Link Belt on Logan 200 Motor and Countershaft Pulleys?

[MBfrontier]

Has anyone used a link belt between the motor and countershaft pulleys on a Logan 200 Lathe? I seem to be getting some vibration from the v-belt that is on now which is relatively new and appears in good shape. I think v-belts are designed to ride in the v-groove instead of a flat like the pulley on the countershaft. Also, it appears there is a raised portion on the inside of the belt where the splice is. It is a Huskee v-belt from Tractor Supply. I replaced the flat leather belt with a serpentine belt which smoothed the lathe quite a bit but there is still a little pulsing from the v-belt. Has anyone else run into this problem with their v-belt?

Thanks for any help. I need it!

Mike B.

 

[wa5cab]

MBfrontier (please sign posts),

I at first thought that someone must have put the wrong pulley on the motor. But I had a look at the Logan 200 manual that I have and it does in fact show three flat pulleys and one V pulley (on the motor). I don't know what the designer was thinking and the manual is no help as it only shows the spindle belt in the parts list. I don't think that link belts had been invented when the 200 came out.

I don't generally like link belts (except for emergency repairs) for various reasons but it might be a good solution here. Just remember that link belts are rated for running in only a single direction so be sure that you put it on in the right orientation (the inner part of the splice should trail).

Robert D.

 

[MBfrontier]

Hey, wa5cab.

Thanks for your input. I looked through my Logan manuals as well. They all show a standard v-belt. I don't know if there are different grades of v-belts that have a consistent diameter on the base flat of the belt. It appears the wrapping of the belt has a seam that causes a different diameter on the base flat.

Mike B.

 

[circlotron]

I'm using a link belt on my Logan 200 with a V motor pulley and a flat counter shaft pulley. It's very smooth and works great.

 

[wa5cab]

Mike B.,

On a normal setup (V-pulley to V-pulley), so long as there is no bulge on the "V" side, it wouldn't make any significant different if the ID bulged. But on a flat pulley, it certainly would or could. I don't know when the Logan 200 was originally designed but my bet would be that it dates from the days when overhead power shafting was the norm. Hence a flat pulley on the input to the counter shaft. When V-belts and individual electric motors came in, either you could buy 2-step flat motor pulleys or someone at Logan tried a V-belt on the input flat pulley and it ran so they never bothered to change the input pulley. Link belts were still in the distant future.

I think that in this case, the link belt would be the best solution.

Robert D.

 

[MBfrontier]

Thanks for the input.

I picked up a linked belt today and adjusted the length and installed it on the drive motor pulley and countershaft pulley. While turning on the lathe I stood back waiting for a thrown belt but was surprised when the motor started and the vibration was gone. I am very happy that replacing the worn countershaft, oilite bushings, serpentine belt on the cone pulleys, and link drive belt resolved the vibration/oscillation issues. I did a little facing and turning and I'm happy with the results. Here's a few pictures after the maintenance:



Mike B.

 

[geckocycles]

I ran into that too on my Logan. All V-Belts are not created equal. I would sand the high spot on your belt or get a better one. When I had my belt on the larger pulley it was very close to the housing and would hit when I had the Logan leather belts on. They stretch and loose their adjustment, flop make noise ect. I can't believe these were still being sold by Scott when I had mine. After a couple of belts and endless conversations with Scott he sold me this Synthetic belt. Almost like plastic but it never stretched a bit and I could leave the top cover down all the time with no ill effects.

Check belt alignment as when the belt hits or rubs the side of the countershaft pulley it will make the countershaft jump too. For that matter if the sides rub on any of the belts it could make the countershaft jump.


Here is some more on my old logan.
http://www.hobby-machinist.com/showthread.php/163-Show-us-your-Logan-lathes! post #16
http://geckopc.com/Logan Lathe.htm

 

[MBfrontier]

geckocycles, thanks for the input.

I replaced the countershaft with TGP steel rod and new oilite bearings as well as the link drive belt and cone pulley serpentine belt. I spent a little time making sure everything was properly adjusted and aligned before turning on the machine. I ran the machine with the covers off to check belt alignments were correct. The link belt is running on the center of both flat surfaces on the countershaft pulley and the serpentine belt is running in the center of the cone pulley steps. Hopefully, I won't have to change belts again for a very long time.

I am in the process of making sure this lathe is worth tearing everything down for paint and perhaps bushings and other minor parts. I've had this lathe since 2013 and I'm just getting around to working on it in earnest.

Mike B.

 

[Redlineman]

Interesting topic;

These machines were designed well after line shafting was on its way out, and were never intended for anything but motor drive. For what it is worth, and from what I understand, these Logans started out as a contract item for sale by Montgomery Ward to compete with the Sears/Atlas lathes. I do not know any details regarding any agreements between the two, but somewhere near 1940-42 Logan began selling them under their own name and officially went into the machine business for the next 30 years or so.

As for the flat countershaft pulley, it is my assumption that it was made with flat surfaces merely so the belt could be swapped between ratios with ease. A little lift on the motor plate and it slips right off.

My lathe has a completely rebuilt drive box, along with a new motor sheave and v-belt (most certainly from Chinee). I have run it a few times since getting the headstock and drive units back together, and experienced more vibration than I thought was proper. I had a notion, and stuck a tripled over piece of thick shag carpet under the 2x4 I had the peg leg sitting on, and that quelled a fair bit of the vibration. Still, I think it could be improved. I had assumed I had a bad sheave or something. I might just give this link belt idea a try!

 

[wa5cab]

Redlineman,

A slight bump on the ID of a V-belt isn't particularly uncommon because it doesn't normally make any difference when running on the V-pulley that it was designed for. Plus the ID of a V-belt is the narrowest part of the belt and running it on a flat pulley would reduce the torque rating by a factor of more than five. No engineer worth their salt would deliberately design a machine to run a V-belt on a flat pulley. If they wanted to or had to use a V-pulley on the motor, they would have put a V-pulley on the countershaft. It would actually save money because of significantly decreased material requirements.

Robert D.