# Serpentine belt conversion ?



## bisley45 (Oct 6, 2012)

I am in the process of setting up my horizontal drive and am putting a serpentine belt on it (46.5") how far should I mount it from the headstock ? the army manual says 15 3/4 " but that is to far for the belt I think. or do I need a longer belt? any help would be greatly appreciated. I am right at 13 1/4" see pics.


----------



## McRuff (Oct 6, 2012)

Put your adjusting/tensioning rod on and set it to the middle of the travel, move your drive unit till it is straight up and down, this would be roughly the correct position.

Just as an FYI, my belt is 47" long and my unit is mounted 16" from the center line of the spindle to the centerline  of the pivot on the drive unit. Theres about 5" of space in between the lathe and motor.


----------



## bisley45 (Oct 6, 2012)

thanks McRuff


----------



## pjf134 (Oct 7, 2012)

As long as the motor don't hit the lathe it will work. I have seen them right up to the lathe and work. I use a link belt on mine and can change it in 2 minutes and it does not slip, but the motor v belt will, and it does track on the center of the flat pulleys with a little adjusting at first. A serp. belt should last a long time, but I perfer a quick change belt instead of tearing down the lathe to install a one piece one. Mine has been on for over a year and a half and still looks new.
Paul


----------



## yachtsmanbill (Oct 7, 2012)

Just a little blip about some stuff here tonite... My 9A runs a 4 groove V belt. I bought an add-a-link belt from harbor freight but decided to use the old one. It was OK and the length was good... why not eh? I did use the link belt on my first 9A 20 years ago and it was a good fit and quiet. It just doesnt make sense to take the headstock all apart for a belt!
    On the drum switch wiring issue. Mine has a few jumpers inside plus youll need to be certain you have a reversable motor as well. Like old cars, stuff got changed out to keep them going for "just one more trip" if ya know what I mean. Look inside the switch cover for a schematic. Mine is oil soaked and illegable, but its there! You can also google "reversing drum switch schematics" for some help. Get a meter!!   ws

http://www.youtube.com/watch?v=rCH2RLAheaw&feature=youtu.be


----------



## pjf134 (Oct 9, 2012)

How long did the link belt last on your first 9A? I also was wondering about a under mount SB9 if there was enough room to put a link belt there as I have not tried that yet because I do not have a under mount one, but a v belt type pulley system might be ok and a flat pulley system might run into the bed cut out with a link belt. Just wanted to know if anyone has tried that.
Paul


----------



## yachtsmanbill (Oct 9, 2012)

Sometimes (and I really do mean that tongue in cheek!) ya gotta hand it to the chinaman... Hrbr Frt is notorious for import junk, BUT, the link belts are some kinda high tech nylon re-enforced plastic that runs surprising smooth and as of last communique with the new owner of my 1938 SB9A, the belt is still like new. We had several machines at work that used the old rubber style and after 50 or so years they started to fray.
   I bought a new one a few weeks ago as I had to remount the 9A onto the 10 under drive cabinet, but the OEM V belt was just the right length and I figured to use it until it breaks then replace it with the chinaman belt. Always make happy ending Joe! Unless youre gonna make a museum piece, its your call. The UD cabinet Im using had a few big holes cut out for the belting etc. Watch the video and youll see some 1/4" white fiberglass sheeting that I fit over the holes, bedded in construction adhesive, and bolted through.  Im utilitarian; I make stuff like this to work and use.
   I dont think you can underdrive your SB9 unless it was built that way... no way to run the belt around the headstock... 
 Happy Chipping!!!   ws


----------



## McRuff (Oct 9, 2012)

yachtsmanbill said:


> It just doesnt make sense to take the headstock all apart for a belt!
> On the drum switch wiring issue.



It does when your replacing a flat belt. Besides it doesn't take but about an hour to disassemble all of it and have it back running. If it was a v-belt set up then fine but the serpentine belt is the best set up for the horizontal flat belt drive.


----------



## pjf134 (Oct 10, 2012)

yachtsmanbill,

That HF like belt was made in USA most likely by Fenner and does work well and will use it again when the need arises. I bought the link belt for a temp fix and was going to tear down the lathe for a re-build and was going to go with the serp. belt, but I liked it so much I stayed with it. I guess my link belt will outlast me, but I should get one for the shop for other machines. If I ever decide to move my lathe to a different location it would be nice to take the belt off in less that 2 min. and move the lathe and put the belt back on in no time at all.
Paul


----------



## yachtsmanbill (Oct 10, 2012)

Sorry! Somethings I take for granted like Central Electric and Chicago Pnuematic stuff from HF...Cheap is good, but the stuff has no balls. The belt was $25, and it was a hit and run at the store. Theres stuff that I like there and wont hesitate to go there for, but machinery stuff is light duty and sometimes a single use tool.  The best thing I ever got there was a 2 foot long paintbrush with an angled head. I was painting the bilges on a 65 foot Hatteras yacht that I just sold and it really made difficult reaches easier with good results to boot!
   I see youre running that belt on crowned flat belt pulleys. Does it track pretty well? Just curious. The machine looks good! After the snow flies here in a few more weeks itll be shop time for next years projects... Model T Ford and lots of boat parts. Now if I could only sell the Dumore TP grinder with 100 new wheels or trade for a steady rest...On another note, please be aware; the guy that sold me this machine had the drum swith mounted in the same spot as yours, and was reaching inside the back gear quill cover to try and get the gears engaged when his belly hit the switch. As though a bolt of lightning from above came crashing down, I hit the knife switch to disable the machine. A second later wouldve been a trip to the ER. 
   Does yours have a lead screw reverser plunger or do you need to loosen the bolt to change directions> Is there also a tin inside gear cover? Theres a lot of subtle differences in these machines!         ws


----------



## yachtsmanbill (Oct 10, 2012)

McRuff said:


> It does when your replacing a flat belt. Besides it doesn't take but about an hour to disassemble all of it and have it back running. If it was a v-belt set up then fine but the serpentine belt is the best set up for the horizontal flat belt drive.



In a few weeks you may hafta walk me through knocking the headstock apart. The back gear trunnion is cracked and missing and I have a new headstock to replace it with. Ive been reading up on the job but sometimes Id rather listen to the voice of experience! * THANKS!! *ws


----------



## pjf134 (Oct 10, 2012)

ws,
 My lathe did not look like the pic above when I got it. The oil dried up in it and rust was all over it and nothing worked. The gear box was stuck and would not move and I could not even take it apart because the taper pins inside of the box was facing the wrong way, that was the worst part of the rebuild. My reverse gear is a plunger type like the gear box tumblers. My link belt tracks on the center of the crowned flat pulleys just fine after some adjusting of the counter shaft. I do have some extra covers for it and did not put them on and are sitting on the bottom of the bench. I do have pics of the tear down in my gallery on this site for reference. My lathe is from 1968 and is just a little different from yours. See pic of lathe when I first got it.
Paul


----------



## GK1918 (Oct 11, 2012)

I too have thought maybe getting a spare link belt local China Harbor 15min away and they have them.
I still run flat belts.  My belt on SB is a good 30yrs and is quiet not sure in a pic. if you can see
the belt is as wide as the pulleys  what I have read or saw is the belt is kind of narrow.  Though its
wide it works perfect so it stays only because I do have a Clipper lace machine.  My drill press,
power hack saw and two SBs all have this same belt which I have a few rolls of.  Link Belt nice back
up in the draw.     So I dont know If you can see this belt _this a 9A long bed.


----------



## GK1918 (Oct 11, 2012)

Forgot,,, broken tooth I would repair that right on the machine.  Last wk I did a simalar repair, if you
have a die grinder with cut off disk cut a slot the width of the root of the tooth in your gear, form a
new implant and we simply used locktight and tapped the implant with brass hammer.  What you have
going is it is a clean break thats an easy fix.  Dont worry about locktight it will stay just think of peddling
a bike, the next peddle stroke >(tooth) is already entering the next tooth so theres not a whole lot of
tooth stress.  I bet 99% of missing teeth, was somebody trying to get the chuck off. Thats a sure sign
the tooth was impacted not stripped which involves both gears usually not properly meshed.


----------



## yachtsmanbill (Oct 11, 2012)

Thats probably how the bull gear on mine lost a tooth. I have a spare gear minus 6 teeth. I was gonna either cut one out and braze it in, or drill and tap a pair of 1/4-20 holes, locktite 2 screws in place and file to fit. I agree about load sharing on teeth. Also picked up a belt hinge kit from an antique auction 2 weels ago. Anyone need a piece??   ws


----------



## JeremySCook (Oct 27, 2012)

Hi,

I've been trying to get a serpentine belt hooked up on my New (to me) South Bend lathe with some failures.  Looks like the belt is meant to be about 1", but after reading this forum, been thinking about purchasing something like this: http://www.amazon.com/Power-Twist-V-Link-Belt-wide/dp/B001DSZWJ2/ref=pd_cp_hi_0 Woudl that work, even though it's a bit skinny?

I thought I had it running last night - linkec it with about 7 strands of wire, the belt assembly soon broke!  Also tried zip ties with even less success.


----------



## curioushooter (Oct 27, 2012)

I had a bit of trouble of with this as well. This is how to fix it. Or at least I know this method works. There may be (and probably are) better methods.

I have a South Bend 10L ("Heavy 10"). You should leave at least 10th of an inch of clearance of either side of the cone pulley, so a 1.1 or 1" belt is fine. Make sure the belt is long enough. 

I happen to know for a fact that the Motorcraft serpentine belt for a Ford Expedition is very tough and excessively long and the perfect width for a 10L. There are cheaper serpentine belts that have softer materials that don't bond as well. I would recommend using the best house brand (like NAPA, or O'Rileys, or KOI's or Autozone) or an OEM. 

You want to "skiv" the belt. Take a belt sander and sand down the belt just until it begins to get to the fiberglass backing. Then take the other end of the belt and rough it up a bit (this end will not have very much soft rubber material and will be hard plastic until you get to the fiberglass). This should be about 2-3 inches long (I found longer and it actually is weaker as the narrow diameter cone pulley will peel it off. Shorter than one inch and there may be insufficient surface area for the adhesive. 

NOW, don't use cheap adhesive (I saved a buck on it and wasted a $17 belt doing so). I found the LOCTITE brand plastic superglue with the activator marker and a tube of glue to be the best. Follow the directions exactly. 

I recommend putting some aluminum foil or plastic wrap or paper bags over your cone pulley. Glue and press with your fingers into the large cone pulley and try to keep it straight. Hold it for a minute or tow. Don't UNDER-DO this holding and get impatient. Don't wiggle when you hold it either. 

Athen let it sit a few hours. I let mine sit overnight. When done this way it hasn't failed in well over a year of regular use. 

Anthony


----------

