BELT HELP!

[dcarino_04]

Hello my last new short turret belt broke on my a-2 and the parts order is not here yet. Anyone know of a part number for this belt i can pick up at grainger or autoparts store?

[Kanga (James)]

The book says A49.5" for cast indexing cam and A50 for stamped. I've seen A48 used on cast cams, but I've never used a non-OEM belt myself.

How on earth did the short turret belt break? Shouldn't happen...

[wepauls]

be prepaid to pay over $10.00

[Roscoe]

A badly worn short drive pulley will "yank" a short turret drive belt in two.

[dcarino_04]

Well i don't know what happened intially, however i know why the second and only spare belt snapped. Upon further inspection of the second brand new belt it was sliced perfectly on a 45 degree angle... the original belt that broke just broke perfectly in half. I looked at the turret cam and found a RAZOR sharp line on it like some one tried to pry a belt on or off, for what ever reason i don't know. I ground down the burr and smoothed it out. I don't know how my mechanic did not know how to correctly install a short turret drive belt but i took the time and showed him. While searching in google earlier i found part number A48 which im guessing is the inside cricumfrence since the belt packaging says 1/2 X 50in. I picked one up from a local auto parts store and slapped it on, the machine runs fine! yes i paid, well the center paid 10.99 for the belt but we needed it.

[dcarino_04]

Roscoe: the short drive pully is one of those new aluminum one piece deals. Are you talking about the two piece pullies or is this across the board?

[Roscoe]

One piece, when they "round out" they don't slip as well. Seen it numerous times.

[dcarino_04]

Yesterday the gates belt was working fine with the machine from about 10am to 430pm. I got a 180 call and checked it out. The bottom pully on the turret clutch was extremely hot and the turret indexes with mega force. Looking from a top view with the gearbox on your right the left side of the belt was really tight where as the right side was extremely loose. The bottom pully is one of those black aluminum ones from qubica/amf. What should i be looking for to make sure its the pully. If that pully is bad that is a bad deal because those pullys are only about 2.5 years old!

[Mechanick]

maybe loosen up some of the tension on the long turret belt spring.

[Roscoe]

Change the pulley with a new one and see if that makes the difference. Sounds bad.

[dcarino_04]

that was the plan i have a bunch of turret clutches on standby im going to just throw another in and check it out and then compare a known good pully with the one i removed.
@mechanick: i loosed it to the point where it had barely any tension it is either super strong or it doesn't have enough tension to index. Its crazy i have never had this happen.

[madminstrel]

Following on from Mechanick, I would definitely check the tension on the long turret belt. If the spring tension is OK, check the tensioner pulleys on the motor mount. If the pivot pin is hard to move, then the long turret belt can be stuck at a high tension. This can also contribute to the breaking of the short turret belt and certainly cause the over heating problem. You may need to overhaul the tensioner assy.

[Kanga (James)]

When not using the OEM belt you run the risk of inconsistent drive. Standard 'V' belts aren't designed for use with a clutch, this is the reason you need to add so much tension. It may work for some, but success isn't guaranteed. The OEM belt is a clutching belt, designed to maintain consistent friction without wearing down prematurely, and is slightly wider, so it contacts more of the pulley. This also makes both the pulley and the belt last longer.

I've heard of someone using the green Gates clutching belts...seemed happy with them.

[madminstrel]

I used to use a green gates belt. It was cloth impregnated, designed for agricultural machines. Worked a treat AND permanently stopped the squeal that the ordinary v-belts would cause. I also had a very light tension applied to the long turret belt. Turrets worked well.

[Steve Stafford (JBEES)]

The bottom pully is one of those black aluminum ones from qubica/amf.

If this is truly an aluminum pulley...get rid of it. I know of no one that sells an aluminum pulley for this application as it would not hold up. Let us know...