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Author Topic: Building a 4th Axis from scratch.  (Read 17460 times)

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Offline Pythagoras

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Re: Building a 4th Axis from scratch.
« Reply #10 on: March 09, 2009, 07:23:31 AM »
I'll never regret setting up this section. Your work is inspirational.
The Pythagorean theorem: The sum of the areas of the two squares on the legs (a and b) equals the area of the square on the hypotenuse (c).     a² + b² = c².

Offline Tweakie.CNC

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Re: Building a 4th Axis from scratch.
« Reply #11 on: March 09, 2009, 08:42:33 AM »
Thanks Guys.

I will post more pictures as the project progresses.

Tweakie.
PEACE

Offline Pythagoras

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Re: Building a 4th Axis from scratch.
« Reply #12 on: March 09, 2009, 12:40:24 PM »
What is the method of working out the diameter of the gear so thats you can cut the teeth to fit around exactly?
The Pythagorean theorem: The sum of the areas of the two squares on the legs (a and b) equals the area of the square on the hypotenuse (c).     a² + b² = c².

Offline Graham Waterworth

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Re: Building a 4th Axis from scratch.
« Reply #13 on: March 09, 2009, 04:25:07 PM »
Try this :-

Graham
Without engineers the world stops
Re: Building a 4th Axis from scratch.
« Reply #14 on: March 09, 2009, 04:59:15 PM »
By mounting the blank on a bearing so it can freewheel and cutting with a tap as Tweakie has done, I would think all you need to do is make the circumference at the PD an even increment of the taps pitch..then add the depth of the thread to the PD to get the OD.
RC

Just rambling while waiting for ya Tweakie.....thanks
« Last Edit: March 09, 2009, 06:58:00 PM by Overloaded »

Offline Tweakie.CNC

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Re: Building a 4th Axis from scratch.
« Reply #15 on: March 10, 2009, 03:45:17 AM »
Hi Folks,

My approach to cutting the gear wheel was nowhere near as technical as it should have been. I already had a 60 tooth spur gear so I knew in advance the diameter the finished gear was to be cut to. I machined 60 slots around the circumference of the blank (for the tap to engage) and went for it like it was a knurling operation on a lathe. The initial problem is that the number of teeth versus the circumference did not match because I did not machine the blank to the finished shape )=(   it was initially too large in diameter at the point where the tap first touches (difficult to explain but I hope you understand). So there was some argument between the tap and the blank but this subsided to harmony when the diameter and pitch became correct.

As with all things, if I was doing it again I would probably do it a different way but the way it was done worked. I have since seen examples of this type of gear which has been cut radially into two discs which are spring loaded against each other as a way of eliminating backlash.

Tweakie.
PEACE

Offline Tweakie.CNC

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Re: Building a 4th Axis from scratch.
« Reply #16 on: March 10, 2009, 09:23:33 AM »
Just finished making the stepper motor mounting this morning - can't wait to try it out but I have to do a bit more electronics to extend my driver card to include a fourth axis driver.
Fortunately, I have a stepper test rig so I can run it on the bench just to make sure there are no tight spots and that the stepper has enough torque.

Here are a couple more pictures.

Tweakie.
PEACE
Re: Building a 4th Axis from scratch.
« Reply #17 on: March 10, 2009, 09:55:51 AM »
Looking GOOD Tweakie !
You're THERE man.
Making chips soon....or dust.....probably both.
Thanks,
RC

Offline Tweakie.CNC

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Re: Building a 4th Axis from scratch.
« Reply #18 on: March 10, 2009, 10:00:29 AM »
I haven't the faintest idea how to set up Mach to drive a fourth axis yet. There are plenty of posts on this subject (i've checked already) so I will have to do a lot of reading before I can make anything.

Tweakie.
PEACE

Offline budman68

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Re: Building a 4th Axis from scratch.
« Reply #19 on: March 10, 2009, 02:03:55 PM »
Looks like a great unit there, tweakie  :)

Dave
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