[wildwestpat]

Hi Dale


Just had a look at the documentation on the C11 Revision 8 board that I have on a machine that is in bits at the minute. The missing wire is from the common adjacent to the three red wires and should go to the return on the 10amp driver amplifier card. I suggest that when you finalise the wiring you get some four core screened wire for the amplifier drives but that is being picky again!

Ok I got the drift the wire that exits at the bottom of your posted picture is the USB - still worth checking that it is OK with the load of the breakout board. Some versions of Windows has a settings screen for the power available at the USB sockets and this could be set incorrectly if your PC has this feature or there might not be enough current available in which case the voltage will dip below the desired 5 volts. DO NOT join to the 5 volt high current supply that comes in mid right of your photo. It would also be a good practice to decouple this supply at the breakout board but it looks as if you are using screened wire. The 0 volts of the break out board and the common earth strip should be joined. DO Not join the usb screen () volts from computer) to anything other than the designated breakout board pin adjacent to the +5 volt usb pin.

This might explain some of the peculiar action. Take comfort in the fact that faults often keep together and when you rebuild a part functioning box the rule has to be check and check again. I also recommend a cup of tea between doing and checking and to make a schematic drawing against which the wiring can be checked. Put a clean copy of the corrected wiring in a plastic bag stapled inside the box when it is working. That way it will be there when or should I say if you need it in the distant future.

As far as I am aware the RoutOut bits should be OK so I would not race off and order replacements until you have reached a dead end.

I am retired and try and check this forum every day so get back if you are still having problems or let us know that it is fixed.

Regards

Pat

[wildwestpat]

I'm running a lightobject controller on a home made table. It works just great when I run a manual torch switch. ------------------------- If I power off and back on the controller, it works for a few more cycles, then does the same thing. I am thinking it has to do with the relay, or the controller.

Sorry I do not have any experience of torch cutting. I can't abide loud unexpected noises! Hope someone can help you although you might attract the experts if you posted the question under a heading that has plasma cutting problems in its title as the issue could be either the torch current control or the axis drive.

Sorry

Pat

[Dale gribble]

Hi, Pat

Thanks for the reply. I'll will modify the daisy chain to the brass fingers. With regard to the BB I've uploaded two txt files and two jpegs. I've had to do it this way as the files are over 500kb. The cable from the PC usb port came with the BB and is only used for the inputs side of the BB, power required 70ma the outputs side are powered with 2.5amps. I did try a different BB with no opto it was basically a direct connection the to the parallel port I had the same resonance. What I have wired from the BB to the driver are step, Dir, and rtn ( ground ) I have placed the jumper on the BB so com are ground. I have not connected the enable cable to the driver. I was thinking of adding the star point ground to the output power side of the BB but was unsure if this was safe to do and where exactly to place it. Your guidance on the matter would be most helpful.

My picking is to avoid any problems with cross coupling between he amplifiers.

Please pick away I need all the help I can get

Kind regards

Dale

[Dale gribble]

Hi Pat,

I've uploaded an image of the BB and Driver and added some arrows of where the additional earth wires go. Can you have a look and let me know if I've fully understood your instructions

Kind regards

Dale

[Dale gribble]

Hi,

Ok I've added from my earthing block a wire to my BB output power side. And i think I get it now. As I've done an continuity check from the earth block to the com on the BB and then to the RTN on my driver both are closed circuit.

So if I understand it correctly everything on the output side from the BB must have a common earth.

My results are, resonance is slightly improved . It has more or less gone when running 0 to 1000mm/m ( 62 rpm ) but from 1000mm/m to 1400mm/m ( 62 - 88 rpm ) its still pretty bad. I think the finish on my part would show the resonance running at these speeds. It seems the resonance has moved a little higher in the rpm range. I did one last tweak and set my driver amps down in incremental step from 4 to 1 amp and at 1 amp this did remove most of the resonance but the trade offs of slow speeds and low power are not acceptable to me.

Thanks Pats for all the help and guidance you have given me. I feel now I can construct a more professional control box.

I did email routout for any help they could supply, but did not get any response.

I'm off now to go and cry in the corner on the room and contemplate my next move.

Kind regards

Dale gribble

[wildwestpat]

Hi Dale

No good geting into that corner. Anyone who has tried to make anything has to accept some failures on the way to perfection. Don't spend any money on changing drivers until you have read my closing remarks.

Now it appears that you have sorted the earth loops. Yes the idea is to stop the high currents that are circulating in the motor circuit getting back into the low level signal side of the control circuits. The 10 amp driver amps for example have their own isolated 5 volt supply for their low level interface circuits for 'step' , 'direction' and 'enable'. The confusion is where does common return go for the inputs. The choices are to the common star earth or the breakout board common. Since the breakout board you are using has the ability for a common to either the +5 volts or zero (I use zero to indicate this is the supply to the output circuits of the breakout board) you have selected to use the zero volts. I would guess and it is a guess that both the output of the breakout board common and the return from the inputs to the 10 amp driver should go direct to the star earth. Also the zero of the +5 volt supply should also be connected to the star earth. Then the only circulating current is the breakout board current and the variations should be relatively small so that if the earth connections at the star are OK any resistance that is common to the input / outputs will be minimal. i.e. you should have avoided positive feed back type oscillations in the electronics due to earth loops. This is why your 10 amp drivers have opto isolation on their inputs - a good feature and I would suggest removing the link to the star earth and taking the 10 amp return direct to the breakout boards common for the axis you are driving leaving the breakout board earth adjacent to out put pin 1 connected to the star earth - this is marked ground on the pcb.

This should give you the maximum potential from the electronics assuming all the earths to the start are OK. Might be good to measure these if you have a low resistance test meter just to be sure. It is possible to get poor bonding with the multi way blocks you are using as the wire can slip out from under the screw. If you are going to make more boxes I suggest using crimp on connectors and earthing tags as available form Maplin. There are some nice metal cases available from tool shops sold as metal cases for portable electric tools. These will have better screening properties and much better heat dissipation although you will probably still need a fan input and vents. I use two fans one blow the other suck so that I can use some light threads attached to the exhaust to signal that all is well as I use air filters on the fans to keep any chips and dust out of the electronics.

Now to return to your resonance problems. Have you compared the stepper motor size you are using with those used by other designs for similar size machines and of course using similar drive mechanics. I am asking as the size selection of a stepper is tricky. Bigger does not necessarily mean better. Bigger motors can move more mass but the basic movement is in jerks. This means that the mechanical construction has to be able to take the step to step jerk. Look to other designs that work to see what size steppers they are using. You might get some response if you put pictures of the gantry and the lead screw supports on the thread as these can also be resonance sources.


Regards

PS (I am assuming you have been through the Mach3 stepper tunning process as set out in the user manual.)

Pat

[Dale gribble]

Hi Pat,

Thanks for your reply.

Pat I think you have found the problem with your comment regarding my motor sizes. I have being carrying out further trials today on my x axis connected to mechanics with moving the earth as you mentioned in the last post. Also I like to mention routout did reply to my email and mentioned the two dip switches next to the resolution switches are for damp resonance. I tried all four combinations but the best was the default setting.

Next I tried my large z motor 12nm, this is just lying on my table. I checked if the motor was still resonating without the mechanics attached. It was, and the thing would dance across my table pretty quickly. Next I attached my smaller y axis motor 8nm and this has very little resonance which is more then acceptable and if I used Lovejoy type coupling to absorb the tiny amount there is, I'll have a sweet set up.

I think I just need a 6nm for the z axis and 8nm for the x axis and I'll be up and running. Pat thanks for all your help, I was minutes from spending £600 on a new power supply and 4 Gecko's.

Kind regards

Dale

P.S.

I've uploaded some photos of the beast, the tables a mess due to tool trials for the last two weeks trying to get it to run smoothly. I'll update this thread with the results when I get my new motors.

[wildwestpat]

Hi Dale

Glad you are now on the road to happy cutting!

Your build looks good and the only comment I would make is that the motor supports look a bit on the weak side of perfection. The motor is a large mass and you have it suspended out from the framework that supports the lead screw and could resonate at some point. If you have bother with the lower power motors I suggest you think about adding side plates to the brackets. These could also serve as a mounting for some form of cage to stop you burning yourself on the stepper motors which will be a too hot to touch after a cutting session - however not hot enough to cause a burn!

Glad to have saved you a bit of cash which will soon be taken by tooling and materials I am afraid.

Good luck and have fun but please make sure every thing is earthed for safety and that you have shields on any mains connections inside your boxes.

Pat

[Dale gribble]

Hi Pat,

I agree with your comments on my z and x axis motor supports, this part of the build is where I am less than happy with. I'll add some triangle shape brackets each side to increase rigidity. My plan is now to move the two 8nm motor from my dual drive y axis and use them on my z and x axis and then buy two 6 nm motor for my y axis which should be more then enough.

I always planned to build a rotary table in the future maybe I'll re use one of those 12nm motors for that project. Thanks again for all your help Pat

Kind Regards

Dale