttle for the engine "its tryn to run on-demand like a pressure washer, that's not what we want"
-Larger reserve tank
-longer control sticks (not required)
-We need the flow, but maybe not as much pressure depending on the model pf the valve and the working psi of the pump
-Your Boom Cylinder is fast/quick because the hoses are short compared to the other functions
-Remember those cylinders have a piston with a flat face (extend) and a reduced face (retract) due to the area take up by the rod. F=PxA more surface area requires less pressure to get the same force. Speed comes into play also with port size and how the valve can be throttled... But that's putting t he cart before the horse at this point.
-so you will have more fluid in the system when extending or have the cylinders extended, and more fluid in the tank when retracted. and we need extra area in the tank to allow it to "breathe" rather than becoming pressurized if undersized.
Well I hope you can use some of that to get you going again. I think you have done a excellent job designing and building a very useful tool and I'm sure you"ll get it where you want/need it to be sooner than you might think. Unless I'm late to the game and the kinks have already been well ironed out. maybe i should check your other videos before posting this? nahh I can always run back a delete it if I'm found to be a fool again! haha
Put caster wheels between swivel plates further out to take some of the forces off you bearing
You need to install a proportioning valve to slow down the jumping of the hydraulic system.
I'm thinking if you add 3 to 4 foot circular track(greased or with heavy plastic) around rotating bearing to stop it from adding as much tilt when swinging around. Not sure exactly how to do it though.
he going be waking up in the middle of the night screaming no more drilling holes for the next few years...lol
The excavator is nice, but you're faster with the shovel. )))) The wooden template for the holes is a good idea.
Shovels just aren't as fun though! And there's People like me out there, when it comes to lifting anything heavy I'm a one armed Person, my left arm can only handle regular daily activities so something like this would be great for me.
The valve timing needs to be timed, it will slow it down or a reduction valve ft that ram will slow it down.
Does the piston rod on the boom cylinder have a larger diameter than the stick and bucket cylinders? It's hard to tell but if so there is your speed difference. A quick test for the valve would be to simply swap the boom and bucket curl hoses at the valve and see if the problem moves with the hose position or remains. Use adapters to reduce the flow, 3/8" to 1/4" then 14" back to 3/8" cost you less than $20 bucks.
Best of luck.
👍
Nice build. Can u share the hydrolic parts?
Very impracive machine.. can u just tell me which hydraulic pump u used?
Nice build, needs some fine tuning but its probably just fine for a homeowner in need of a digger like that every couple years or so
Hydraulic In-Line Adjustable Variable Flow Control Valve will give you more control and adjustability. This way you won't need to buy multiple hydraulic restrictors to see which one works the best.
I’d much rather have this than the one from HF! Hopefully you get her dialed in!
cool 1st attempt but that bearing isn't going to last too long. i think it needs to be beefier in several areas
The squarest square I have ever squared 😂😂😂
Put a 1/16 orifice in line and it will slow the cylinder down
Other then that i5hink it's great I'd love to build one!
Add some length to ure boom stick the travel time will make boom /dipper arm more controllable less jerk an not as fast also you need counter wt on back of machine
If you put wheels under the bottom. It would help on bouncing alot. Put at least 4. Would be great to take make adjustment. And not expensive.
For rotation try a cement mixer gears look a few vids up before you buy to see what gears are in witch mixer
Next time you attempt the project a good donor piece of equipment is a log splitter get all your hydraulic stuff off the log splitter for the most part the back frame with the wheels
I can't believe nobody mentioned a "lazy Susan".
Pretty sweet machine. You'll get the kinks ironed out.
i think you can put in some restrictor like washers that have a smaller hole to slow down the flow to that cly. see a hydraulic guy
Its funny, I did, he said "I'm not an engineer"
@@BrandonsGarage if you have room for a bigger diameter cly that can slow it down to
you are GREAT..! Paolo from Italy
You may want to consider slowing your drill speed.
I'd suggest a bit more investment into educating yourself on metal work and tooling/setup could help tremendously. Annular cutters, calipers, and a drill press would be ideal and save you so much time and material it's ridiculous, and cost less than you imagine if you buy used. Fab tricks like welding two tabs together to machine identically matching parts can raise the quality of your efforts simply and no added tools. I've learned tons just by watching fabbers on YT, I'm sure you could benefit as well!
I’d hate to be the spotter…lol but dang that’s amazing how you made this if u can control it better it would be perfect..Made in the 🇺🇸👍
looking at your project fantastic but there seems to be a lot of flex in the plate that the arm sits on ,, you ort to strengthen this i a lot or the base plate will bend with the pulling of the bucket hydraulics and the arm hydraulics
Surly you can see the bracing for the boom and the flat form bearing has a gap creating a diving board effect you have nothing supporting the boom no bearing surface when rotating nothing holding it stiff when moving the boom that’s why it’s nodding so badly
That was an AWESOME build! You did a great job!
I'm no expert at all, but from my experience on heavy equipment, I think the problem with the boom cylinder is it's location..
I I've never seen it on the bottom of the boom. I've only seen it mounted on the top of the boom. I truly believe that it's boom problem is because the boom cylinder is below the boom instead of being on top of the boom.
Also, you should get a bigger engine to be able to run at the rpm you need without it bogging down.
Many mini excavators have the cylinder on the bottom of the boom. It may be attached at too slight of an angle, but seems to have a sufficient amount of strength, just needs to be slowed down with a flow restrictor.