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View Full Version : logan lathe bullgear slipping



ak95xj
01-15-2012, 04:24 PM
I picked up a logan 200 lathe..

Noticed the bullgear was slipping

http://i205.photobucket.com/albums/bb284/ak4130/Picture016.jpg

The 3 pulleys alongside it were able to slide left to right about 1/16" so the pin on the bullgear would not stay engaged..I loosened the setscrew on the bullgear and moved it closer to the pulleys until there was no side to side play..This worked for only a few cuts and then seemed to loosen up again..Wondering if maybe there is some other way to adjust this,or maybe somethings wrong etc..

The belt looks pretty ratty too

ak95xj
01-15-2012, 04:25 PM
http://i205.photobucket.com/albums/bb284/ak4130/Picture017.jpg

Mike of the North
01-15-2012, 04:52 PM
My Logan was doing the same thing, I think there where two set screws I had to remove one to get to the one that tightened up on the shaft.

RussZHC
01-15-2012, 05:21 PM
If I understand Mike correctly, I'd investigate that first...how much play is there along the spindle between the interior ends of the bearings compared to how much "stuff" has to fit in that space?

The general set-up in that area is similar to the Sheldon I redid (and many South Bends are also similar) left a fair bit of room initially and there is usually some method of adjustment w some way of trust bearing (actual roller/ball bearing of some sort or flat washer to take up slack)...not sure if that comes into play here. Again using the Sheldon as example, there were a couple of Woodruff keys locating various items on the spindle but the length of the those keys was a fair bit shorter than the corresponding keyway of say the bull gear which in turn means, to me anyway, the bull gear is not precisely located...if it engages the pin properly (as it sounds like is NOT the case with yours), and the gear teeth are fully engaged (width) does it matter precisely where it is located..? Just saying my experience is that it is not as precise as one would think (though for me it became more precise in solving turning and facing issues)

Edit: a mis-alignment of the cone pulley would possibly explain if the edges of the belt are a bit rough too...and correcting that may move the hole(s) the bull gear pin goes into closer...

Don Young
01-15-2012, 09:41 PM
You may be missing a spring or ball that is intended as a detent to hold the pin in engagement. I do not know exactly what the Logan used but that is what I would look for.

Duffy
01-15-2012, 10:52 PM
A "poor man's" ratty belt replacement: go to Tandy and buy a belt blank and a tube of leather cement, (less than $20.00 total.) Skive, (bevel,) the overlapping ends, clamp between blocks overnite and you are good to go. Otherwise order a replacement from Logan Actuator.

J Tiers
01-15-2012, 11:34 PM
There is a retainer system for the pin.

Either that is not working, OR the pulley is moving away. It should be easy to determine which, see if there is space between the pulley and the gear when the problem occurs.

If there is 1/16" movement, the pin's receiving hole may be egged out to the point that it can push the pin out of position. Or the hole it slides in maybe egged and allow it to tilt. The best cure in that case may be to take out the pulley and gear, determine which has the problem, and possibly drill out and insert a closer fitting sleeve.

Problem could be the pin's hole, OR the pulley having an egged hole, or some of both.

Or the pulley could be slipping, the retaining catch may be faulty, etc.

You have to find out which

martik
03-26-2012, 03:47 AM
My south bend 9 used to do that. It was the pin slipping out of the pulley assembly. I stuffed some contact cement in there as a temp fix until I finally removed the bull gear and replaced the retaining spring.

firbikrhd1
03-26-2012, 10:50 AM
With regard to the belt, since you have a Bull Gear issue anyway, take the time to remove the spindle, investigate and repair the problem and while you're at it, get a serpentine belt from the auto parts the right length to replace the belt. The serpentine belt will slip far less than leather and never stretch.

atty
03-26-2012, 11:23 AM
With regard to the belt, since you have a Bull Gear issue anyway, take the time to remove the spindle, investigate and repair the problem and while you're at it, get a serpentine belt from the auto parts the right length to replace the belt. The serpentine belt will slip far less than leather and never stretch.

+1 on the timing belt. I use 18 gauge flexible wire to lace up the ends. Far superior to the original leather belt.