Gerald I got those calculations from the information in this post.

Particularly this: I believe if I am reading the the spec sheet correct. The inductance is 1.5, the same as the example. Or what am I doing wrong?

From this question:

....it looks like you only want a transformer to feed the PMDX-136. Then you confirm that you are only looking at the transformer:

However, the PMDX-136 will increase the voltage by a factor of 1.414X (-1.5) see page 6 of http://www.pmdx.com/Doc/PMDX-136_Manual_10.pdf

So, if you want 39V out of the PMDX, then the transformer output must be 29V, and that is why I wondered if you mistyped the 39.

Practical experience tells us that a 30VAC, 300VA transformer works fine for those motors wired half-coil.

If you are buying a ready-made DC supply, then 40VDC, 300VA is fine.

I neglected to clarify. I have pretty much decided not to use the PMDX 136. I will either build a PS or buy one. I would like to buy one but not sure where. Building one does not seem to complicated...

If you are building one, you shop for a 29 or 30 V transformer. Many use a 25 V because that is fairly common.

If you are buying a ready-made power supply then you shop for 40V.

Blake check these out.

Capacitor
at digikey

Transformer and Bridge
transformer
bridge
at parts express

just food for thought. :)

Blake

I have bought the same motors and i have builted my PS.
I intend of wiring them also half coil so i used these specs :

Toroid : 28v 300VA
Rectifier : 25A
3x capacitors 10000 63v
33k resistors on the G203V Geckos.

I get a nice 39v output from my PS.
Hope it helps.

Sergio

Looking good Blake, trying to keep up with you.

You might pass me up... I had quite a bit of work come in here in the sign shop, so MM is not progressing very fast this week. Grinding rails is also proving to be a bit of a challenge, wish I would have went with the BWC rails.

The bad thing is, is that I am without a router right now since I sold my shopbot to fund this MM. I have to get it up and running soon, I use it quite a bit to fabricate my signs.

Your build is looking great also!

Blake-

I pondered the BWC rails too, but they were out of stock (thank God) when I tried to order them, so I went the grinding route. For almost nothing(certainly less than the additiional cost of BWC's), a local industrial knife sharpening shop ground, straightened and put an edge on one side of my angle iron( both sides would have been more). In about an hour, I did the other side, and, "Bob's your uncle", in less than a week I was done.

It just hit me today. Did you use the skate to grind the rails? Or did you start before you got the parts?

I had some bearings from another project so I built my own skate. It aint pretty but it works.

Grinding the angles was easy. It was getting em cut straight where I had the trouble.

Progress Pictures
 

Some proof that we aren't sleeping in Mississippi. :D

Yeah - Not sleepin at all :D Nice work.

I see my title changed... just like magic!:D

How are you passing the parallel connector into the control box? Do you cut it off and solder all the wires back together or is there something easier?

Hi Blake

Look at the solution from Alan C at this post

http://www.mechmate.com/forums/showt...3&postcount=25

Regards Polder

I have this rectifier. I have 33 AC volts going into it and 87 DC volts coming out... What am I doing wrong? I have a 30 volt transformer so I was expecting something like 42 DC Volts.

Blake, it's not unusual for a completely unloaded power supply to give a high reading. Of course, you don't want to risk your expensive electronic devices to prove this. You can use a dummy load (resistor) across the output to get a measurement. A low wattage light bulb (like 15 or 25 watts) can act as a dummy load.

Blake, a rectifier cannot cause a 260% increase in voltage. My first reaction is that your voltmeter is (very) faulty. Can you provide some pictures of your wiring connections and your voltmeter setup?

Blake

Did you wire the rectifier like this :

http://i890.photobucket.com/albums/a...ectifier-1.png

Yes I did Sergio. Thanks for taking the time to draw that very clear diagram. I wish I would have had it sooner because I had to do some digging to find out how to wire it.

The problem cleared itself up as I worked with it. I am not sure what happened but I am suspecting that it was a grounding problem. It is securely grounded now and reading correctly.

Where is the information on how to set up Mach 3? Also this might be a stupid question but why is it that Shopbot software cannot control the MechMate?

Look at the Mach3 website for their support and videos.

The shopbot software only runs in their own controller. You can use a shopbot controller if you want to.

Would their controller replace the breakout board? I already have my box put together with a PMDX-122 and I am planning to use Mach3. I loaded it up last night and I am endeavoring to figure it out. I had Shopbot 3 pretty much mastered. That is why I asked.

Yes, their controller replaces at least the PMDX-122, maybe more. I am not up to date with what they sell these days.

See this thread from July '08:
Version 201 Controller Board from ShopBot

Kitchen Table Project
 

Actually make that the Sign Shop Table Project.

Page 4 of the PMDX-122 user manual located hereshows the options for powering the board. I have a standard 115acv to 9dcv adapter that will plug right into the coaxial jack on the breakout board. If I am understanding the manual correctly I can use that, am I right?

9VDC is fine. I have even used a 9V battery as a test.

Thanks for the quick reply! I have not been able to get my motors to turn yet... Just kind of going over the whole thing trying to troubleshoot it.

Getting the motors to turn can be very frustrating. In the Troubleshooting section you will find some help if you get stuck.

We Have LIFTOFF!!! It was the charge pump settings in mach3. Man you don't know how good that makes me feel!:D

Blake,

Be vary careful NOT to disconnect the Power Supply from the Gecko's "live."
The problem is that the Gecko's act to discharge the capacitor. If you don't have them connected when the power supply is turned off, there is no place for the charge on the capacitor to go.

Also, do not turn on the power supply while it is disconnected from the Gecko's, then turn it off and connect the Gecko's without discharging the capacitor. This is the same as putting a switch between the power supply and the Gecko's which is strictly forbidden by Geckodrive, Inc.

The best thing to do is to use a "low" value (1 to 5 ohms) "high" wattage (15 to 25 watts) resistor to discharge the capacitor if the Gecko's are not connected when you turn off the power supply. Just touch leads to the resistor to the two poles of the capacitor. You will draw a small arc. You should not use a straight piece of wire or screw driver for these large capacitors.

After verifying that your power supply is producing the correct voltage, you should connect it to the Gecko's and leave it connected. You should turn on and off the power supply on the AC side, not the DC side.

Hope this helps.

Congratulations...I know the feeling.:)

I was typing while you were posting your success.

I love the loud bang made by discharging the capacitor with a screw driver :)
Connecting a light bulb accross the cap is another way to discharge, you will know the cap is fully discharge when the light goes off.

Well done Blake!

Complete except for cables
 

All that is left is to hook up the motor cables. And install limit switches. I hope to have it operational tomorrow. The limit switches will have to wait till some more signs are complete. My wife is calling herself a Mechmate widow.:D

Looking good Blake! :)

Very nice Blake!

Wow !!! :eek: Lookin great !!!