Reply with Quotehummmmm.....
by the time one adds a pc board and shipping, i think your looking at slightly over $60 us. for parts alone. (each unit )
.. makes stepper drives look prity good.
uhu parts list
any errors brought to my intentions would be greatly appreciated
by the time one adds a pc board and shipping, i think your looking at slightly over $60 us. for parts alone. (each unit )
.. makes stepper drives look prity good.
yeah, but seems like pretty much everyone has stepper motors though, looks alittle more sophisticated and whatnot with the servo's.
I think you'll only need one opto isolator as well.
You'll have to look at the bigger picture.
Speed with a servo is much higher than with a stepper. A servo has a lot of torque left at max speed. You have feedback, meaning no more lost steps. Servo motors are available at very interesting prices at ebay etc.
Compare the prices of steppers with those of DC servo's or DC motors and encoders.
I bought myself a bucket full of DC Servo's from a local scrapyard for E25 (~$30). This encluded 4 100W Dunkermotor 63x55 (Max 2 Nm) and one 240W Dunkermotor 80x80 (Max 6Nm) (motors that run for about E300 each new) including 3 500CPR encoders and a bunch of ball bearings (enough for the cnc conversion of both my lathe and my mill).
If I start with Steppers I'd have to spend around $500 for 5 reasonably strong steppers and still need drivers for them. Take for instance the Gecko drive for a good performance stepper driver. This adds another $500 to the list.
5 UHU controllers in deluxe version (professionally produced PCB) will set you back about $300. This still leaves a gap of $700 to find some servo's. Encoders can be had for ~$20 - $25. A good DC motor
http://cgi.ebay.com/High-Torque-DC-M...QQcmdZViewItem
http://cgi.ebay.com/DC-servo-motor-w...QQcmdZViewItem
And a big one:
http://cgi.ebay.com/GE-DC-MOTOR-48V-...QQcmdZViewItem
I'd say the equation looks pretty good.
Erik Jan
What goes down, should come up.
Yes, it is somewhat expensive, however, compared to what? Stepper drives compared to servo drives is sort of like comparing a bicycle to a race car.Originally Posted by smarbaga
by the time one adds a pc board and shipping, i think your looking at slightly over $60 us. for parts alone. (each unit )
.. makes stepper drives look prity good.
Then comparing servo drive to servo drive - I am building the high current version 30 AMps 150 Volt - This has better ratings than other offerings (Gecko) AND at less cost, so to me, this controller is a good value.
Chris
I was just comparing smarbaga's parts list to the parts list that Erik posted (the excel file) http://people.freenet.de/Mode1/UHU_P...uecklisten.xls There are a few differences in the quantities of resistors to order, as well as some that arent even included (100 and 22k ohm). I also noticed that the package style changes for some of the capacitors as well. So if anyone is planning on making a PCB out of the layout included in the zip file, you'll need to double check before you order.
I sent uli some beer money for some micro's. About how long does it usually take to get them to the states?
Jeff,
you'll have them possibly this weekend. They were shipped by air mail today.
Uli
Uli you have not givin me a price did you get my email?
thank you
Rob
hello :
i made the parts list off of the pc board silk screen and not the schematic.
i didn't see the one uli posted.( musta missed it )
Erik,
I have a couple of questions for you...
#1) I notice on the traces, you applied a thick layer of solder on the heavy traces (power side traces). Is this required, and if so, could I just solder in some wire in those areas to beef up the traces?
#2) The diodes P6KE15CA, are they bi-directional diodes?
#3) The IRFP260 Mosfets and the heatsink. Is it okay to directly attach a heat sink to those, or must there be an insulator between the heat sink and the mosfet?
That's all for now, I am sure there will be more to follow as I am getting closer to finishing the assembly.
Thanks!
Chris
#1 I beefed up the thickness of the traces as a precaution. The amount of power that flows trough them is enorm so a bit extra area to flow through won't hurt.
#2 They are bidirectional.
#3 They MUST be isolated from the heatsink!!!
What goes down, should come up.
Wouldn't it be easier to go with say a 2oz. copper board. I deal with a piece of equipment that pulls 15 amps @ 120 volts with a Molex plug soldered to it with no problem. The original 1 oz. boards would burn up after a while. What oz. boards are you using.
If it's not nailed down, it's mine.
If I can pry it loose, it's not nailed down.
Thanks Erik,
I am glad I asked!
Chris
Yes you can add extra wire to beef it up.
I do not know.#2) The diodes P6KE15CA, are they bi-directional diodes?
There MUST be a insulators between the fet's and the heat sink.#3) The IRFP260 Mosfets and the heatsink. Is it okay to directly attach a heat sink to those, or must there be an insulator between the heat sink and the mosfet?
Or else you will blow it up.
I used 1 oz material for my first board (prototype for me as I don't know what the hell I am doing). So, I will solder in some additional wire onto the traces to beef them up.
Chris
i have started to order parts for the uhu
all the parts will be available in about 5 days
*** particulars ****
1. all logic level caps will be 25v
2. 1000 uf will be 200v
3. 4 x irf540 ( substituteable for heavier fets)
5. no pcb (yet)
6. no heatsink
7. no standoffs
8. not sure about IR2184 ( will let u know )
PS: i think buying all the parts in 1 package will save several shipping expences,
a lot of hunting, wrong part orders, and wrong part shipments.
package shipping should be about $5.00 in the usa.
buyer will just pay actual shipping cost and shipping method of his prefference.
You are right - I am doing a lot of hunting and finding and such, so if you are selling a packaged component kit, that will save folks a lot of headaches. I am also finding that some of the components won't fit (Lead spacing on Caps) so I have to re-order some of those as well.
Chris
Erik,
Another question on the PCB. Sorry for all the Qs, but I am hoping to have some success here in a week or so.
For the OPTOs, I have the HCPL2631 chips (I got them from Mouser). From what I can determine, from the conversations here and the layout drawing, I only need one of them on the board and that it should go into the row of holes that are offset a bit - called OPTO3. Is this correct?
Thanks!
Chris
You are correct. If you checkt Schalt.pdf you will see reference to ic11 IC11 has leg 2 and 3 connected and pin 5 to the ground.
Good luck with your build and keep asking those questions. It's no problem.
Erik Jan
What goes down, should come up.
Thanks Erik!
I will keep asking questions and will probably have a million of them when I get it to the point of plugging it in and setting it up. Things are looking good so far though!
Chris
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