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Will do. I want to add a single tooth dog clutch to my lathe and need to cut a few gears to make it happen. This indexer seemed like a perfect tangent to go off on. :eek:Quote:
Originally Posted by cjsamples
For $7 shipped I am willing to try.Quote:
Originally Posted by hoecken
A tb6600 board cost slightly more and will not self destruct for no reason. But they still require some rework if you want maximum performance.
Well for $14 I ordered a 6600. I figure at this rate I'll end up with a gecko anyway, so I might as well try some cheap ones out.Quote:
Originally Posted by H500
Hello All,
Is anyone selling this board? If so I think I'd like to give this project a go.
Thanks,
Lee
http://www.worldofward.com/rotarycontroller/Quote:
Originally Posted by cruisor
Steve
I like the job you have done on this and would like to build one. However the limitation of 1/2 step at 90:1 ratio will cause me to have to change my existing driver which has a microstep of 10. I looked for the source code on your web site but couldn't find it. Is the problem a limitation of the 18F452 or the firmware.
Regards
Rick
I think it is more a case of steps per table turn that is the setting required,
I use a 36:1 ratio although with half stepping however there is a maximum number of steps per turn of table limitation.
John.
Steve, can I ask a question about assembling your board to the display? They align perfectly back to back such that the display interface holes are in line. Ideally I'd use a pcb header on one side and socket on the other, but on the controller board the solder pads end up on the wrong side to solder either pins or socket. The only option seems to be to solder pins to the display from the "wrong" side so they project downward towards the back of the controller, assemble the boards together with spacers, then solder the pins to the controller pads. Am I missing something here please? If I'm not making sense I'll try to take and post some photos.
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Answered my own question! I just used plain copper wires between the boards. Now working perfectly, will post some pictures of the unit.
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I just posted some photos of my unit plus the dividing head it controls at the Model Engineer site.
What did you do today? (2015) | Model Engineer
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Sorry John for the lack of reply (and every one else). CNC Zone had 'unsubscribed' me from this thread!
No problem Steve!
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I just completed my second indexer using the parts I had left over from number one. It adds digital indexing to the mini-lathe.
New box
Attachment 279488
Indexer fitted to Lathe
Attachment 279490
You can see a video of it on YouTube:
https://www.youtube.com/watch?v=7kgCz75ASxg
Malcolm
If anyone still struggles getting 18F452's. I've updated the firmware in the download section of my website to include a version for the 18F4520 (which is also slightly cheaper...)
Firstly, my thanks to Steve for starting this project and thanks to everyone who contributed. Well over a year ago I collected together all of the parts needed to build this controller, I finished it this morning - almost!
My issue seems to be a simple one - at least the fault is, but I just cannot get my head around it. I might possibly have the wrong driver/motor combination but having come this far, I hope not. My problem is, if I program the controller and set the dip switches on the driver to accomodate my 90:1 ratio, 360 degrees is really only 330 odd degrees of table movement. I have tried a few combinations but the problem gets worse, not better. Below are pics of my Stepper Motor data sheet and Driver Data sheet. Everything else, controller, keypad, LCD display I bought directly from Steve. If I set the dip switches to 400 steps/rev as shown at the bottom of the Data Sheet I get wierd things happen, If I set it to 800 - the lowest I can get it to run at - I then set the number of steps per rev to 65535 and this gives me the 330 odd degrees of revolution instead of 360. The Stepper motor data sheet tells me it is a 1.8 degree motor. Whatever that is! So I don't know how many steps it actually is?
Any help from you guys would be gratefully received, even if it is bad news, like the wrong stepper motor, at least I can sort it out. Thanks very much.
The basic problem is that you need it to work at 400.
Here's why. With 400 steps per revolution of the motor and a 90:1 ratio then 360 degrees would be 400 * 90 = 36,000.
The largest number you can enter into the controller is 65535, and with an 800 ratio you'd have 800 * 90 = 72,000.
(Which is why you're only turning around 330 degrees: 65535 / 72000 * 360 = 327.675 degrees)
So you need to set the controller to 36000 and the driver to 400 and it should all work fine.
If the stepper driver works at 800 there's no reason it shouldn't work at 400, what's the problem you're having?
Hi.
Below is the from the manual explaining how to calculate the number of steps per rev..
Your stepper motor is a 1.8 degree so that's 360/1.8 = 200 steps per rev. If you set the dip switches for 400 steps per rev, table is 90 to 1
So you need to set the controller to 36000 ( 2 x 200 x 90 = 36000.)
"Value is the number of steps per rev of stepper motor (eg 400 steps if half
stepping) multiplied by the worm ratio of the table. So if you're using a half step
driver and a 200 step motor along with a 90 to 1 ratio table then that would be 36000"
Kwackers posted his reply why I was still typing !!!
Sorry wrong answer. Didn't notice the other replies...
Gentlemen, thank you ever so much for your time.
It is all working perfectly!
As is always the way with these things, a friend called me moments after I had made the post. I had emailed him a copy of the Driver Data Sheet. This is what he saw: If all of the Dip Switches (For the Microstepping) are set to ON then that is the default for the motor - 360 degrees divided by 1.8 = 200 steps. I scooted back down to the workshop, put the four switches to ON and a value of 36000 in the setup - Hey Presto! all working exactly as it should. My thanks to you gentlemen for the advice.
Now, and this is a personal thing, but it only echoes what a number of others have said in the thread and is by no means a criticism . Nowhere on the data sheet does it say: "Leave switches to ON for native mode of the stepper motor" or anything even remotely alluding to that state. It is typical of electronic data sheets and when you are usually well versed in Hammers and Spanners, the subtlties of cryptic data sheets are lost on me/us. It is one of the main reasons I don't dabble more in electronics.
Having said that, this is terrific and I am looking forward to embracing a few more projects now that dividing, even rotary cutting, has just gotten that much simpler. The "fault" at 400 rpm, I think it is the table/coupling,spindle or something along those lines, binding in one direction and not the other. No matter, it just WORKS!
Thanks again.
I built my indexer some years ago with a home-made PCB and local parts and thought I had it working at that time. I hadn't had reason to use the rotary table in the meantime (except for "quickies" with another, manual table) but came to use the indexer in earnest today. I had a similar problem to NNeast in that the output angle was way off what I demanded.
I went looking for the place, in setup, to enter the Steps for 360 deg and it isn't there in my version. The firmware rev I have is 2.11 which is a bit old but it seems odd that this parameter - or something similar - is missing since it's fundamental in calculating angles.
I expect I'll end up reprogramming the Pic, or buying another, but I have a job set up on the mill and wondered if perhaps Steve could comment based on his knowledge of the firmware. I did look for a way to reset everything in the hopes that everything would come back but I can't find one.