Re: [CAD_CAM_EDM_DRO] Gecko 2xx "Nema 42 modification"???

Hey Paul,

Hanging out in this chat group is so much more fun than working... If
only it paid the bills! Thank goodness I have all this stuff written in
my notebook... Here goes,

I selected a toroidal transformer rated at 45V, 14A (625VA). Bridge
rectified, with a 12,000uF Cap, this yields ~65VDC. The make of the
transformer is Plitron - made here in Toronto, but I purchased it thru a
local distributor.

The connectors are AMP (now Tyco Electronics) Circular Plastic
Connectors (CPC's) Series 1 purchased online from Digikey. The CPC's
are cheap with each piece a couple of $. The crimp tool is VERY
expensive but is needed to do a good job of the crimp terminations.
(Solder tab version pins may be better for small qty's)

The motors are Sanyo Denki Model 103H89222-5241 (Mendonet P/N
426-1870-SB) 1,869oz-in, 6 Amp, 2.70 Volts 0.45 Ohms, 5.40 Mh,
6.43" Length Motor website http://www.mendonet.com/steppers/nema42.htm
shows torque/speed curve. I purchased the Geckos and the motors all at
the same time, from Mendonet.

I use shielded cables everywhere, with shield grounding done only at the
Gecko box end. All cables are 18G multistrand with aluminum foil
shielding and cost approx. $1 per meter. It's not super flexible cable
or anything exotic. Before I learned about the Gecko step rate
multiplier board problem I had assumed motor noise was getting into my
step signals so I even replaced the cables inside the box (after the
photo was taken) with sheilded cable but I don't think that was
necessary as the problem remained.

Now, back to work...

Cheers, Peter



Paul R. Hvidston wrote:

> Nice work, Peter. I'm very impressed with the quality of construction. Is
> the transformer one of those 86vct, 20A Banner Magnetic beasties? What DC
> voltage are you applying to the Geckos? What's the cabling you use to the
> motors (size, shielding)? Nice looking connectors on the panel and at the
> motors. Expensive? Oh, and can you share some of the specs for your big
> motors for comparison? Questions, questions, questions ;-)
>
> Cheers!
>
> Paul R. Hvidston, N6MGN
> ACKSYS Engineering
> Upland, CA
> ----- Original Message -----
> From: "Peter" <prenolds@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Wednesday, February 27, 2002 10:04 AM
> Subject: Re: [CAD_CAM_EDM_DRO] Gecko 2xx "Nema 42 modification"???
>
>
>
>>When I said direct coupled, I should have made it clear that the motor
>>is connected to the leadscrew via a Heli-Cal brand helical motor
>>coupler. This is a zero backlash "spring" that allows for a bit of
>>alignment error. They're not cheap but they work great.
>>
>>I just posted 3 pics in the main Photos folder which show the motors
>>mounted (the X-axis photo best shows the coupling) and one showing the
>>Geckos. Files are named NEMA42... and Gecko Drive...
>>
>>Cheers, Peter
>>
>
>
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