# 820 countershaft repair



## John TV (Jul 4, 2020)

I could use some advice on what people think is the best way to repair my counter-shaft casting.

I had a chance to disassemble my Logan 820 countershaft that had significant wear. I was hoping to see bushings that could be replaced but on my model, the ¾ inch shaft runs directly in the cast iron casting.

I am still quite new to this hobby and my skills are getting better but still limited. I have another Logan 10” lathe to use and a Van Norman 12 Milling machine and other small equipment to attempt repair.

The ¾ inch shaft is badly worn and can easily be replaced. I was thinking that drill rod might be a good shaft material since it is quite accurately sized and strong. If you have other suggestions please let me know what you think.

The casting however is a larger problem for me. The “non pully” end is still quite close to the shaft diameter and seems quite round when looking at it without measuring. 

The pulley side of the casting, however, is very wallowed out with a very visible oval wear pattern with the oval shape being drawn down in the direction of the motor, possibly caused by excessive belt tension and little lubrication. Pictures are below, but crude measurements are almost 1/8 inch of wear in casting.

Now how to repair this? My first thoughts are to bore the holes to a larger size and use bronze bushings of the correct size. The only machined surfaces on the casting are the areas where the holes have been bored. How do I set up the casting to allow boring accurately without line boring capability? Secondly, although the castings are quite thick, a busing large enough to take care of the 1/8 inch wallow would need to be around one inch which doesn’t leave a lot of cast iron remaining for strength. How little is acceptable.

My second thought on the casting repair was to braze the wallowed out portion to a smaller size and use the better hole to guide a custom made cutter (I would make) of ¾ inch size to “bore” out the excess brass material. I’ve not done much brazing and not sure of getting that large a part hot enough with my small torch to get a good braze.

My third thought was to use something like Babbitt with a much lower melting point and fill the wallowed hole completely and then use the custom made cutter I would make to “bore” the hole using the better hole as a guide.

Fourth thought, send out the part to someone with line boring capabilities willing to do a small job.

I could sure use your thought and advice on what you folks might do to repair this part. I’m sure there are many other ways I have not thought of and my limited experience and equipment might limit my options.

John from Minnesota
	

	
	
		
		

		
			










Sent from my iPhone using Tapatalk


----------



## Nutfarmer (Jul 4, 2020)

Cold roll is what I would use for shafting. A step up would be stress proof. Drill rod will work fine ,just expensive. There is  plenty of material to bore out oversize and bush  back to shaft size. Line boring would be ideal ,but it can be set up with the new shaft in the vertical mill and bored close enough. The wear is mostly going to be in one spot . After rebushing  it is helpful to use a piloted adjustable reamer to align the bore   of the bushing when fitting the new shaft,but it can be done with out one. The fit should be a running fit and if it's a little loose it will still work fine.


----------



## benmychree (Jul 4, 2020)

Nutfarmer hit the nail squarely on the head.


----------



## John TV (Jul 4, 2020)

Thanks for the response gentlemen. 

Work holding setup may be a challenge for me. Don’t think I have the vertical room to use any kind of vice. So thinking something sacrificial on the table, then clamp on the very outside edge of the machined surfaces that are perpendicular to the bore. Only have about an 1/8th to clamp down on. 

Not sure I have any ideas to stabilize upper bore. Any thoughts?


Sent from my iPhone using Tapatalk


----------



## benmychree (Jul 4, 2020)

maybe an angle plate with some blocking in between?


----------



## CluelessNewB (Jul 4, 2020)

That's odd, the manual shows "0799" Oiless Bushing


----------



## John TV (Jul 4, 2020)

I agree I was expecting a bushing too but another owner responded on a previous thread on disassembly that they just had the shaft running in cast iron too. 


Sent from my iPhone using Tapatalk


----------



## John TV (Jul 4, 2020)

Think I need to order a reamer, a shaft and some bronze material, can play with set up before I get the items. 

Looks like a piloted reamer is a bit out of price range so ....

Press fit for one inch bronze? How much interference? 1/2 to 1 tho?

Thanks for all the guidance. You are all awesome. 

John 


Sent from my iPhone using Tapatalk


----------



## pablo (Jul 4, 2020)

hay john dont forget pablo is near


----------



## John TV (Jul 4, 2020)

Hi Pablo, 
Good to hear from you. You are likely hearing the same fireworks I am. Happy 4th of July. 


Sent from my iPhone using Tapatalk


----------



## John TV (Jul 4, 2020)

Just a quick check of my van Norman Mill. I’m not sure I have enough vertical travel. I need to mount the boring head and have an 8 inch part and the length of the cutter/reamers does not leave me a lot of vertical travel, if any. I may have to figure out how to do this horizontally with the mill in the horizontal mode 


Sent from my iPhone using Tapatalk


----------



## Nutfarmer (Jul 5, 2020)

Doesn't your Van Norman have a universal head? If so you could turn the head 90 degrees mount the casting right to the bed of the mill and shim  the casting parallell to the mill spindle . Then bore to size . Use the same set up to fit the shaft to the bushing. Bore the bushing with the same sit up . Then no expensive reamer  to buy. It's just a shaft running in a bushing. Should be do  able on your mill.


----------



## John TV (Jul 5, 2020)

Yes it does have a universal head and that’s what I was referring to in my post above when I meant the horizontal position. 

I’m quite new to this and have not done much creative blocking and shimming of work on the mill. I primarily of use vices. I was hoping to bore from one side for both holes but again I may not have the Y axis travel for that. Keeping the bore properly aligned (especially on the shaft bore) will be a challenge I have not delt with before. 

John


Sent from my iPhone using Tapatalk


----------



## Nogoingback (Jul 5, 2020)

It might be helpful to clamp the casting to the mill table and indicate off a shaft through the pivot holes rather than trying to align to the 
worn surfaces.


----------



## John TV (Jul 5, 2020)

I was thinking the same thing. I am quite sure I will need to bore from each side. I could align first 1” bore using a 3/4 inch shaft, then turn part around and using a temporary collar at 1 inch with 3/4 center boar, use that to align my second bore. Then do same thing with for the final shaft bore just with smaller bar for alignment. Does this sound realistic?

John


Sent from my iPhone using Tapatalk


----------



## wa5cab (Jul 5, 2020)

You should be able to buy replacement bushings from Logan.  Or at least find out whether they ever shipped any machines not already bored for the bushings.


----------



## John TV (Jul 5, 2020)

I have two Logan lathes, a 1948 MW 2136 which does have bushings. And this 1947 820 that did not. If the bushings on the 2136 are any indication they would not be thick enough to compensate for the wear on the pulley side. It is almost 1/8 inch wallowed out at worst point. So I assume I need to make thicker custom bushings. 

I also suppose it’s possible it did come with bushings and someone in the past removed them/completely wore away , but the non pulley side is still quite a close fit. 

Sent from my iPhone using Tapatalk


----------



## wa5cab (Jul 6, 2020)

Well, that would seem to answer the question of whether some machines were shipped with no bushings.  If it were mine, I would bore out the good hole for the stock bushing.  I would bore out the bad hole and install a steel bushing with  Locktite.  After the Locktite cured, I would subsequently bore the steel bushing for the bronze Oilite bushing.


----------



## John TV (Jul 6, 2020)

I hadn’t thought of that approach, thank you. That way future bushings could be stock. Makes sense. 

Two questions on tolerance. 
How much clearance for the loctite? I have not used loctite before other than for threads. What loctite product do you recommend?

How much interference fit for the factory bushing?

Thanks for all the help everyone. 


Sent from my iPhone using Tapatalk


----------



## Herk (Jul 6, 2020)

I had very much the same problem.  I drilled oversize on a drill press (sorry no pictures) doing my best to try to get the bit to follow the original bore not the egged out bit.  I still had a slight misalignment mostly because I had to drill each side of the yoke independently from the outside.  I corrected the misalignment with a reamer.  Yes, this means that each of the bushings are reamed slightly off center, and there is a slightly excessive clearance on either side of where I had to correct the axis.  I'm not worried, the Oilite bushings are still better than the shaft running in iron, and even at the tender age of 49, I doubt I'll live to see them worn out again.


----------



## wa5cab (Jul 6, 2020)

Tip to keep the drill bit from following the center of an egged hole.  Don't use a drill bit, use an end mill.  Preferably 4-flute and oreferably sindle ended.  Start with the smallest size end mill that will cut, and progressively go to a larger end mill.  You can probably expect some chatter.  Probably need to use the lowest spindle RPM.  When the hole is round again, switch back to drill bit.  Don't make the steel bushing until you finish with the hole. 

 As far as clearance or interference between the new steel bushing and hole, look on the Loctite web site.  It has been so long since I did one that I forget.  But I think that it should still be a slight interference fit.  The name of the product used to be Bearing and Bushing Seat I think.  And the color was I think green.

On the fit for the Oilite bushings, again go with what they say.  And do NOT use the Loctite on them.  Because of the oil in the bushing it won't help any and it will plug up the pores and keep fresh oil from getting from the oil cup into the bushing.  If the iron casting has no oil cups, I would add them and not expect to have to top them up but once or twice a year.


----------



## mattthemuppet2 (Jul 6, 2020)

Smoke up the shaft with a candle and pour some lead in there?

Getting those two hole co-linear is not trivial by any stretch. Line boring it on your other lathe would be the way to go in my opinion, then press in appropriately sized bushings. A piloted reamer would be ideal or you risk reaming one of the holes (usually the first one) off axis. That's what happened when I rebushed my Atlast countershaft, took alot of farting around to get the shaft in.


----------



## CluelessNewB (Jul 6, 2020)

My 820 has the older style countershaft with the 2 separate holders for bronze bearings.  When I got the lathe the bronze bushings and shaft were trashed.  I find it a bit ironic that this seems to be such a common problem on these old Logans considering that the very first thing in the list of places to lubricate is "Two oil cups on top of the countershaft bearings".


----------



## Nogoingback (Jul 6, 2020)

CluelessNewB said:


> My 820 has the older style countershaft with the 2 separate holders for bronze bearings.  When I got the lathe the bronze bushings and shaft were trashed.  I find it a bit ironic that this seems to be such a common problem on these old Logans considering that the very first thing in the list of places to lubricate is "Two oil cups on top of the countershaft bearings".



That's a spot where the extra cost of a couple of ball bearings would have been worth it.


----------



## CluelessNewB (Jul 7, 2020)

Nogoingback said:


> That's a spot where the extra cost of a couple of ball bearings would have been worth it.



Which I believe may have been done in later V-belt models.  (This image is in a 200 series manual I downloaded from somewhere) It shows pillow block bearings.


----------



## wa5cab (Jul 7, 2020)

Yes, that is a much better design.  Unfortunately, it is also more expensive.


----------



## John TV (Jul 7, 2020)

You have all given me great tips and I’m always amazed at how much I learn from the various posts. Thank you all. 

I think I’m going to attempt setting up a line bore on my mill in the horizontal position. Bore to 1” and insert custom 932 bronze bushings. The larger bronze bushings allow me the ability to remake them if I screw up the first attempt or need a reamer to correct alignment. 

Crossing my fingers this works. I can’t get to this for a week or so but will get back with pics if it works...or looking for sympathy if it doesn’t work. 

John from Minnesota 


Sent from my iPhone using Tapatalk


----------



## John TV (Sep 11, 2020)

Logan Line boring update

Finally got around to my first attempt at line boring with my friend Rick. Needed to repair a Logan 820 counter shaft that had wobbled out more than 1/8 inch causing the shaft to squeal badly.
Although it ultimately went ok and we learned a ton, out nuub skills certainly showed up a few times.

On my old VanNornan #12 mill I set up the line boring as in the picture below. I figured I had just enough Y axis travel if the boring bar had two cutters. So first made the boring bar. See pic below. Had the idea of using the shank of 1/4 inch drills as the “tool steel” for the cutting bits. Picked up a pack of 4 HF Drills, cut and ground to fit in 3/4 inch bar.

First lesson, don’t use HF drills for tool steel, shanks not hard enough!

Had to touch up cutting edge after each adjustment or just rubbed. Once the boring bar was, time for boring.

Lesson two, don’t have both cutters on same side of boring bar.

Yep, 3/4 inch bar flexed like a bugger. Took several “skim” cuts to get the bar to stop flexing and cut a mostly round hole.

Finally done with boring but holes are not exactly the same size because adjusting the two cutters alike was close to impossible, or so it seamed to us.

Time to make the bronze bushings. Finish not great but came out ok. see pic below. Drilling and boring went ok but lesson three. Tried to make a 1 thou interference fit.

Lesson 3. Learn how to use and read telescopic gauges.

Not sure I ever got the same reading twice. Luckily we could “fit” the bore to the shaft with many “test fits”.

Time to press in the bushings. We allowed a 1/4 inch portion of the bushings a smaller of to start the bushings, then pressed them in with a hydraulic press using a “pusher” bar with a diameter of just under 3/4” to keep the internal bushings round. It worked great.

With the bushings pressed in time to test the shaft. Shaft went through first hole great and aligned perfectly with second shaft but...

Lesson 4. Bushings shrink a bit when pressed in.

When pushing shaft through second bore, it hung up about 1/2 way through. Ended up making the end of the shaft a crude reamer by sawing teeth and grinding relief to cut the bore just a smidge larger. It worked.

Completed counter shaft below. I still have to drill oil access holes and make a small channel for oil disbursement.

So thank you all for suggestions and advice in previous threads. All is well that ends well and we have big smiles that this turned out ok.






















John from Minnesota

Moderator, I meant to post this in “820 countershaft repair”. If you could move this to that thread it would be appreciated. John

I did not move the next post in the other thread because it also referred to something to do with the back gears which was discussed in the original thread.  WA5CAB   

Thanks moderators, you folks are awesome. John
Sent from my iPhone using Tapatalk


----------

