# 7x Spindle And Spindle Bearing Upgrade



## brav65

I have had my 7x12 HF mini lathe since December but have been working on my mill. I finally got the lathe out of the box and cleaned up this week. I am now ready to get it all adjusted and ready to go. I picked up a new spindle with a 4 inch collar  that will accept a 4" chuck with no adapter required. I am also going to install new tapere roller bearing and a Machtach tachometer with the reader inside the head. Here are the parts:







I am planning to take pictures along the way which may help others who are considering this project. I will also put together a complet parts list and suppliers for each part. I have been researching this for the last few weeks. Any suggestions or comments would be greatly appreciated. 

Brooks


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## sigp2101

This is going to be interesting and educational. Thanks for doing it!


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## wrmiller

Should have said something Brooks, as I have that spindle collecting dust on a shelf somewhere (may use it in a project someday). Bought it for my 7x16 but mine used the long spindle like the LMS lathes do. I did do the upgrade to tapered rollers. Big difference. I think you will like this upgrade.


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## brav65

Thanks guys. I orded the spindle from Amadeal in England $65 delivered to my door. I will probably regret putting all the money in this little lathe but it will be a good learning experience.


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## David Kirtley

Remember that you are supposed to cut down one of the spacers to make room for the new bearings. I don't know that they still carry it but they also had a puller kit at micromark that is for the bearings on the mini lathe. I have one and it is nicer than doing it without.


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## brav65

Thanks David I looked at micromark and did not see the kit. I have some threaded rod, copper tube, PVC pipe and wood to make my own rig. I bought an extra spacer so I could turn it down prior to tear down. I am also adding a segmented wheel for an optical reader that is part of a tachometer I will be adding to the lathe. I want to locate it inside the headstock to keep contamination away from the reader. I will also be able to rout all wiring internally to give a more finished look. I am some what of a perfectionist when it comes to projects so I take a fair amount of time to research and design my projects to make them appear to be OEM. Just my pride showing is all. It's nice to have people ask where I bought something and then tell them I made it.


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## LEEQ

I look forward to seeing it come together


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## sigp2101

Where did you find specs for bearings?


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## intrepid

wrmiller19 said:


> Should have said something Brooks, as I have that spindle collecting dust on a shelf somewhere (may use it in a project someday). Bought it for my 7x16 but mine used the long spindle like the LMS lathes do. I did do the upgrade to tapered rollers. Big difference. I think you will like this upgrade.


Uh-oh, I thought all the spindles were interchangeable.  So if this spindle won't fit the Microlux 7x16, where can the 4" be found to fit?  I was also hoping to do this modification also.  The taper bearings for sure.


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## wrmiller

The one I bought (Bull?) with the 4" flange only fits the geared, i.e., two-speed heads. My 7x16 used a considerably longer spindle which is the same one the LMS high-torque lathe used. According to Chris at LMS the MM 7x16 is basically the same lathe as the one he sells, just with a longer bed. As to your question about a spindle to fit that lathe? I never found one and ended up selling the lathe (but not for that reason).


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## David Kirtley

I believe all the bearings are the same though. The one exception is that the tapered roller bearings are a bit wider and require modifications of the spacers.


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## brav65

sigp2101 said:


> Where did you find specs for bearings?




I ordered them from LMS and were listed as a fit for the HF 7x12.


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## brav65

intrepid said:


> Uh-oh, I thought all the spindles were interchangeable.  So if this spindle won't fit the Microlux 7x16, where can the 4" be found to fit?  I was also hoping to do this modification also.  The taper bearings for sure.




I purchased my spindle from Amadeal in England.  LMS has the drawing of the spindle and I confirmed with Amadeal that it should fit.   The drawing of the spindle is below:


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## brav65

I am hoping to get going on this project over the weekend.  I have been working on a carriage lock and lapping in my cross slide.


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## wrmiller

brav65 said:


> I purchased my spindle from Amadeal in England.  LMS has the drawing of the spindle and I confirmed with Amadeal that it should fit.   The drawing of the spindle is below:



I bought mine from a English company selling on Ebay. We didn't realize that I needed the longer spindle until I opened up the box and held it up next to my lathe. 

The bearing sizes are the same though, and as someone said you will have to modify the spacers a bit if you decide to go with rollers as they are a bit wider.


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## intrepid

wrmiller19 said:


> The one I bought (Bull?) with the 4" flange only fits the geared, i.e., two-speed heads. My 7x16 used a considerably longer spindle which is the same one the LMS high-torque lathe used. According to Chris at LMS the MM 7x16 is basically the same lathe as the one he sells, just with a longer bed. As to your question about a spindle to fit that lathe? I never found one and ended up selling the lathe (but not for that reason).


Well then,
I guess it will just have to be adaptors for the 4" chucks on my lathe


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## wrmiller

intrepid said:


> Well then,
> I guess it will just have to be adaptors for the 4" chucks on my lathe



That's what I did.


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## clevinski

Brooks,

I did this modification a few months ago on my Real Bull 7 x 14.  At the same time, I added a clear access plate to the headstock so I could see when the gears and bearings needed lubrication.  This has proven to be very helpful.







Arc Euro has an excellent manual on cleaning up the Chinese mini-lathes, and it includes step by step instructions for switching to tapered roller bearings.  You will have to check their photos against your lathe to make sure the configurations are the same.  For example, their photos showed the pulser disk for the speed display inside the headstock, whereas it is to the left of the headstock on the outside of the spindle nut on the Real Bull.  As I recall, their were several spacers that had to be changed in their design because of the internal pulser disk.  I mention this because you said you planned to do something similar.

After removing the spindle and the bearing, I used a Harbor Freight gear puller to get the bearing off.  It was worth what I paid for it and have used it several times since.  Polish the areas where the bearings will sit; I used Scotch Brite.  Then I used this trick a good friend recommended.  Freeze the spindle overnight in your freezer.  Place the bearing in the oven at 250°F for about an hour.  This will cause the spindle to shrink and the bearing opening to expand, making it much easier to assemble.  I calculate that this bought me an additional .0006" to .0008" of clearance.  But you have to work fast.  I did this on my mill last weekend, and had the bearing/spindle assembled in under 3 minutes from the time I removed the bearing from the oven.  It actually slid on by hand.

There are a lot of other issues (your spindle will project by an extra 1/8 inch or so, for example), but I really like the mod.  I would be happy to answer any questions you might have.  I have dozens of photos of this modification that I'd be happy to share.  Photos of the access port modification can be seen here.

Good luck!


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## brav65

clevinski said:


> Brooks,
> 
> I did this modification a few months ago on my Real Bull 7 x 14.  At the same time, I added a clear access plate to the headstock so I could see when the gears and bearings needed lubrication.  This has proven to be very helpful.
> 
> 
> 
> 
> 
> 
> Arc Euro has an excellent manual on cleaning up the Chinese mini-lathes, and it includes step by step instructions for switching to tapered roller bearings.  You will have to check their photos against your lathe to make sure the configurations are the same.  For example, their photos showed the pulser disk for the speed display inside the headstock, whereas it is to the left of the headstock on the outside of the spindle nut on the Real Bull.  As I recall, their were several spacers that had to be changed in their design because of the internal pulser disk.  I mention this because you said you planned to do something similar.
> 
> After removing the spindle and the bearing, I used a Harbor Freight gear puller to get the bearing off.  It was worth what I paid for it and have used it several times since.  Polish the areas where the bearings will sit; I used Scotch Brite.  Then I used this trick a good friend recommended.  Freeze the spindle overnight in your freezer.  Place the bearing in the oven at 250°F for about an hour.  This will cause the spindle to shrink and the bearing opening to expand, making it much easier to assemble.  I calculate that this bought me an additional .0006" to .0008" of clearance.  But you have to work fast.  I did this on my mill last weekend, and had the bearing/spindle assembled in under 3 minutes from the time I removed the bearing from the oven.  It actually slid on by hand.
> 
> There are a lot of other issues (your spindle will project by an extra 1/8 inch or so, for example), but I really like the mod.  I would be happy to answer any questions you might have.  I have dozens of photos of this modification that I'd be happy to share.  Photos of the access port modification can be seen here.
> 
> Good luck!




Thank you for all the information. I have already printed out the ArcEuro info you mentioned.   I am planning to work on the lathe next weekend. I have been busy working on my 4Runner this weekend. New brakes and suspension.


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## brav65

sigp2101 said:


> Where did you find specs for bearings?



I purchased the bearings from LMS.  They list machine comparability for each style of bearings.


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## sigp2101

brav65 said:


> I purchased the bearings from LMS.  They list machine comparability for each style of bearings.



Arc Euro has really good suggestion for bearings, think I will try to use those if I ever decide to upgrade.
7026B angular bearings seam to be of the same size as originals unlike 30206 taper roller bearings which are wider according to them.


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## brav65

Well I got started on tearing down the lathe today. Following the ArcEuro instructions it only tools about 30 minutes.

















I took lots of pictures to ensure that I can put everything back where it belongs..






When you start to take the high low gear change selector off make sure you take out the spring and ball bearing out as they are easy to lose.






My spindle came out of the headstock with a couple of firm taps from a dead blow mallet. I pulled the bearing off the spindle with a gear puller so I could salvage the bearing cover for re install later. 

I also cut a windo in the headstock so that I will be able to lubricate the bearings and gears without having to pull the head stock off. 

















Tomorrow I will make up a cover with a window in it and get everything re installed


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## wrmiller

Very nice! Brings back memories.


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## clevinski

Really nice job!  I think you're going to like the results!


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## wakeup

I'm about to do a similar upgrade to my Sieg C3 (7 x 14).  I noticed the Arc Euro suggestion of using angular contact bearings.  The SKF engineering book gives the following values
Deep groove (standard) bearings dynamic load rating  19,500N
Angular Contact bearings dynamic load rating 23,800N
Taper roller bearings dynamic load rating 40,200N

So TRB have nearly twice the load rating of the next best.
I'll be using Taper Roller Bearings!!
cheers
Bill


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## clevinski

I used the tapered roller bearings and have been very pleased with the results...


Thanks,

Charlie
New Jersey, USA


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## wakeup

I finished the TRB upgrade a few weeks ago and I'm very pleased with the results, although the bearings are very critical on adjustment.  Seems to take a few goes to get them just right.  Worth it in the end though!!
cheers
Bill
ps Next up is the tapered gibs for the saddle, followed by thrust races for the cross and compound slides.  Then I'll probably sell it!!


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## brav65

wakeup said:


> I finished the TRB upgrade a few weeks ago and I'm very pleased with the results, although the bearings are very critical on adjustment.  Seems to take a few goes to get them just right.  Worth it in the end though!!
> cheers
> Bill
> ps Next up is the tapered gibs for the saddle, followed by thrust races for the cross and compound slides.  Then I'll probably sell it!!



Hey Bill my lathe is still on my bench in pieces.  I got a new job with 12 hour days and am a single dad with little energy left at night.  I have had my new spindle in the freezer for 4 months waiting to put the new bearings on!  I have thought about selling mine once assembled and moving up to a larger lathe, we will see... Good luck


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## ffmowers

"Arc Euro has really good suggestion for bearings, think I will try to use those if I ever decide to upgrade.
7026B angular bearings seam to be of the same size as originals"

Maybe it's just me, but aren't the bearings 6206-2RS (or for angular contact, 7206B)? Typo maybe?


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## wakeup

I'm sure that the Arc Euro suggestion of angular contact bearings is a good one.  The advantage of them is that they are the same size as the original ball races...so no special/new spacers are required.  However taper roller bearings will take nearly twice the loads of angular contact bearings, I've copied the stuff from my earlier post, with the load ratings of the relevant bearings................
Deep groove (standard) bearings dynamic load rating 19,500N
Angular Contact bearings dynamic load rating 23,800N
Taper roller bearings dynamic load rating 40,200N
This means everything is a lot stiffer, more rigid.  Rigidity is a good thing!!
Best of luck!!
cheers
Bill


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## brav65

Well you guys will be surprised to know that my lathe is still in pieces sitting on my bench.   I walk by it every night after a 14 hour day and think I have to finish that project!  I will finish the write up once I get back at it.  My project at work ends in April so maybe then.


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## hman

Brooks -
Best wishes getting back to the lathe after your hot-and-heavy project!  Life happens.  
PS - Is the spindle still in your freezer?  I guess, being a single dad, you don't get a lot of complaints about icky, oily parts being in there.  And when you do get to it, it should be well chilled!


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## Zoltan

Whatever happened with this project?


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