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Re: Dismounting the headstock bearings

 

Gotcha. If it was me, I'd start with two things. First would be pulling the headstock apart and addressing the bearing adjustment problem. The inner race on the outer bearing needs to be able to slide on the spindle to set the preload. I did mine the old fashioned way like you'd polish engine crankshaft journals. If you haven't done that it done by bolting the spindle down firmly, wrapping sand paper around the spindle, wrapping a long shoelace or the like around the paper a few times and pulling the ends of the laces to turn the paper. There are probably YouTube videos that show what I'm describing. It works better than just trying to hand sand as it keeps pretty even pressure all the way around the part. If you decide to do it use fine grit paper, like no courser than 800 to start, as yours is probably pretty close. I may even start with 1,000 as yours is probably within fractions of a thousandth if the bearing already goes on but doesn't slide. Go slow and check fit often. As we know It's easier to remove material than put it back. :-) ?You just want it slide, just. If you go too far then the spindle can move in the inner race and we don't want that. It's a time consuming process, lots of cleaning and testing for maybe only two or three rotations of the paper before cleaning and testing again but it's worth the time. You'll be able to set it perfectly.?
?
My second thing to check would be the lead screw and half nuts to see if there's a burr or anything causing irregular movement and adjust of the base, compound and cross slides. That may cause the ghost thread. You can check if it's from the compound or cross slides by locking them down tight with the gib adjustment screws and taking a test cut. I'm sure you know it's really a process of eliminating variables until you find which part is causing the problem and then addressing that part to eliminate the issue.?
?
Ryan
On Feb 9, 2025 at 10:23?AM -0500, Pierre-Raymond Rondelle via groups.io <pierreraymondrondelle@...>, wrote:

Ryan,

I'm not speaking of alignment accuracy that would mainly lead to a machine a taper instead of a cylinder but of runout of the chuck that is currently resulting in an irregular machined surface. And you're right in your rationale, telling that, depending on the location the machining is preformed, the effect is greater when the distance to the chuck is increased. I admit not having checked the conjunction of the bad surface with the distance from the chuck. I take note to do that during the final verification after fixing the trouble.

I don't also remember if I said this : the roughness is drastically improved as well by decoupling the gear train from the 40-teeth drive gear at the end of the spindle. This phenomenon lets me thinking that the two bearings aren't pre-constrained enough. I don't understand yet why the ghost thread it's close to the lead screw pitch (2mm). I gonna change the ratio of the gear train to check it.


On 08.02.25 21:38, Ryan H via groups.io wrote:
1/100mm is about .0003". Over what distance are you trying to maintain that? Just curious as it shouldn't be a problem on shorter lengths with everything properly adjusted and aligned especially the saddle and headstock. I may have missed where you said but if you're saddle travel isn't perfect you're not gonna get .0003" unless you work only in the "good" area of travel. Then the headstock has to be done but anyway...
?
The inner race of the inner bearing can be an interference fit on the spindle albeit very slight. Like tap it with a wooden hammer handle only to fully seat it.?
?
?The inner race of the outer bearing should be a very snug slip fit on the spindle. That race has to be able to slide just like on a vehicle. ?It's fairly time consuming process. ?Sounds like your spindle wasn't properly fit for the bearing. If it was the race would move so you can set it. I think you're first step is going to be to rectify that and from there you're going to be set on that part.
Re: Dismounting the headstock bearings

 

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Ryan,

I'm not speaking of alignment accuracy that would mainly lead to a machine a taper instead of a cylinder but of runout of the chuck that is currently resulting in an irregular machined surface. And you're right in your rationale, telling that, depending on the location the machining is preformed, the effect is greater when the distance to the chuck is increased. I admit not having checked the conjunction of the bad surface with the distance from the chuck. I take note to do that during the final verification after fixing the trouble.

I don't also remember if I said this : the roughness is drastically improved as well by decoupling the gear train from the 40-teeth drive gear at the end of the spindle. This phenomenon lets me thinking that the two bearings aren't pre-constrained enough. I don't understand yet why the ghost thread it's close to the lead screw pitch (2mm). I gonna change the ratio of the gear train to check it.


On 08.02.25 21:38, Ryan H via groups.io wrote:

1/100mm is about .0003". Over what distance are you trying to maintain that? Just curious as it shouldn't be a problem on shorter lengths with everything properly adjusted and aligned especially the saddle and headstock. I may have missed where you said but if you're saddle travel isn't perfect you're not gonna get .0003" unless you work only in the "good" area of travel. Then the headstock has to be done but anyway...
?
The inner race of the inner bearing can be an interference fit on the spindle albeit very slight. Like tap it with a wooden hammer handle only to fully seat it.?
?
?The inner race of the outer bearing should be a very snug slip fit on the spindle. That race has to be able to slide just like on a vehicle. ?It's fairly time consuming process. ?Sounds like your spindle wasn't properly fit for the bearing. If it was the race would move so you can set it. I think you're first step is going to be to rectify that and from there you're going to be set on that part.

Re: ANSWER TO GUIDE RULE - OT

 

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Not bothered about having flat spaces next to the tools, that’s what benches are for.? They’ll be roughly the same height as my current benches so it’ll work out. ?There might be some depending on how things work out, but smaller is better is it frees up more space.

?

I find those flat spaces that the Crasftsmans has are a bit clunky, having to take them off & on whenever you switch tools is probably more trouble than they’re worth.

?

Tony

?

From: [email protected] <[email protected]> On Behalf Of Charles Kinzer via groups.io
Sent: Saturday, 8 February 2025 11:23 am
To: [email protected]
Subject: Re: [7x12MiniLathe] ANSWER TO GUIDE RULE - OT

?

You have to consider that the Craftsmen "rotary triple" gizmo for three tools also provides a little flat workbench space on each side of the tool.? That is probably useful.? It is true that you could probably fit two doubles in the same space, but you would have next to zero flat working space.? Of course, that may not matter to somebody if they have some flat space elsewhere.

?

Charles E. "Chuck" Kinzer

?

On Friday, February 7, 2025 at 04:02:05 PM PST, Tony Smith via groups.io <ajsmith1968@...> wrote:

?

?

The lathe & mill are roughly the same weight (45kg & 55kg?) and the centre of gravity would be roughly at the pivot point (biased towards the mill as it’s heavier & taller) so flipping wouldn’t involve too much effort.

?

Most of these set-ups let you go in both directions, mine would only go one way so less chance of it getting away from me.

?

I’ve got a CAD model of the lathe, if I had one for the mill I could model the whole thing and see how it balances.

?

Tony

?

?

From: [email protected] <[email protected]> On Behalf Of Ralph Lehotsky via groups.io
Sent: Friday, 31 January 2025 5:08 am
To: [email protected]
Subject: Re: [7x12MiniLathe] ANSWER TO GUIDE RULE - OT

?

Unless it would have an assisting motor, I don't think that I would be able to flip a mini-lathe or a mini-mill.? I can barely lift one, and usually have to disassemble parts of them when considering a location move.? Otherwise, for lighter bench tools, I think it's a great idea.

?

ralphie
Re: cutting with rotating cutter

 

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Thanks Roy
I am cutting clock wheels for my private clocks.
Even though the Carriger has a very tight fit when I cut wheels, I feel there are a little bit twist when I return the cutter for next tooth.
One way is to stop the cutting wheel before return.

Anyway, I needed your words before making this crank.
(an interesting project)

Johannes
Mexico
?

From: [email protected] <[email protected]> on behalf of Roy via groups.io <roylowenthal@...>
Sent: Saturday, February 8, 2025 17:46
To: [email protected] <[email protected]>
Subject: Re: [7x12MiniLathe] cutting with rotating cutter
?
Yes!
?
Either method works, The carriage wheel gives more rapid carriage movement, a leadscrew crank gives more precise movement. Adding a leadscrew crank is pretty easy & gives you the option of using? whichever works best on a particular project.
?
Roy
Re: cutting with rotating cutter

 

Yes!
?
Either method works, The carriage wheel gives more rapid carriage movement, a leadscrew crank gives more precise movement. Adding a leadscrew crank is pretty easy & gives you the option of using? whichever works best on a particular project.
?
Roy
Re: Dismounting the headstock bearings

 

1/100mm is about .0003". Over what distance are you trying to maintain that? Just curious as it shouldn't be a problem on shorter lengths with everything properly adjusted and aligned especially the saddle and headstock. I may have missed where you said but if you're saddle travel isn't perfect you're not gonna get .0003" unless you work only in the "good" area of travel. Then the headstock has to be done but anyway...
?
The inner race of the inner bearing can be an interference fit on the spindle albeit very slight. Like tap it with a wooden hammer handle only to fully seat it.?
?
?The inner race of the outer bearing should be a very snug slip fit on the spindle. That race has to be able to slide just like on a vehicle. ?It's fairly time consuming process. ?Sounds like your spindle wasn't properly fit for the bearing. If it was the race would move so you can set it. I think you're first step is going to be to rectify that and from there you're going to be set on that part.?
?
?
On Feb 8, 2025 at 1:59?PM -0500, Pierre-Raymond Rondelle via groups.io <pierreraymondrondelle@...>, wrote:

Ryan, I agree with you and I'd like to add some comments.

Concerning the use of tapered bearings, my lathe came with them and I didn't touch them until I decided to get rid off a bad surface aspect. A little bit rough with a ghost wave of the same pitch as the lead screw. I slightly improved this situation but I can't manage to tighten the spindle nut enough to go further. Hence this thread.

On to the other hand, I'm not looking at a thou but 1/100mm and a good surface aspect and ... the very last 1/100 are extremely harder to reach !

Concerning a wheel hub, make the experience to put the car on a jack and twist the wheel. You will be surprised, the clearance is probably pretty greater than a thou.
On a mini lathe, the tapered bearings are there more for reducing the stray movements than to withstand loads. The sole difference I noticed is that on a wheel hub, the adjustment is very easy because the inner ring is not pressed in but slipping on the spindle. I found an explanation for that, please, read my other post.



On 08.02.25 07:05, Ryan H via groups.io wrote:
My tapered rollers have been in for 10 years. I haven't touched them in 3 1/2 years since I installed my els. I pulled the rear when I had the nuts off to install some parts for that and in the prior 6 1/2 years hadn't done a thing. They're fine and still as smooth as the day I installed them and maybe even smoother. ?The preload has never needed adjustment after a couple days of getting it set and my lathe will hold less than .001" over 12 inches. We're talking about bearings meant for vehicle use. Carrying 2 tons and absorbing constant impacts and lasting tens of thousands of miles. I packed mine with synthetic bearing grease. It's still there. Our little lathes turn a couple thousand rpm tops and how often are you running it wide open? ?And how long are you running it? ?We're not talking the equivalent of a hundred plus mile a day, five day a week commute here. We're maybe covering the same as a hundred miles a year, maybe. ?And at a lot less load. The angular contact are probably easier to install from what I've read as there's no need to sand the spindle for the slip fit tapered rollers require but either will last a lifetime with extremely minimal if any required maintenance if property installed.?
cutting with rotating cutter

 

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Question:
Is lead screw a better tool to move the carriage correct in both direction than use the hand feed wheel?
If so, I will make a crank on the right side of the leadscrew.

(I am lazy, I do not want to stop the cutting wheel after a cut before returning it for the next cut.)

Johannes
Mexico
Re: Dismounting the headstock bearings

 

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Hi Jon,

Thank you for your reply.

For your information, my lathe chuck is a 100mm (4"). As far as I know the bearings are of the tapered type but I didn't verify, just referring to the drawing and the BOM.

I have neither any problem with the dismounting / mounting jigs nor the procedure but I'm only concerned by the fact that I can't manage to tighten the spindle nut farther, hence I can't adjust the clearance. This is exactly the same on the milling machine spindle except that the bearings have angular contact. On another spindle (the Unimat lathe's one, w/ angular contact) tuning the clearance is not an issue at all.

I considered again the design rules and I compared them : the conclusion is that it fits with the situation but contradicts the common sense !

- bearings are normally of class 0.

- external cages : P7 fixed bore on the gear side of the lathe and R7 for heavy loads on the chuck side => press needed.
Internal rings : n6 rotating arbor on the gear side and p6 on the chuck side where the load is heavier. => press needed.
This doesn't allow any adjustment ??? So what's the use of the adjustment nut couple ?
Another question waiting for response: Since the spindle id hard to dismount, how can the spindle bearings be maintained, cleaned and greased ? The manual doesn't tell anything about that.

- Should I consider the reverse (fixed arbor and rotating like on a car)
external cage : rotating bore, P7 or R7 for heavy loads (no adjustment)
internal rings : fixed arbor, g6 or h6 (adjustment allowed on the arbor)


On 07.02.25 19:20, Jon Rus via groups.io wrote:
Hello PR,
My experience with these bearings is that they can be hand tight, up to press tight.? On an automobile the bearing is slip fit on the spindle and press tight on the hub, so use your judgement carefully.
Do you have a 3" spindle mount or 4" spindle mount???
[...]

1. Before disassembly, make a special bushing to go into the small end of the spindle so that it will grab just the edge of the spindle and still pass through the inner diameter of the
[...]
Re: Dismounting the headstock bearings

 

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Ryan, I agree with you and I'd like to add some comments.

Concerning the use of tapered bearings, my lathe came with them and I didn't touch them until I decided to get rid off a bad surface aspect. A little bit rough with a ghost wave of the same pitch as the lead screw. I slightly improved this situation but I can't manage to tighten the spindle nut enough to go further. Hence this thread.

On to the other hand, I'm not looking at a thou but 1/100mm and a good surface aspect and ... the very last 1/100 are extremely harder to reach !

Concerning a wheel hub, make the experience to put the car on a jack and twist the wheel. You will be surprised, the clearance is probably pretty greater than a thou.
On a mini lathe, the tapered bearings are there more for reducing the stray movements than to withstand loads. The sole difference I noticed is that on a wheel hub, the adjustment is very easy because the inner ring is not pressed in but slipping on the spindle. I found an explanation for that, please, read my other post.



On 08.02.25 07:05, Ryan H via groups.io wrote:

My tapered rollers have been in for 10 years. I haven't touched them in 3 1/2 years since I installed my els. I pulled the rear when I had the nuts off to install some parts for that and in the prior 6 1/2 years hadn't done a thing. They're fine and still as smooth as the day I installed them and maybe even smoother. ?The preload has never needed adjustment after a couple days of getting it set and my lathe will hold less than .001" over 12 inches. We're talking about bearings meant for vehicle use. Carrying 2 tons and absorbing constant impacts and lasting tens of thousands of miles. I packed mine with synthetic bearing grease. It's still there. Our little lathes turn a couple thousand rpm tops and how often are you running it wide open? ?And how long are you running it? ?We're not talking the equivalent of a hundred plus mile a day, five day a week commute here. We're maybe covering the same as a hundred miles a year, maybe. ?And at a lot less load. The angular contact are probably easier to install from what I've read as there's no need to sand the spindle for the slip fit tapered rollers require but either will last a lifetime with extremely minimal if any required maintenance if property installed.?
Re: Dismounting the headstock bearings

 

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No, tapered bearings aren't sealed, see my other post, you'll see that I'm wondering how to ensure their maintenance. The gear side might be accessible for oiling when the nuts, the pulley and the head gear are dismounted but not the chuck side, covers on both sides.

No, it's in excellent condition, not dry ! Oil is present everywhere I have access, depending on the manual requirements. The use is quite light, lower than weekly, 2.5-year old, it's well protected and permanently, no rust, no dust, no remaining swarf.


On 08.02.25 05:04, Jon Rus via groups.io wrote:

I am on the fence about ACR vs TR,?
Did you get rubber seals on your bearings??
Do you oil them regularly??
Maybe 1 drop before each use?
Does oil leak out the bottom of the bearing or middle of the headstock?
Grease in TR at least is good for a while, maybe even a year before needing repacking like wheel bearings.
How are you working with them day-to-day, project to project??
Re: Dismounting the headstock bearings

 

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You're correct but the lathe was delivered with such bearings.


On 08.02.25 04:59, Jon Rus via groups.io wrote:

I believe the OP has tried to install tapered roller bearings and can not get the preload just right.? I could be wrong tho, even very wrong is possible.....
Re: Dismounting the headstock bearings

 

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Roy,

I already have tapered bearings but my problem is that they are mounted tight and I can't manage to reduce the clearance between them.


On 08.02.25 01:49, Roy via groups.io wrote:

What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
Re: Dismounting the headstock bearings

 

Hi John.?
?
Yep, my lathe is a two speed one and I have the LMS metal gears in it. To me the gears are pretty quiet. If I grab the chuck and rock it back and forth there's some gear clunk naturally but running I don't find it loud at all. The plastic drive pulley on the motor made a more annoying noise before I swapped it for a metal one... ?But I have to qualify that by saying I think I got a bad plastic gear because it broke within the first few minutes so I didn't really get a chance to get used to the sound of the plastic. Really all I know is the metal gear sound.?
?
I had the headstock off about 4 years ago (so it had been 6 since I'd been in it) when I really aligning everything and the grease I'd put in was still good. I'd used the same moly wheel bearing grease on those parts. I smeared a fresh coat around while I had it off just because but it didn't need it.?
?
Ryan
On Feb 8, 2025 at 1:13?AM -0500, Jon Rus via groups.io <byghtn5@...>, wrote:


Thanks Ryan for your experience and results report

Is your lathe a 2-Speed and are you running metal 2-speed gears as well? How is the gear meshing noise?

TKS, John




On 2/8/2025 1:05 AM, Ryan H via groups.io wrote:
My tapered rollers have been in for 10 years. I haven't touched them in 3 1/2 years since I installed my els. I pulled the rear when I had the nuts off to install some parts for that and in the prior 6 1/2 years hadn't done a thing. They're fine and still as smooth as the day I installed them and maybe even smoother. ?The preload has never needed adjustment after a couple days of getting it set and my lathe will hold less than .001" over 12 inches. We're talking about bearings meant for vehicle use. Carrying 2 tons and absorbing constant impacts and lasting tens of thousands of miles. I packed mine with synthetic bearing grease. It's still there. Our little lathes turn a couple thousand rpm tops and how often are you running it wide open? ?And how long are you running it? ?We're not talking the equivalent of a hundred plus mile a day, five day a week commute here. We're maybe covering the same as a hundred miles a year, maybe. ?And at a lot less load. The angular contact are probably easier to install from what I've read as there's no need to sand the spindle for the slip fit tapered rollers require but either will last a lifetime with extremely minimal if any required maintenance if property installed.?
On Feb 7, 2025 at 11:04?PM -0500, Jon Rus via groups.io <byghtn5@...>, wrote:
I am on the fence about ACR vs TR,?
Did you get rubber seals on your bearings??
Do you oil them regularly??
Maybe 1 drop before each use?
Does oil leak out the bottom of the bearing or middle of the headstock?
Grease in TR at least is good for a while, maybe even a year before needing repacking like wheel bearings.
How are you working with them day-to-day, project to project??

Thanks in advance
John



On 2/7/2025 7:49 PM, Roy via groups.io wrote:
What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

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Thanks Ryan for your experience and results report

Is your lathe a 2-Speed and are you running metal 2-speed gears as well? How is the gear meshing noise?

TKS, John




On 2/8/2025 1:05 AM, Ryan H via groups.io wrote:

My tapered rollers have been in for 10 years. I haven't touched them in 3 1/2 years since I installed my els. I pulled the rear when I had the nuts off to install some parts for that and in the prior 6 1/2 years hadn't done a thing. They're fine and still as smooth as the day I installed them and maybe even smoother. ?The preload has never needed adjustment after a couple days of getting it set and my lathe will hold less than .001" over 12 inches. We're talking about bearings meant for vehicle use. Carrying 2 tons and absorbing constant impacts and lasting tens of thousands of miles. I packed mine with synthetic bearing grease. It's still there. Our little lathes turn a couple thousand rpm tops and how often are you running it wide open? ?And how long are you running it? ?We're not talking the equivalent of a hundred plus mile a day, five day a week commute here. We're maybe covering the same as a hundred miles a year, maybe. ?And at a lot less load. The angular contact are probably easier to install from what I've read as there's no need to sand the spindle for the slip fit tapered rollers require but either will last a lifetime with extremely minimal if any required maintenance if property installed.?
On Feb 7, 2025 at 11:04?PM -0500, Jon Rus via groups.io <byghtn5@...>, wrote:
I am on the fence about ACR vs TR,?
Did you get rubber seals on your bearings??
Do you oil them regularly??
Maybe 1 drop before each use?
Does oil leak out the bottom of the bearing or middle of the headstock?
Grease in TR at least is good for a while, maybe even a year before needing repacking like wheel bearings.
How are you working with them day-to-day, project to project??

Thanks in advance
John



On 2/7/2025 7:49 PM, Roy via groups.io wrote:
What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

My tapered rollers have been in for 10 years. I haven't touched them in 3 1/2 years since I installed my els. I pulled the rear when I had the nuts off to install some parts for that and in the prior 6 1/2 years hadn't done a thing. They're fine and still as smooth as the day I installed them and maybe even smoother. ?The preload has never needed adjustment after a couple days of getting it set and my lathe will hold less than .001" over 12 inches. We're talking about bearings meant for vehicle use. Carrying 2 tons and absorbing constant impacts and lasting tens of thousands of miles. I packed mine with synthetic bearing grease. It's still there. Our little lathes turn a couple thousand rpm tops and how often are you running it wide open? ?And how long are you running it? ?We're not talking the equivalent of a hundred plus mile a day, five day a week commute here. We're maybe covering the same as a hundred miles a year, maybe. ?And at a lot less load. The angular contact are probably easier to install from what I've read as there's no need to sand the spindle for the slip fit tapered rollers require but either will last a lifetime with extremely minimal if any required maintenance if property installed.?
On Feb 7, 2025 at 11:04?PM -0500, Jon Rus via groups.io <byghtn5@...>, wrote:

I am on the fence about ACR vs TR,?
Did you get rubber seals on your bearings??
Do you oil them regularly??
Maybe 1 drop before each use?
Does oil leak out the bottom of the bearing or middle of the headstock?
Grease in TR at least is good for a while, maybe even a year before needing repacking like wheel bearings.
How are you working with them day-to-day, project to project??

Thanks in advance
John



On 2/7/2025 7:49 PM, Roy via groups.io wrote:
What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

开云体育

I am on the fence about ACR vs TR,?
Did you get rubber seals on your bearings??
Do you oil them regularly??
Maybe 1 drop before each use?
Does oil leak out the bottom of the bearing or middle of the headstock?
Grease in TR at least is good for a while, maybe even a year before needing repacking like wheel bearings.
How are you working with them day-to-day, project to project??

Thanks in advance
John



On 2/7/2025 7:49 PM, Roy via groups.io wrote:

What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

开云体育

I believe the OP has tried to install tapered roller bearings and can not get the preload just right.? I could be wrong tho, even very wrong is possible.....



On 2/7/2025 7:49 PM, Roy via groups.io wrote:

What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

I like the part The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
This ball bearing I purchased 1,000 at a time in class 3 / motor grade. It very good ball bearing.?
?
Dave?
?
Here basic chart on ball bearing?
?
On Fri, Feb 7, 2025 at 04:49 PM, Roy wrote:

What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: Dismounting the headstock bearings

 

What this whole thread is overlooking is the fact that the OEM bearings are deep groove ball bearings; the cheapest option! An upgrade to angular contact bearings gives more thrust resistance to the spindle, resulting in the lathe becoming more rigid. Tapered roller bearings would be the most rigid, but, sealing them is much more complex.
?
I upgraded mine to angular contact bearings years ago & have been happy with the results! My preload setting method is to simply adjust preload for slight heating at full speed.
?
The only benefit to higher precision bearings in the spindle is reducing wallet weight!?
?
?
Re: ANSWER TO GUIDE RULE - OT

 

You have to consider that the Craftsmen "rotary triple" gizmo for three tools also provides a little flat workbench space on each side of the tool.? That is probably useful.? It is true that you could probably fit two doubles in the same space, but you would have next to zero flat working space.? Of course, that may not matter to somebody if they have some flat space elsewhere.

Charles E. "Chuck" Kinzer

On Friday, February 7, 2025 at 04:02:05 PM PST, Tony Smith via groups.io <ajsmith1968@...> wrote:


The lathe & mill are roughly the same weight (45kg & 55kg?) and the centre of gravity would be roughly at the pivot point (biased towards the mill as it’s heavier & taller) so flipping wouldn’t involve too much effort.

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Most of these set-ups let you go in both directions, mine would only go one way so less chance of it getting away from me.

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I’ve got a CAD model of the lathe, if I had one for the mill I could model the whole thing and see how it balances.

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Tony

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From: [email protected] <[email protected]> On Behalf Of Ralph Lehotsky via groups.io
Sent: Friday, 31 January 2025 5:08 am
To: [email protected]
Subject: Re: [7x12MiniLathe] ANSWER TO GUIDE RULE - OT

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Unless it would have an assisting motor, I don't think that I would be able to flip a mini-lathe or a mini-mill.? I can barely lift one, and usually have to disassemble parts of them when considering a location move.? Otherwise, for lighter bench tools, I think it's a great idea.

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ralphie
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