Of drive belts and tailstocks...

I purchased a pair of machine matched "A" belts from Browning, and once I installed them I realized I wasted my time and money. The pulley grooves are worn unevenly after 60 years, so my matched belts are running unmatched. Is there anyone with a CNC lathe who offers pulley truing? Even if there were not enough aluminum left to get perfectly matched grooves any improvement would be beneficial.

Continuing will the rebuild, I started cleaning my tailstock. Unlike the rest of the lathe I have gone through, the tailstock base in is bad shape. Both the flat way and Vee way are worn badly. Do any of the bed regrinding companies offer tailstock regrinding? If I could get the base reground to a more accurate condition I can then shim up the tailstock top piece to proper height.

Thanks

bll230 said:

Continuing will the rebuild, I started cleaning my tailstock. Unlike the rest of the lathe I have gone through, the tailstock base in is bad shape. Both the flat way and Vee way are worn badly. Do any of the bed regrinding companies offer tailstock regrinding? If I could get the base reground to a more accurate condition I can then shim up the tailstock top piece to proper height.

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I scraped in my tailstock base to level after leveling the lathe bed, then shimmed up the body on the base to get the center of the quill to the spindle axis. There's very little area under there and it doesn't take long at all to scrape in (use the far right end of the bed, it's least worn for this). Note that if your lathe bed is worn to any significant degree that you'll have a hell of a time finding a happy medium across the whole lathe bed, but the tailstock ways are *not* normally too worn.

Why would you just not have a new pulley made?

Going to all the trouble and work setting up the old pulley for machining would take a lot of time. And if you don't have enough metal left to completely true it up you are left with an unbalanced pulley for all your trouble..

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bll230 said:

I purchased a pair of machine matched "A" belts from Browning, and once I installed them I realized I wasted my time and money. The pulley grooves are worn unevenly after 60 years, so my matched belts are running unmatched. Is there anyone with a CNC lathe who offers pulley truing? Even if there were not enough aluminum left to get perfectly matched grooves any improvement would be beneficial.

Click to expand...

I don't know why an CNC lathe is needed to true up V belt pulleys; An engine lathe will cut them?
Dan

swatkins said:

Why would you just not have a new pulley made?

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Or better yet, just buy a new pulley. I don't understand what all the fuss is about. I have no idea what you're working on but there are a
heck of a lot of over the counter pulleys out there--I'm sure you could find one that will work...

LKeithR said:

Or better yet, just buy a new pulley. I don't understand what all the fuss is about. I have no idea what you're working on but there are a
heck of a lot of over the counter pulleys out there--I'm sure you could find one that will work...

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I really don't know what he is working on either but I suspect it is a 10 ee since it uses a double pulley and this is the Monarch forum

IF it is a 10 ee you could buy a new pulley but I suspect the cost is going to be really high, so someone could probably make one cheaper, no CNC needed..

Danny VanVoorn said:

I don't know why an CNC lathe is needed to true up V belt pulleys; An engine lathe will cut them?
Dan

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Very little material needs removed. Or PARTS, even.

Run with one belt at a time. An OLD or "sacrificial" one, as it is going get a chip or three throw its way. Sheet-metal guard can help.

Fab a jig, true up one pair at a time right on the lathe, "in situ" as the saying goes..

Needs a bit of care and attention to detail, good ALIGNMENT and measuring skills, and most of all - the patience in set-up, and determination in-use to "make it RIGHT" as to matching fore and aft, both ends.

But big bucks, third-party resources, nor rocket science it is none of.

They are only "light metal" after all. A well-crafted form-tool can skive them. No "usual" axis traversal required. Pivot and micrometer stop, rather. I did mention ALIGNMENT?

Some among us need only a "filing guide" set to the proper angle. Might be best to not try that "at home" unless the master(s) who taught you were born prior to 1900...

In any case ...Screw the pooch?

THEN you seek less-worn, used, ELSE fab new ones.

10EE use, they DO have a tad of "rocket science" in their shape, features, uncommonly large raw material for the size of the lathe. A SB it was never.

BTW.. with NEW belting, an 10EE can run run fine on ONE belt.

Faster wear on belt and sheaves is all. A single "A" belt can take the full HP.

A pair wears far more slowly, AND.... are EXPECTED to be just different enough to help cancel-out each other's seams, lumps, bumps, wear spots, damage spots, and natural resonances a bit.

Lot of us just CLEAN the worn sheaves and go do more critical repairs..

The advantage of CNC is the double vee shape could be programmed and then the machine cuts both pulley profiles a thousandth at a time so one can watch the progress and stop it when desired. Remember, not necessarily looking to produce a like new item, but to improve what I have. Cutting the entire double vee profile a thousandth at a time would be impossible on my South Bend.

You don't need 'thousandth tolerances' for a belt vee and you only need to machine one side of the less worn vee to reach your goal.

Get two pins and put them either side of the deeper pulley in the vee and measure across the pins with a caliper. Now set up your pulley in the SB lathe with the compound angle correct for one flank of the vee. Cut the flank and check that vee across the pins, take another cut of known depth and check again, now you know how much closer the pins get for every amount shaved off. Knowing this you can calculate how much more to take off to hit your target.

That would work if I were trying to simply make two new grooves identical, but this is a representative drawing of my pulley grooves.

The two grooves have rounded sides, that are different depth, different curvature, and different width. The pins would be measuring against the rounded surface, which is in an unknown position. Having one groove with one rounded surface and one straight surface, neither of which matches either side of the other groove wouldn't be much of an improvement.

bll230 said:

That would work if I were trying to simply make two XXXX grooves identical,

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Fixed that for you. "New" does not apply. "Identical", or near-enough, does apply.

Just treat the wear as a sloppier than average roughing pass, probably because it WAS run for long years with only one belt, and finish it up as a good-enough match.

So far we are only talking about one pulley... What does the other one and the idlers look like ?

The idlers on mine have a ton of wear from the backside of the belts.. So much that there are .200 groves worn in them..

Need to make all new idlers as there is not enough material to just clean them up...

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swatkins said:

So far we are only talking about one pulley...

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BOTH spindle and motor/gearbox ends, both rows, in my suggestion.

What does the other one and the idlers look like ?

The idlers on mine have a ton of wear from the backside of the belts.. So much that there are .200 groves worn in them..

Need to make all new idlers as there is not enough material to just clean them up...

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Click to expand...

Use the ZAMAK originals for hubs and steel sleeve 'em perhaps?

My vintage 1960 EE has AL pulleys, no Zmac that I can find, The idlers looked possible like zmac, but when truing them, they proved AL. You are not likely to find some stock pulley that is close to a EE setup. Even different years have different offsets on the hubs, as I found when installing a larger pulley on the spindle of mine.

Toms Wheels said:

My vintage 1960 EE has AL pulleys, no Zmac that I can find, The idlers looked possible like zmac, but when truing them, they proved AL. You are not likely to find some stock pulley that is close to a EE setup. Even different years have different offsets on the hubs, as I found when installing a larger pulley on the spindle of mine.

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The idlers produce corrosion salts more like ZAMAK on the more neglected of two 10EE here.

Wartime, idlers would NOT have been scarce Aluminium. Hollow steel tube more likely had Zinc & such been scarcer.

Just to add, if you do have a pulley made, or a good original one, it is worth the effort to have it dynamically balanced. At least it was to me. I don't run up to 4K often if at all, but it sure is smooth... I had a guy here in the local machine group that worked for a big time dragster engine builder, and he offered to balance my original EE pulley. He said it was way out, and took a bit of work to get it right.