# James Logan Model 820 Rebuild



## James_Douglas (Apr 19, 2015)

I have posted some bits an parts on my logan 820.  I thought I would post a set of photos for those interested.

James.


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## James_Douglas (Apr 19, 2015)

I also want to thank everyone who has posted in the past.  I used almost every suggestion I have seen.  One thing I keep seeing on the rebuild is keyways that are not the correct size, typically too long and they don't let gears seat down as far as they should so be advised.

On new parts from Logan, I am having issues.  No response on the bearing preload question sent a week ago.  Also, I got a "new gear" that was clearly glass beaded with media embedded in the space between the bronze bushing and the steel.  Also glass bead was embedded in the bushing. Not good.  If the gear has shelf surface rust press out the bushing and blast it, just not with the bushing in it.  The glass bead will destroy the shaft in short order...what were they thinking?

Also, on the LA-314 bronze bushing (for the change gear shaft) the thing did not fit.  The threads were cut so fast and/or so deep that the top of the threads "mushroomed up".  It would not fit into the gear shaft hole.  Also, the keyway was not cut deep enough so after I fixed the threads, carefully, I could not get the key in.  I just punted and used the old one.  On several of the bushings I have to hone/ream them to fit.  On some, they were on the loose size.

If I were to do it over again, I may not purchase bushings from logan.  Although more work and more time, I would remove the old ones, size them to the shaft wear and have then made by a local shop.  Lessons learned.

Thanks again. Now onto the apron, cross-slide, and tailstock.

JD.


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## gr8legs (Apr 20, 2015)

Keep up the good work - you'll have a real 'show piece' when it's done!


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## James_Douglas (Apr 22, 2015)

Since several people are rebuilding their logan lathes, I am posting an email I sent Logan and the response.  People can draw what ever conclusions they want.  My take away from the communication is that Mr. Logan has an attitude of "take it or leave it".  He is not interested in discussing any part issues.

On the headstock bearings.  He stated quite clearly to me on the telephone that "the bearing I sell have the same specifications as the original".  In his emailed response he hedged saying that " You were shipped the correct bearings and these are the same ones we have supplied for many years, specified based on our conversations with bearing engineers."

My research using original New Departure Bearing books from the 1940's clearly show that the double row headstock bearing had a preload.  The bearings now being shipped by Logan do not. I find Logan's response to be less than full disclosure.

My email and their response is below.

James

***********************

-----Original Message-----
From: Logan Actuator Co. [mailto:sales@lathe.com]
Sent: Monday, April 20, 2015 13:48
To: James Douglas
Subject: RE: Question on Logan 820 bearing
> Also, since last week as I progressed through the lathe, I found a
> couple of new parts that had issues. One is with an idler gear
> (LA-216-A). When I took it out of the plastic bag to mount the gear,
> it was obvious that the gear had been glass beaded and had hand file
> marks on side. Now that is not a big deal as it may have been old
> stock that had gotten some surface rust on it. But, there was glass
> bead imbedded in the edge of the bearing and into the bearing
> material. This will destroy the shaft in a not too many hours. What
> is going on with this?
> I had a busing the correct size and cut a new one to length and it
> only took a couple of minutes, but really...glass beading something
> with a bronze oilite bushing in it. I suspect management needs to
> have a talk with someone.
You may return the part if it is not acceptable.

> The second item is LA-314. I could not get it to slip into the gear.
> The threads were cut so fast and deep that they "crept up" and were
> several thousands larger than the gear hole. I hand dresses then down
> and then ran a die on them. So, now it fits. Then I went to put the
> key in and the keyway cut into it was not deep enough. I just used
> the old one.

Is your old key correct? It is not a square key, it is rectangular.
Again, if the part is not acceptable, you may return it.

> I am not asking for any money back. I wanted to let you know so that
> you can take a look at Q&A. On the LA-216-A gear, I had another one I
> purchased from you 4 or 5 years back and never used. It was in
> cosmolene or something similar and looked great. Why I got another
> one that needed glass bead work I don't know. But one cannot
> sandblast (glass bead) anything with a bronze bushing in it.
>
> Please advise on my bearing question below. I will be starting the
> apron, cross-slide, and tailstock in the next week and will place more
> orders. Thank you.
>
> James.
>
> -----Original Message-----
> From: James Douglas
> Sent: Monday, April 13, 2015 10:35
> To: 'Logan Actuator Co.'
> Subject: Question on Logan 820 bearing
>
> ATTN: Scott Logan,
>
> Hello Scott,
>
> I don't want to beat a dead horse. However, I was suspired when I
> opened the box with the bearings inside. They are SKF. Prior to
> talking with you on the telephone and prior to ordering the bearing
> from you, I had talked with SKF and a lot of other bearing
> manufacturers. They all told me the same thing. They did not make
> any double row bearings with a built in preload.
>
> I assumed that you were having the bearings made by a specialty house
> with a preload just as the original 5000 series New Departure bearings
> that Logan used in the 820 lathe (see attached).
>
> I emailed and talked with SKF engineering this morning. I read them
> off the part number on the box and the part number off the bearing.
> Their
> response was:
>
> ****************************************************
> SKF 3208 A-2Z is by design a bearing that has internal clearance.
> This
> bearing has axial internal clearance equal to 0.0004/0.0011 in.
> which is
> considered in the "normal clearance" range. Other identifiers in the
> part number to specify internal clearance are:
>
> C2: axial internal clearance smaller than normal
> C3: axial internal clearance greater than normal
> C4: axial internal clearance greater than C3
>
> Again, this bearing cannot be preloaded as manufactured.
> *****************************************************
>
> There is no marking on the box or the bearing to indicate that it is
> anything other than a what SKF calls a "normal clearance range".
> Also,
> they stressed that clearance range and preload are not the same things
> and I was told not to confuse the two. They also made it clear that
> this bearing "cannot be preloaded as manufactured".
>
> Since the preload is what makes the lathe shaft not walk forward or
> back and there is no provision to set any preload on the shaft (by
> design)
> then the bearing needs to have a preload.
>
> Can you shed any light on this for me please? If the bearing was drop
> shipped, is it possible that I did not get the correct bearing?
>
> Thank you for your time.
>
> James.
>
> James Douglas
> PO Box 210252
> San Francisco, CA 94121
> JDD@8bells.com

You were shipped the correct bearings and these are the same ones we have supplied for many years, specified based on our conversations with bearing engineers. We have never had a problem, but if you are not satisfied, you may return them, unopened.

LOGAN ACTUATOR CO.
550 Chippewa Rd
Harvard IL　 60033
Tel (815) 943-9500
Fax (815) 943-6755


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## James_Douglas (May 16, 2015)

Anyone have to shim the bottom brackets on the saddle?

I just stick mine back on and when I tightened the fillister head screws in front and the bolts in back it locked the saddle in place.  The saddle stop is off.

I also had Greg's problem with the shaft on the cross.  I put it back in for now.  I will take it out and have may machinist turn it way down and make a threaded sleeve out of something real hard.  Then freeze the shaft and heat the sleeve and press it on.  The rest of the shaft is fine.

I may also have to get Greg to post a copy of his plans for the wheel pin. 

I have been able today to use the lathe to dress various parts of the tailstock, saddle, and apron.  How nice!

The motor that came with it a moose 1 HP unit.  It barely fits on the motor stand and the pulley is way forward and just clears the housing.  I need another motor.  Any recommendations?

James.


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