Anyone here capable of gear cutting?

[PixMan]

Hi guys!

Just wondering if anyone here (in the US) has the machinery and cutter needed to cut a metric gear (or 3) for me.

I have a 1974 (or so) Victor 1640 lathe, made in Taiwan which I got used as a gift. It didn't come with any of the change gears needed for cutting metric threads. The primary one is a 70 tooth gear, 126mm O.D., 20mm I.D., 11.6 mm thick with a 6mm keyway.

While I have a great many tools in my shop I don't have a dividing head and I'm not inclined to build nor buy one at this time. I would be willing to buy a cutter if needed, and I will be making the blank and cutting the keyway in the next few days.

For now I'm able to cut metric threads because I borrowed one of these gears from a local guy who has the exact same lathe, but I do have to return his gear. From looking at the threading chart on the machine, this gear will enable me to cut several different pitches, including the M20x1,5 and M25x1,5 that I have to do. I will need to also make an M14x1.25, and for that I need a 35T gear made. Other pitches require a 30T gear as well. I believe these would be 14.5º teeth.

For that one I don't yet have the dimensions, though the guy who loaned me the 70T gear should have one to measure. Other gears I should have are a 28T and a 54T, though I'd only need those to do a 27TPI thread. With no taper attachment and plenty of pipe thread dies I doubt I'll ever need those.

It's not often that I need to cut metric threads, but having the gears would increase the value of my machine and I want as much capability with it as I can get.

Anyone able to help? I know very little about gears as I haven't made any since trade school in 1973-1977.

Thanks!

Ken

[EdK]

Ken,

If you don't get anyone here to make the gear you might want to check out Rush Gears. You can design the gear on their web site and download a CAD file of it. Since they make the gears to order you can specify all of the details. I ran the 70 tooth gear through their design web page and tweaked the pitch until the OD was 126mm. The pitch ended up being 1.75 and I used 14.5 degree pressure angle.

I don't know how pricey they would be from them but it might be worth checking if all else fails.

Ed

   

[Sunset Machine]

Sounds like a couple hours of work, 70 teeth. Wouldn't mind, but I'm in the middle of dividing heads. The old one would work fine but it shames me (teeth within .005, ugh), the new one is untested, and I'm quite a few weeks from being able.. So I'll have to pass but here's some more info.

[dallen]

SDI is pretty reasonable on there stuff if its in stock, or where your at Boston Gear would be my first choice, buy blanks and finish them yourself
My old chinese enco has imperial gears on it for the change gears

[PixMan]

(12-19-2013, 08:49 AM)dallen Wrote: SDI is pretty reasonable on there stuff if its in stock, or where your at Boston Gear would be my first choice, buy blanks and finish them yourself
My old chinese enco has imperial gears on it for the change gears

When you say buy blanks and finish myself, do you mean buy gears that are the right number of teeth and pitch then finish the width and the bore? I can make true "gear blanks" all day long.

I was aware of Rush, that's a great site. I was just thinking that if someone here had the means and will to cut the teeth on a blank I'd make, I'd rather keep the work within our circle.

[EdK]

(12-19-2013, 09:17 AM)PixMan Wrote: ...

I was aware of Rush, that's a great site. I was just thinking that if someone here had the means and will to cut the teeth on a blank I'd make, I'd rather keep the work within our circle.

I certainly understand.

Ed

[dallen]

SDI sells gears with just a hole in them so you can bore them out to whatever you need.

I've cut some gears but I'll be the first to admit I'm not the greatest, plus I don't have the cutters needed to do the job with.

[PixMan]

I can't seem to find anything suitable on SDI/SP's website. I'd be thrilled to find one that just needed a bore and keyway done. Boston Gear doesn't seem to have anything either.

Oh well. I'll ping the guys on PM and see who might be able to help.

[tekfab]

Hi Ken, dont know if this lot have what you need www. hpcgears.co , if they do and the problem is getting them shipped across to you then just shout and I'm sure we can help somehow.
Mike

[PixMan]

Thanks Mike but I can get someone over here to do it. I posted on the PM website and got a couple of responses straightaway.

One question: How do I determine if the 70 tooth gear I borrowed has a 14.5º pressure angle or the more common 20º PA?

I don't own one of those fancy gear tooth gauges, just the usual tools and a precision bevel protractor.