Pat's New Indexer

[pfulghum]

I finally got my indexer making sawdust.
I mounted it parallel to the Y do to ease of mounting and I can leave it mounted without disturbing my normal 4x8 cutting area.

That is a Harbor Freight lathe with the bed cut off by 2". - $180
That is a 2x8 "I" beam from the scrap metal yard - $12.
Oriental Motor - $250
Gecko - $120
Power Supply $120
Coupler - $50.

50 Hours labor - $0


Friends like Dirk Dunham and Mike Richards helping pave the way... Priceless.


I am limited to 12"x30" material. That is plenty to get me up the learning curve.

Here are some pictures ....

The indexer itself..
You can see my Fein Vaccuum plumbing in the background.


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The Headstock...Note the innovative use of the tool rest to give me 2 full axis of alignment and the fine wood block to get the Z alignment.

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The control box....Is that a Gecko?


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Looking down from the top.

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Let me know if you have questions.


-- Pat

[Brady Watson]

Looks great, Pat!

-B

[steve4460]

Hi Pat

That looks cool .
How did you get that gecko to work in that alpha box ?., and how many could be hooked up to it ,and how ?.

Bot on

[myxpykalix]

Pat, I have a question...how do you keep your shop so clean? I noticed that it looks like you have a wormgear clamp connecting the indexer to the lathe. Here is a link for a double locking collar that i think might be better:
http://legacywoodworking.com/products.cfm?product=82
You probably can find it cheaper elsewhere but this is what it looks like.

[pfulghum]

Stephan,
RE: Gecko I took the control signals (direction and step) from the "B" axis header. THe yellow and red wire feeding the gecko. Ground (green wire) fro the ground bus bar. Power for motor was 30VDC from the power supply on the left. 120VAC from the filter in upper right of control box goes to bus bar below gecko and give the power supply 120VAC. Quite simple.
One Gecko driver per motor.

-- pat

[pfulghum]

Jack,

RE: How to keep shop so clean? sweep regularly and don't photograph the real mess



RE: Under that hose clamp is a $40 double locking flexible shaft clamp very similar but provides upto 5 degrees of off center. Mcmaster part number 6208K166. There is a custom made left hand twist shaft (Thanks Dirk Dunham) that is screwed into the left side of the headstock. I think that the threads for that side were probable either 13mm or 12mm, but we retapped them to be 1/2-13 left hand. Being a fine peice of machinery that comes from Harbor Freight (a hint of sarcasm) this connection doesn't run exactly true.

The hose clamp is used to take some of the flex out of the flexible collar.

-- pat

[ljdm]

I have an unused lathe, all I need is to hook it up to a stepper motor. Can I use the Acc driver for this?

[Brady Watson]

Yes. But if you are running a PRT motor must draw no more than 2 amps.

-B

[ljdm]

Brady - think a PR Z motor would do it? Would be easy to use the coupling from the ball screw-motor connection to tie into the lathe shaft. Don't need a lot of turning power, just torque to keep part positioned, correct?

[richards]

Lou,
Which Shopbot do you have - PR, PRT, PRT with 4G, PRT-Alpha, PRS-Standard, PRS-Alpha?

Any machine using Gecko drives can handle stepper motors pulling up to 7A. The current limiting resistor on the Gecko must be changed. If the stepper motor requires more than 2A, the Gecko must have a heat sink. (I would move the Gecko from the controller card and mount it onto a large heat sink.) The "reduced current" jumper must be moved to the regular setting. Of course, the power supply must be capable of suppling the needed current.

If you have a PRx-Alpha, you could do what Pat has done and add an additional power supply, a Gecko and your own stepper motor.

If you have a pre-Gecko PR or PRT, I assume you could still use Pat's method, but I've never seen a controller card for one of those machines, so I can't tell you where to pick up the step and direction signals (or even whether you would need to use a G202 [common 5V signal], or G203v [common ground signal]).

Regardless of which machine you have, you can make it do anythng that you want it to. Sometimes the question is: "Just how badly do I really want to make it do that?"

[dirk]

Geckos won't work on a PR box as there are no step and direction signals (Unipolar design). Geckos on a standard PRT box will be slow because of the low step rate put out by the old controller. You might also note that if you use the x or y channel to drive the indexer it is best if the unit values for x and y are close to the same value.
Dirk

[richards]

Dirk,
Thanks for the info. It looks to me that ALL PR and PRT users should upgrade to the 4G configuration to get full use from their machines.

[mitch_prest]

do you need any other software to run the indexer... you make it seem pretty simple to get up and going like this.. hell of a good way to learn without spending big bucks..

mitch

[pfulghum]

Mitch,
Everything I have done so far is with the Indexder software that came with Shopbot.. Flutes, spirals, etc.

Dirk Dunham (down the street from me) uses Artcam 10 (or 2008 version) for really cool 3d stuff. I would suggest looking into Cut3D as well.
--pat