Yet anothter "Valkyrie" clone
| Attachment | Size |
|---|---|
| stepdirection.c | 4.12 KB |
| rename_to_makefile_without_extension.txt | 9.78 KB |
Here you can find Version 2.0:
http://letsmakerobots.com/node/19239
Inspired from Tinheads "Valkyrie 2.1" is started building my own CNC last weekend. Until now the X and the Y axis are ready and i also got one Motor running.
Differences to Tinheads CNC:
- drawer guide rails with ballbearings
- the table is moving and not the Y-axis
- Sanguino instead of Arduino
The Motors i'm using are from an old Tektronix Plotter. (They are nearly two years older than me... Produced Feb. 1978) They have 1.8° per step so i'm going to have a wonderfull resolution...
Update:
This evening i changed the leadscrew a littlebit and now the X-axis works much better. So i have now 2/3 of my cnc working ;-) It also painted an eagle file ;-) And makes funny music while doing this ;-)
I also found out that the G01 F Statement can set the feedrate higher than max. Feedrate. Is there a good reason for this? If not i'm gonna change this in the sourcecode. Editing the gcode by hand is a lot work ;-)
Tommorrow i will start assembling th z-axis.
Next Update:
It's done!!! at least for now ;-)
YAU (Yet another Update):
Yesterday evening i tried to mill a PCB. After about 1 hour good work it started loosing steps. First on the Z-axis and then on X too. I think i will have to increase the Voltage. 'til now I'm using 5V and the motors stay cool. So there is ptential for more torque i hope. I'm driving the Motors in fullstep mode with 2 Coils powered a time. I think this is the strongest mode they can be driven...
Update: New Video
Update 14. Feb. 2010:
Today I switched over to EMC2 to control the Mill. For this I had to change the Stepperdriver Firmware a littlebit so that it will accept step/direction signals. I attached the sourcecode and the makefile to this page.
Result: its working really good with EMC2. I can drive all axis at double speed because EMC accelerates the Steppers so they don't loose steps.
Update 19. Feb. 2010
My dremel clone broke down tonight - still running but a 1mm mill-bit makes about 2mm line. You can fell that theres a little play on the bit-clamp. So i'm going to buy a new one. But now i have to make a decision dremel 300 or proxxon FBS240E or Proxxon IB/E
Dremel:
+ up to 40.000 RPM
+ cheap 50€
+ 125W
- they don't say anything about accuracy
- hard to mount
Proxxon FBS240E:
- only 20.000 RPM
+- a littlebit more expensive 60€
- 100W
+ collet-chuck (Spannfutter)
+ seems to be better mountable
- they don't say anything about accuracy
Proxxon IB/E:
- expensive 90€
- 100 W
- only 20.000 RPM
+ is professional mountable
+ has a high accuracy 3/100mm
I hope they have them all available in the hardwarestore tomorrow so that i can get hands on them. If anybody reading here has a quick suggestion, please post....
Update 26. Feb. 2010:
It's a Proxxon! A FBS240/E. And it seems to work quite good! But the axis speed of my mill is much to low (120 mm/min). So I decided that i need a new stepper-controller. This time with integrated current-limiting. I took a look at a lot of available circuits on the net but then I've found this one:
It's just 20 Euros (PCB) and gives me some important new features: sleep and boost. For 20 Euro i cannot make my own pcbs... (time, material, failures...) I will try 12V tomorrow. Lets see what speed i will get out of it ;-)
Greets
Daniel
Update 1.3.2010:
I installed the new stepperdriver and it was a great success! Had a little trouble with some old atx-powersupplies but now it works!
Old speed was 2mm/sec and acceleration of 1.5 mm/sec^2 on all axis
New speed:
X: 6mm/sec 10mm/sec^2
Y: 10mm/sec 13mm/sec^2
Z: 15mm/sec 20mm/sec^2
All 12V, X and Y running at 1A each, Z at 2A.
Things to change:
- find a cheap bigger powersupply 30-40V 4-5A
- exchange Motors on X and Z (the motor on Z is the strongest!!!)
- change the 8mm thread-rod on x axis to a 12mm one (to get rid of the wobbling problem.....)
Update 9.3.2010:
The Proxxon ist also a piece of....
Tonight it broke down. A 1mm tool makes an about 2mm hole... I will try to get my money back tomorrow. Instead of the proxxon i ordered a Kress 800FME. With this I hope I will have enough power and longtime qualitiy. The give 10 Years warranty and its a professional tool.
Not so good:
Last week milled a really good holder for the proxxon. But this is unusable for me now, because the kress spindel has an 43mm mount...
Update 16.3.2010:
The Kress spindle cuts everything like butter ;-) Now i can do some Aluminium too:
@ Tue, 2010-03-02 16:28
Cool :D
The sound of it is just awesome :D
Need to switch to the new drivers/motors soon ... as soon as I replace the drivers I fried this morning :( and make the new ones ...
@ Mon, 2010-03-01 16:21
Hi,
I see you are really getting into it :D
BTW:
- change the 8mm thread-rod on x axis to a 12mm one (to get rid of the wobbling problem.....)
What wobbling problem?
@ Mon, 2010-03-01 16:47
Hi
(i hate the subject-force here ;-) )
Yeah it was really fun seeing the emc sample project been drawn in about 2-3 minutes!!!
the X-axis moves a littlebit left and right every turn of the thread rod. i think its a littlebit bended... so a 12mm one should perhaps a littlebit better....
Greets
Daniel
@ Mon, 2010-03-01 18:56
The bent-rod wobble
I also get a wobble from bent rods, on the Z-axis more than the other two axes. The result is that the spindle spirals up and down in little circular motions. The bent rod was my fault -- I lost patience while slowly and cautiously cutting through the rod with the Proxxon tool and tried to break the rod before it was cut through. The rod did not break, and just bent. Tightening down did not really work because of slight misalignments between the rails and between the rails and the lead screws due to the poor quality of my Y-axis stage. The problem should go away when I remake the X-Y-Z stage on a family member's CarveWright CNC machine, which can cut and drill more precisely than I can.
-John
@ Tue, 2010-03-02 10:15
ok
thanks for your reply!
i think i will have to change a few things on the x-axis rails. Perhaps i will get som real linear-rails on ebay... or the other idea is to mount 1 or 2 additional drawe-rails in 90° angle to the old ones, so that their play is eleminated buy the other ones.
Greets
Daniel
@ Mon, 2010-03-01 17:23
I think 12 mm would ...
... make things even worse if it is not very straight (which happens often with these cheap rods), because it will be a lot less flexible. I don't think that would help. My rods are bended as well but the rails force the rods to flex a little them selves rather then moving the X axis sideways.
If the X axis wobbels then you might need to check the rails you use and tighten them up if possible, or make sure that the whole assembly is sturdy enough if the play is not from there.
@ Mon, 2010-03-01 17:45
Hmmm
thats not so good. I have no way to tighten the rails...
Then i have to think about another way to get rid of this problem.... perhaps i will have luck on ebay ;-)
Greets
Daniel
@ Mon, 2010-03-01 17:59
I hate to say that but...
@ Sat, 2010-02-27 23:36
Regarding step/en/dir ..
How did you get the driver to receive the step/dir signals properly? It looks like I'm kind of hit in the head today, I can get mine to read them reliably.
I saw you used the initial sda and scl pins, did you take out the 4k7 pull up resistors, or you kept them?
@ Sun, 2010-02-28 00:45
Hi
i used the standard i2c layout, similar to yours. I had some problems with "goststeps" so I tried both, with & without the 4k7 (at my bords they are 3k9 I think.... had no 4k7 available) and both worked. I didn't change anything on the hardware-side of the stepper drivers to convert them to step/dir.