1933 - 9 Quick Change - Any source for an Apron Worm clutch ?

Other then watching eBay?

Its 44 tooth... the id of the clutch ID 1 5/8 and the OD is 2" to the base of the teeth... They are pretty sharp and no longer shaped correctly... so I am looking for a replacement...

thank you...

Here's what I have :







The worm doesn't look bad... little thin in the middle but not bad :

I had one that looked like that. It slipped occasionally but otherwise worked. I shimmed it to engage more of the unworn part of the teeth until I found a used one on ebay.

that was my plan as well...

I was also thinking to keep this one and after I get a replacement and figure out what I'm doing (this is my first lathe) and I could remove all the teeth and about 1/8 inch of material and hob a sleeve and epoxy it in place...

How does it work now? Mine was much worse but was still functional, just occasionally annoying.

Loctite 609 would be preferable over epoxy but if you are going to make a ring why not make the whole part. You will need a 2" OD material either way.

Try it with Aluminum first.

it works the way it is but I assume at some point it'll stop working... figure I'll get a replacement before then...

and yeah I could build a new one and just might do that but figure repairing it will be a good exercise... also figure I can use tube stock rather then bar to build the sleeve...

now the half nut looked like it needed immediate attention



I picked one up from the 1928 model off of eBay... to doesn't have the safety cutout from the side that my 1933 has but I figure I have file it in...

so i figure i can tilt my milling machine spindle at the helix angle, grind an acme thread tool bit as a fly cutter,

move the Z axis up or down, while rotating the gear blank in the A axis to generate the gear profile. then rotate the A axis or index the blank to cut the next tooth. correct me if i'm wrong but that should properly generate a worm gear correct?

but i ended up having a plastic worm gear 3d printed. i know there are a lot of people who need this gear, if you can make one, i suspect you could sell a dozen of them but it will take time for people to find out that you have one.

I was thinking of making the worm then milling about half a dozen slots lengthwise and making a hob... heat it up and harden it then I could cut the worm gear...

how's the 3d printed one holding up? I have a 3d printer... do you have a stl? what did you print it out of?

I had it printed from PLA; PETG or nylon, other plastics might be more appropriate for a worm gear but pla is the hardest and easiest to print plastic available.

So I just modeled a helical spur gear using the "key involute gear" plugin for sketchup. I believe the helix angle is 4 degrees iirc. I can't recall the pitch radius i used, but i may have another one printed .050" larger in pitch diameter.

I could spend the time to make an enveloping worm gear by stacking 5 or 7 different helical gears on top of each other, each of different pitch diameter and offset angularly by the right amount, but mine works just fine as a simple helix.

So the amount of work that gear has to do is almost nothing, it did take a little bit of time for the clutch surface to wear in so that the action is reasonable, but I left the cluch engaged for several hours with the carriage jammed up against something, i didn't measure it but it was producing something like 50 or 100 pounds of thrust on the carriage, and in a few hours i didn't notice any smearing of the plastic.


if you can draw me a cross section of your gear i can modify the model i have now, yours is different than mine but the gear pitch and diameter appear to be identical.