[txcncman]

I'm sure you can find a machinist somewhere on earth who has a collet chuck.

Wait. I thought they were all banished to Mars.

[Shane1234]

Wait. I thought they were all banished to Mars.

no, farmed out to china to make oil filters for trucks.

[cnc2]

I didn't search any further, I'll do it after the weekend.

Thanks !
cnc2.

[fizzissist]

Because I need to find a machinist who has a collet chuck first, the one I've found has an automatic long bar stock feed collet chuck, which isn't meant for accuracy more that 0.1mm.
cnc2.

You must travel is some pretty pathetic machining circles... A bar fed collet "isn't meant for accuracy more that(n)n 0.1mm." .... You're kidding, right?

A plain old 5C collet, bar fed or otherwise, from Hardinge, will hold +/-.1mm till the cows (or in your case, goats) come home. It'll hold 0.02mm TIR without working up a sweat.

[cnc2]

You must travel is some pretty pathetic machining circles... A bar fed collet "isn't meant for accuracy more that(n)n 0.1mm." .... You're kidding, right?

OK that was a typo...about the pathetic machining circles, I'm not a machinist I'm a software guy, 0.1mm I was talking about that specific lathe, it's an old hydraulic lathe, it's so old that it has no screen...etc. it's programmed by putting some sort of sticks in a table of holes and pushing a few buttons, so old that it had Euro-board format (100x160mm) logic cards for AND OR NOT XOR...I think it was a turnomat I'm not sure if it's the brand or model...it's made for pulling a long bar from behind through the chuck...as everything hydraulic it'd only take a p'shiit to chew the teeth of the pulley, the chuck has no adjustment that I know...I saw some gas hose fittings it made and the finish was crap.

A plain old 5C collet, bar fed or otherwise, from Hardinge, will hold +/-.1mm till the cows (or in your case, goats) come home. It'll hold 0.02mm TIR without working up a sweat.

Cows ? goats ? Why ?

[fizzissist]

OK that was a typo...about the pathetic machining circles, I'm not a machinist I'm a software guy, 0.1mm I was talking about that specific lathe, it's an old hydraulic lathe, it's so old that it has no screen...etc. it's programmed by putting some sort of sticks in a table of holes and pushing a few buttons, so old that it had Euro-board format (100x160mm) logic cards for AND OR NOT XOR...I think it was a turnomat I'm not sure if it's the brand or model...it's made for pulling a long bar from behind through the chuck...as everything hydraulic it'd only take a p'shiit to chew the teeth of the pulley, the chuck has no adjustment that I know...I saw some gas hose fittings it made and the finish was crap.



Cows ? goats ? Why ?

Given your description of the lathe, I'll stand by my cows & goats statement.
Seriously.

[cnc2]

Given your description of the lathe, I'll stand by my cows & goats statement.
Seriously.

Is that a Troll on your avatar ?

[fizzissist]

Amongst a few of the others here that I know of, you've got a minimum cumulative professional experience time in decades, not including mine.

We are rather amused at the problem, and have offered inputs based on those decades of real world, hands on experience on the shop floor. Apparently there's something either lost in translation, or you're just not getting it... unless it's all of us. Entirely possible. Anything's possible.

Sorry if I've got you all worked up.

[txcncman]

Is that a Troll on your avatar ?

I thought it was a killer rabbit. That is why I am so scared of him.

[cnc2]

Amongst a few of the others here that I know of, you've got a minimum cumulative professional experience time in decades, not including mine.

That's what makes CNCzone such a great place, thanks for sharing !

We are rather amused at the problem, and have offered inputs based on those decades of real world, hands on experience on the shop floor. Apparently there's something either lost in translation, or you're just not getting it... unless it's all of us. Entirely possible. Anything's possible.

Sorry if I've got you all worked up.

I get the picture, my main problem is in finding a honest/reliable machinist, the one with the hydraulic lathe and collet chuck wanted to try...from what I understood if I let him try, he might screw my stock and I'd have nothing to say about it. I once asked him to turn/bore a 0.5mm deep pocket in a 2mm thick piece of round aluminum stock, he plunged 0.5mm and the finished pocket was 0.8mm deep...that's +/-0.3mm...all of his lathes are in an terrible condition. I bet he has no dial indicator, I never saw him use one.

If I fail to find a machinist who can implement any of the solutions you guys offered, I think I'll wire EMD the bores it'd cost $30 for the four pulleys, with an accuracy of +/- 5 micron.

What do you guys think ?

Thanks !
cnc2.

[vidio1]

Sounds like your building a Timex for NASA to me.....

[BAMCNC.COM]

Sounds like your building a Timex for NASA to me.....

Ahahahaha Ditto

[txcncman]

Sounds like your building a Timex for NASA to me.....

This thread just keeps ticking...

[cnc2]

Hi guys !

After we found out that machining soft jaws for the CNC lathe(school machine shop) would be too expensive for such a small job, the operator directed me to a well equipped machine shop, he said they have collet chucks and CNC machines...I visited that shop and they told me that I'll have to wait for two weeks before they can start my job, I think I have no other choice.

And BTW, I'm way ahead of NASA

Thanks !
cnc2.

[tjb1]

I can't wait until you order the belts!

[cnc2]

I can't wait until you order the belts!

That would be the case with NASA, in my case the belts are already here...I told you I am way ahead of them

Thanks !
cnc2.

[tjb1]

That would be the case with NASA, in my case the belts are already here...I told you I am way ahead of them

Thanks !
cnc2.

Do they have a tolerance greater than .1mm?

[cnc2]

Do they have a tolerance greater than .1mm?

I don't know and I don't think so (rubber belts), but having accurately machined pulleys will at least allow me to rule them out while troubleshooting issues, and the belts are intended to be replaced at some point and I might switch to polyurethane belts if I don't like the rubber ones.

The machinist who didn't want to do the machining told me that it'd 0.1mm out of concentricity, at best ! with no guarantee.

Positioning tolerance isn't my main concern here, the theoretical resolution(smallest movement) is from 0.1 to 0.3mm. Accurately machined pulleys should ensure a constant belt tension and reduce vibrations.

Thanks !
cnc2.

[Delw]

Hi guys !

After we found out that machining soft jaws for the CNC lathe(school machine shop) would be too expensive for such a small job, the operator directed me to a well equipped machine shop, he said they have collet chucks and CNC machines...I visited that shop and they told me that I'll have to wait for two weeks before they can start my job, I think I have no other choice.

And BTW, I'm way ahead of NASA

Thanks !
cnc2.

theres your problem right there if your not paying enough to have someone cut jaws than you might as well us a drill and file and do it on a park bench.
you guys at school arent all that bright what the heck do they teach you there.

if your using the school cnc surely you can buy your own jaws for a small job. your going to pay a "REAL" machine shop more than the cost of jaws to even look at it.

[Shane1234]

theres your problem right there if your not paying enough to have someone cut jaws than you might as well us a drill and file and do it on a park bench.
you guys at school arent all that bright what the heck do they teach you there.

if your using the school cnc surely you can buy your own jaws for a small job. your going to pay a "REAL" machine shop more than the cost of jaws to even look at it.

my thoughts exactly as well. its usually the non-machinist types that cringe over dollars spent to do things the correct way.