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I'll be following this thread. I'm curious as to how you plan to preload these bearings. I'm also in the planning stages for the cnc conversion of my Rambaudi V2. I've got all the spindles and...

He means the schematic and pcb layout that were in a zip file in the original posts. I have checked and the server is down. I have brought the matter to the attention of one of the moderators of the...

They won't. UHU only accepts incremental or quadrature.


Erik Jan

Slight calculation error. 500 lines are read 4 fold. This means 2000 steps with a 500 cpr encoder. Also 100000 steps per second.

Mach can only output about half. so you'll need the step multiplier...

Those motors look like very good candidates for the UHU. Heavy off coarse but they look like they have 4 brushes, which makes for very smooth running.

Erik Jan

Just asking for the type of motor is probably going nowhere. This may be caused by any number of circumstances. The largest source of noise on the motor lines IMHO will be arcing of the brushes.
...

This is getting interesting. A post from Stefan8051 from Januari on cncecke.de shows that he does not exactly know how to calculate the snubber net...

There is a way to use the enable signal for the H-bridge as a release for the brakes. You'll have to do some hacking with the board but it is possible.

Of course the brakes cannot be used for...

Have you turned the shaft yet. You'll clearly feel "steps" in the rotation. This prevents a cheap motor from being used from what I have read. It will start to oscillate. Besides that, the lower the...

[QUOTE=xtal;277753]I have some Globe Motors [hollow shaft] that came out of StorageTek tape transports the appear to be brushless [ three power leads]

The motors are unusable. The UHU...

These Dunkers are good. I hear nothing but good stories about them. They can take quite a bit more voltage then indicated.
Good choice. Higher voltage is better (lower amps).
I have four slightly...

The multiplier multiplies the input steps.

If you have a 1000cpr encoder you need 4000 steps per revolution.
If you put in a step multiplier if 2 you need 2000 steps. This equals using a 500cpr...

Done a little snooping on the German board. Something i came across that is easy to fix is a ferrite bead in the motor leads. The heating of these resistors may be cause by HF noise in the motor...

The exact names for it eludes me but the UHU has a mechanism that allows a certain error between the actual position and the required position. The PID loop is setup so that any "error" between...

Sounds like interferance.
Did you hook up the encoders as per datasheet? Some require extra resistors for pullup or pulldown.

Keep power wires clear from signal wires!

1. Clean up wireing.
2....

If you check out the attached pictures you see a small addon print with the schematic that will encode and decode differential signals to provide less interferance.

Erik Jan

If anybody needs high quality UHU boards, Stefan (stefan8051(at)gmx.de) will be ordering new prints. This is the guy that originally designed the board. He has since sold many high quality boards....

No problem. Just keep the following in mind.

Most will be using Mach to control their machine.
Mach pust out pulses at 45000Hz max.
500cpr encoder read in quadrature gives 500x4=2000 pulses per...

You need the exact diodes as specified.
The 100n RM15 is a cap (100nF) leg 15 apart.

There have been no changes to processor or board layout since october 2005.
There is however movement in that...

The terminal program that is used to set the UHU parameters has a display that displays the position error. This is used to set the UHU parameters. That along with the manual by Uli that contains a...

P=U*I=56x12=~700W !!!

Try ebay and look for dc motor.
Encoders can be found looking for rotary encoder. Your looking for differential (best) or normal encoders (A and B)

Calculate the force...

If it's for a gantry type homebuilt, I sugest you keep looking for something smaller. 150 to 250W would be more than enough. These could do very well on something like a Bridgeport.

Uli is very...

That's a big sucker. Should work. You may want to use heavier Fets though. Peak current is very high.

As with any hobby project, no garantee.

Erik Jan

UHU was originally developped from the elm-chan project. In general the opinion about that controller is that is was meant as a proof-of-concept.
Of the original code there is not much left. I'll...

Hey Joe,

I'd really like to recieve a set of dwg's to your machine.
[email protected]

Erik Jan

Try Post #1.

Erik Jan

But what kind of motor requires 30A continous current.
My biggest 240W motor (Dunkermotor 80x80 40V) asks 6 amp continuous at rated power. Peak current is 60A

Parvex RS640 require ~30amp...

Yeah, tell me, what illegal tools.....

No seriously. This project was designed in Germany by a group of people gathering on www.cncecke.de. I recently saw a pic from Uli (who wrote the program)...

Hi Bill,

Things are well. I have found a couple of new (4 pole) servo's that I'm gonna hook up to my BF20 mill.

The Ametek motor's I have are a bit bigger though. I'll wait and see if somebody...

I just scored 2 big Ametek DC motors but cannot find any specs online.
Can anybody shed some light?
~100mm dia ~180mm long

Ametek / Lamb Electric Div
799001-900 Rev.M
01A(E56617) 116249-00...