I ran across your channel a year or so ago and just now looked at these older videos. You look years younger and more joyful in 2023 than when this was filmed. Whatever you’re doing, it’s working for you.
I was thinking about building one of these, and here we are. I like your ideas, I will borrow some of them. Thank you very much for sharing this. Cheers!
Yours is quickly becoming my favorite UT channel. Next I would like to see a Fusion 360 discussion, followed by a step by step construction. You seem to know what you are doing. So, go for it. Thank you!
My hat is off to you sir. The amount of work put into just the CAD is staggering. It is hard to believe that someone can actually complete a project like this :) One step at a time I suppose. Thank you for making such great videos.
Hi James. Looks like an interesting project. Like many wannabes I'd like to add one to my arsenal. I like your idea. One suggestion, if I may, would be to add some pressurized air to the spindle body to help keep the grinding dust out of the bearings. I know you have rubber seals on the bearings but the dust will find it's way in and the result will be short bearing life. Just a pound or two of pressure will do wonders without forcing the lubricants out of the bearings. Something to think about while you build the spindle holder. I look forward to the rest of the build.
i'm working on building a toolpost grinder at the moment, and have been researching angular contact bearings, which is how i found this video. it's alarming how similar your design is to mine, but i had planned on using a j6 taper/chuck combination. i love your use of er20 collets though, and i think i'm going to brazenly steal your idea. lol. thanks for the video! =)
No worries. I brazenly stole it from someone else. :) I looked into angular contact bearings initially, but couldn't find the size I needed for a price I wanted to pay. Time will tell if I made the right choice.
Speaking of "ODD" threads... My Lathe / Endmill combo from Harbor Freight, has M42x2 Threads that hold the Backing Plate on. I can't find a replacement backing plate ANYWHERE... And this lathe doesn't allow me to cut threads, so I can't even duplicate it to change the chuck. I literally had to make an adapter plate for my new 4 jaw.. Lucky for me, my uncle has a HUGE old lathe from the 40's that can easily hold a 8in plate. So I was able to machine a cast iron plate with the 3jaw pattern on 1 side, and machined it to fit the 4 jaw on the other, so I can fit both onto the 1 backing plate. I really wish I could just get a 2nd backing plate, but I can't find one any place at all. Even Harbor Freight, or Central machinery, couldn't even order me one, as they changed them on the new machines, and don't make anymore of this type. I only paid $500 for this machine in total, and the new ones are going for around $1500... Also the new combo machines now use a 1.5"x8tpi spindle so SAE backing plates fit. The rest of the machine is all metric tho.. This isn't a "terrible" machine although the belt trans doesn't allow you to really slow it down enough, with the slowest speed being around 450rpm, and the 2 motors are rated at 1hp but have a hard time starting the spindle when its really cold out. The grease causes them to need help getting spinning. lol As for tolerances. The best I can get on the lathe is about 0.001 (using my 4 jaw) and around the 0.003 on the endmill, just because it swings out of the way, so it doesn't effect the lathe operation. But in return there is the smallest amount of play in the arm itself so just cant do any better.. Finally, the cross slide / carriage has a TON of play in them, and need some rework. The set screws they use to keep it tight, back out all the time, and dig right into the bed, making it a mess. So I use the locking screws to help keep it tight, which makes using it a pain, as the knobs are fairly small and the lead screw pitch is really large. Something like 8mm.. Would be a ton better if it was 1/2 that.
That's possible. I've done a little grinding with it and haven't had any issues. As long as the temperature changes slowly, the drawbar will expand, too, but you may be right. It would need to be a pretty hefty spring.
Have you thought about making both pulleys with two different diameters giving higher rpm's for small internal grinding?? Lov the design think I will build one. Thanks like your videos. . Will be getting my PM 1236 lathe and 833 mill in August .
Hi, Do you think the ball races could have been fitted just by chilling the ER shaft and warming the races ? I have no experience of this so would like your opinion. Very good project, entertainment and engineering. Regards Dave M.
A very appealing project -- but now, afterwards -- have you perhaps had any ideas regarding how the design might have been simplified while retaining the same qualities?
I could have just purchased a tool post grinder. :) I actually like the design. It's working out well, and it's something I can put my name on and be proud. I may have been able to save some time by buying a spindle or pulleys, but that's not really the point. Spending time in the shop making something cool is its own reward.
Very nice design. Will you give out or sell the drawings? I would love to make one for myself. I have the same need for a toolpost grinder as you. I plan on making a ER40 Headstock chuck as well.
i like the model and the reason why . But there is a little someyhing that i am a little less sure you install the bearing half in the casing and half in the bearing nut this mean that you will have to machine 4 separate hight precision diameter for the bearing but you need a looser fit on the bearing nut to be able to screw it ! personaly i would fit almost all of the bearing in the casing leaving only 1mm for the nut to squeeze it but maybe i dont understand why you do it that way !
Got to this channel while looking for videos about Lathe CNC conversion and I'm very pleased with your teaching. I'm a fan of 3D print as well and learning Fusion 360 little by little. My question here is how did you get that industrial drawings from? Is it made with Fusion 360 as well? Thanks
You could have increased the spindle diameter if you ran it past the tool post base. If you did this you could have added the top distance of the tool post holder to the total diameter which would have given you 3/8 to 1/2" more spindle diameter. | top of tool post holder O - spindle bore ------------------------------------- | |--------------- | bottom of grinder end of tool post holder The other thing is that those bearings won't do well if you decide to do internal grinding with small wheels. It would be better to double up the bearings at each end and Belville washers are usually used stacked back to back and front to front up to several washers.
@@user-wo7rz3yn4o Once you get down to small diameter wheels, less than 10mm (3/8") the rpms need to be high, in the range of 25k plus minimum. A greased 6804, like is being used here has a limiting rpms of ~ 15k.
@@user-wo7rz3yn4o First, I would hang the end of the tool post over the cross slide to allow for spindle diameter options (see my original response above). You have to decide how much you want to spend, what size lathe and what type of work you want to do. Of course, angular bearings are the best but you can get pretty close with an ABEC 5 or 7 in a cheaper bearing if you build carefully. What you could do is use a single shield for the outer bearings and unshielded for the tandem inner bearing. This way way you could build a sealed oil filled housing which would give you greater bearing speeds. Using the 6804's doubled up sandwiched with Belville washers in the middle for the front bearing assembly you can get up to ~25k using the same spindle. Depending on your motor you might be able to get away with one bearing in the back with a single shield facing outside. You would have a more robust grinder with higher speeds. Don't overtighten the Belville washer assembly, just take out the play. You don't want to use one bearings on each end in a single housing, you can't get reliable preload on the bearings because as the spindle warms up the preload changes, that's why you use two bearings in the front with Bellville's and set your preload there, the spindle will also last longer. Again, it depends on what you need, if you do a lot of internal grinding then use smaller bearings in tandem with a smaller diameter spindle. Also remember, as a rule, you want to keep the spindle as light as possible for starting inertia and balance. You should use stressproof steel for the spindle also and machine your final tolerances in situ, you'll get a lower TIR (total indicator reading). Just my opinion but I've built and repaired a fair number of spindles. I didn't watch this whole series, he may have changed things.
My 3D printers are all metric, but my manual machines have imperial dials, so I mix units all the time--especially on projects that use both machines. My sense of size is better with metric units, though, so I'm much more likely to think something like "hmm...that should probably be about 3mm" than I am to think "that should be about 1/8 inch". Oh, and lest we forget, I'm cheap, so I use a lot of metric import tools.
Mixing systems is fluent European. I'm British, which is nearly European, and worked in the steel industry for a while. It was absolutely normal for a back-street precision machine shop to order 1 metric tonne of 19mm bright mild steel in 10' 3" lengths. Then he'd ask what the tolerances on the bar diameter were, and we'd tell him they were plus nothing, minus 3 thou. Neither buyer nor seller blinked once during this conversation.
I ran across your channel a year or so ago and just now looked at these older videos. You look years younger and more joyful in 2023 than when this was filmed. Whatever you’re doing, it’s working for you.
I was thinking about building one of these, and here we are. I like your ideas, I will borrow some of them. Thank you very much for sharing this. Cheers!
Yours is quickly becoming my favorite UT channel.
Next I would like to see a Fusion 360 discussion, followed by a step by step construction. You seem to know what you are doing. So, go for it.
Thank you!
Cool project. I love the way you cover your thought processes along with various cad views. Nicely done.
My hat is off to you sir. The amount of work put into just the CAD is staggering. It is hard to believe that someone can actually complete a project like this :) One step at a time I suppose. Thank you for making such great videos.
That was many years ago. And, in fact, I used it yesterday.
Hi James. Looks like an interesting project. Like many wannabes I'd like to add one to my arsenal. I like your idea. One suggestion, if I may, would be to add some pressurized air to the spindle body to help keep the grinding dust out of the bearings. I know you have rubber seals on the bearings but the dust will find it's way in and the result will be short bearing life. Just a pound or two of pressure will do wonders without forcing the lubricants out of the bearings. Something to think about while you build the spindle holder. I look forward to the rest of the build.
Very nice, logical, and clearly explained. Well done.
Love your presentation. Have been ordering all the parts to make this for my Griz G9972Z.
i'm working on building a toolpost grinder at the moment, and have been researching angular contact bearings, which is how i found this video. it's alarming how similar your design is to mine, but i had planned on using a j6 taper/chuck combination. i love your use of er20 collets though, and i think i'm going to brazenly steal your idea. lol. thanks for the video! =)
No worries. I brazenly stole it from someone else. :) I looked into angular contact bearings initially, but couldn't find the size I needed for a price I wanted to pay. Time will tell if I made the right choice.
@@Clough42 The problem is causes the design.
I sure would like to know if those bearings are turning out to be a suitable choice.
I will like to assum, this bearing are similar in a grinder of price around $700.00, if no more.
I personally would like to see the modeling process with Fusion 360.
Speaking of "ODD" threads... My Lathe / Endmill combo from Harbor Freight, has M42x2 Threads that hold the Backing Plate on. I can't find a replacement backing plate ANYWHERE... And this lathe doesn't allow me to cut threads, so I can't even duplicate it to change the chuck. I literally had to make an adapter plate for my new 4 jaw.. Lucky for me, my uncle has a HUGE old lathe from the 40's that can easily hold a 8in plate. So I was able to machine a cast iron plate with the 3jaw pattern on 1 side, and machined it to fit the 4 jaw on the other, so I can fit both onto the 1 backing plate. I really wish I could just get a 2nd backing plate, but I can't find one any place at all. Even Harbor Freight, or Central machinery, couldn't even order me one, as they changed them on the new machines, and don't make anymore of this type. I only paid $500 for this machine in total, and the new ones are going for around $1500... Also the new combo machines now use a 1.5"x8tpi spindle so SAE backing plates fit. The rest of the machine is all metric tho..
This isn't a "terrible" machine although the belt trans doesn't allow you to really slow it down enough, with the slowest speed being around 450rpm, and the 2 motors are rated at 1hp but have a hard time starting the spindle when its really cold out. The grease causes them to need help getting spinning. lol
As for tolerances. The best I can get on the lathe is about 0.001 (using my 4 jaw) and around the 0.003 on the endmill, just because it swings out of the way, so it doesn't effect the lathe operation. But in return there is the smallest amount of play in the arm itself so just cant do any better..
Finally, the cross slide / carriage has a TON of play in them, and need some rework. The set screws they use to keep it tight, back out all the time, and dig right into the bed, making it a mess. So I use the locking screws to help keep it tight, which makes using it a pain, as the knobs are fairly small and the lead screw pitch is really large. Something like 8mm.. Would be a ton better if it was 1/2 that.
Two types of nuts can be found. Bigger with coarse thread and smaller nut with finer thread, so you should be able to replace the nut if needed.
the spindle expanding and retracting prolly has an effect to the drawbar tension as well , figure you need a spring ring behind that too
That's possible. I've done a little grinding with it and haven't had any issues. As long as the temperature changes slowly, the drawbar will expand, too, but you may be right. It would need to be a pretty hefty spring.
I'm not sure that would be necessary. If made of similar material I'd guess the drawbar will expand by a similar amount.
Have you thought about making both pulleys with two different diameters giving higher rpm's for small internal grinding?? Lov the design think I will build one. Thanks like your videos. . Will be getting my PM 1236 lathe and 833 mill in August .
Hi, Do you think the ball races could have been fitted just by chilling the ER shaft and warming the races ?
I have no experience of this so would like your opinion.
Very good project, entertainment and engineering.
Regards Dave M.
A very appealing project -- but now, afterwards -- have you perhaps had any ideas regarding how the design might have been simplified while retaining the same qualities?
I could have just purchased a tool post grinder. :) I actually like the design. It's working out well, and it's something I can put my name on and be proud. I may have been able to save some time by buying a spindle or pulleys, but that's not really the point. Spending time in the shop making something cool is its own reward.
Well done!
Subscribed.
Unfortunately I don't have all the equipment needed, do you if I can buy one of this somewhere? I hope you see this message. Regards
DZSales ER20 - 9/16" Collet.
Very nice design. Will you give out or sell the drawings? I would love to make one for myself. I have the same need for a toolpost grinder as you. I plan on making a ER40 Headstock chuck as well.
i like the model and the reason why .
But there is a little someyhing that i am a little less sure
you install the bearing half in the casing and half in the bearing nut
this mean that you will have to machine 4 separate hight precision diameter for the bearing
but you need a looser fit on the bearing nut to be able to screw it !
personaly i would fit almost all of the bearing in the casing leaving only 1mm for the nut to squeeze it
but maybe i dont understand why you do it that way !
Why not use a straight shank arbor in a 1/2 or 9/16 collet?
Do you have the dxf drawings fore this project available?
Got to this channel while looking for videos about Lathe CNC conversion and I'm very pleased with your teaching.
I'm a fan of 3D print as well and learning Fusion 360 little by little. My question here is how did you get that industrial drawings from? Is it made with Fusion 360 as well? Thanks
Yes. I made the drawings in Fusion 360, directly from the design.
@@Clough42 Ah ok. This is a great feature. Could you explain in a short video how to proceed? Thanks
You could have increased the spindle diameter if you ran it past the tool post base. If you did this you could have added the top distance of the tool post holder to the total diameter which would have given you 3/8 to 1/2" more spindle diameter.
|
top of tool post holder O - spindle bore
------------------------------------- |
|--------------- | bottom of grinder
end of tool post holder
The other thing is that those bearings won't do well if you decide to do internal grinding with small wheels. It would be better to double up the bearings at each end and Belville washers are usually used stacked back to back and front to front up to several washers.
Why would those bearings he used be a problem for internal grinding? Speed ratings?
@@user-wo7rz3yn4o Once you get down to small diameter wheels, less than 10mm (3/8") the rpms need to be high, in the range of 25k plus minimum. A greased 6804, like is being used here has a limiting rpms of ~ 15k.
@mosfet500 good to know. I am planning on building a tpg based on this design...what would be more suitable bearings?
@@user-wo7rz3yn4o First, I would hang the end of the tool post over the cross slide to allow for spindle diameter options (see my original response above). You have to decide how much you want to spend, what size lathe and what type of work you want to do. Of course, angular bearings are the best but you can get pretty close with an ABEC 5 or 7 in a cheaper bearing if you build carefully. What you could do is use a single shield for the outer bearings and unshielded for the tandem inner bearing. This way way you could build a sealed oil filled housing which would give you greater bearing speeds. Using the 6804's doubled up sandwiched with Belville washers in the middle for the front bearing assembly you can get up to ~25k using the same spindle. Depending on your motor you might be able to get away with one bearing in the back with a single shield facing outside. You would have a more robust grinder with higher speeds. Don't overtighten the Belville washer assembly, just take out the play. You don't want to use one bearings on each end in a single housing, you can't get reliable preload on the bearings because as the spindle warms up the preload changes, that's why you use two bearings in the front with Bellville's and set your preload there, the spindle will also last longer.
Again, it depends on what you need, if you do a lot of internal grinding then use smaller bearings in tandem with a smaller diameter spindle. Also remember, as a rule, you want to keep the spindle as light as possible for starting inertia and balance.
You should use stressproof steel for the spindle also and machine your final tolerances in situ, you'll get a lower TIR (total indicator reading).
Just my opinion but I've built and repaired a fair number of spindles. I didn't watch this whole series, he may have changed things.
Sir I need this design for my lathe
No problem. I have published a complete set of drawings in the blog post here: clough42.com/2018/05/24/toolpost-grinder-part-24-first-test-grind/
Since my lathe isn't that big, I have the same problem as you have
Double up your load end bearings.
Wow. An American that can speak fluent European.
My 3D printers are all metric, but my manual machines have imperial dials, so I mix units all the time--especially on projects that use both machines. My sense of size is better with metric units, though, so I'm much more likely to think something like "hmm...that should probably be about 3mm" than I am to think "that should be about 1/8 inch". Oh, and lest we forget, I'm cheap, so I use a lot of metric import tools.
Mixing systems is fluent European. I'm British, which is nearly European, and worked in the steel industry for a while. It was absolutely normal for a back-street precision machine shop to order 1 metric tonne of 19mm bright mild steel in 10' 3" lengths. Then he'd ask what the tolerances on the bar diameter were, and we'd tell him they were plus nothing, minus 3 thou. Neither buyer nor seller blinked once during this conversation.
Do you have the dxf drawings fore this project available?