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Author Topic: PoppaBear needs some help please!!!  (Read 9139 times)

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Offline poppabear

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PoppaBear needs some help please!!!
« on: November 25, 2011, 09:33:24 AM »
Greetings,

     This is a slightly off topic question, but I am hitting a wall on a machine design.

Does anyone KNOW of a Gear manufacturer that sells, PRECISION Gears that are AFFORDABLE?!!!!
Little to none, or adjustable backlash (by maybe moving center distances).

I need a supplier (preferably in the US, where I can speak to someone who speaks understandable English).
Accountable quality control would be a must. Thus the US (or Canada), request above.

I am building a very custom "A" axis, plus an indexer so I need:

  • Worm/Wheel gears (with large diameter ID in the Wheel.
  • Right Angle Bevel Gears.(Helix or striaght is ok as long as low to no backlash


I was going to cut my own, but, I got a quote from a company for a HOB to do the Worm/Wheel above an it was INSANELY
expensive, they wanted almost $900.00 dollars plus 13-14 weeks lead time.........  They must be on Crack.

Scott
fun times
Re: PoppaBear needs some help please!!!
« Reply #1 on: November 25, 2011, 10:15:01 AM »
We usually get that sort of thing from Stock Drive Products or Quality Transmission, although finding someone who knows anything about the product is a challenge.  You pretty much have to know what you need and order it on-line.

http://www.sdp-si.com/
http://www.qtcgears.com/

We're slowing coming to the realization that if we can't make it in-house, it can't be done.  Trying to find reasonable price, acceptable quality and engineering/tech support all at the same time is just about impossible.  Machine shops around here are completely insane on price.  The last job we needed done was quoted $3000, which was no more than 5 or 6 hours on a manual mill.  We bought a used Bridgeport for $1500 and did it in house.

We now need to run some production on a mill, so we're looking for a CNC.  I found a SuperMax with a Anilam controller.  The controller is supposed to be dead, so thinking about putting a Mach3 controller on it.  It's not even worth the ride downtown to get a quote on having these jobs done locally.
 

Offline BR549

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Re: PoppaBear needs some help please!!!
« Reply #2 on: November 25, 2011, 11:21:24 AM »
HIYA SCott Face with that I usually find a surplus gear box and use the gears out of it to build what I want.

Also don't know the size you are looking for but gear sets from small rear differentials (golf karts,etc) are a source as well. Most are precision ground and hardened.

Also look into the outboard motors lower units. A lot of them went to precision gears and are in the small range.

Just a thought, (;-) TP
« Last Edit: November 25, 2011, 11:32:18 AM by BR549 »

Offline BR549

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Re: PoppaBear needs some help please!!!
« Reply #3 on: November 25, 2011, 03:50:09 PM »
Scott have you thought about belt driving the 4th?

Just a thought, (;-) TP

Offline poppabear

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Re: PoppaBear needs some help please!!!
« Reply #4 on: November 25, 2011, 10:30:33 PM »
need a worm gear to hold the rotary, belts cannot hold against the moment of cutting force toward the outside of the rotary table.
fun times

Offline BR549

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Re: PoppaBear needs some help please!!!
« Reply #5 on: November 25, 2011, 11:02:18 PM »
What ratio? What size center hole?


(;-) TP

Offline rcaffin

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Re: PoppaBear needs some help please!!!
« Reply #6 on: November 26, 2011, 04:14:00 AM »
Little to none, or adjustable backlash (by maybe moving center distances).
Almost by definition, zero backlash means you can barely turn the gears.

Big questions:
What diameters are you looking for?
Is this for production use or just for a short job?
Can one gear be brass (the big one)?

I have heard of people making their own worm&wheel sets using a large tap. Seen it done once. Yep, can be done that way.
Also, if you google 'hob cutter' you will find a number of web sites which show how to do it fairly easily.

Note: for prodduction use you probably want to go for the full involute gear profile. But for a 'quick fix' a much simpler profile is quite usable. Adjustable backlash is required...

Cheers

Re: PoppaBear needs some help please!!!
« Reply #7 on: November 26, 2011, 10:31:47 AM »
Have you considered a harmonic drive?  If you really want low backlash and a pro-setup as well as reasonable speed it is hard to beat a good harmonic drive. They are not exactly cheap but sometimes you can find a good deal on the bay...peace

Pete

Offline Dan13

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Re: PoppaBear needs some help please!!!
« Reply #8 on: November 26, 2011, 11:41:46 AM »
Roger,

While making a worm wheel with a tap like some do will transfer the movement, it shouldn't be considered for efficiency critical or, more importantly, for high load transmission applications. The tooth profile is not thick enough to carry high loads and the helix would be probably too small leading to reduced efficiency. There are many other considerations as well to this.

Dan

Offline RICH

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Re: PoppaBear needs some help please!!!
« Reply #9 on: November 26, 2011, 01:03:58 PM »
Have you looked at Simpson's posts on his 4th axis?
If too small then what size are you talking about?
One can always modify a lathe or mill head.......
RICH