Gear Cutters

[Brian Rupnow]

Well there we go. A milestone for me----I have cut gears!!! Other than a bit of breath holding, there was nothing dificult about it. The most difficult part was coming up with the money to buy a set of cutters. Fortunately my 3 week contract that turned into a 13 week contract took care of that part quite nicely. There is only one test left now------And that is to make up a set of shafts at the correct distance apart and see how these two gears mesh.

 

[tel]

;D Congrats Brian - it really is that easy!

For easy height setting refer to the pic below - see the little tit on the arbour holding the blank? Well that is turned to match the tip of the tool tooth and makes setting up a breeze. Yeah, I know, you had a centre in yours, but that's really 'belt and braces' for small gears!

 

[Metal Butcher]

And near as I can tell, its perfect. ---At least when i went one more cut beyond the last pass between teeth, it didn't proceed to eat the next tooth.!!! ;D ;D

I have to agree. The gear looks great! Congratulations!

Now, if you could make up a few pairs of 2 to 1 ratio, say, 36T & 18T, or 40T & 20T 48 & 32 pitch, send them to me and I'll be more than happy to evaluate them by hands on inspection, and in a real world installation and use.

Of course, I'll do this for free! ;D

-MB

 

[Troutsqueezer]

;D Congrats Brian - it really is that easy!

For easy height setting refer to the pic below - see the little tit on the arbour holding the blank? Well that is turned to match the tip of the tool tooth and makes setting up a breeze. Yeah, I know, you had a centre in yours, but that's really 'belt and braces' for small gears!

Where's the little tit? I don't see it. I wanna see it...

 

[tel]

Well, here's a nice pair of tits!

 

[Paulsv]

Brian- a question if I may: Did you cut the teeth full depth, in a single pass?

 

[Brian Rupnow]

Brian- a question if I may: Did you cut the teeth full depth, in a single pass?

Yes I did. It did not seem to put any undue strain on the mill, and I didn't get the sense that it was labouring, nor clattering at all. Steel might be different, but for aluminum and brass a full depth cut of 0.090" worked fine.---Brian

 

[bezalel2000]

Well, here's a nice pair of tits!

A couple of really pretty birds there tel. They must be off your workshop calendar.

What month are they?

 

[Brian Rupnow]

I used some of my newly learned "gear math" to determine the pitch diameter of each gear, and having ciphered that out, came up with a center to center distance of 1.1665". I drilled and reamed a pair of holes on those centers, and it appears to be "spot on" because the gears mesh just great!!!

 

[Blogwitch]

Brian,

http://www.homemodelenginemachinist.com/index.php?topic=17185.msg178179#msg178179

Now wasn't that easy. Too much worry and trepidation on your part.

Another string to your bow, only another few thousand to go, I am about 1/3rd the way there.

Well done for getting over the barrier.

John

 

[chuck foster]

i knew you could do it brian :bow:

so what is next on the build list..............a clock, after all it uses lots of gears.

i/we await your next project.

chuck

 

[Brian Rupnow]

Thank you gentlemen for the kind words.---As a follow up to this post, and the wrong gear being sent with the original order. Travers sent me paperwork so that I could return this gear to Travers at no cost to myself. Its gone, winging its way back to Travers. However, Travers still have to send me the correct gear, which has of course been fully paid for with the original invoice.----The question now, falls into the category of "the cheques in the mail". I will let you know when and IF a replacement gear actually reaches me.----Brian

 

[Brian Rupnow]

Here is a quick question. I read somewhere that when you get into the smaller gears (as in less than 12 teeth on the 24DP gears, things get rather "Hinky". My cutters only go down to a 12 tooth gear. I assume that if you require something smaller, that is is where you buy precut bars as I think Chuck suggested?---Er---Nevermind. I went back to the beginning, re-read Chucks post, and followed the link. It seems you can buy what they call "Pinion wire" down to 6 teeth in 24DP by the linear foot. (When they are not out of stock.)
https://sdp-si.com/eStore/Direct.asp?GroupID=438

 

[Brian Rupnow]

This afternoon I made myself a little "Show and Tell" block, with both gears, shafts, and a knurled handle to operate them with. I'll drop by the shop where my machinist friend who modified my arbor works and show him. He gets a real kick out of the fact that I am now machining things. Mike knew me for 20 years in my roll as design engineer, in fact he had a hand in building many of the things I designed while working for Volkswagen of Canada. The fact that a guy who spent his entire life designing things has now turned his hand to machining things amuses Mike to no end. : :

 

[Blogwitch]

Brian,

You are now realising how different it is to design AND machine at the same time.

I was very lucky in that I did both at the same time from a fairly early age (30), with my machining starting a lot earlier.

It is for that difference that there is so much animosity between the office and shop floor. If more design engineers went onto the shop floor and talked to the people who had to make the part, then less boo-boos would be made.

I think maybe that is why your friend is so amused, a design engineer that actually listens, learns, then makes the part himself.


John

 

[Ken I]

Like Boggs I did both and it has always been a design philosophy of mine not to design anything I can't make (or at least know how to make it).

Over the years I was challenged a number of times by toolmakers saying things like "This can't be made" - my normal response was to go and make it.

Over time they learned the correct approach was to ask me how to do it.

Ken

 

[dgjessing]

So I flipped around the tool I used to do the first efforts and ground it to do about a 3mm pitch:

The other end is about 6mm pitch.

They ain't going to match up with any standard or commercially available gears, but they ought to work just fine ;D