Mexico's 1st Mechmate Finally is cutting #55 - Obregon, Mexico
 

Hi
After a few reading in this forum, i have decided that, I will go for The building a MechMate.
I have already got the plans, and visited my local Steel Vendors
and I can not get the exact steel profiles
Like :
76x78x 7 kg/m channel (10 10 302 D A ) I have 101.6x40x 6.70kg/m
180x70x21 kg/m Channel ( 10 10 322 S A) 203.2x59x 20.46 Kg/m

I hope this changes be ok

All Opinion will be welcome an appreciated!!

Hi Conrado, welcome, and good luck with your build!

Those alternative sizes are just great - I wish I had them here!

Conrado,

Welcome and have fun with your build. You will appreciate Joe's laser cut parts when you get them.

Last weekend, I started to cut and weld the table
pictures will be posted soon

Hi Conrado,
Im starting also to build, I already have Joe´s laser cut parts, got them last may, but waited long to start, Im just making some room to start. I Live in Monterrey,and you? Where are you getting from does steel profiles?
Regards,
Hector

Hi Hector
I got my steel profiles from local vendors, as you can see, at the beginning of my thread, they are no exact match but will work fine, I almost done with the table.
Im still don`t have the laser cut parts, problems with my paypal acount, but almost done. (sorry Joe)
Im from Obregon, Sonora, Im Civil Engineer, I work on the mechmate only weekends.
Glad to Know another "paisa" in this forum

Best Regards

Hi Again Conrado,
I mean the Channels from what manufacturer, I have checked with villacero, ahmsa, and others and I can´t match those specs in the profiles...could you check for me with your vendor of who´s that steel from, I like does profiles you got...by the way Im an architect...same thing just in weekends...
I´ll send you my email...add me to your messenger list, maybe we can chat later, and for sure help each other in this endevour...:)

Conrado,
could not send you...a pm with my email, something is configured from you not to receive emails or pm.

Hector:
I got you on my messenger, wilL be in touch for numerous issues related to our Background (Building) and of course MECHMATE

Table is done, pmx122 card arrived, geckos, in transit
Sorry I have few posts, and no pictures, but I only have one day at a week, I hope to post some pictures soon.
Since now I have no questions, because someone else already did it in this forum and is easy to look around for answers.
Again Thanks Gerald and friends

Conrado,

You are making good progress. Please post some pictures.

Thanks for the news Conrado.

Hello :
I got a question about my rack, I have a 16 pitch rack is it good for my mechmate?
I ´ve read that a pitch less than 20 the travel become rought
should I change it?

How wide and tall is that 16 pitch rack? Are you using direct-drive or geared motors? What ratio?

hello Gerald :
I have 5/16"x5/16 " 16 pitch (store mistake I asked for 1/2"x1/2" 20 pitch) but Im looking to use what I have, is this ok?
Im planing to use Geared Motors 7:2 from oriental motors (PK296a2a-sg7.2)

It will work, but you will have more wear than those of us with 1/2" wide racks. Use 24 tooth pinions with 16 pitch to get exactly the same performance as 30 tooth pinions with 20 pitch.

Thanks Gerald :
I already have 30 tooth pinions with a 3/4" face
and my mechmate will be only for hobby, not heavy use

I appreciate your help
if you need something from this side of the World I will be glad to help

Hello:
I´m planning to buy the power supply from antek, and my choice would be the
PS-6N56N17R5 (see the link , http://www.antekinc.com/PS-6N56R.pdf).
my motors are PK296a2a-sg7.2 from oriental driven by pmx122 card and G203V geckodrives.

Opinions will be appreciated.

I would choose a 35V power supply and wire the motors bipolar half-coil (Black/Yellow wires on the A coil and Red/White wires on the B coil). The AnTek PS-5N35 or the PS-5N39 would be a closer match.

The PMDX-122 requires more than 5VDC. This section from the manual might clarify the power requirements of the PMDX-122:

4.7 Power Supply Connector (J11)
Connector J11 is used to provide +7 to +12 VDC or 6 to 9 VAC power to the PMDX-122. This connector is a standard 2.1mm diameter coaxial power connector that is compatible with many wall-mounted power packs.

If you choose to wire the motors Bipolar Series (Black/Green wires on the A coil and Red/Blue wires on the B coil), you should use a 70VDC power supply that gives about 8A such as the AnTek PS-6N70R12.

Thanks Mike
I appreciatte your comment

Hello
I`m working in the kitchen table project
I have everything wired, conected, but motors dont move
got green light at the pmdx 122, and geckos too,(none flashing), no red lights
measured dc volts from "common" to "direction" at the G203V
had a reading of 2.2 V.
measured dc volts from pmdx 122 transformer supply and got 10.1V
measured dc volts from gecko 203v toroidal transformer and got 91.2 V

Motors when "on" stuck, and "off" go free again, no warming, or sound
(wired A black, A- green, B red, B- blue,...yellow free, .....white free)

the G203V troubleshooting flow diagram says, controler is not supplying the correct command voltage level to the G203V, how to solve it?

The MAXIMUM voltage for a Gecko G203v is 80VDC. The 91.2V is too high for that device. The G203v is tested at 100VDC, but it will eventually fail when the voltages are over 80V - especially when you have a sudden unexpected surge.

The 2.2 V on the on the control lines is too low. The G203v is rated at 2.5V to 5V. I am surprised that you're getting that reading from the PMDX-122. That break-out-board should be able to give you about 5V on the control lines.

Try reading the +5V and Ground lines on the PMDX-122. I'm not at the shop, so I can't tell you which pins to check, but one of the Jumpers (J8, if I remember correctly, has a +5V screw-in terminal and a Ground terminal). If you don't have 5V across those two points, there is a good chance that the D1 diode (small surface mounted device that is very close to the external DC input terminal) has fried. That happened to me. I had mistakenly used too high of a DC voltage to feed the PMDX-122 and blew out that diode. I replaced the surface-mount device with a standard 1N4007 device, so that will never happen again.

In any case, if you really have +5V on the J8 terminal block, then we'll have to explore other possibilities that may be causing the 2.2V on the control lines. (Do you have the PMDX-122 jumpered correctly to produce a COMMON GROUND for the G203v? PMDX-122 JP1, bottom two positions for the G203v, Top two positions for the G201 and G202 devices.)

Hi Mike, thanks for answer

The jumper are exactly as the pmdx 122 manual for geckos, except for the jumper JP1, is hooked at the bottom two pins.

the power supply is rated for 80 Vdc, and as you know is givin me 91 Vdc, any sugestions to solve it?.( I can get 45 Dvc, i have ++0-- terminals actual is + - conected and are giving 91 DVC if i conect +0 or -0 i got 45 DVC

I checked the J8 and ground and got 10.1 V.

hello again
I had an error at reading voltaje.
I read fron j8 to ground exactly 5 v, from my power supply 41 VDC
that seems right to me, but from "commom" to "direction" is 1.2V so i think I you are right. I must fried the D1 diode, I will check tomorrow
and I will keep posting.
Thank you

The D1 diode is used to convert A.C. half-wave D.C. so that the on-board 5VDC regulator can work. It is only needed when you use A.C.

If you have 5VDC on J8, then the PMDX-122 board is able to convert your voltage to 5V, and everything should work properly.

Try disconnecting the G203v stepper drivers from the PMDX board, then read pins 1 and 3 on J1, J2, J3 and J4. You should have about 5V. (Be sure that you try both CW and CCW. At one setting, you will have 0V. At the other setting, you should have about 5V.)

The power supply may have to be changed with another. You need an A.C. transformer that gives you 55VAC or less. After its conversion to DC, you will get a little less than 80VDC. I use a 50VAC toroidal transformer to get 70VDC, which is as high as I go so that the power supply can withstand the occasional high voltage days that the power company provides from time to time.

Conrado, did you get your power supply from Antek, and did Antek send you the wrong specification?

yes I got from antek, the power supply is rated at 38 DVC, now Im geting 42 DVC. (PS-5N38)

but guess what?, D1 is missing! , the rest of the diodes are present and conected, must be lost by handling in excess :( .

Now if I can get a replacement, what is the specifications to order?

Conrado,
Having an unregulated power supply deliver more or less voltage than expected is quite common. AnTek lists the voltage based on 115 VAC or 230 VAC input voltage. If your voltage is more or less than either 115V or 240V, the output will also be different. Assuming that the toroidal transformer was built with the correct number of turns, if you're getting about 10% higher output than expected, you might be getting about 10% more line voltage than expected. (It's not uncommon where I live to have 120VAC to 124VAC instead of 115VAC.)

By removing a few turns of wire from the SECONDARY windings (one turn at a time), you will be able to fine-tune the transformer. I've never had to do that, but others do it regularly to get exactly the output voltage that they want. Work slowly and be sure to let the capacitor(s) drain after you turn off the power supply. Things can get a little complicated because many transformers have two outputs - so that you can get half the rated voltage at 2X the current. If your transformer has two outputs, you should take equal numbers of turns off each output so that the two outputs are still matched in output voltage.

If the PMDX-122 is missing the D1 diode, you probably should notify PMDX and ask for instructions. The D1 diode is a surface-mount device, so it may not be easily available. (Where I live, I would have to order it from Digi-Key or some other parts store. Local suppliers don't handle surface-mount components unless I'm willing to order the minimum quantity - which is usually at least 1,000 parts.)

If you use a DC supply to power the PMDX board and IF you solder in a jumper wire in place of the D1 diode, the on-board 5V regulator will function properly; HOWEVER, that fix will only work with a DC power supply. If you use an AC power supply, the 5VDC regulator will be destroyed. The purpose of the D1 diode is to clip (remove) the negative AC voltage that is present with an AC power supply. It only passes the positive portion of the sine wave. That half-wave is compatible with the 5VDC regulator.

Hello Mike:
My supply here is 125V to 127V, so its consistent with the antek power supply I have. for the PMDX122 I use a 9V rated transformer.

I got a D1 diode but R31 and R32 are missing too. My suspect is that I blew hot air accidentally when wiring.
I will give a last effort to get my pmdx work properly, if not I will order another PMDX122.
Im able to get D1, R31 and R32 form another circuit board.
Can anyone send me a close up picture for the PMDX122, I want to check the R31 and R32 values.

Conrado,

R31 and R32 are NOT installed on either of the two PMDX-122 boards that I have.

If you think that you may have unsoldered D1 somehow, be sure to check the entire board with a good magnifying glass to verify that the diode did not fall across some other trace. (That's one thing that I really, really hate about surface-mount devices. They are so small that it's easy to miss a 'bridged' connection.)