Great attempt. It’s not a failure. You succeeded in determining that twenty small balls isn’t better than three large ones. And you got to make a great looking tool as well.
A force of 30 kilos can be exerted on a ball. In 10 balls, this force will be distributed over 10 points. To smooth with 10 balls I think we would have to exert 10 times more force to smooth and compact the surface of the metal.
I think the idea of using a single ball is a good one. However, if the goal is for the surface to be as smooth as possible, then maybe using a very large diameter ball would help. ...Think of it as being similar to the way that a large radius cutting tool for the lathe leaves a smoother finish than a small radius. Using a single ball in a milling tool is going to have some drawbacks though... With an infinitely rigid mill and tool, then the further you offset the ball from the centerline, the more even the finish will be. On a real mill though, the more the ball is offset, the more it's going to deflect. Using two large diameter balls might be a good compromise? Depending on the capacity of any given mill, maybe 30mm balls, set with 1mm of clearance between them could work? I like your idea with the spring loading, but it's gotta be something really stiff. The valve springs from an OHV car or truck engine might be good, and an engine overhaul shop would probably sell you a used one for next to nothing. I look forward to seeing more of your videos.
@douglashank8480 but the larger radius of the ball will reduce surface pressure so you will need to push it into part longer. You may be right about being smoother though.
These are too big words for a simple man like me, but thank you for the encouragement and the honor of appreciating my work. Words are magical sometimes and can do wonders. Thank you Ivan!
Hi Hank and thanks for visiting my channel. Unfortunately, my lathe and my milling machine are very limited. The idea to use more balls started from another project that only had three balls. The first result was disappointing and that's why I designed this multi-ball tool. Unfortunately, I can't use bigger balls because my pressing force can't be very high, so I use small diameter balls but the result are below expectations. I resigned myself to the idea that plastic deformation leaves those marks, regardless of the chosen solution. Thank you again for your comment and for your suggestions. I'm honored.
Hi Jimmy, I hope you are well. One thing I see right off @ 5:33 is your indicator is at a steep angle to your work piece. That will give you “cosine error” since you are measuring on an angle more than 90 degrees.
Hi Arnold ! I hope you are well too, thank you. I will have to buy a dial indicator with longer action. I couldn't seat properly because I was very close to the chuck jaws. Thank you for your comments !
While he would be getting a cosine error, wouldn't that only matter if he was measuring different heights instead of just centering his part? From what I'm seeing there is nothing wrong in using it at such an angle for this purpose.
You’re on the right path. Polishing steel via burnishing is a metal displacement process that tends to work on metals that are 45HRC and below. Perhaps you are trying to polish a steel that is greater than 45 HRC not allowing the bearing balls to displace the metal as smoothly as possible. Try testing out your burnishing tool on a variety of metals to see what the range of results can be achieved with the tools at varying spring pressure, feeds and speeds. Great looking tool!🤠
Unfortunately, I don't have data on all the types of steel I have. I can only approximate their hardness ”by eye” and I can tell you that the metal plate used is not very hard. I have not tried on aluminum or copper or high alloy steel. But it's an good idea. Thank you very much for your comment !
I was intrigued by this idea, based on what I have seen accomplished with single ball burnishers on Lathes. And I had this thought. The ball bearing burnishing works because of the force applied to the surface through the 'single point' contact of the ball bearing with the surface to be finished. With a single bearing, you will get more contact force than with multiple bearings, given the same downward force to begin with. By increasing the # of bearings, you are decreasing the burnishing force, hence why you are not seeing any improvement. I would consider trying to develop a tool that only uses one bearing and see if that improves things.
Yes, it may be a good idea and it's worth testing, but I honestly have no illusions that the result will be perfect. But who knows? My theory was that a small ball is better than a large one because the track is deeper and doesn't require a lot of downforce but as expected, opinions are divided. Thank you for the suggestion. I will take it into account.
I think the idea of using a single ball is a good one. However, if the goal is for the surface to be as smooth as possible, then maybe using a very large diameter ball would help. ...Think of it as being similar to the way that a large radius cutting tool for the lathe leaves a smoother finish than a small radius. Using a single ball in a milling tool is going to have some drawbacks though... With an infinitely rigid mill and tool, then the further you offset the ball from the centerline, the more even the finish will be. On a real mill though, the more the ball is offset, the more it's going to deflect. Using two large diameter balls might be a good compromise? Depending on the capacity of any given mill, maybe 30mm balls, set with 1mm of clearance between them could work? I like your idea with the spring loading, but it's gotta be something really stiff. The valve springs from an OHV car or truck engine might be good, and an engine overhaul shop would probably sell you a used one for next to nothing. I look forward to seeing more of your videos.
Hi, I think you are doing well in trying to make improvements - so I applaud your motivation & dedication to it!! Have you considered conical rollers? this way you have a larger, linear surface contact area so it will help flatten the surface instead of pushing a groove with the small point contact of the balls... I hope you keep experimenting. Stay safe and well - Anthony (from Australia)
Hi Anthony. Yes, I thought about conical rollers but unfortunately my pressing force is reduced. I can't press harder and for your idea to be effective I assume that a more robust machine is needed. Thank you for your message of encouragement and the kind words you sent me. It means a lot to me. Stay safe and well too, my friend !
You probably need a smaller diameter race for the parts your trying to burnish. I haven't seen rotary burnisher used since 1970's but it was used to burnish bearing bores (also finished them to 0.003mm tolerance, 35mm and 42mm bearings) The pressure was quite high considering it was being used on cast iron, setting tool broke a few castings when tool setter went too far. It also got used on stainless steel when parts were being made to take to a 'Trade Show' in London (UK) I made the parts then got laid off ( along with another 29 people 😕- last in, first out)
Those patterns look like my mill makes when it is out of tram. Perhaps you can try playing with tram adjustments. I would even go so far as to suggest taking it so far out of tram that the back bearings don't touch, when it is spinning the front bearings are pressing left to right, but the back ones are going right to left. You don't see it with a fly cutter when trammed properly because the material has already been removed. Hope that makes sense.
You may be right, but unfortunately all the result of those who have built something like this are similar to what I got. My conclusion is that no better results can be obtained, regardless of the improvements made. Same result. Thank you very much for your comment!
Unfortunately, you won't even find it on planet earth :)) I adapted this chuck to fit my lathe and if you want, watch my video ”No mistake allowed” and maybe it will help you to modify one as I did. Thank you for your comment !
One of the reasons you are having trouble getting a good finish with the fly cutter is because you are using a carbide insert tool. Try a piece of high speed steel stoned to a super fine finish ( I use a 150 grit wheel and finish with diamond or stone) a real light depth of cut, .002” or so, fine feed and oil. I did have one machine that would not give a nice finish with a flycutter at all, ever. If you are having problems with loose particles try using an orbital sander with 180-320 grit paper before the burnishing tool and wipe it down in between
Great build, sorry not results you where looking for but, maybe think of it as if you where doing this on lathe. Would they not be a lot more pressure pushing against the part you want shiny?🤔 maybe more downward force with quill?🤔 not exactly sure, but that's our 2 cents and hope it helps 😉👍
It is a true that a bigger press could be a solution but unfortunately my milling machine is not very robust and because of this its pressing is limited. I regret enormously that I cannot try this idea :(( Thank you very much for your comment !
I don't think the race is allowing the bearings to feed with the part. to feed across the surface I think the bearing would almost have to be in a caster. otherwise as you feed across the work, the ball will try to climb up one side of the race making it lower at that point. it would take much more work, but a set of bearings in individual casters fixed to one head may do better, in theory. this would also give you an opportunity to put and extremely high spring rate on each caster so that each will self adjust as well as adjusting the unit with a heavy spring. another option would be to use a hydrodynamic bearing of sorts so that the ball bearing doesn't connect to race allowing for aliment with the axis motion and rotation.
Everything you say makes sense and can explain my failure with this tool, but unfortunately I don't have the motivation to made another improved model at the moment. It will take at least two days for my enthusiasm to return :)) Thank you for your comment and your suggestion !
Do you think the diameter of the burnishing tool vs. the width of the plate along with the small chips left after fly cutting the surface may affect the results? My thought is maybe the ball jumping up and then back off the surface causes an adverse reaction? I think you idea is great, just keep trying to improve your design. Thanks for sharing.
I had this idea of trying to process a sanded surface with a belt sander in order to have a more friendly surface with this tool, but I gave up because if I prepare the surface so thoroughly, this burnishing tool is no longer useful. It is very likely that you are right. Thank you very much for your comment !
Nice try but I doubt the surface will be flat or even as the balls will try to ride over the edge and bump along........a surface grinder is the method we use, and it is a tried and trusted solution to a flat and fine surface.
Theory : the Z force on the spindle is coupled to the work is 100% for (one) burnishing ball but it takes longer to cover a given work area. We have to apply X amount of Z force for X times more balls. To achieve same smoothness but X times faster. The spring idea goes adversely that. A polish compound and a buffer mat can do just that, faster and shinier.
My goal is to use this process and try to improve a tool already exists and through my ideas to make it usable by all of us. So far it seems that I have not succeded. I am not a standstill to polish a piece and make it shiny but I don't know the method to do it :)) Thank you dear friend for your comments ! It is always a pleasure to read your comments. As for your theory, it may or may not be true. It's a bit beyond me.
I like the idea of using a thrust bearing. But im thinking it would help to remove at least every other ball. The more ball bearings you have the higher the load it can take before deforming the surface. And your trying to deforn the surface..
I think there are a couple things you could do to improve results. One is fortunately easy to test. I think every time a ball goes off the side of your part it will relax downward a bit, and then when suddenly slammed back into the workpiece, it will have to jump back up, creating a bit of chatter. Does the finish improve when going down the middle of a workpiece wider than the circle of balls, such that there isn't an interrupted "cut"? The other thing that might help is applicable to then other design, but impossible on this one. You may be able to interrupt the formation of the waves before they get to such a height as to overwhelm the balls by having two sets of three balls, such that one is further out from the axis of rotation of the tool by one ball radius. That would make each ball flatten the peak of the wave created by the previous ball.
The contact surface of the ball with mirror is extremely small. Hm. A very interesting idea. Let each ball have its radius and its path so that it does not follow the same tracks? Did I understand correctly?
I think this tool works fine, the unsatisfactory result was due to a poor job with the fly cutter. Increase the radius on the cutter, increase spindle rpm, and reduce feed rate.
Increasing the radius of the fly cutter will cause my entire machine to be off-centered with negative results. I tried all the settings you mention and those hills are visible regardless of feed rate or spindle rpm. The surface is mirror as it should be but those metal waves cannot be removed or I don't know how to do it. Thank you for watching and for your comment !
@@JIMMY916 I wasn't clear, I meant increase the radius on the grind of your cutter, the radius of where the tool steel is contacting the work. After grinding my bits, I drag them on a sharpening stone to create the radius.
@@JIMMY916 I just dug out my smallest fly cutter which has a very unusual grind but always leaves a beautiful surface finish. If you have an email, Ill gladly send you some pics of the grind angles so you can try yourself. This bit cuts on the heel...
I suspect with a light machine like yours less is more, IE you can’t put enough pressure on 20 balls to achieve the desired effect. Kind of like a stuntman sitting on a bed of nails.
Great and logic example (bed of nails) :)) My light machine may be a problem. Except that a stronger pressure would bury the balls deeper in the material and instead of small waves it will produce a ”tsunami”. I can't do this test unfortunately :((
So Are you feeding with a rack or leadscrew? We repair a lot of ammonia compressors that use mechanical packing and the finish has to be flawless. My lathe makes a repeating ridge every .010” or so near as I can tell is because the feed drive gear has an imperfect tooth. The Ganesch CNC lathe uses a ballscrew drive and doesn’t have a problem finishing. My lathe won’t cut a super fine thread otherwise I would use the leadscrew for finishing. One other issue could be stick slip causing erratic carriage movement like when you are trying to get a nice finish on low carbon steel with too light of a cut.
Great attempt. It’s not a failure. You succeeded in determining that twenty small balls isn’t better than three large ones. And you got to make a great looking tool as well.
Yes, it is true that at least I have this consolation :)) Thanks for the encouragement !
@@dagorithe yea, id try simply removing done of the balls
A force of 30 kilos can be exerted on a ball. In 10 balls, this force will be distributed over 10 points. To smooth with 10 balls I think we would have to exert 10 times more force to smooth and compact the surface of the metal.
I think the idea of using a single ball is a good one. However, if the goal is for the surface to be as smooth as possible, then maybe using a very large diameter ball would help. ...Think of it as being similar to the way that a large radius cutting tool for the lathe leaves a smoother finish than a small radius.
Using a single ball in a milling tool is going to have some drawbacks though... With an infinitely rigid mill and tool, then the further you offset the ball from the centerline, the more even the finish will be. On a real mill though, the more the ball is offset, the more it's going to deflect. Using two large diameter balls might be a good compromise?
Depending on the capacity of any given mill, maybe 30mm balls, set with 1mm of clearance between them could work?
I like your idea with the spring loading, but it's gotta be something really stiff. The valve springs from an OHV car or truck engine might be good, and an engine overhaul shop would probably sell you a used one for next to nothing.
I look forward to seeing more of your videos.
@douglashank8480 but the larger radius of the ball will reduce surface pressure so you will need to push it into part longer. You may be right about being smoother though.
You are simply a genius!
Thank you very much for the great idea and wonderful video!
These are too big words for a simple man like me, but thank you for the encouragement and the honor of appreciating my work. Words are magical sometimes and can do wonders. Thank you Ivan!
@JIMMY916 Don't understate your skill set mate. Your machining is bloody good.
@stevo68 Thank you for your appreciation and for your advice.
That's a really great idea! Thanks for sharing.
Hi Hank and thanks for visiting my channel. Unfortunately, my lathe and my milling machine are very limited. The idea to use more balls started from another project that only had three balls. The first result was disappointing and that's why I designed this multi-ball tool. Unfortunately, I can't use bigger balls because my pressing force can't be very high, so I use small diameter balls but the result are below expectations. I resigned myself to the idea that plastic deformation leaves those marks, regardless of the chosen solution. Thank you again for your comment and for your suggestions. I'm honored.
Nice experiment. We shared this video on our homemade tool forum last week 😎
Thank you !
Hi Jimmy, I hope you are well.
One thing I see right off @ 5:33 is your indicator is at a steep angle to your work piece.
That will give you “cosine error” since you are measuring on an angle more than 90 degrees.
Hi Arnold ! I hope you are well too, thank you. I will have to buy a dial indicator with longer action. I couldn't seat properly because I was very close to the chuck jaws. Thank you for your comments !
While he would be getting a cosine error, wouldn't that only matter if he was measuring different heights instead of just centering his part? From what I'm seeing there is nothing wrong in using it at such an angle for this purpose.
Always good to do some experimenting. Just don't stop and go for it.
Thank you sir for the nice words and encouragement !
You’re on the right path. Polishing steel via burnishing is a metal displacement process that tends to work on metals that are 45HRC and below. Perhaps you are trying to polish a steel that is greater than 45 HRC not allowing the bearing balls to displace the metal as smoothly as possible. Try testing out your burnishing tool on a variety of metals to see what the range of results can be achieved with the tools at varying spring pressure, feeds and speeds. Great looking tool!🤠
Unfortunately, I don't have data on all the types of steel I have. I can only approximate their hardness ”by eye” and I can tell you that the metal plate used is not very hard. I have not tried on aluminum or copper or high alloy steel. But it's an good idea. Thank you very much for your comment !
You could probably switch out the regular bearings for carbide or zirconium bearings for hard steels.
Still an amazing result!
@@chriskoszewski9812 Thank you Chris!
I was intrigued by this idea, based on what I have seen accomplished with single ball burnishers on Lathes. And I had this thought. The ball bearing burnishing works because of the force applied to the surface through the 'single point' contact of the ball bearing with the surface to be finished. With a single bearing, you will get more contact force than with multiple bearings, given the same downward force to begin with. By increasing the # of bearings, you are decreasing the burnishing force, hence why you are not seeing any improvement. I would consider trying to develop a tool that only uses one bearing and see if that improves things.
Yes, it may be a good idea and it's worth testing, but I honestly have no illusions that the result will be perfect. But who knows? My theory was that a small ball is better than a large one because the track is deeper and doesn't require a lot of downforce but as expected, opinions are divided. Thank you for the suggestion. I will take it into account.
I think the idea of using a single ball is a good one. However, if the goal is for the surface to be as smooth as possible, then maybe using a very large diameter ball would help. ...Think of it as being similar to the way that a large radius cutting tool for the lathe leaves a smoother finish than a small radius.
Using a single ball in a milling tool is going to have some drawbacks though... With an infinitely rigid mill and tool, then the further you offset the ball from the centerline, the more even the finish will be. On a real mill though, the more the ball is offset, the more it's going to deflect. Using two large diameter balls might be a good compromise?
Depending on the capacity of any given mill, maybe 30mm balls, set with 1mm of clearance between them could work?
I like your idea with the spring loading, but it's gotta be something really stiff. The valve springs from an OHV car or truck engine might be good, and an engine overhaul shop would probably sell you a used one for next to nothing.
I look forward to seeing more of your videos.
Hi, I think you are doing well in trying to make improvements - so I applaud your motivation & dedication to it!!
Have you considered conical rollers? this way you have a larger, linear surface contact area so it will help flatten the surface instead of pushing a groove with the small point contact of the balls...
I hope you keep experimenting. Stay safe and well - Anthony (from Australia)
Hi Anthony. Yes, I thought about conical rollers but unfortunately my pressing force is reduced. I can't press harder and for your idea to be effective I assume that a more robust machine is needed. Thank you for your message of encouragement and the kind words you sent me. It means a lot to me. Stay safe and well too, my friend !
Have you considered belleville washers instead of spring?
No, I didn't think of using that type of washers. It's a good idea. Thank you for watching and for your comment !
Good catch!
For the effect you need to increase the spring stiffness significantly. i suggest using disc springs.
Thank you for suggestion! Could be a good idea.
You probably need a smaller diameter race for the parts your trying to burnish.
I haven't seen rotary burnisher used since 1970's but it was used to burnish bearing bores (also finished them to 0.003mm tolerance, 35mm and 42mm bearings)
The pressure was quite high considering it was being used on cast iron, setting tool broke a few castings when tool setter went too far.
It also got used on stainless steel when parts were being made to take to a 'Trade Show' in London (UK)
I made the parts then got laid off ( along with another 29 people 😕- last in, first out)
I am honored that people like you visit my channel. Thank you for your comment sir !
Those patterns look like my mill makes when it is out of tram. Perhaps you can try playing with tram adjustments. I would even go so far as to suggest taking it so far out of tram that the back bearings don't touch, when it is spinning the front bearings are pressing left to right, but the back ones are going right to left. You don't see it with a fly cutter when trammed properly because the material has already been removed. Hope that makes sense.
You may be right, but unfortunately all the result of those who have built something like this are similar to what I got. My conclusion is that no better results can be obtained, regardless of the improvements made. Same result. Thank you very much for your comment!
you should look into springs with higher spring force perhaps washer springs other than that it looks nice.
Yes, could be a good idea. Thank you for your comment!
Lucky you with the 4 jaw chuck which matches the machine. I'm unable to find one in the U.S.
Unfortunately, you won't even find it on planet earth :)) I adapted this chuck to fit my lathe and if you want, watch my video ”No mistake allowed” and maybe it will help you to modify one as I did. Thank you for your comment !
One of the reasons you are having trouble getting a good finish with the fly cutter is because you are using a carbide insert tool.
Try a piece of high speed steel stoned to a super fine finish ( I use a 150 grit wheel and finish with diamond or stone) a real light depth of cut, .002” or so, fine feed and oil.
I did have one machine that would not give a nice finish with a flycutter at all, ever.
If you are having problems with loose particles try using an orbital sander with 180-320 grit paper before the burnishing tool and wipe it down in between
Yes, could be an explanation. Thank you for your comment !
Great build, sorry not results you where looking for but, maybe think of it as if you where doing this on lathe. Would they not be a lot more pressure pushing against the part you want shiny?🤔 maybe more downward force with quill?🤔 not exactly sure, but that's our 2 cents and hope it helps 😉👍
It is a true that a bigger press could be a solution but unfortunately my milling machine is not very robust and because of this its pressing is limited. I regret enormously that I cannot try this idea :(( Thank you very much for your comment !
I don't think the race is allowing the bearings to feed with the part. to feed across the surface I think the bearing would almost have to be in a caster. otherwise as you feed across the work, the ball will try to climb up one side of the race making it lower at that point. it would take much more work, but a set of bearings in individual casters fixed to one head may do better, in theory.
this would also give you an opportunity to put and extremely high spring rate on each caster so that each will self adjust as well as adjusting the unit with a heavy spring.
another option would be to use a hydrodynamic bearing of sorts so that the ball bearing doesn't connect to race allowing for aliment with the axis motion and rotation.
Everything you say makes sense and can explain my failure with this tool, but unfortunately I don't have the motivation to made another improved model at the moment. It will take at least two days for my enthusiasm to return :)) Thank you for your comment and your suggestion !
Do you think the diameter of the burnishing tool vs. the width of the plate along with the small chips left after fly cutting the surface may affect the results? My thought is maybe the ball jumping up and then back off the surface causes an adverse reaction? I think you idea is great, just keep trying to improve your design.
Thanks for sharing.
I had this idea of trying to process a sanded surface with a belt sander in order to have a more friendly surface with this tool, but I gave up because if I prepare the surface so thoroughly, this burnishing tool is no longer useful. It is very likely that you are right. Thank you very much for your comment !
Nice try but I doubt the surface will be flat or even as the balls will try to ride over the edge and bump along........a surface grinder is the method we use, and it is a tried and trusted solution to a flat and fine surface.
I tried all the methods and almost the same result with this burnishing tool. Thank you for your comment !
ceramic balls?
Steel balls.
Theory : the Z force on the spindle is coupled to the work is 100% for (one) burnishing ball but it takes longer to cover a given work area. We have to apply X amount of Z force for X times more balls. To achieve same smoothness but X times faster. The spring idea goes adversely that.
A polish compound and a buffer mat can do just that, faster and shinier.
My goal is to use this process and try to improve a tool already exists and through my ideas to make it usable by all of us. So far it seems that I have not succeded. I am not a standstill to polish a piece and make it shiny but I don't know the method to do it :)) Thank you dear friend for your comments ! It is always a pleasure to read your comments. As for your theory, it may or may not be true. It's a bit beyond me.
I like the idea of using a thrust bearing. But im thinking it would help to remove at least every other ball. The more ball bearings you have the higher the load it can take before deforming the surface. And your trying to deforn the surface..
Yes, there are many things that can be improved. Thank you for your comment Michael!
Perhaps it would work on aluminium.
I haven't tried yet. I will definitely do it and we will see the result in a future video. Thank you for your comment !
I think there are a couple things you could do to improve results. One is fortunately easy to test. I think every time a ball goes off the side of your part it will relax downward a bit, and then when suddenly slammed back into the workpiece, it will have to jump back up, creating a bit of chatter. Does the finish improve when going down the middle of a workpiece wider than the circle of balls, such that there isn't an interrupted "cut"?
The other thing that might help is applicable to then other design, but impossible on this one. You may be able to interrupt the formation of the waves before they get to such a height as to overwhelm the balls by having two sets of three balls, such that one is further out from the axis of rotation of the tool by one ball radius. That would make each ball flatten the peak of the wave created by the previous ball.
The contact surface of the ball with mirror is extremely small. Hm. A very interesting idea. Let each ball have its radius and its path so that it does not follow the same tracks? Did I understand correctly?
Separately to the question of if it works better, this design seems to be much easier to produce, especially if you remove the spring.
@@theorbtwo Unfortunately the spring has no role. Yes, it's much easier to build. Thank you for your comment !
Seven times the balls maybe needs seven times the force.
Yes, but the harder I press, the more visible the marks become. This model is not superior to any other model. Unfortunately, no improvement.
Очень смешно, Вась, такая чистотота, как у тебя, из под резца выходит, резцом много круче чистоту сделать можно чем вот это твоё НОУ-ХАУ.
Thanks!
5x the bsll bearings will necessitate 5x the force on the tool forcthe sand result
True.
I think this tool works fine, the unsatisfactory result was due to a poor job with the fly cutter. Increase the radius on the cutter, increase spindle rpm, and reduce feed rate.
Increasing the radius of the fly cutter will cause my entire machine to be off-centered with negative results. I tried all the settings you mention and those hills are visible regardless of feed rate or spindle rpm. The surface is mirror as it should be but those metal waves cannot be removed or I don't know how to do it. Thank you for watching and for your comment !
@@JIMMY916 I wasn't clear, I meant increase the radius on the grind of your cutter, the radius of where the tool steel is contacting the work. After grinding my bits, I drag them on a sharpening stone to create the radius.
@@JIMMY916 I just dug out my smallest fly cutter which has a very unusual grind but always leaves a beautiful surface finish. If you have an email, Ill gladly send you some pics of the grind angles so you can try yourself. This bit cuts on the heel...
I will be happy to see your model. Mine is a bit limited. Please send me pics on nicolae1979nicolae@gmail.com Thank you very much my friend !
Aha. I understand now. I am a slower...Thank you !
I suspect with a light machine like yours less is more, IE you can’t put enough pressure on 20 balls to achieve the desired effect.
Kind of like a stuntman sitting on a bed of nails.
Great and logic example (bed of nails) :)) My light machine may be a problem. Except that a stronger pressure would bury the balls deeper in the material and instead of small waves it will produce a ”tsunami”. I can't do this test unfortunately :((
It is looking like you will end up replicating the original with 2 balls.
So Are you feeding with a rack or leadscrew?
We repair a lot of ammonia compressors that use mechanical packing and the finish has to be flawless.
My lathe makes a repeating ridge every .010” or so near as I can tell is because the feed drive gear has an imperfect tooth.
The Ganesch CNC lathe uses a ballscrew drive and doesn’t have a problem finishing.
My lathe won’t cut a super fine thread otherwise I would use the leadscrew for finishing.
One other issue could be stick slip causing erratic carriage movement like when you are trying to get a nice finish on low carbon steel with too light of a cut.
Maybe :))
@@pvtimberfaller My machine is a hobby one. It's very limited tool. Unfortunately.