HobbyCNC Pro Problems

I just completed soldering up the HobbyCNCPro 4 axis board. I wired it up to a 36v 10amp power supply. I put it in an enclosure, wired up and mounted multiple fans with filters.

The problem is that only the X-Axis part of the board is working properly. Y-Axis does nothing except cause the motor hum to go high and low in pitch (but same volume level). The Z-Axis only goes one direction (down) and is very choppy when it does move.

I wired up the Y-Axis motor to the X-Axis part of the board, and moves freely and smoothly, so i know that it isn't a wiring problem or faulty stepper motor or friction on the axis.

I reflowed all solder joints, and have check the polarity of all capacitors, resistor networks, and IC Chips.

The EMC2 settings for each axis are the same. I'm running in 1/1 step. When the X and Y motors are connected to the X-axis chipset (not at the same time ofcourse) They can each move at a good 40ipm. anything above and it gets too loud and vibratey.

I dont understand why the Y-Axis doesn't work. I've wired to the A-Axis (4th) and changed the pin settings in the config (to make the computer think it's controlling Y when it's really sending to A, and the motor still doesn't work.

Sometimes the X-Axis doesn't work smoothly after i've set one of the other axis's; i have to try moving the y or z axis in the opposite direction they were trying to go, and then the x-axis works. (maybe the motors are drawing the full 3Amps and the power supply can't keep up or something, to be able to power the X-Axis.

Any help would be greatly appreciated. My goal was to get some Air Cuts this weekend.

Thanks,

Ian

Lot of ground to cover, and you have probably tried these but..

Check voltage/amp outputs on the good and bad axis to the motors.
Dramatically increase your step and direction timing to see if any improvement.
Dramatically increase your acceleration rate and dramatically reduce your velocity.
The z moving only one direction could indicate the direction signal for z is not being applied to the board.
Also make sure the direction and step signals are not reversed anywhere.

Rick G

You might try disconnecting all the motors and then connect only one motor at a time to see if you do in fact have enough amps to power all.
Put amp meter on the power supply to see what your draw is.

Check your parallel port outputs

Rick G

THOSE LIERS!!!!!!

I brought out my multi tester and set it as an ohm meter. I put a paper clip in the female pins of the 25pin printer cable, and tested to check the connection. Turns out some pins are connected to random other pins.

Pin 2 and 3 are swaped with each other. Some pins dont even go anywhere.

Things like, Pin 7 on female is connected to pin 10 on male side. plus some Pins aren't even connected to the other side, even though there are the stubs on the male side!

Those store reps at the electronic supply store LIED and said it was full 25pin direct connect . LIERS!

This gives some extreme hope that all other components work, it's just the printer cable that is ka-put.

I've already chopped up some of the outer casing of the plug so that the cable can bend sharper, so it's not like i can return it.....

Going to a different store this time, and i'm bringing my Multitester with me to confirm that it is an actual FULL Straight through 25pin cord.

Thanks for the heads up BigJohnT. And i bet you Rick have suggested that to other people aswell.

Thanks,

Ian

EDIT: Checked again, and Pin 2 female is connected to pin 3 Male
................................................Pin 3 female is connected to pin 2 Male

So messed up!

the settings in emc2 for the hobbycncpro chopper has:

pin2 - x step
pin3 - x direction

When in the HobbyCNC Instructions that came with the board has:

pin2 - x direction
pin3 - x step

So that printer cable pin 2 and 3 swap, with the emc pin setup, since, the emc settings is swapped compared to the instructions, but the printer cable swapped them again.. Hope you understand this part.


EMC Outputs xstep out pin2 of printer port on computer > goes into pin2 on cable> comes out pin3 on cable > going in pin3 on board, which, in the instructions, says that pin 3 should get xstep, which it ends up getting.

Whew. good to know it's the messed up printer cable so happy now.

So what you have is not a parallel cable at all but rather a serial null modem cable
One way to avoid incorrect "parallel" cables is to buy cables listed as IEEE-1284 compliant

My parents found a straight through DB25 cable in our house, i tested all the pins and it's FULLY wired; only problem is that it's 2 feet long . It works; al axis work perfectly , so happy now, knowing that the only problem ws the cable. I ordered a 6 foot from a local store for $7; should be at the store by wednesday for pickup.

www.a-power.com/product-21298-556-1

Will test with Ohmn meter before i cut up the outer casing so that i can still return it if neccessary.

I can still mess around with the 2 foot cable for the next few days to do tests.

Thanks,

Ian