Link Belt on Logan 200 Motor and Countershaft Pulleys?

[MBfrontier]

I leveled the lathe with one inch rubber pads and shims under the lathe legs and the drive box peg. That worked well but there was pulsing coming from the drive box. You could see the countershaft bearings rock back and forth on the side of the drive box when the lathe was running. The serpentine belt on the cone pulleys improved the pulsing considerably but you could still see some pulsing on the countershaft bearings. All of the pulsing was gone after I installed the link belt on the v-belt drive pulleys.

I purchased the link belt from Harbor Freight. It was 20 bucks with a 20% off coupon.
http://www.harborfreight.com/vibration-free-link-belt-43771.html

When I had the spindle out to install the serpentine belt I noticed a lot of play in the cone pulley. It looks like I'll have to replace the Oilite bearings in the spindle cone pulley. Does anyone have a source for these?

Redlineman, You're right. Yesterday, I read on the Logan Lathe sight that the flat countershaft pulley enabled easy belt changes between large and small pulleys.

Also, I've watched your Logan 200 Rescue thread since 2013. I'm glad to see you're back at it. As you can see, I'm finally getting back to working on my lathe. My delay falls into the "Life is what happens when you're busy making other plans" category. Anyway, I'll be interested to see how you feel your lathe runs once it is completed.


Mike B.

 

[Redlineman]

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.

Well....

I agree in principle, or course, but an engineer worth MORE than salt might look at the situation more globally. He might calculate that - beyond his own engineer's nose - being able to easily flip the belt up and down was a worthy attribute to the end user. He might then calculate that the large surface area of the countershaft pulley - in this application - more than made up for the loss of grip by making it flat surfaced. He might further have the notion that offering some means of escaping the ravages of a crash through belt slippage - arguably the greatest attribute of flat belt machines - might save a lot of people a lot of grief and money.

Of course, they did go V in later years on the more powerful modern machines, but 10s of 1000s of these old chippers have worked very well as designed for over half a century now. I'd say they did OK.

 

[Redlineman]

Hey Mike;

You've got me intrigued with this idea. Your keen driveline observations now have me itching to fire mine up and pay closer attention to just where the vibration may be coming from. I'm going to have a look at the primary drive for signs of extraneous motion, and at the v-belt for surface quality. If I remember from many months ago, my vibration was fairly high in frequency. More of a buzz than a shake. I had thought to run the motor without the belt on and it was very smooth, as I recall. I was hoping it was not the new sheave I had just installed. It would not surprise me that the no name v-belt was lumpy. Hmmmm....

I have my lathe mounted on neoprene leveling pads, and at the point I enjoined the carpet cobble, it occurred to me that I should buy a fifth neoprene pad for the motor stand. I need to drop the leg and weld a nut plate in the bottom to screw it into. I don't look forward to horsing that drive unit around again!

I hear you about life getting in the way. You need to join the slow race that TomKro and I have been having in getting our machines back together. Seems like you would be a good fit. The more mutual motivation we can generate amongst ourselves, the better!!

 

[Redlineman]

Hey All;

I did some studying of my drive unit. First, the belt seems fairly smooth and uniform in its makeup, with no obvious lumps or deviations. It is pretty stiff however. I note that when it runs it flops around a bit, which does not help. I might need to tighten it a bit more just to get rid of the flop. Noting the characteristics when all together and running, I then removed the belt. A moderate decrease in noise & vibration, but still a majority amount present.

This machine did not have the original double row motor pulley. I purchased two single sheaves of approximately the correct size from Surplus Center. I know they are Chinee, but they seem quite well made. I had to mount the larger outer sheave inside out to get alignment, rendering the external shoulder where the set screw is redundant, and so had to drill/tap a set screw hole in the valley of the V to lock it down. I removed the outer sheave, and had a more notable reduction in vibration. Subsequently removing the smaller inner sheave made little difference. I was a bit surprised how much vibration the motor had running by itself, but it pales in comparison.

So, it seems my vibration is largely coming from the large sheave. I am wondering exactly how one goes about balancing such an item? It also occurs to me that I may have upset that balance by drilling the second set screw hole. It certainly would not cost me anything to drill a similar hole on the opposite side and see if that helped the situation. I'd hate to go back and have to do all the sheave searching again, as it was a PITA the first time...

 

[MBfrontier]

Hey, Redlineman.

Fortunately, the motor in my lathe had a pulley on it that seems to work fine. I'm not sure if it is the original. The motor is an Atlas so I know it had been changed somewhere back when. When troubleshooting my vibration issue I ran the motor with the pulley on it by itself and there was no vibration.


I'm not sure how you would go about balancing the pulley setup on your lathe. If I understand you correctly you are using two separate pulleys next to one another with set screws holding them in place on the motor shaft? Are you sure both pulleys are round? Have you tried checking them with a dial indicator?

 

[Redlineman]

Hey;
No thread jack intended.:whiteflag:

This is my attempt at replicating the original double sheave they came with.



Proper alignment dictated that I turn the outer pulley around, and for that I had to drill the central set screw hole. I am wondering if this has thrown it off? I had not gone deep enough to check the sheaves for roundness. All I can say right now is they look very nice and are visually round when spinning. I'm not sure that thousandths of an inch matter in this context, and I think I would be able to see any deviation that would.

It may turn out that the $136 that Logan wants for a new replacement sheave would have been money well spent!

 

[MBfrontier]

No thread jack taken.

You know the vibration has to be motor/pulley related. I find it interesting you said you were surprised the motor has vibration with the pulleys removed which makes me wonder about the condition of the motor. While looking at your picture I was wondering how far the motor shaft extends into the outer pulley insuring proper alignment. I'm sure you are checking everything but I'm just sharing some thoughts.

I can tell you with the drive belt disconnected my motor runs with no vibration with the pulley on. In my case the only suspected component left was the drive belt. The drive belt had no visible defects that I could detect so the decision to replace it was only a $20.00 investment in a linked belt and a drive to HF. Fortunately, it worked. It seems it doesn't take much deviation in any of the components to cause the drive box to pulse.

I'm trying to eliminate any major issues before I invest the time in cleanup, paint, etc. I'm fortunate that the lathe is running so I can evaluate a change in component or adjustment immediately after the change or adjustment is made.

I can tell you that vibration or pulsing in the motor box transmits to the lathe and shows up in the cut. Now, the cuts are much smoother. I hope yours turns out the same.

 

[MBfrontier]

Here is a short video I made today showing the motor pulley running without any belt hooked up from the time the switch is turned on to the time it stops on its' own after it is turned off followed by a very short portion of video with the linked belt attached. The clicking noise when the belt is attached is coming from the Cushman 6 inch chuck. I don't know how much this will help but I figured it can't hurt. If the saying "A picture is worth a thousand words" then I'll let you calculate the word value of the video. Since I've never posted a YouTube video before it was an interesting learning experience.

[video=youtube;mwF_0saiesM]https://www.youtube.com/watch?v=mwF_0saiesM[/video]

Here is a picture of a piece of 1 1/2 in. aluminum I turned to show the type of finish I am getting. I know it's just aluminum but the point is it is much better than it was.



Mike B.

 

[wa5cab]

Sounds like there may be something loose inside the motor. Either a stator or rotor winding or a lamination. If so, there is probably nothing practical that you can do about it.

Robert D.

 

[mrbreezeet1]

As far as the belt from the motor to the flat countershaft pulley, l am using a cogged type V belt from auto zone, and it is very smooth also.
Was about $5.00.
Just another possible option.
You can look at my belt and see it is made nice and even and smooth.