Cables and Biss-C Encoder DIY for AKM54K motor

Scored a pretty affordable AKM54K Kollmorgen servo, will be building a simucube 1 system with it. The servo has a basic 8k encoder, I will be adapting a mige biss-c encoder to the servo, I’ve already been discussing the project with a few gurus, and I have access to some aluminum machining services through a friend of mine.

Servo is in the mail and I need to order the mige biss-C, a few questions:

  1. I have the ability to make my own cables to my own specified length, just need to source the connectors. Is there a guide on where to get the exact power connectors for an AKM54K? It looks like an M23 connector, 8 pin, but not sure if there are different lengths etc

  2. What size cable should I use for power and encoder? Should I size to 25A for Ioni Pro HC? Would 16 AWG suffice or should I up to 12, same question for the encoder cable.

  3. Does anyone know the mige connector that is used for the encoder? Would like to try to source that as well if its cost effective, if not I’ll just include it in my order from Lisa (unless someone has a mige biss-c they want to let go of/sell)

  4. What are the dimensions and taper for the biss-c encoder and rear end of the shaft on the AKM54K? Can’t find that spec anywhere. Need this to adapt the AKM54K to the mige biss-c

For reference, the model code for the motor is AKM54K-CCCN2-00

I think I may have been watching that same servo on eBay - if you got it, nice!
This was basically my plan as well - I have an AKM52k with a 2048ppr encoder.

To adapt the AKM shaft to the Biss-C, I think might be a bit of a guessing game until you get the servo opened up.
However, this thread on the iRacing forums shows Sam Maxwell converting an AKM52G to a Heidenhain - the shaft on the AKM5x I believe to be standard across the variants, which Sam measures at 12.7mm. In his case, the Heidenhain accepts a 6mm shaft, so he is able to use a 12.7mm x 6mm CNC coupler.

The Mige Biss-C however, accepts a tapered shaft, which starts at 9mm OD, and ends at 8mm OD, with a nose on the end which is tapped I think to M5 - I haven’t translated the drawing - but I’m attaching it. So you could use a couple much like Sam, just have to make an adapter shaft.

I drew up an overly long STL file, with the intent to 3D print the shaft adapter, and trim to length to fit the Biss-C reasonably. In Sam’s example above (I’ve attached a photo) with the Heidenhain, you’ll see it no longer fits in the AKM’s cover, so he cut a custom backplate from plexi/lexan. You can likely do the same as he shows.

Here’s the drawing for the Biss-C encoder with the dimensions - I’m a few years out of machinist school so I may be mis-reading, but I think I’m close.

If you want the STL file I made, let me know, I haven’t printed any (don’t have a Biss to convert with…yet). Like I said, it’s overlong to cut to size, but it is tapered, and has a solid nose on the end for drilling/tapping to attach to Biss. Though - it may be that’s actually to release the encoder from the shaft…never had one apart to know, and the drawings don’t make it clear…Also, I think my STL is 9mm diameter shaft - but I don’t readily see a 9mm x 12.7mm coupler, but that could be easily upped to a more common diameter (10mm maybe) so you’re not searching high and low for a rare coupler.

Biss-C Drawing/Datasheet


I did grab that one, I just got it delivered 10 minutes ago. It’s smaller than I thought, it has a 95mm hole spacing instead of the mige 110mm. Can’t wait to start messing around. Did you hook up the 52K with the 2048 encoder? How does it feel with that resolution?

Thank you for the drawing. I ordered a Biss-C from Lisa, so thats probably a week out. I wouldnt mind checking out the STL file, if you cant upload it here I can send my email. I’m going to try to open it up and remove the encoder this weekend and I’ll post what it looks like.

Well - I’m exited to watch your progress!

The 2048 isn’t bad at all - I don’t have much to compare it to, however, as I went from a Logitech G27 to my DIY Simucube 1 AKM52 build. I imagine the fidelity gets better with a higher resolution encoder, and I’ll someday update it - just haven’t e-mailed Lisa to order one yet. But with proper profiles set for iRacing, and custom FFB for Project Cars2 and Automobilista 2 - the Simucube is really a treat; even with the lower rez encoder, the curbing, road texture, steering feedback/etc., are really very impressive and similar to my real world vintage race cars.

Here’s a link to the STL:

It’s not much, I used Tinkercad, YMMV - feel free to use it, or trash it :slight_smile:

This coupler on eBay may just work; or, make that STL file a hair larger diameter to 10mm and get a standard 12.7mmx10mm coupler.

I’ve heard horror stories on getting the AKM’s apart, Sam may mention in his thread a disassembly method. I understand heat application, and good tight fitting allen keys are necessary.

I should just pull the trigger and buy the encoder and cables, and put them on the shelf until I can take my SC1 out of action for a bit. :thinking:

And obviously, if you have machining capability, you can just have your own coupler machined. easy peasy!

Thanks for the STL. You can wait till I do the experiment if you want haha, I might build an encoder cable and just use it with the 2k encoder until my biss-c comes in. But my simucube/iono hc havent shipped yet for some reason.

International bank money transfers take a few days to show up on our account, order will be cleared when it checks out.

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