Gates belt # Craftsman lathe?

[Hu Lowery]

I need a craftman lathe model 351.217150 replacement primary belt. I do have the Craftsman part number and have located a replacement. However, I got very short service life out of the first belt. Although it was old, it was unused. I have also read posts of similar very short belt life from other owners. I also ran across an old thread somewhere in my searches for the belt that indicated that it was a Gates belt and that there was a better quality belt available from Gates also. No parts numbers mentioned though.

The catch with these Gates cog belts is that there are a handful of tooth profiles and they are not interchangeable so getting the same length and width belt isn't enough. Anyone have either of the Gates numbers for this belt?

Hu

 

[Bill Boehme]

Old belts whether used or not get hard and brittle and wear out or break quickly. Reeves drives are very hard on belts if your lathe happens to be that type. You can download one of the various Gates catalogs to get all the detailed size information that you need. There is a place in Louisiana that can supply any kind of belt that you need. I will see if I can locate their name. Seems like they are in Lake Charles if my memory is right. Is the belt cogged (synchronous) or notched?

 

[Bill Boehme]

It's way up north in Lafayette (as Justin Wilson used to say). They are called Belts for Anything.

 

[Hu Lowery]

contacted them

It's way up north in Lafayette (as Justin Wilson used to say). They are called Belts for Anything.

Bill,

Thank you, just contacted the folks in Lafayette. The Gates site defeated me fighting with it last night. You have to sign up to even do a search then I must of signed up to the wrong area. Each area needs a separate account? Don't know and hopefully it doesn't matter.

Lots of fond memories of Lafayette. I'm just a little further away now but used to live about sixty miles from there. Most weekends when I was in high school and for a few years afterwards a running buddy and I would head to Lafayette and surrounding areas to party. Schoolmates tried to tell us there were closer places to party to which the reply was "not really!" Ali Landry, former Miss USA, is from one of those little towns near Lafayette, Breaux Bridge. A looker for sure but like I told a friend, she wasn't even the prettiest girl in Breaux Bridge! Maybe I need to go hand fetch that belt just for old times sake . . .

Thanks a bunch!
Hu

 

[Bill Boehme]

... A looker for sure but like I told a friend, she wasn't even the prettiest girl in Breaux Bridge! Maybe I need to go hand fetch that belt just for old times sake . . .

I need to order some Poly-V belts from them. Maybe you can pick them up for me and swing by here on your way back home and drop them off. I'll let them know that you will be paying for them and then I can pay you back ... uh ... when the eagle flies ...

"Lookers" you say? Maybe I need to make a run to Lafayette to pick up them belts myself.

 

[Mark Mandell]

That is a version of a reeves drive lathe. I ran my JET 1236 reeves with a Fenner drive (link belt) for years and it did just fine.

 

[Hu Lowery]

belt

That is a version of a reeves drive lathe. I ran my JET 1236 reeves with a Fenner drive (link belt) for years and it did just fine.

Mark,

This is the belt between the motor and the Reeves drive, not the Reeves drive belt. I see there is a synchronous belt with teeth on it, maybe not the same as a cog belt or at least the cog belts I was looking at. The folks in Lafayette are supposed to be extremely knowledgeable about belts, hopefully they will get me straightened out!

I have flat sprockets with teeth the width of the sprocket that this belt runs on with no raised edge on one side to keep it in place. The sprockets running true with each other are apparently all that keeps the belt properly aligned. This belt relies on the teeth on the bottom to transfer force. Looks like I need about an eight tooth per inch belt to fit this, the tooth profile is the next concern. This is more like a timing belt in a car engine than the V-belts that drive accessories or did before the serpentine came along.

Hu

 

[Bill Boehme]

I wonder why they chose to use a synchronous belt rather than something more readily found like a poly-V belt unless it does not have provisions for tensioning it (perhaps that is why one side of the sheave is open). The industrial Reeves drives and commercial products like riding mowers use belts that resemble a V belt except that they are a lot wider and have a thinner height. They are also wrapped as opposed to having raw edges like the typical automotive v-belts (the kind they used before they went to K-section serpentine belts). My Delta lathe came with an A-section wrapped belt, but when they sent a replacement it was a regular raw edged belt. It worked, but it was a bit harder to change speeds.

BTW, it is possible that the synchronous pulley has a slight crown like a bandsaw wheel which keeps the belt self-centered.

 

[Hu Lowery]

danged engineers!

I wonder why they chose to use a synchronous belt rather than something more readily found like a poly-V belt unless it does not have provisions for tensioning it (perhaps that is why one side of the sheave is open). The industrial Reeves drives and commercial products like riding mowers use belts that resemble a V belt except that they are a lot wider and have a thinner height. They are also wrapped as opposed to having raw edges like the typical automotive v-belts (the kind they used before they went to K-section serpentine belts). My Delta lathe came with an A-section wrapped belt, but when they sent a replacement it was a regular raw edged belt. It worked, but it was a bit harder to change speeds.

BTW, it is possible that the synchronous pulley has a slight crown like a bandsaw wheel which keeps the belt self-centered.

Bill,

These sprockets could be crowned as you say. I suspect not as running off the end of the sprockets is one thing that killed this belt. Another issue is that the speed adjustment will grind against the belt if you aren't careful. Easy to hop the flimsy plastic that is supposed to serve as a max speed stop and I think it was making contact before then anyway. I see pictures of other lathes like this with the same damage to the belt. I made some modifications to try to prevent the metal rubbing on the belt the last time I was in the headstock but there was some damage from rubbing and running off the end of the sheaves already.

I think the main reason for this type of belt and sprocket set up is that there is very very little adjustment available, I don't think enough to get a standard V-belt on and off. The belt for the Reeves drive is the segmented variety too though with the smooth sheaves that have no reason for that unless it is how tight the belt has to wrap around one sheave or the other one at maximum and minimum RPM. I think it might have been a case of fancy design syndrome in the engineers all around! Danged engineers!

Hu

 

[Bill Boehme]

If it is the kind of belt that looks like this, it is to increase efficiency, especially if the sheave size is small.

 

[Hu Lowery]

that is the style of the Reeves drive belt

If it is the kind of belt that looks like this, it is to increase efficiency, especially if the sheave size is small.

View attachment 6131

Bill,

That is the style of the Reeves drive belt. I suspect it is used to be able to make the tighter bends without overheating and destroying itself. I don't know how they calculate maximum efficiency but I suspect it doesn't actually matter with the size of that belt and the motor on this lathe. The belt is probably rated for far more load than this equipment can produce. Some power lost in the transfer but I doubt slippage is a significant issue.

Hu

 

[Bill Boehme]

Efficiency is simply mechanical power out divided by mechanical power in. This can be measured in a lab using a dynamometer. When a belt wraps around a pulley, the back (the exterior part with the writing on it) stays the same length, but the rubber V compresses which is basically a way of storing energy just as in a spring. When it unwraps, the stored energy is released and so things balance out except that being rubber, it is not 100% efficient so some of the energy is lost in heating the belt and a tiny amount in scuffing the belt.

There are design guideline for each size belt for things such as pulley diameter and speed. As you would expect, running a V-belt on very small diameter pulley at very high speed is less efficient than a larger diameter pulley at slow speed.

There are more things, too. At very high belt velocities not related to pulley diameter, aerodynamic effects become significant. For example, when a belt starts to wrap around a pulley, all of the air that is between the groove and the belt has to be squeezed out before the belt can make solid contact and grip the sidewalls of the pulley. Similarly, when the belt unwraps, a vacuum is created which makes the belt want to stick to the pulley. All of the energy spent overcoming these aerodynamic effects is lost energy since it goes into the surrounding air. There is also a limit to how fast the rubber V can rebound after it has been compressed when wrapping around the pulley.

Due to centrifugal forces, there are also maximum RPM limits for pulleys. This depends on the material, moment of inertia, and other factors.

 

[Hu Lowery]

done deal!

My belts for the lathe arrived in two working days. They were in a nice package with a pen, a quality mint in a wrapper that said "thank you" on the outside, a business card, and both the invoice and credit card receipt. Most importantly it was the right belt, I ordered two on the assumption I would never need a spare if I had one on hand. At that two including shipping was just a bit cheaper than what one would have cost me somewhere else.

Thank You Phyllis, beltsforanything.com Nice to be giving an attaboy, um attagirl! seems more common to be complaining about rotten service or poor quality.

Hu

 

[odie]

All drive belts are subject to heat and time........any automotive store will have belt dressing. This will extend the life of any drive belt. I'm still using my original drive belt to my 21 year old Woodfast lathe, and although it looks well used, it still grips well and is as pliable as a new belt. I normally give all the drive belts in my shop a good coating every couple years. (Table saw, drill press, planer, jointer, compressor, 6x48/12" disc sander......and, the lathe!)

Note: I've suggested belt dressing before, and there seems to be those who disagree with that advice.......but, the drive belts on my shop tools are tangible proof of the value of using it on a regular basis.)

ooc

 

[Hu Lowery]

suspect it is because of the dissimilarity of dressings

All drive belts are subject to heat and time........any automotive store will have belt dressing. This will extend the life of any drive belt. I'm still using my original drive belt to my 21 year old Woodfast lathe, and although it looks well used, it still grips well and is as pliable as a new belt. I normally give all the drive belts in my shop a good coating every couple years. (Table saw, drill press, planer, jointer, compressor, 6x48/12" disc sander......and, the lathe!)

Note: I've suggested belt dressing before, and there seems to be those who disagree with that advice.......but, the drive belts on my shop tools are tangible proof of the value of using it on a regular basis.)

ooc

I have used quality belt dressings for many years. I suspect some that don't like dressings have been burned by the dissimilarity of dressings. Some are garbage, either lube or they actually break down the rubber. A good belt dressing helps it remain pliable and reduces dry rot and UV damage if the belt is exposed. They may improve grip which can make a belt a little noisier. Some of the things sold to quieten belts are just lubricants which makes the belts slip worse than ever, only quietly at least for a little while. This is a toothed belt running on toothed sprockets in an area never exposed to UV. Heat will probably do the most damage other than a basic design flaw.

The speed control rubs against the back of the belt if you turn the knob too far, can even bind hard enough to make the belt start burning. I removed as much of the metal that can rub against the belt as I thought advisable, modified the linkage so greater speed is created with a little more clearance, and verified at least ten thousandths running clearance where I arbitrarily decided was two-thousand RPM, max speed. I think I am pretty close to maximum speed, for the first time I can also run the lathe at minimum speed. The main thing is that I have a minimum and maximum speed setting and markings in between. I have a strong impression that I'm turning far less speed than indicated but haven't purchased a tach just to check something I can't change. I judge speed by vibration and what is coming off the cutting edge, seems OK for now.

I hope to sideline this lathe in the next six months or year so there shouldn't be any additional issues with belts in that time. If I do keep this lathe as my primary machine for very long I think I will be taking the entire Reeves drive sprocket system in to have it hard chromed to fight corrosion which is the primary issue. A little rust or trash gets into the sliding sheave halves on the drive and it is time for a disassembly.

This lathe isn't much but it has taught me a lot, a lot of what I don't want in a lathe too! No doubt some of the issues are my own doing though, the design and lack of strength in it's construction makes it unsuitable for blanks that seem like it should be able to handle them. The two horse motor and 15x38 swing and distance between centers seem to indicate much more lathe than this is. I did improve things considerably making a saw horse style stand to sit it on with a little ballast. The stand is screwed and glued, very solid and stable so far.

The picture was taken before the stand was complete but gives the general idea where I went with it.

Hu

 

[Bill Weaver]

I have used quality belt dressings for many years. I suspect some that don't like dressings have been burned by the dissimilarity of dressings. Some are garbage, either lube or they actually break down the rubber. A good belt dressing helps it remain pliable and reduces dry rot and UV damage if the belt is exposed. They may improve grip which can make a belt a little noisier. Some of the things sold to quieten belts are just lubricants which makes the belts slip worse than ever, only quietly at least for a little while. This is a toothed belt running on toothed sprockets in an area never exposed to UV. Heat will probably do the most damage other than a basic design flaw.

The speed control rubs against the back of the belt if you turn the knob too far, can even bind hard enough to make the belt start burning. I removed as much of the metal that can rub against the belt as I thought advisable, modified the linkage so greater speed is created with a little more clearance, and verified at least ten thousandths running clearance where I arbitrarily decided was two-thousand RPM, max speed. I think I am pretty close to maximum speed, for the first time I can also run the lathe at minimum speed. The main thing is that I have a minimum and maximum speed setting and markings in between. I have a strong impression that I'm turning far less speed than indicated but haven't purchased a tach just to check something I can't change. I judge speed by vibration and what is coming off the cutting edge, seems OK for now.

I hope to sideline this lathe in the next six months or year so there shouldn't be any additional issues with belts in that time. If I do keep this lathe as my primary machine for very long I think I will be taking the entire Reeves drive sprocket system in to have it hard chromed to fight corrosion which is the primary issue. A little rust or trash gets into the sliding sheave halves on the drive and it is time for a disassembly.

This lathe isn't much but it has taught me a lot, a lot of what I don't want in a lathe too! No doubt some of the issues are my own doing though, the design and lack of strength in it's construction makes it unsuitable for blanks that seem like it should be able to handle them. The two horse motor and 15x38 swing and distance between centers seem to indicate much more lathe than this is. I did improve things considerably making a saw horse style stand to sit it on with a little ballast. The stand is screwed and glued, very solid and stable so far.

The picture was taken before the stand was complete but gives the general idea where I went with it.

Hu

HU
I have the same lathe which I bought several years ago might be a few years older than yours, but so far it has done me a very good job.....(knock on wood) The one thing that I don't like about it is the out rigger when you swing the head to do larger work you have make sure to have things tight because of vibration.
I do have an alternate one that I use for smaller work.

 

[John Torchick]

Take the old belt to any automotive store and let them match it. The guy that I bought my old lathe from did this- got a perfect match.

 

[Hu Lowery]

The pivot point and more about belts

Bill,

My lathe is a minimum of eight years old. I bought it eight years ago when a guy had it when I went to pick up my NC router. I never used it until a few months ago. When I had to take it apart to free up the Reeves drive it was spotless inside so it seems it was totally unused before a few months ago. I can't tighten the pivot up enough that the headstock assembly doesn't wobbly back and forth a quarter inch or more with a heavy blank on it that has just been rough balanced. More annoying is that the alignment on mine seems to creep off and after aligning it perfectly I will check it a few hours later and find it has moved some. Makes it terribly irritating when I reverse a piece.

I'm thinking about doing away with the pivot feature and mounting it permanently to the ways. What I would really like to do is redesign things a bit and have it slide on the ways like the floating head lathes. Could probably do that by losing about a foot of distance between centers and raising the headstock and tailstock up an inch or two. Hard to say the old lathe is worth that much trouble but I might get the itch one day.

I don't have the outboard turning set up for this lathe. If you do, any chance of getting you to post a picture?


John,

These are specialty belts not matched in automotive use. The primary belt is only 8.5" long and runs on toothed sprockets like a timing belt on an overhead cam engine. The Reeves drive belt is wider in cross section than any automotive v-belts and is metric dimensioned. Might replace it with something that spun an eighteen wheeler air compressor or something from an industrial application but I'm just hoping this one survives!

Hu

 

[Bill Boehme]

Sounds like the Craftsman lathe at least uses a proper Reeves drive belt. The Delta and Jet Reeves drives use ordinary A-section belts. Is the Reeves belt wrapped or does it have raw edges like a typical automotive belt? If it has been used a lot it might be hard to say because Reeves drives can quickly wear a belt out.

 

[Hu Lowery]

raw edges

Sounds like the Craftsman lathe at least uses a proper Reeves drive belt. The Delta and Jet Reeves drives use ordinary A-section belts. Is the Reeves belt wrapped or does it have raw edges like a typical automotive belt? If it has been used a lot it might be hard to say because Reeves drives can quickly wear a belt out.

Bill,

It is a cut edged belt and it really looks to me like just due to the nature of a Reeves drive the width and length aren't that critical. Sears sometimes plays single source games and rumor has it that is the story with this belt. Phyllis said that she did run down that it was a metric belt but she couldn't do any crossovers from the Sears number. I might try a parts house that has a lot of heavy truck customers or an industrial supply if I ever need that belt. I remember a similar belt on my air compressor under the hood of a ten wheel gas burner many years ago.

Hu

 

[Bill Boehme]

Bill,

It is a cut edged belt and it really looks to me like just due to the nature of a Reeves drive the width and length aren't that critical. .....

Maybe not critical in the sense of being able to work, but very important with respect to drive ratio. Unlike conventional belt drives with fixed diameter pulleys where the ratio of pulley diameters determines the output speed, with Reeves drives the belt length and the width both play a role in determining the output speed. If a longer belt is used and the spring loaded pulley is on the motor shaft (which is usually the case)the output speed will be faster. If a wider belt is used then the output speed will be slower. If it is longer and wider then you will just have to try it and see what happens. Also, unlike conv3entional belt drives, the distance between the two pulleys changes the speed. In the above scenario, moving the pulleys farther apart causes the speed to decrease. However, if the spring-loaded pulley is on the output spindle, the opposite will be true. On cheap Reeves drives, the speed regulation is very poor because the spring-loaded pulley doesn't have anything to dampen spring vibration so the spacing between the pulley haves is usually fluttering back and forth. This gets exacerbated by the fact that these pulleys are typically warped after a few hours of use. All of this should be enough to discourage anybody from using a Reeves drive.

 

[Hu Lowery]

intermediate dummy shaft

Maybe not critical in the sense of being able to work, but very important with respect to drive ratio. Unlike conventional belt drives with fixed diameter pulleys where the ratio of pulley diameters determines the output speed, with Reeves drives the belt length and the width both play a role in determining the output speed. If a longer belt is used and the spring loaded pulley is on the motor shaft (which is usually the case)the output speed will be faster. If a wider belt is used then the output speed will be slower. If it is longer and wider then you will just have to try it and see what happens. Also, unlike conv3entional belt drives, the distance between the two pulleys changes the speed. In the above scenario, moving the pulleys farther apart causes the speed to decrease. However, if the spring-loaded pulley is on the output spindle, the opposite will be true. On cheap Reeves drives, the speed regulation is very poor because the spring-loaded pulley doesn't have anything to dampen spring vibration so the spacing between the pulley haves is usually fluttering back and forth. This gets exacerbated by the fact that these pulleys are typically warped after a few hours of use. All of this should be enough to discourage anybody from using a Reeves drive.

Bill,

This system has the motor output transferred through the little belt I changed to an auxiliary shaft. That shaft has the manually adjusted sheave on it which is directly activated by the speed control knob. The sheave on the headstock spindle is the one that is spring loaded.

At the lowest speed setting I seem to be turning less than half of the indicated four hundred RPM. No idea if that translates all the way through the speed ranges or not. I'm very skeptical concerning the markings on the machine relating to actual RPM, one reason I wouldn't sweat it if changing a belt changed RPM. As long as the Reeves drive is working right the speed settings are fairly repeatable and I have to settle for that. Without a tachometer I don't know if the entire speed range is lower than the labeling indicates or if I am getting a wider range of speed than is indicated on the labeling. Of course I could be wrong about the lack of speed at the 400RPM marking but I don't think I am that far wrong, I have turned a lot of metal at low speeds with gear driven metal lathes.

I set maximum speed to be when the top of the belt is even with the outside of the sheave, bottom speed is controlled by where the belt starts flopping. That was at an indicated roughly 650RPM before the last time I went in the machine. Now I can go down to the indicated slowest speed, 400RPM, but I am more comfortable that the belt isn't slipping at about 450RPM. The speeds indicated on the controls are 400, 500, 800, 1000, 1200, 1600, and 2000 RPM so splitting those speeds is a bit of guess work at best.

Here is a link showing a pretty good view of a Reeves drive like mine.
http://aroundthewoods.com/imgslathelube/im002193.jpg

Hu

 

[Bill Boehme]

One other thing to not believe is the horsepower number that Sears states. I have a few Sears tools and they avoid stating motor parameters for obvious reasons. Saying that it is 2 HP is laughable. Maybe 3/4 HP, but even that is being generous. However, for that size lathe there is no way that you would ever need 2 HP. If it has 3/4 HP then that is plenty adequate. If it is 1/2 HP, then you might bog it down if you really were heavy handed when hogging out some wood.

 

[Hu Lowery]

no doubt right there too

One other thing to not believe is the horsepower number that Sears states. I have a few Sears tools and they avoid stating motor parameters for obvious reasons. Saying that it is 2 HP is laughable. Maybe 3/4 HP, but even that is being generous. However, for that size lathe there is no way that you would ever need 2 HP. If it has 3/4 HP then that is plenty adequate. If it is 1/2 HP, then you might bog it down if you really were heavy handed when hogging out some wood.

Bill, I suspect you are right about the horsepower too. Size isn't everything in an electric motor of course but this one is the same size or smaller than my 3/4HP Dayton motor of similar vintage and doesn't seem to have much torque at all. Best I could tell my capacitor numbers have wandered pretty badly, no doubt part of the problem but not all of it. It runs a starting capacitor with a manual switch to shut it down and a running capacitor. Might break down and try changing them out if I keep running this lathe as my primary for very long.

Hu

 

[Bill Boehme]

I have several large three-phase motors in the 1.5 to 3 HP range awaiting various projects as soon as I find that round TUIT that I need. Some things that differentiate them from other smaller motors include physical size, weight, and electrical requirements. The 1.5 HP motor is about as heavy as I am comfortable lifting without concern about risking back injury.

I have a pretty good idea of the size of the headstock on the Craftsman lathe and it would be pretty difficult to fit anything bigger than a 3/4 HP motor in that envelope and still have room for pulleys and other necessary stuff. I used to have a Craftsman air compressor that claimed to be 3 HP but only drew enough electrical power to run a 1/3 HP motor. At least they got it partly right -- they just forgot to put the "1/" in front of the "3".

 

[stu senator]

belts

If it is a timing belt, or any other kind, go to McMaster.com

Put in belt on the top for the search and there will be all sorts of types of belts suggested as you type "belt".

Look at each for a description of the types and then make your selection as to type, pitch (if timing belt) width and material and buy.

They stock all kinds of stuff and did accept plastic. I don't know what the minimum charge is.

Good luck.

 

[Hu Lowery]

the little yellow hardware store

If it is a timing belt, or any other kind, go to McMaster.com

Put in belt on the top for the search and there will be all sorts of types of belts suggested as you type "belt".

Look at each for a description of the types and then make your selection as to type, pitch (if timing belt) width and material and buy.

They stock all kinds of stuff and did accept plastic. I don't know what the minimum charge is.

Good luck.

Stu,

One of these days I will learn to check McMaster-Carr for everything! Been dealing with them off and on since they really were the little yellow hardware store. Haven't seen a hardcopy catalog in years now. They don't carry the big metric belt I need for the Reeve's drive, I'll have to check the measurements but I think a US crossover might work.

I have bought a boatload of metal machine tooling from them and some stock now and then. If they have a minimum it is pretty low, I never encountered it! If I do I'll just call a friend with a machine shop, he is always ready to order something from them.

Thanks for the reminder. McMaster-Carr has been a reliable supplier for a lot of years and one of my favorites.

Hu

 

[Bill Boehme]

I bet that they don't put mints in the package like the dealer in Lafayette does.

 

[John Torchick]

hu, the NAPA auto belt worked on the Reeves drive just fine until the Reeves drive went down the tube. Thanks for the correction on the type of belt.

 

[Hu Lowery]

hu, the NAPA auto belt worked on the Reeves drive just fine until the Reeves drive went down the tube. Thanks for the correction on the type of belt.

John,

I haven't tried an automotive style belt but just guessing I think it would limit RPM and might slip even when new due to the comparatively narrow width for this Reeves drive. I suspect it would at least turn the lathe in a pinch if I could find one short enough for the Reeves drive though. Looks like I could get closer with the industrial belts from McMaster-Carr, might even find one that works as well as the original other than the RPM numbers being off which seem like BS anyway.

The little belt I replaced won't begin to go on my wrist, it is 8.5" total circumference. I knew it was short but when the belts I ordered got here I thought I was had when I saw the belt all in one piece, didn't think it could possibly go around the sprockets. Fits like a champ and at the moment my lathe is in better running shape than it has been since before it left the factory.

I do much appreciate your post, extra information is always good.

Hu

 

[Tom Antrim]

Craftsman Belt

I need a craftman lathe model 351.217150 replacement primary belt. I do have the Craftsman part number and have located a replacement. However, I got very short service life out of the first belt. Although it was old, it was unused. I have also read posts of similar very short belt life from other owners. I also ran across an old thread somewhere in my searches for the belt that indicated that it was a Gates belt and that there was a better quality belt available from Gates also. No parts numbers mentioned though.

The catch with these Gates cog belts is that there are a handful of tooth profiles and they are not interchangeable so getting the same length and width belt isn't enough. Anyone have either of the Gates numbers for this belt?

Hu

People assume you were talking about the Reeves belt but I bet your talking about the small belt off the motor. I have a 351.217150 and have replaced that belt a half dozen times. Recently I replaced the Reeves variable pulleys and motor and am going to a VFD and 3 phase 1.5 HP motor. I am sick of that little belt.