Reply with QuoteHi Guys,
It Works!!!!
For those that have been following this thread I am happy to report that this evening there is 4th axis motion control. I'll fill in the details later, as with most things I do there is a story to go with the adventure.
Robert
You dont need an access window when using an Oldham coupler. You attached the hub on the motor and the tables shaft and press the disk on either and as long as you have the disk lined up, you simply push the mount onto the shaft it will slide together.Originally Posted by philbur
Hi David, I'm curious as to how you gain access in order to attach the shaft coupling between the motor spindle and the RT spindle.
Phil
The nice thing about Oldham couplers, is they are fairly inexpensive have zero backlask and offer room for some miss alignment.
http://www.mcmaster.com/#oldham-couplings/=9mpmev
As an FYI, I bought and undersized clamp style hub for the table side and tapped it to match the threads on the shaft. Thread on, and tighten the clamp.
David
Last edited by David Bord; 11-08-2010 at 12:01 PM. Reason: added link
Hi Guys,
It Works!!!!
For those that have been following this thread I am happy to report that this evening there is 4th axis motion control. I'll fill in the details later, as with most things I do there is a story to go with the adventure.
Robert
I for one would be veryinterested in the details - was the pinout posted earlier correct? Details please.
Jeff E.
Here are a few additional details:
The hole for connector on the side of the control box was a bit small for the XLR 5 pin connectors I decided to use. One of those step drills from HF quickly bored the hole to size. I then machined a 1/4 inch thick adapter mounting block to convert the XLR mounting holes to those 4 screw holes already in the Tormach.
I had all the wiring ran in the machine when I broke a pin off the XLR so I took everything back out and replaced the connector. This time I also used heat shrink and tie-bands. I think it was just a bad connector from the start as the XLR connectors are generally bullet-proof.
I made a heat sink similar to those in the Tormach for the Gecko drive from a 8x12 inch heatsink scavaged from an old production disk drive temp cycle setup. Cutting the heatsink was easy using the table saw and good safety gear.
The Gecko is fastened to the heatsink with four 6-32 screws. I just drilled and tapped the heatsink with the drive somewhat in the center.
The drive control wires (ribbon cable header) are just temporary at the moment. I will make a better adapter now that I know every thing works. There are only three connections, pulse, direction, and a common high side connection. The drive enable is not used.
The only gotcha in the project was that I somehow managed to offset the motor connection to the drive by one. In other words the motor A connection got connected to drive B pin, motor A' to drive C, motor B to D and motor B' to the enable pin. Please DON'T Do this as it quickly destroys a Gecko. I have no idea how I missed that as I checked and recheck everything a couple times. Once I replaced the drive with a second, wired it correctly, MACH 3 had control of the drive using the + and - keys of the keypad.
The control pinout in post #8 is correct, at least for my PC1100.
Now on to making the motor to rotary table adapter then I will be all ready to destroy a vast collection of milling cutters!
If you have questions I'll certainly attempt to answer them.
Robert
Robert - thanks for the information.
Jeff E.
Does anyone know if a current set resistor is used in the tormach wiring? I dont think so based on Roberts previous post but wanted to ask just in case.
If not, is the current set dip switches on the Gecko set based on the Tormach or the Motor? I assume based on the motor?
David
Hi David,
My Gecko uses an external current sense resistor placed between two connections on the drive module. I selected a value of 3.0 amps based on the motor I am using. The Tormach drives in my machine have DIP switches to select the drive current. Again, I would select a setting based on the motor being used.
There is nothing in the wiring of my Tormach used to select motor currents. The ribbon cable going to the drive contain the control signals (direction, pulse). The other wires are the power supply and of course the 4 wires to the motor itself.
Update: I have been very busy so have not had much time to work on completing the 4th axis. Just finished the first version of the motor to table adapter last night but really don't like how it came out so plan to try something a little different. All the wiring and control stuff appears to be working as I can control the motor via MACH on the PC. Hopefully over the holiday weekend I can get this project complete, we'll see!
Robert
Rob, hope you dont mind me asking a few clarification questions. When you say adapter pinout, do you mean the 9 pin serial female connector that is on the ribbon cable for the A axis(just trying to verify)?Yes, that is the cable and adapter into the drive module.
I pulled the drive this noon, here is the adapter pinout. Use at your own risk, but the following appears to be how it is wired:
Ribbon Drive
------ -----
1 N/C
2 N/C
3 P+ and D+
4 P-
5 D-
6 N/C
7 N/C
8 N/C
9 N/C
10 N/C
It looks like the drive in internally always pulled active or enabled and not controlled via the ribbon cable to main machine control board.
The pulse and direction pins are on pins 4 and 5 respectively. There is a common pin for either the high or low side of the pulse and direction opto isolators in the drive (I am guessing it's a high common as the drive is labeled + on those signals).
There appears to be 2 conductors (of the 6) in the ribbon cable which are not being used (spares).
Now to verify if the common is high or low and then it should be a-piece-of cake to get the 4th axis working.
I am not using a Tormach drive for the 4th axis but rather a Gecko as there are a couple extras in the drawer. No reason to spend a couple hundred on a Tormach drive module when there are a couple Geckos gathering dust.
Thanks,
Robert
If so, any way I can get a clarification if pin 1 starts at the break in the ribbon cable(or the first wire after the last wire used for the Z axis on the ribbon cable) Then the last two wires that are not used on the ribbon cable which would be pin 7 and 8 I guess on the plug IF they were used?
My machine didnt come with the plug. It was a bare ribbon cable and I wanted to verify I didnt put it on wrong?
David
Hi David,
The connector pinout is the black colored 10 pin IDC ribbon connector which is plugged into an adapter board connecting to the electronic drive module. There is a picture of the adapter early in this thread which someone else posted(post #7). Pin #1 was marked on the ribbon connector via a triangle as is the industry standard for ribbon connectors. If you need some photos let me know and I'll take and send you some.
I did not have a 4th axis connector supplied with my Tormach so I just used a 5 pin XLR (audio style) connector.
Robert
Thanks Robert, that matches what Tormach gave me yesterday as well. Appreciate the response!
David
Guys,
Any benefits/drawbacks from wiring my stepper motor in either bi-polar series or bi-polar parallel?
In series the motor draws 3.2 amps and has about 4x the phase inductance and resistance as wiring in bi-polar parallel.
Wired as bi-polar parallel current draw is 6.2 amps.
Is either way of wiring give the motor motor more torque or speed? Holding torque is the same for both wiring options based on documentation.
My Gecko can handle the 6.2 if that matters.
David
Hi David,
Here is a link that should answer your question... There are advantages and disadvantages to which ever configuration you pick.
Stepper Motor Connection Options
I assume your step motor is a 6 wire configuration.... If this doesn't help let me know and I'll find you an answer.
Robert
Here is how my motor to table adapter turned out...
Robert
Robert, thanks for the help on the stepper/driver questions really appreciate it! I rewired for bi-polar parallel.
Nice looking motor mount! How does it attach to the table and what type of coupler did you use?
David
Hi David,
Thanks... The mount came out much better on the second attempt... It has some setscrews in the blue colored section which tighten against that black steel collar on the worm gear of the table.
I am still working on the final coupler but was planning to make or use something similar to the Oldham style. Everything appears to work nicely, now I just need a little time to figure out how to get SprutCam to drive it all. I have driven it using MDI of MACH, very exciting!
Glad you have the step motor figured out..... Always good to make progress!
Robert
I realize this is an older post but wondering if someone could help me with connecting a gecko 201x to my rotary table. My mill is an early one. #062 I think is the serial number. Anyway, my ribbon cable only has 8 wires left unused for the rotary table. Looking at Tormachs print, the last two wires would not be used, so that only leaves six. How do I determine which of those six are to be used. Is there a way to use a multi-meter and figure this out? Looking at the post in this thread, it only looks like three wires would be needed. Step, Direction and a common, I am right about that? If anyone has any detailed pictures that would help, could you please post them. In post #22 I cannot tell which of the wires are going to which pin. Any help will be greatly appreciated.
BSims66173,
The pinout for the connector is listed several places in this thread. Pin #1 on most ribbon cable connectors is marked with a triangle. Keep in mind that the machine I did this on has a 4 digit serial number and was one of the last machines before the series II machine appeared.
As noted I am also using a Geckco drive, just don't remember the model at the moment.
Robert
I understand about the triangle to designate pin one on the connector, but mine did not have a connector on it. It was just a bare end of a ribbon cable with eight wires. The tormach instructions say the last two wires are not used so that leaves the six wires. I just don't know which of the six i need to use. The pin designations in this post say pins 4 and 5 are the step and direction and a pin seven is a common. How can I determine which is which? Thanks for your reply.
Pin one of ribbon cable typically is marked with a colored strip. When you press an IDC header connector onto the cable the pin one marking of the cable goes where the triangle on the connector is located.
If I remember correctly the pins 9 and 10 of my header did not have a cable wire connected to them.
Robert
Re: Tormach Drive Cable Pinout
I found this thread after helping sliptonic trace the +5v , step & direction connections to a Tormac stepper driver
see this post using a tormach driver
http://www.cnczone.com/forums/tormac...ml#post2107952
this diagram combines all the information to use a Tormach driver with your own control or
use a generic stepper driver in a Tormach machine
John
