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Model K16...new apron worm gear AND what is this 4th shaft in the apron for??

A couple pics I found of the tape job.
Dear lord that looks like you were being punished for something really bad. That pile of tape bits next to it is the part that gives me PSTD. haha Nice work. It was worth the effort as the paint job on the apron came out nice.
 
The apron was reinstalled yesterday. Went well enough. (No shafts reinstalled yet)

After hanging the apron I noted that the cross feed handle would now only rotate < 360 degrees???

So off the apron came and back on the bench. That's when this 'abnormality' was noted for the first time. Below is a pic of the apron gear that stands proud on top of the apron and drives the cross feed when powered.

I think I know the answer (call Monarch $$$) but I thought I'd check here also. (Reprofiling that tooth would presumably bite me down the road?)

The shaper and horizontal mill are who knows how long away from being up and running. Would like to try to make something like this myself...but now the focus is getting this Monarch back together.


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The rest of that gear looks really good... my go to would be to have someone just tig up the end of the tooth with nickel then hand file into a nominal shape.

Also depending on what the DP and PA of the gear are Boston gear may have a fit.

Another thing... are you sure you didn't have the threading stop engaged on the crossfeed dial? That behavior you describe is pretty much how that operates is why I bring it up...
 
Well I'd like to see the whole length of tooth, to give a better opinion. Looks like the apron was drawn up to carriage using bolts without the gears being in mesh, and caught that one. Might have a ding on the mating gear also.

While unfortunate, this is not terrible. In a high speed gear box, we'd want to change that. The apron, and that gear are not high speed though. In fact they crawl along pretty slow. As fast as you can turn the dial by hand. . .is its top speed. And while some force is applied to those teeth, it does not see tremendous power or torque.

I'd grind and file the bulging portion of tooth out and let it ride. Pretty sure you'll need to clean a ding off the one in carriage also.
 
Well I'd like to see the whole length of tooth, to give a better opinion. Looks like the apron was drawn up to carriage using bolts without the gears being in mesh, and caught that one. Might have a ding on the mating gear also.
Wow, that makes sense. And I know just the guy that did that. It did ‘suck up’ with a lot of effort. I NEVER considered the intermesh. If you hadn’t pointed that out I might have repeated it.

I’ll check the mating gear. Conventional wisdom says that’s a cast iron or cast steel gear?

I’m actually ok at welding cast with nickel rod and stick welder. Oven preheat and hours long oven cool down. But I would not try myself on something that small. I’d just melt that tooth of.
 
I would guess steel on the gear. I know Monarch heat treated gears in the headstock, but those spin faster, and would have more load and torque applied to gear teeth. My impression is apron and qcgb gears are not as hard, but I'm not 100% sure if its a difference in type of steel or heat treat process.

Try pm-ing member Emanual Goldstein, he's quite a bit more knowledgeable about gear making.
 
Well I'd like to see the whole length of tooth, to give a better opinion. Looks like the apron was drawn up to carriage using bolts without the gears being in mesh, and caught that one. Might have a ding on the mating gear also.
Happy to report there is no matching ding on the mating gear. I'll start with the file, reinstall and test the motion.

Here are 2 pics showing the whole tooth. A little blurry but they show the 'mashing' was even.

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Looking at how that smooshed down, must not be hardened, or not very much. A hardened tooth would have chipped or broke off, or carriage or apron would have cracked, something. . .Could be the gear for dial is harder, its not a 1:1 ratio, dial gear is smaller, maybe 4:1 I'm guessing.

When you think your done filing, you can probably do a test run in the apron without mounting apron to carriage. Just mount the gear in apron and spin it, to see if you still have a hard spot on the gear below it.

When you do mount apron, move cross feed dial back and forth as you drawl up close with bolts, to get gears meshed.
 
To aid in filing the gear tooth, make a form gauge. Take a piece of sheet metal and file it until it fits perfectly in one of the undamaged gear profiles. Or, you could make a gauge from some epoxy like JB Weld. Just coat the gear teeth with wax or grease first.
 
To aid in filing the gear tooth, make a form gauge. Take a piece of sheet metal and file it until it fits perfectly in one of the undamaged gear profiles. Or, you could make a gauge from some epoxy like JB Weld. Just coat the gear teeth with wax or grease first.

I've made a cast of the remaining teeth with Cerrobend (a Wood's metal alloy). There are other alloys that have very close form replication particularly in size but I can't recall the names. Just cast it on some decent teeth, blue up the cast, mark the new teeth and file away the blue.
 
If the gear can be turned so that the side of the tooth that still has its full profile has cutting force working toward the chuck.
Cutting can be done in either direction but I usually cut towards the chuck. Others may cut away from the chuck. Either way.
It could also be tig welded back up as said before.

That really mashed. down.
 
That really mashed. down.
I'm fortunate I didn't wreck anything else when drawing up the apron. My father always stressed that things should go together 'easy' on assembly. I forgot/ignored that solid advice.
 
Do you know the DP, PA and # of teeth? That looks like a spur gear that you could find from Browning, Martin, Boston, or Linn and modify the bore hub, or teeth if necessary. I find NOS spur gears on ebay and seldom pay more than $50-60 for them. I know the end train gears are not hardened as I've modified them and that one looks doable. Dave
 








 
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