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[Lathe] Help finding belts for a old lathe

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Mafoo

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#1
Hello, I hope I have selected the correct category for this post!
I will apologize in advance if I use incorrect terminology the last time I used a lathe would be at school and we were never allowed to take those apart to understand.

2017-02-21 12.17.22.jpg
I have a small old metalworking lathe that was gifted to me. It is quite old and in need of a lot of TLC of which I have started, the motor is a lovely old Hoover reversible 1HP AC motor which I have rewired with some modern cabling (adding it's reverse switch at a later date). I am in the process of cleaning up the layers of grime and re-lubricating, however I have run into a problem identifying what belts to use on it. It arrived to me without any belts or manuals so I was hoping for some help identifying what I need. It seems to be a twin belt system with one being used to bring power from the motor to the pulleys for speed changes.

2017-02-21 12.17.03.jpg
I have taken measurements on the pulleys
the pulley on the motor measures as it's depth 10.6mm the gap at the top is 9.2m and the bottom is 4mm running a loop of string around them comes out at 580mm
the pulley on the main unit measures as it's depth 6mm the gap at the top is 8m and the bottom is 4mm running a loop of string around them comes out at 470mm
the pulleys on the orange arms lever forward on a pivot just behind the main unit (not visible in photographs), from that I assume I would be looking at having the belt between the machine and first pulleys actually shorter than the measured amount and the belt to the motor longer allowing the pulleys to float on the pivot rather than resting on the motor.
Although i have given the measurements in metric the machine itself is definitely imperial in construction as I have had to order up some imperial allen keys!
I also had a question about fastening the machine down to the base it is on, currently i have some loose bolts just so it doesn't slide around to much when i am cleaning parts. However the holes measure at about 7~ mm should I just get some M7 threaded bolts and nuts (with washers) to fasten it down with or should i get something in a imperial size that matches the holes exactly to minimize shifting of the machine?

Thank you in advance for any advice on this!
 

Bob Korves

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#2
Pulleys are probably sold to different dimensions where you are than in the US. Here, we measure the width of the pulley groove at the widest part and the outside diameter around both pulleys to determine what is needed. We take those dimensions to an industrial supply store and they determine what we need. The various manufacturers have different part numbers, that may not reference the exact sizing. There are lots of different belt configurations, some quite similar to others. When we see grooves like those here in the US, we think A series or B series industrial belts. If the machine was not built in the US, it might well be different. Make sure to allow for tightening and for stretching a bit with time.
 

Ulma Doctor

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#3
Hello Mafoo,
i can't really tell scale by the picture, but at a guess it appears that the belts are fractional horsepower belting
by the looks, i'd say that they take A (or 4L) belts
580mm= 22.83", round up and add an inch and you'll need 24"- by that logic you'd need a A24 belt
470mm=18.5", round up and add an inch and you'll need 20", again by that logic you'll need a A20 belt
there is no corresponding imperial thread equal to an M7- a 5/16-18tpi may be what you need to fasten the lathe down
1/4"-20 tpi is a smaller bolt and i don't believe that would be the best route to go
if the bore measures 7mm, i'd consider punching it out to 8 mm then you could go either metric or imperial, 5/16 and 8mm are close enough to call equal (.312"=7.92mm)
i hope the information is useful
 

Mafoo

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#4
Thank you Bob, i will go re-measure centre to centre and diameter of pulleys later tonight draw up a diagram. I suspect i need to take my measurements along to a supplier whom can advise (probably take one of the pulley to match the profile)
 

Dave Paine

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As Bob mentioned, in the US the codes normally define the width at the top of the pulley and length as the circumference of the top of the belt.

Your 9.3mm sounds like a 3/8in wide belt which may be "A" size. You really need the length on the outside. You can estimate this by the distance between the centrelines of the two pulleys + (radius of the outside of each pulley x 3.142).

A website to give you an idea of the belt specifications.

http://www.vbelts4less.com/V-Belt-Specs_ep_45.html

The motor pulley is easy to purchase and install. The spindle pulley is not so easy to install since you would need to remove the spindle. It will be easier to use what in the US we call a link belt. Not sure of the name in your location. These belts are not cheap, but they will save a lot of hassle in removing the spindle.

A web site to illustrate what a link belt looks like. You should be able to find some local mail order place. Some sell a fixed length, like this link. Some sell by the foot. This is an "A" size. I have two of these belts on woodworking machines. They work well, just a bit more air noise than a fixed belt.

https://www.woodcraft.com/products/4-foot-of-1-2-link-belt
 

Mafoo

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#6
Thank you for the replies, the spindle is actually not to difficult to remove I have done it about a month ago to assist cleaning so I am not to worried about that, although I can certainly see the benefit of the link belts should a failure occur I can just replace the failure parts without needing to dismantle the machine.
I think I need to go back and re-measure as has been suggested. I think it would be worth me doing some more research see if I can find a nearby supplier that I could take the pulleys to to see if they can match what the belt type is, but if I can't do that accurate measurements are going to be what I need either way!
 

Bob Korves

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By the way, automotive belts might look like a good fit on those pulleys, but are not the same cross section and will not perform well with those pulleys, if they are what I think they are. Stick with industrial sources, not the auto parts store...
 

Bob Korves

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#8
It also might be a good idea to measure the outside diameters of all the pulleys and then do the math to see what kinds of speeds you will be getting with the pulleys and motor you have, before you finalize anything.
 

chips&more

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#9
You are getting good advice. IMHO, your lathe is not a serious HP generating machine. That said, just about any belt you find will probably work, even a round belt. I would not worry if the belt does not fit the “V” perfectly. You do not have that kind of lathe that needs all the power transmission it can get. You just want something that makes it go around. And something that does not slow the lathe down because the belt does not flex well enough. Dave.
 

Silverbullet

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#10
In my opinion the 3/8 or 10 mm linkbelt would be your best option. The size ,,length,, is up to the travel on your engagement lever . The plus side you don't have to take the spindle bearings off , to install the drive belt. There are more bonuses they're quiet and have good traction. Harbor freight sells them fairly cheap too. Still it's up to you , even a 10 mm round belt will work on them , leather sewing machine belts or the new rubber type you can cut and glue together urethane . Let us know how you make out.
 

markba633csi

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#11
That's an interesting lathe- do you know who made it?
Mark S.
 

tq60

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#12
Stop and look for another motor.

That lathe looks to be small so having one hp of power input then speed reduced the power will be much more than the frame can handle and mistakes will not cause stall but will break something.

Please confirm the size so proper motor can be suggested.

1/2 may be good.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 

Mafoo

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I read the rating on the motor wrong when i first got it, after some cleaning it is a 1/6 HP
2017-02-24 17.32.32.jpg

I am now up and running with belts. I found a local engineering supply company that were kind enough to help me size them up and gave me a really good price on them!
2017-02-24 18.08.26.jpg

ran it for about an hour rounding a piece of wood to test it. It seems to have some kind of mechanical overload kickout if it is to much load which is good.
The belt from the motor although gripping seems to be quite slack so i might go get a slightly smaller one but it works great.

With regards to make and model i have no idea I cannot find any distinguishing marks

I still have a bit of a way to go before I would say it's properly working, I want to fit a stop go reverse electrical panel to the front, the bolts to hold it down properly are on back order so i am using some temporary ones atm (M7 is somewhat uncommon!). in the fastest gear the belt inside rubs a part on the mechanical kickout so i need to add a spacer below the machine to bring it up an inch so it doean't rub.
 

JC54

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I have just joined forum and think that I am rebuilding a similar lathe to yours. Have a look at http://www.lathes.co.uk/flexy/index.html. Mine is the Simat version that has no makers name or numbers etc. I am building it into a "box" so that I can use it on study desk or put in cupboard out of way when not needed. I thought that it would be more accurate for small engine parts than my 1910 Drummond in main workshop. This is my lathe as I got it off E bay.
 

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Silverbullet

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I have just joined forum and think that I am rebuilding a similar lathe to yours. Have a look at http://www.lathes.co.uk/flexy/index.html. Mine is the Simat version that has no makers name or numbers etc. I am building it into a "box" so that I can use it on study desk or put in cupboard out of way when not needed. I thought that it would be more accurate for small engine parts than my 1910 Drummond in main workshop. This is my lathe as I got it off E bay.
Nice little lathe , neat power feed set up all gear drive. And hi and welcome to the site.
 
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