A 4 Facet Drill Bit Grinder DIY Style Final
ฝัง
- เผยแพร่เมื่อ 5 ก.ค. 2024
- #shopmadetools
In this episode....
I discover some errors in the 2D drawings which I had shared on Dropbox. These errors have been fixed and you can download the latest version now.
Calibrating the eccentric wheel for primary clearance angles.
CNC drag engraving the markings on the eccentric.
Sharpening an 11/32" and a 3/32" drill bit start to finish
Test drilling in aluminium and steel.
Announcing the next project.
The link to the dropbox files is here: www.dropbox.com/sh/38ahn5tz4q...
For anyone wanting the native Autodesk Inventor files, I will be uploading these soon. - วิทยาศาสตร์และเทคโนโลยี
I really enjoyed your closing comments. Farting around in the shop can be its own reward!
I think that there is always some sense of achievement to be gained from every project. Even the failures will have some elements that go well. Just achieving the same outcome with less work or in fewer steps is a goal in itself.
Regards,
Mark
I wish you lived next door mate! Building it was more than half the fun!! Thanks!
Perhaps our attitude to our hobby should be the same as the fisherman's: "Even if I caught nothing, at least I wasted the whole day" 😉
Thanks for sharing your fun with us, Preso.
Great work as usual Mark. Don't worry about what others say. As long as you like what you are doing, that is the important thing. In the end this turned out to be a well made functional machine.
Thanks Jon. I had fun building it and I actually used one of the drill bits I had sharpened on the lathe today and it cut beautifully with two (mostly) identical spiral chips coming out of the hole. Which is better than the usual dust and fine mangled chips I usually get.
Regards,
Mark
You are right about learning something every day. I learn something from all of your videos thankyou very much.
Balanced my drill press after 30 years of chasing bouncing parts around on the table. I built a dynamic auto balancer, simple and effective. The first time I saw one in action was a high-speed cd rom reader, the type that didn't shake. I used a ball bearing outer race and its balls discarding the cage and inner race. I 3d printed an object to center the race on the vibrating shaft and also stop the balls falling/flying out. The outer race has less than 180 degrees of balls and has no lubricant. When rotating, the balls will reposition themselves and cancel the shaft vibration. A used ball bearing is fine, provided the race and balls still have an undamaged mirror surface finish.
Like your projects.
-Cheers Peter
Peter, that's very interesting. So, I'm guessing it's a totally passive system? I will try to find some more info on Google.
Regards,
Mark
Mark, you've done an excellent job at crafting a way to keep fidelity with the original plan/design. I'm not certain that eccentric wheel with marks on it is the best way to go, but as you said, accuracy isn't as important as precisely being about to set the angle for both sides of the bit. Alternatively, perhaps if the larger trunnion blocks had one of them larger still, it could be engraved with angle marks. The eccentric could still be used to set the adjustment, but the angle read from the larger trunnion block. 🤷♂🤷♂
I agree with your sentiments completely, you should always be striving to learn new things and challenge yourself outside of your comfort zone, I think it helps to stave off the dreaded Alzheimers as well. It's quite often more about the journey, than the destination. I used to say I will learn something new every day up until the day I die, but then I realised I might learn something that day as well, ie: what happens when you die. Keep up the good work. 👍
Thank you for showing the end of this very interesting and informative project. Well done on making such an attractive and useful machine. 👏👏👍😀
I know it's totally off topic, but I like the stopwatch trying to escape while you were grinding the bigger drill bit :)
And you're absolutely right. It's a project. It's a hobby. It's all for fun.
Michel, I told you the grinding wheel was out of balance! By the way, we are visiting Belgium in early November. We'll probably be visiting Liege on our way back to Frankfurt. Maybe we can call in for coffee, or a famous Belgian beer?
Regards,
Mark
@@Preso58 Brilliant idea. You're more than welcome. Email me.
Gday Preso, firstly I think you really nailed this build, secondly your absolutely spot on with what you said, we need to learn something everyday and farting around in the workshop is a great way to do this, awesome job mate and I’ve enjoyed the build, cheers
Thanks Matty. I think you and I understand the value of pushing the boundaries of our skill sets.
Regards,
Mark
Hey Mark! Great project! You don't need to justify a thing that you do! We are lucky to get to peer over your shoulder, and I for one apologize for all the ninnys who think that their opinions on your choices are so important that you need to hear about it! Forge ahead!
Thanks. I always say that making things is good for our mental health. It doesn't always matter if it's successful or not. Sometimes just one part of a bigger project turns out exactly the way you want it and that should be enough.
Regards,
Mark
Great series that with a good result. Looking forward to the next project.
Thanks mate for another great series. I do appreciate you sharing the high points and the occasional low points. Keep them coming!
You do such a great job . I hope it will inspire some of the young ones to make stuff. Anything just use there hands .i was inspired by my metal work teacher .Nobby Clarke . Best thing ever happened to me .. thankyou
Inspiration?
Well…. As well as inspiring the ‘…young ones..’ ( ie., under 50 🤣), you certainly are inspiring us ‘old ones’ to get on with it 👏👏
Your videos also give me a great deal of pleasure Mark.
Thank you for all that work .
Regards
Robert
Chilly Sydney
🤣
That’s a beautiful build. The utility of that can’t be over stated. I appreciate the finishing details a great deal. That’s the icing on the cake. As was that bird at the end. What a buzzard!
That was quite a project. Press on!
I can’t wait until the foundry update, I work in a foundry for many years. You would tend to think that I have my own foundry, but I don’t. Perhaps I can build one in the future, we shall see, either way I am hindered by a lack of funds. Great video by the way, really enjoy your videos and thank you for sharing your knowledge in a way that I can understand and appreciate.
I always imagined that running a home foundry would be expensive and difficult but my first attempt at melting aluminium in a very crude furnace went well enough that I was encouraged to keep going. At the end of the day, the raw materials are just sand and clay and a supply of clean scrap aluminium. Propane is definitely the way to go if you are starting out and it does melt aluminium, eventually, but diesel is quicker and it can get way hotter but it's a bit more tricky to handle.
Regards,
Mark
@@Preso58 I just might have to look into it some more, I know I can purchase a kit for $200 but if I can build something for less then that would be the route I’d take
Every project I do is only to learn something I didn't know before. Great job Mark.
That's it!
Regards,
Mark
The drill grinding machine looks fantastic, the finish makes it look top quality, and worth the effort to have done it, in my opinion. Great job. Funny thing when I watch your videos is I often find myself smiling along when you are working - you have that kind of mellow, intelligent and soothing style. Great series and I look forward to the next project. A diesel burner - what could possibly go wrong?
Thanks Glenn. I am both excited and a little scared about the diesel burner. It's only one step away from a full on jet engine.
Regards,
Mark
Another project well done.
Thanks for sharing and letting us watch as you work.
Great build. Thank you so much for the videos.
I' ll be there for the next one . They say beauty is in the eye of the beholder , cheers .
If you milled a couple of flats on the collet spindle you could use a scanner to tighten the collet, possibly easier than the vise
Great video and project Mark. I enjoy your projects a lot. Looking forward to the next ones as well.
Thanks for sharing.
I would definitely recommend making a centering jig, its literally 2 flat, parallel rods at equal height with a ``valley`` between them in the simplest form, hell, they neednt even be parallel, they can be converging at some point in the imaginary distance, it just matters that you get them flat and level, so things dont roll off them when you lay a mandrel down across them... Balancing is easily done by a hand drill or a dremel with a rotary burr... I would advise you to use a cbn shaver to turn the i.d. and the o.d. of the cbn portion concentric, as to have the abrasive portion dynamically balanced... After that, lay it on the balancing jig on a mandrel and balance the whole wheel by removing aluminium from the cup section, the outer edge... Dont go too deep nor use too large of a drill, the balancing can be done with a 3mm drill or a 4mm one with ease... Just make shallow pecks on the heavy side...
Once balanced, the wheel will actually cut much much nicer... I have a `yuge surface grinder, and its 6inch discs are literal weights, and if i even consider not using a perfectly balanced stone(they have balancing arbors, so its just shifting small weights around, no drilling), the surface finish shows it... You can see the oscillation in the surface finish, and its a monster of a machine, compared to this little jig you have running a 4inch disc... Sure, the cbn wheel is much lighter than a vitrified corundum wheel of cheese, but nonetheless, 3 tonnes of cast iron are literally orders of magnitude more rigid than this little thing, and i can still optically detect the imbalanced wheel just by looking at the surface it produces... Compared to wheel-machine mass ratio, my 3 kg wheels are still a fraction of machine mass compared to your cbn wheel to machine mass, especially as most of your machine weight comes from the motor, which is not a structural part nor grants anything apart from mass and drive...
I would also argue that drill grinding and any tool grinding for that matter, should actually demand better surface finish than most work, as the surface finish of the cutting tool literally translates into the surface finish it produces when used in future work... To the point that i would consider in your place, getting a 1000 grit vitrified diamond wheel to hone the tools after using the cbn for ``cutting`` work, vitrified or electroplated, but i prefer glass bound, as its much more resistant to contamination with abraded material and thus being reduced in quality of the surface finish it produces... Tho, glass insulates the diamond, so either very slow speed or flood cooling are necessary for ferrous grinding, as not to dissolve the diamond into the metal... That or a slow speed carbide grinder, which can hone hss with no problems... Diamond isnt that reactive with steel, you really have to grind with it to produce enough heat to cause local dissolution of diamond into steel... Honing with some wd40 will allow you to gain a razor sharp edge, that despite the logic will last longer than regular, as the polished edge has significantly reduced tendency to grab, snag or chip due to friction, as a polished surface is the smallest version of the surface, due to lack of any micro terrain that can catch or accumulate shit that then catches... Especially for drilling alu and copper that love nothing more than catching an edge and welding onto it...
All the best and warmest regards!
Steuss
Interestingly, Clough42 just released a video on balancing grinding wheels. He used a Dubro model aircraft propeller balancer. I just checked and they are available and fairly cheap. He seemed to think it worked well for a large grinding wheel so I may investigate that. The only issue is making some sort of mandrel for the cup wheel since it only has a tapered shank on one side of the wheel. I have some 16mm precision ground rod so I may be able to mount the wheel on that but it's always best to balance it on it's own mandrel.
@@Preso58 I would consider making a centers balancing jig, rather than the usual two level shanks, as that would allow you to indicate the mandrel of the grinder on the lathe with a tenth`s indi, or finer(some severe medication recommended beforehand), drill in the two centers, and voila, you have a mounting mandrel that both a balancing mandrel at the same time... You could technically use the lathe and 2 dead centers with some light spindle oil in the female centers to balance the discs, or check for balance, but i really dont want to even recommend that, as cbn dust of any sort around the lathe or any machine is essentially a terror to consider...
I think i`ve seen the vid you alluded to, but yes, many types of balancing jigs can be used to work a stone into order, but consider which design best suits your situatio and mounting system... As you said, the stone is best balanced on the running mandrel itself... I would even consider balancing the pulleys on both the motor and the spindle of that little machine, just for additional smoothness of running... There is always some imbalance to any rotary part that has not been sorted out, or is a perfectly ground shaft with purely concentric geometry... Even most of the machine spindles have some little imbalance due to most of them having threads or keyways or some such nonsense that is never perfectly cut to result in 100% balanced part... Generally its disregardable, and on high end machines, its sorted in the factory to run to less than 0.001 grams of imbalance, but yeah, lets cut this rant here...
All the best and kindest regards!
Steuss
Very nice work as always.
your CNC jaw couplings sound like my CNC jaw couplings
Great job.
I’d like to see a video of yours with your hands free of injury 😂
Me too!
Regards,
Mark
Thanks for sharing 👍 I enjoyed this build.
nice project !
cheers ben.
Why not put flats on your round cam to give you fixed detents for specific angles.
Good idea but that detail escaped me. I guess it would make it more complex to machine and for the most part I tend to leave the eccentric set on one value when sharpening batches of drills of roughly the same diameter.
Regards,
Mark
Look like this will be a cool video 👏👏
You seemed to be worried about people saying it might take too long to do them hence the timing of it. It takes what it takes to get a nice sharp drill bit and a sharp drill bit is quick and efficient. Think of the time it takes to use a blunt drill bit
Awesome build as usual! Did you consider staggering the numbers so that they every one is higher up the line than the adjacent one? This allows you to dial in the all angles of the trunnion from both sides of the eccentric wheel.
No, unfortunately not. Staggering is something I usually do after a few drinks. It would improve the legibility if they were arranged as you say.
Regards,
Mark
Hi Mark if you watch the video when you are grinding the small drill bit it looks like it twisted in the collet or could have been my eyes .. But nice machine.
Stuart, that is possible. I did regrind the 3/32" drill bit again after shooting the video and I tried to be more thorough. It's hard when the camera is running and I am loathe to stop and double check everything because it means loads of editing later and people start to suspect that something "tricky" is going on.
Regards,
Mark
Its a cool project. I like it, but im way too lazy to build one. Ive got a big enough table on my grinder to brace my shakey hands, and enough magnifiers to correct my failing eyes. I just keep hand sharpening.
Is there a problem with the grind angle if you have to take a lot off the face? You align the original cutting edge with the clear perspex template but as the grinding progress the grind is flowing the twist in the drill and not staying parallel with the wheel.
I'm guessing it's not so bad if it's only a touch up and not a complete regrind.
I could be way off the mark of course. My own drill Sharpening attempts are rugged at best😅
Yes, you do sometimes need to check the alignment if you need to grind heavily to remove a chip or a badly formed angle. It only takes a few seconds to realign it though.
Regards,
Mark
Great finale!
Oh, how about Joey on the Barbie? Any good? Just kidding. Lol
Ahh, but you can buy kangaroo fillet for the barbie. Gotta have it cooked rare though. It turns to the consistency of rubber very quickly.
Regards,
Mark
@@Preso58 me thinks the shrimp might be a better choice. Thanks for the info.
Educated guess: Once you do not have to explain to us (and yourself) what to do next, then it will become much faster. I think it looks much more complicated than it appears once done a few more times. Some will say they can do it all on the bench grinder anyway 🙂. (try to grind a 1.6 mm carbide drill on benchgrinders, then we talk again)
I saw a nice Fresnell plastic lense in the stationary shop, I am thinking of incorporating one in the alingment jig. (still having most of the other work to do).
It's always hard to carry out multi step procedures while a camera is running. I like to stop often to check setups but that means a lot of editing later. As it turned out, I tried to sharpen the two drill bits in one take without stopping and something always went wrong and I had to start over again. I am sure it will go more smoothly after I have ground my first hundred drill bits!
Regards,
Mark
Instead of an eccentric you should make a spiral (3D print it or hand filing aluminium) the contact point will sit in one place and be in-line with the pivotal point create no turning force on the spiral.
Great video and great results from your efforts. As to the pressure needed on the small bit, I think the chisel point is the resistance and could be defeated by making a tiny split point on it, just a suggestion, no comment on the execution however. Enjoyed the build and I will take a good look at your prints, might make a nice winter project for next year. Cheers Preso!
I did go back and re-sharpen the small bit. I find it really hard to concentrate when the camera is rolling. I was trying to hurry the process along for the camera but if you slow down and take the time to check what each stage of the grind is doing it actually saves time since you don't have to do it over again. However, the main thing is practise.
Regards,
Mark
I think your final remark was a little cutting, I am sure that to it’s mate it is a beautiful bird. On a serious note, a useful piece of kit, compared to building a Quorn the time spent is minimal.
Hi Mark, thanks for the mention the caps look good.II made the flute alignment jig for my Kennet & it’s a great improvement thanks for that. I’ve probably ground 20 or so bits and like you was unhappy with the grit getting everywhere. I made a thin leather apron that hangs down from the table edge it’s made a difference. As you mention casting why not have a go at a new wheel guard with a vacuum port? You could also incorporate that extra depth for the wheel that you had to add to the Quorn one, I have exactly the same issue as I also have the Quorn guard, I’m looking at doing something similar.
Tony, yes, the caps do look nice. I have a Prusa 3D printer and I bought a spool of genuine Prusament (filament) with a sparkly fleck in it. The surface that is against the printer sheet comes off with a lovely texture and if you can arrange the print with that surface uppermost they always look like a factory made part. I did consider casting a new wheel guard but it would be a complicated pattern and would need a core to give the hollow port for the vacuum. It's just a nuisance dust when grinding HSS but carbide is a different thing altogether. Apparently, carbide dust is full of cobalt and other heavy metals and definitely not good for one's health. I will look into adding some thin leather as a skirt to protect the Vee slot and the wheels.
Regards,
Mark
👍👍😎👍👍
Hi Mark, in one of the earlier videos in the series, you were talking about having to remove the back corner of the relief grind.
Could one rotate the drill bit collet assembly while grinding the relief angle so that the resulting facet on the drill bit is not flat, but rather is conical in shape?
I understand the current configuration with the 180 degree stop will only allow you to make this conical grind on only one of the flutes, but I'm curious if rotating the bit will result in a consistent clearance angle. If that works, one could come up with a two stage rotary indexer allowing one to rotate the bit 180 deg and then about 90 deg to grind the conical relief angle.
Hope I'm making sense...
Love your videos and projects, you share so much info. Thanks!!
I guess you could do that but the split point attachment can be used to remove the heel of the drill point. I do need to carry out some more tests on the whole rig. Unfortunately, I sort of lost interest in the build once it was completed and I moved on to another project. I had sharpened all the blunt drills in my metric and imperial set and then the machine got put away in the cupboard.
Regards,
Mark
Fantastic job as always Presso 👍 Another fairly epic little series going by how much little Joey has grown😊 Just gotta figure out how to convert growth rate/time taken into bananas 😁 Cheers mate 🍺
Thanks Bill. I think we missed the really cute stage when the joey was all back legs. More like an ungrateful adolescent now.
Regards,
Mark
Hi Mark, thanks again for sharing and inspiring. BTW - That 'CBN' wheel may not necessarily be CBN. It looks suspiciously like one I picked up on ebay being sold as diamond/cbn. It turned out it was sold by a seller who thought they were the same thing, but noted higher demand for CBN over diamond... Thought that may be helpful.
I suspect it is just a diamond grit plated onto a steel body. However it seems to grind well and the surface is holding up well. A quick check on Ebay showed that their were two price points for CBN. The genuine article was about 4 to 6 times the price of what I paid. The Chinese equivalent is a bit vague about the composition of the grit so I guess you get what you pay for.
Regards,
Mark
Yeah, totally agree Mark. I challenged the seller and he refunded my purchase price, all too quickly for me to be convinced he didn't know they were diamond not CBN. Having said that, the wheel seems to run really well due to the damping effect of having so much mass in the steel. I ended up finding some reasonably priced genuine CBN wheels out of Ukraine. I know, bit of a risky purchase hey! However the seller was very genuine and really appreciated the patronage. Only down side was that it took about 8 weeks to arrive. I'm super happy with the product and would recommend without hesitation. It's really fast to remove HSS material but leaves a fine grind finish. Let me know if you would like a link to the product.
Regards, Craig.
37:06 Not the best pub pick-up line, Mark.
Maybe that's why it took me so long to find a girlfriend!
Regards,
Mark
30:49 Is that an illusion or am I seeing the bit wobble?
No, it was the drill press table which I had forgotten to lock. However the drill bit was bending a little under load. I did regrind the 3/32" bit afterwards and got it to cut much better. Trying to carry out complex operations with a camera running is always a challenge as you have split your attention between two tasks.
Regards,
Mark
@@Preso58 Thanks
I don't have a drill sharpener (actually I have a very used Drill Doctor clone which I don't like enough that I just buy new drills all the time). While watching your video it seems to me that your order of operations is backwards. You ground the secondary facet and then the primary facet. And you didn't reset the drill's lips to be horizontal (if you had to feed the drill bit into the grinding cup/wheel while grinding the secondary facet). I think that might be why you sometimes don't get a constant width primary facet.
Can you try this to see if you get a more consistent primary facet:
1. Set the back edge of the most worn lip of the two cutting edges to be horizontal (ie parallel to the collet's base).
2. Set the trunnion to the PRIMARY facet angle and grind the PRIMARY facet of the first cutting edge, and let it spark out.
3. If the drill is badly worn and you don't get a fill width cutting edge (or full width primary facet) on the first lip, then feed the drill into the grinding cup/wheel and start over at step 1.
4. Rotate the drill 180 degrees to grind the primary face on the second cutting edge and let it spark out.
5. If you don't get a full width cutting edge (or a full primary facet) on the second lip (or if you don't get a straight chisel point) then feed the drill into the grinding cup/wheel and start over at step 1.
6. Then change the trunnion angle to the SECONDARY facet angle and grind both SECONDARY facets (without feeding the drill towards the grinding wheel).
Bruce, thanks, I will try that. I did find that badly worn or chipped cutting edges needed a lot of grinding and after getting some strange results I did realise that the cutting edge had migrated around and was no longer parallel to the collet block base. A quick reset on the alignment jig then allows for a light regrind followed by the primary grind. I still need a lot of practice but the results so far a promising.
Regards,
Mark
This is usually where I get myself in trouble and end up doing a lot of extra work I wouldn't normally do. The cam could have been figured out with just a little bit of trigonometry.
Unfortunately, I failed at trigonometry whilst at school. Mathematics in general gives me the heebie jeebies. I prefer geometry.
Regards,
Mark
at +16:22, the centerline of the Marks don't line up with the center of the eccentric.
Unfortunately, that's an artefact of the PDF. You can correct it by node editing but it was close enough for what I was doing.
Regards,
Mark
I literally hate PDF files for graphics due to the fuzzy edges on lines. I much prefer 2 color (B&W) BMP files. Do files have to be in PDF format for you to use them?
I find that Corel Draw can edit PDF files into vectors very easily. Some circles end up in segments but you can weld them into continuous paths or just draw a new vector circle to replace it. Unfortunately, my version of CorelDraw won't open DXF or DWG files exported from Inventor. There is an add on package that will translate them but it's very expensive. Have you tried Inkscape? It is a free vector drawing programme and it will open PDF files as crisp, sharp, editable vector drawings.
Regards.
Mark
Mark, excellent work as always. Is there any chance you would be willing to share the iam/ipt files you created? Thank you for sharing your work, it is very valuable!
I have put a zip file on my dropbox with all the native Inventor files. www.dropbox.com/sh/38ahn5tz4qw5ypw/AACtAbmXNDYa4x0v9DD1NcEOa?dl=0
Regards,
Mark
@@Preso58 Thank you!
@@Preso58 Mark, Thanks for the inventor files. I opened them today and noticed a few files were missing. Specifically "Z axis carriage no motor.iam" and associated parts. Any chance you could update the download with those files? Thanks again much appreciated!!
@@termlimit I didn't include that subassembly because it was a very specific part that I had recycled from an old 3D printer that I made many years ago. I assumed that other builders would probably substitute another style of gantry using something like linear rail. However I have added it to the zip file on my dropbox.
Regards,
Mark
@@Preso58 ahh ok fair enough thanks for the reply
You could improve the accuracy of your angle setting If you took a small piece of alloy flat bar and were to machine a profile or curved slot the thickness and the radius of the eccentric you made with the base plate surface tangential to the machined slot, so as it turned, the flatbar would translate from left to right with the eccentric, like a cradle so to speak. you could then attach a small perspex plate with a vertical line scribed in the center as a reference mark for your eccentric graduations or a simple pointer or something as a reference to align the graduations. Im tired and struggling to explain the picture in my brain sorry but hope you can understand what i mean 😊
I am sure there are lots of ways to get accurate marks or a more direct way of setting the angles but it's apparently not that critical to have a very precise angular setting.
Regards,
Mark
So....in reality you have made a 6 facet drill grinder.......on the subject of melting metals, specifically ally, I'm leaning to the circular stove element type......they're much easier to obtain and replace..... in the bottom of a bucket of refractory stuff or ceramic wool........one day.