UHU Servo PCB's available

[jfong]

We now have printed circuit boards available for Uli Ubers's AVR microcontrolled Servo boards.

The pcb's are in stock. You will need to purchase the preprogrammed AVR chip directly from Uli.

More info and links to purchase the AVR chip at

www.embeddedtronics.com

Click on UHU Servo link on left side.

regards,

Jim

[jcdammeyer]

Originally Posted by jfong We now have printed circuit boards available for Uli Ubers's AVR microcontrolled Servo boards. The pcb's are in stock. You will need to purchase the preprogrammed AVR chip directly from Uli. More info and links to purchase the AVR chip at www.embeddedtronics.com Click on UHU Servo link on left side. regards, Jim

Hi,

I've purchased one of the Embeddedtronics circuit boards and have just placed a digikey order for the parts I don't have in stock.

I've also attached a spreadsheet with all the digikey numbers and prices in Canadian $ including shipping. Where I've had to buy 10 but need only one I've used the 10's cost. I've also used gold plated machine tool sockets so that the board will be servicable during my Servo learning curve.

I'll post a photo when I've assembled it and also post reports on how it works and whatever issues I have with it.

What I can say is I'm surprised at the Total cost. I'm at $151 Cdn. which doesn't include any sort of heatsink or box. I did spec in connectors that are removeable so that it will be easier to work with. That raised the price. I also went for the faster MUR120 diodes and the IRFP260N FETS which are listed as 200V and 50A. Theoretically I shouldn't toast those.

Less expensive diodes, fets and connectors could drop the price by about $30 and leave it at $120. What amazes me though is that a GECKO 340 with the step multiplier is in the same ballpark price.

So I have a general question. Why even build this if a Gecko can be had ready to go for the same or less? Especially since the 320 is currently on sale.

Cheers,

John Dammeyer

[jfong]

Hi John,

That seems pretty expensive! We have a large inventory of parts (junk pile) here so didn't need to purchase anything new from digikey except the IR fet drivers and op amps. We made the uhu pcb boards because we needed a bunch of servo drives and are selling the extra bare pcb boards on our website. We even traded Uli some pcb boards for the chips. The overall cost for us was minimal.

There has been alot of people who have made the original UHU boards so presume the parts costs was reasonable or have sourced parts from cheaper distributors.

There are DIY electronic builders out there who do have access to inexpensive electronic parts so the costs for them can be much cheaper than buying geckos. I use to live in the San Francisco/Silicon Valley so getting surplus parts (resistors, caps, diodes ect.) was really inexpensive.

Jim
embeddedtronics.com

[jcdammeyer]

Originally Posted by jfong Hi John, That seems pretty expensive! We have a large inventory of parts (junk pile) here so didn't need to purchase anything new from digikey except the IR fet drivers and op amps. Jim embeddedtronics.com

Hi Jim,

I have a lot of the parts here too so it's not quite as much as the spreadsheet shows. I have about 150 IRF640s (200V 16A) so I could have saved a bunch there too. But as an exercise, since I had to get some of the stuff from Digikey anyway, I thought I'd price out the entire project.

Thing is, not everyone has the specific parts in their junk box or inventory. To save money, some might not even use the terminal strips. A junk DB9 for the RS232 could be wired in directly with no plug.

But realistically, in singles, that is about what it costs. Now granted I fed Uli $20 for beer money and shipping. If you had stocked the processors in bulk at $2ea and took a dollar (total $3) then that would have reduced my cost by $17.

And my prices are Digikey Canadian. Where I live there is nothing surplus for electronics and mailing costs pretty quickly add up. For instance, Mouser might be cheaper for some things until the $15 UPS ground charge and the $30UPS customs brokerage charge are factored in. Makes the $8 Digikey cost (overnight too) pretty low. And I didn't add the 6% Provincial sales tax since I'd pay that on a Gecko anyway.

I guess my point is that this project costs far more than is immediately obvious but I'm still wondering what makes the UHU-Servo worth it relative to the Gecko? The FETS are pretty big. 200V and 50A implies I could run a 13A 150V servo. Gecko's are limited to 8A. What does a Rutex cost?

Or is the tuning in software better than the trim pots for the Gecko for a wider variety of motors?

One thing the Granite board insists on is differential encoder inputs whereas I've read that the Rutex has problems there. How about the UHU-Servo? Add a set of differential receivers and the price goes up higher yet.

John Dammeyer

[FPV_GTp]

Originally Posted by jfong We now have printed circuit boards available for Uli Ubers's AVR microcontrolled Servo boards. The pcb's are in stock. You will need to purchase the preprogrammed AVR chip directly from Uli. More info and links to purchase the AVR chip at www.embeddedtronics.com Click on UHU Servo link on left side. regards, Jim

Hi

Jim , what is the price of the printed circuit boards ????

shipping costs to Melbourne Australia ???


cheers

[jfong]

Originally Posted by FPV_GTp Hi Jim , what is the price of the printed circuit boards ???? shipping costs to Melbourne Australia ??? cheers

Hello,

Price as listed on our website is $15US per board. Shipping would be $7US.

Regards,

Jim

embeddedtronics.com

[jfong]

Hi John,

As you have found out, you won't be saving any money by building only 1 UHU servo board. The gecko servo drive is a great deal at $87.

In my case, I will be building 12 servo boards. I know I can buy all the parts in bulk for much less than the $1000 it would cost for 12 geckos.

regards,

Jim

[acondit]

Originally Posted by jcdammeyer Hi Jim, ... Gecko's are limited to 8A. ... John Dammeyer

John,

The manual on the Gecko G320 says 0 to 20 amps, 80 volts.

Alan

[jcdammeyer]

Originally Posted by acondit John, The manual on the Gecko G320 says 0 to 20 amps, 80 volts. Alan

Oops. I was thinking of the stepper controllers. I understand what Jim was saying about building a larger number. There's no doubt about the cost savings then.

But what about the difference in setup or tuning? Is the UHU better that way?

Thanks

John

[boris]

has anyone build cnc controller using EMBEDDETRONICS boards
for servo motors with UHU chip.
please let me know