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Re: Another Banana Bender's Build !!!
Stuck the two encoder bases onto the larger X and Y servos today, will let them cure overnight before I do anything more with them.
Also mounted the encoder onto the Z axis servo drive and connected it to a drive, after a few issues with tuning it is happily holding position so it is ready to go.
Re: Another Banana Bender's Build !!!
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Re: Another Banana Bender's Build !!!
Cheers Mike.
So today I soldered up the X and Y drives, still waiting on a few parts but should be able to bench test the drives/servos within a few days, ready to mount onto the machine.
Also finished mounting the encoders.
Russell.
Re: Another Banana Bender's Build !!!
WOW! Well done Russ.
Chich
Re: Another Banana Bender's Build !!!
Thanks Chich.
Well tonight I tested the higher capacity drive on one of the larger servo's, and after finding a tiny solder bridge under the ic socket for the gate driver chip(that took a lot of finding/swearing !) I powered it all up and got the motor to hold position. It is ready to go into the machine. I need more parts to finish the second drive so that will have to wait.
While I had the servo connected and powered up, I decided to try a mode that the Elm Chan drive has, I thought it got deleted in previous versions but it turns out it works perfectly. The mode is velocity controlled mode, so basically you send a serial command to the drive, and it turns the servo at that exact speed, well there is a calculation to work it out but I just put a random number in...what is the worst that could happen ?
Remember this is a stand alone drive not plugged into a controller of any sort.
Anyway, sorry about the crappy video and audio quality but here is a quick vid on the test run.
Russell.
<iframe width="560" height="315" src="https://www.youtube.com/embed/RdYV4QEj5EQ" frameborder="0" allowfullscreen></iframe>
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Re: Another Banana Bender's Build !!!
So today I started to mount up all the electrical hardware onto the chassis, I am going to re-use the nice stainless steel cabinet that is currently in use on my existing (working) machine, at some point rip that cabinet out and transfer it to the new machine. Sounds a bit ruthless but the original machine has served me well and due for retirement. This way I can get everything as ready to power up as possible, so that the down time between machines is minimal.
I'm keeping the electronics very basic, estop and enable circuitry for the motor drives, and that is about it, it is pretty much just a glorified power supply. The space at the bottom right is for the controller, I'm going to use either a Beaglebone Black with Xylotex output card, or a MESA card of some flavour, not sure at this point.
Cheers.
Russell.
Re: Another Banana Bender's Build !!!
Looking fantastic! Good work Russ.
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Re: Another Banana Bender's Build !!!
Quote:
Originally Posted by
chich2
Looking fantastic! Good work Russ.
Thanks Chich, so far so good, might get a little crowded by the time I squeeze everything needed into that small area.
I have designed some line driver PCB's and I also made a very basic Breakout board to plug into a mesa card, I have a couple of 7i43's in the cupboard and now intend to use one on this and one on a milling machine I am retrofitting. The line drivers are tiny so I put as many as I could onto a 100by100 layout, and will simply cut them out once I have them.
The Breakout board matches my servo drives strangely enough so the connection is simply an IDC 10 ribbon cable with connectors and it should work...maybe ! The line drivers have an RJ45 connection, so the plan is to use a cat5 patch lead from the encoder to the servo drives, just enough cores to take three differential signals and 5volt and ground.
Pics as always, any PCB design guru's please be kind, these boards are just a means to an end, and if they work then that will be a bonus, haha.
Breakout board has provision for four axis of step, dir enable and fault, also I am taking the index pulse from each axis to the controller for accurate homing.
Russell.
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Re: Another Banana Bender's Build !!!
Going to try using perspex covers for the servo encoders, while this may seem a little over the top the idea is to be able to see the LED on the line driver board without having to take any covers off. I also happen to have a few offcuts of 14mm thick perspex that has been looking for something to do.
A visible LED proves that the servo drive has both logic powers available, as the 5v logic is generated onboard from the 12 volt gate drive supply.
I can't do too much more with these until I get the line driver circuit boards, as I have to make sure I have enough clearances to fit them once they are all soldered up.
I machined these on my old router and I almost feel bad since it will be dismantled once the new one is going...oh well
Russell.
Re: Another Banana Bender's Build !!!
Oh WOW! They look amazing!!!!! Are you sure you want to kill the old router?????? :D
Sent from my MB525 using Tapatalk 2
Re: Another Banana Bender's Build !!!
Quote:
Originally Posted by
chich2
Are you sure you want to kill the odl router?????? :D
No, I feel really bad about it, but I do need the floor space in the shed !
Re: Another Banana Bender's Build !!!
Are you sure you can't sell the old router?
:nono:Machine abuse, not a pretty thing:nono:
____________ROFLMAO!!!!!_____________
Mike
Re: Another Banana Bender's Build !!!
Haha I thought of it but that opens up a lot of issues, I have a friend that is willing to "Re-Home" it minus a few parts so it isn't all bad news for the old girl.
He is the same friend that just asked if I am sure I want to kill the old one...lol
Besides Chich2 has more shed space than me !
Russell.
Re: Another Banana Bender's Build !!!
Yes...... Yes...... Kinda like picking up an old dog from the pound..... But a cnc dog!!!!!! Haa ha!
Chich
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Re: Another Banana Bender's Build !!!
We all need an old dog from the pound now and again.
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Re: Another Banana Bender's Build !!!
Breakout boards and line driver boards turned up today, very happy !
Going to try my best to get one of each populated over the weekend so I can finish testing the servo drives. Of course this will mean setting up a PC with LinuxCNC and MESA Card, going to need extra coffee I think !
Re: Another Banana Bender's Build !!!
SOOOOOO COOL!!!!!!!!!!
Chich
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Re: Another Banana Bender's Build !!!
Today I soldered the bulk of the components on both one line driver and one Breakout Board.
The line driver should fix onto the perspex spacer on the servo quite nicely, going to power it up from a servo drive tomorrow before I mount the IC and test power is at the correct pins.
Once the line driver can be powered up properly the plan is to connect it to a drive and check it works properly, I wont need a controller connected to the drive to do this, if the servo holds position then that proves the line driver, cabling and line receiver on the servo drive are working properly.
After that the Breakout board can be powered up and tested with the mesa card then that finishes the electronics, all three drives will be ready to go.
Cheers.
Russell.
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Re: Another Banana Bender's Build !!!
Over the last couple of days I have done most of the cabling required for the estop and enable circuitry, getting ready to transplant into the machine, most of the wiring is done, except for a few things that will need to be hooked up once it all goes in.
Today I powered up the Z axis drive as it has its own power supply and connected the line driver with a Cat5 patch lead to see if it works, after forgetting to put the enable jumper in the drive to make it actually fire the power units it all works perfectly.
Doesn’t look much in the photo but it took a lot of work to get that stupid little blue led to light up !
Russell.
Re: Another Banana Bender's Build !!!
Been a bit busy lately, but managed to sneak up to the shed tonight and take a quick video of the Z axis servo plugged in and jogging, it is a little noisy, and I think the brake is the culprit, will have to look further.
https://youtu.be/tMrEeKA_TbQ
Cheers.
Russell.