Ratchet gear and pawl question

[stephenc]

I want to make a new ratchet gear and pawl for my shaper . I guess that when it was built they didn't figure it needed to hardened or even made out of good material because it badly worn and barely working .

The ratchet gear looks just like the image below ... or it would if it wasn't so worn out .

So my question is ... are the teeth just straight cut ? or should there be a slight pressure angle ?

There isn't enough left of my gear to tell and I don't have anything else with a ratchet gear on it to look at .

[Bob D.]

Don't think your tooth profile is correct. My Amocco 7" isn't square profile. Here is a pic of mine.
Bob

[John Hasler]

I'd make the front face of each tooth (the face that catches the pawl) vertical and slope the back one. I assume that you are remachining the pawl as well.

[spro]

We may note that type of pawl is reversible. (pull up, swing it around) So the ratchet gear has a profile equal at both sides. It cannot be "square" at the tip, nor is it a gear. John H. mentioned a new pawl and that is worth looking into. In a mechanical power feed as this, the backside of the pawl is as important as the front as it must index at each stroke.

[John Hasler]

If it is intended to be reversible then I'm wrong. The teeth must be symmetrical.

[spro]

This is interesting because I've seen those type and it isn't the type that I have with the Atlas. The Atlas has a lever to reverse the feed direction. It works similar to a ratchet wrench so it is designed differently. I expect Bob's Amocco works similar.
Your pawl angle is the key to the small profile of the edge of the ratchet wheel. There is no way that angle is removed closer to the shank. It may be the wheel was the consumable element and the pawl is okay. After chewing up the wheel, maybe not.
edit: There is the simple pin and cast base. The wear occurs in that too. There was a standard or discipline of either the pawl or wheel to maintain correct pressure angle. If the pawl goes all wobbly, it follows the damaged wheel.

[Downwindtracker2]

My shop built shaper came with an old style, not a good Gearwrench, ratcheting box end wrench. I changed it over to a fine toothed 1/2" ratchet. 55teeth working a 1/2" x13TPI cross feed rod. Until you make a proper feed, that might get you making chips.

[stephenc]

Bob thank you for the pic , I tend to be a visual person and picture help me a bunch .
Well sort of , I can see a advantage to making a gear like Bob's ammco.
The pawl would lift out of the teeth easier , and it looks like there's still plenty of "flat" area for the pawl to bear against when driven .

But the disadvantage is that it would be pretty darn easy to just cut a square profile gear . If I make the gear on the shaper it's a simple easy tool to grind , it also would be within my means to make a replacement tool if I was to maybe screw up and break or chip the tool .
It wouldn't be beyond my means to make a simple gear hob out of 01 tool steel to cut the gear on the mill either .

With some care I could grind a tool to match the profile of Bob's gear easy enough .
But I have my doubts I could duplicate it a second time if something was to happen to the tool .
I'd be happy to hear some more good advice ....

Downwind tracker
There is a whole lot of merit to your suggestion of just slapping a ratchet wrench on the thing , it would be a real easy quick fix and I'd bet money that it would last longer then the gear that came on the machines originally.

[John Hasler]

I'd just cut square teeth and then grind the pawl so that it bears flat against them. Round the corners a bit so the pawl can slide over them without catching.

I like the idea of replacing the whole thing with a hardware-store ratchet, though.

[Magicniner]

I'd use the "Rack" cutter from the gear cutter set.

[stephenc]

Russ
The ratchet wrench idea sure is looking like a easy winner . I think I could have it finished in about a half hour versus 4-5 hours it'll take me to make a new gear .

I hate to be lazy .... but dang it's almost to easy and if I find a wrench like downwindtrackers with 50+ teeth it won't change my feeds enough to be concerned about .

My curiosity was up ... home depot sells gear wrench brand .
To work with my leadscrew I'd need to use a 3/4 inch wrench which has 72 teeth .
I'd actualy increase my fine feed selection by quite a bit over the 50 ish tooth gear I have now .
Sure makes it very attractive to do it the easy way ... did I mention the gear wrench is only $12

[Downwindtracker2]

My 1/2" ratchet was just a fleamarket pick-up. The round head ratchets are usually fine tooth. I cut the handle and welded on a slotted flat bar. I have picked up an 80 tooth 1/2" Gearwrench brand ratchet for when I change the feed rod to a 1/2" x 10 Acme. Too bad it wasn't 100 tooth, then it would be one click = .001 feed.

They had a pinned nut on the end, so I just I pinned a 1/2" drive socket on the nut. I'm able to use a speed handle for quick traverse. Kinda inventive or redneck, one of the two.