Resolving the Belt Slipping issue on My South Bend Lathe

Replacing the belt and increasing tension did the trick!

[@billybike57]

I’m just truly fascinated by those belts you use! Thanks for sharing!

[@WinkysWorkshop]

I sell them if you need some. Good belts for old machines. [e-mail]

[@howder1951]

Nice little video Mark, love that scarfing machine, makes splicing a dream to do! Cheers!

[@WinkysWorkshop]

Yeah, I had have that after I retired to make belts for the company I retired from. It works very well.

[@jimfiles3307]

Excellent work.

[@WinkysWorkshop]

Thank you so much 😀

[@rexmyers991]

The lathe sounds smoother with the new belts. I couldn’t hear the clink and gear rattle I heard on start-up before.

[@WinkysWorkshop]

It is smooth but I think the gears were also not engaged

[@thaumaturgicresearchcounci4180]

Wrap around the pulleys is way more effective than higher tension. I would be concerned that the higher pull on the belt will either overload the plain bearings (if that's what your lathe has) or flex the shaft. Using a snubber idler would be effective if you can make room for it. Also with flat belts, longer is better since it damps down shock loads that are often what starts the slipping. My lathes are all set up with wall mounted pulleys and long belts, together with a lightly sprung snubber. Never any issues with slipping despite very low belt tension.

[@WinkysWorkshop]

I really don't think the tension is that significant. Yes more than it was but still not excessive. I designed and built the drive so I don't have a comparison. I do agree that the snubber is a good idea.

[@Zircon10]

Heck, I never had V-belt slippage on my 9” SB between the motor and the countershaft. It was ALWAYS with the flat belt on the cone pulleys. I always ran a leather belt with a long, scarfed, leather-to-leather joint glued together with Titebond. Very quiet that way, no click-click-click from the finger loop joiners. Belt dressing helped with slippage but had to be applied frequently. It’s also difficult to obtain leather belting that doesn’t stretch under tension.

[@WinkysWorkshop]

It was the flat belt slipping. This flat belt is a synthetic belt that will not stretch more than maybe 1/8". The adjustment increased the tension on the flat belt mostly.

[@Zircon10]

@@WinkysWorkshop Aha, I did not catch that. The tension on my SB was an adjustable toggle linkage between the headstock and the pivoting carrier for the jackshaft and motor. It worked effectively like a turnbuckle to lengthen or shorten the linkage, and pushed the carrier away farther from the headstock, thus tensioning the flat belt. I could have used a synthetic belt.

[@WinkysWorkshop]

@@Zircon10 Yeah, moving the motor down and shortening the flat belt increased the tension (the weight of the motor had more mechanical advantage)

[@duneforever8932]

A good project would be to make an annular cutter holder for lathe and mill.

[@kellyodom9596]

That would be cool.

[@WinkysWorkshop]

Interesting challenge.

[@robertwalker7457]

Well done mate, you are pretty much the Head Sherang of belt design and making.

[@WinkysWorkshop]

Wow, thanks... I think?

[@angelramos-2005]

Much better,Mark.Thank you.

[@WinkysWorkshop]

Very welcome

[@Preso58]

Seems like a successful repair, Mark. Is that belt sander specifically for scarfing flat belts? Regards, Preso

[@WinkysWorkshop]

Hello Mark, yes I made the grinder to grind flat belts. When I retired from the printing company I prepared all there belts for 3 year. I made it from surplus machine parts from the presses and binders. I didn't want to do it but they pretty much told me to name my price. I made about 20 belts a week for 3 years. Not a lot of money but a very good hourly rate.

[@stromundspiele670]

i didnt expect to find the brand of my lathe, i bought it in east Germany, i coulde`nd figur out why the dials are slightly of with my indicator (never tought about inches when i read 2.53mm on the indicator. becaus its 1 100 of. spechely because every other thread is metric) and why ther is a 63 tooth gear. sadly it hase 1/10 mm play in the spindle bearing and i only have the gears for metric threds

[@WinkysWorkshop]

Sounds confusing. The play is way too much for sure.

[@jacquespoirier9071]

just clean the pulleys and replace an old glazed belt makes a huge difference.

[@WinkysWorkshop]

I haven't used it much yet but I suspect the new belt along with the additional tension will make a huge difference.

[@garyreisdorf1363]

Mark, Apply Flat belt Dressing to the belt, it increases the friction belt to cast iron.

[@WinkysWorkshop]

No need now that it has more tension.

[@AmateurRedneckWorkshop]

At least belts are easy for you. Thanks for the video keep on keeping on.

[@WinkysWorkshop]

Yes they are! Thanks!

[@saulg7953]

what kind of adhesive did you use for the joint?

[@WinkysWorkshop]

Fixol. Here's a video kzbin.info/www/bejne/g3LLkGmJnr58pLcsi=oDtb5nX9TmwUrW1R

[@magicbytes3835]

Hello Winky, another good video, thanks for sharing, cheers from me. 😃👍👍👍👍👍

[@WinkysWorkshop]

Thanks for the visit

[@jimb9265]

Try to increase the amount of belt wrap on your pulleys. Maybe an auto spring tensioner or something similar. The percentage of pulley wheel wrap may directly correlates to less chance of slipping. Funky setup with all that stuff hanging off the back of the lathe.

[@WinkysWorkshop]

It's not uncommon to have the drive on the back. Many south bend have the same. They also have 1/2 wrap on the flat belts but with a cam to tighten the belt. I do agree that increasing the wrap makes a significant difference but the additional tension I applied is definitely not excessive. When I designed the drive the amount of tension I'd have was a guess. It depended on the motor weight, position and angle. It's been lacking tension for a while. I have compared the amount of tension to similar lathes. I still have much less tension than most but a lot more power at the chuck.

[@thaiexodus2916]

Is that the old Repulsion Induction motor?

[@WinkysWorkshop]

Yes sir, a very nice motor. I cut a slot in the top cover so that I could rotate the brushes to reverse it.

[@thaiexodus2916]

@@WinkysWorkshopOne of the first motors I serviced during training. Replace the brushes and spiff up the commutator every 20 years. 50 lbs per horsepower. Most likely every one of those ever made could be refurbished and put back in service. Ultra versatile traction motor

[@WinkysWorkshop]

@@thaiexodus2916 It's a good motor and yes VERY heavy. I think mine is 50 lbs per 1/2 HP! When I got the motor it would occasionally fail to start. I took the "necklace" out and cleaned it all up and it's worked perfectly ever since.

[@Rustinox]

I'm sure this will be a lot better.

[@WinkysWorkshop]

I agree... i have not tested it yet but I'll bet I suspect it will be much better.

[@thercbarn5001]

I sent ya a email with my lathe some time ago. I pretty much copied what you did with the mount but my drive is really close to my lathe and my motor is within a inch of the ground. I also have some angle in it. I haven't put my lathe to any serious use yet but I don't have any signs of slippage. Mike.

[@WinkysWorkshop]

Thats great. Your motor might be much lighter weigh as well. This would require the motor to be lower to get more tension.

[@thercbarn5001]

@WinkysWorkshop yeah it might be. I got it from Amazon. 5hp I don't recall what the rpm is. It's 220 though

[@WinkysWorkshop]

@@thercbarn5001 Mine is old... maybe 80lbs. I used to fly RC. It was a lot of fun but I had too many iron in the fire and sold out. I always thought it would be cool to have a laser cutter to cut the wood.

[@thercbarn5001]

@WinkysWorkshop yes it would. Maybe I should send you my project. I wanna take 4 saito cylinder heads and make a custom 4 cycle 4 stroke. That's cool that you used to fly!

[@WinkysWorkshop]

@@thercbarn5001 Sounds complex, radial?

[@65cj55]

Years ago i had a old Hercus Lathe with flat belts, someone took a Centrepunch and punched all over the Pulleys to stop the Belt slipping.......ok it was me, don't judge me it worked 🤣

[@WinkysWorkshop]

haha... thanks for the tip. Hopefully it doesn't come to that.

[@jubiletabustamanteserrano2446]

MUCHO PESO MUCHA PRESION PARA ESAS CORREAS MAS PEQUEÑAS ASI ESTA MEJOR

[@WinkysWorkshop]

Yes I agree, thanks

[@SgtCude59]

It's sound better

[@WinkysWorkshop]

A new directional microphone and the lathe was out of gear 😬. But it does sound better too. Thanks

[@Ervan-l9v]

You are going the wrong way. You need to make that belt shorter to cause the motors weight to have more influence.

[@WinkysWorkshop]

The v-belt length has nothing to do with tension but lowering the motor increases the lever length and provides more mechanical advantage (and required a longer belt). It's kind of like putting a pipe over the handle on a ratchet. If the motor was 10" from the pivot point and I make it 20" it will double the upper belt tension. Shortening the upper flat belt (which I did) changed the position of the lever and also increased the flat belt tension.