New Mige BISS-C Encoder


#1

Mige released their new 22Bit BISS-C Absolute Encoder today this will replace the current SinCos version which will no longer be available, I have stock arriving this week I will post some feedback when I have tested the performance

Datasheet

https://mega.nz/#!bBUS2aYC!-_vrGs6Wm7z7OnEb6dutBiJZF2u4S9iXgHTUmeCXW6I


#2

i’have already reported this some times ago but my post has been deleted!


#3

As an additional info that the benefit why BiSS-C absolute is that there is no need for phasing and also no need to position the wheel to the center position while powering up the SimuCUBE. The wheel position will be picked up correctly & immediately once powered up.

Other thing to mention is also that older MiGE motors + cables are not compatible with this encoder, that is due to different connectors and slightly different shaft end on the motor side. So changing the encoder from 5k or 10k incremental quadrature or from motor that has sincos to this encoder is not recommended.

Compared to SinCos encoder that has been on the market for a while, there is no other benefit than the previously mentioned feature.

Hmm… should GD be able to please everybody, it could be done, but for the meantime our focus is elsewhere.


Assetto Corsa and SimuCUBE
#4

There is indeed a plan to include the setup of this feature in to the SimuCUBE Configuration Tool, if suitable encoder model is detected.


#5

i saw lots of people to change encoder to sincos or absoluty encoder. i am an servo engineer and higher resolution is good for speed control and postion control.but for simracing,it is torque control.2500lines are enough.if youwant to get more details,just need to get motors with less inertia.and donot waste your money on encoder.that is my opinion


#6

Its not an upgrade they come pre installed


#7

You can buy the encoders alone, but as mentioned above they will not fit any of the Mige motors that we have been using.

All new motors that are ordered with the Biss C encoder are made special for that encoder.


#8

Worth noting the 2048 SinCos encoders have almost twice the raw resolution of these BiSS encoders, so you’d technically be downgrading anyways.


#9

Yes, you’re indeed correct that torque control is used. If the users would not desire to get improved, more realistic direct drive force feedback experience from the simulator, than what the ffb signal actually is from most of the simulators, then incremental quadrature encoder with 2500 ppr resolution should be (more than) sufficient for the purposes of controlling the motor in pure torque mode without added effects that improve the experience.

Hmm… have you tested the BiSS-C encoder or for what this notion based on? 2048 PPR SinCos is 21 bits after interpolation, in raw resolution.


#10

Hi,
I am about to buid my own OSW
I have try to find informations about the BISS-C 22Bit
In the granite wiki page it is written:
SimuCUBE supports BiSS encoder resolutions up to 21 bits (2M counts/rev).
Will this 22Bit work or will it just use 21bit?


#11

You can set up the resolution from IONI that how many bit is read from the encoder.
Any encoder may work flawlessly also with 22 bit resolution or higher, but 21 bits is officially supported max resolution for SimuCUBE use.


#12

I will be posting setup instructions and SimuCube screenshots for the BISS-C encoder on our website in the next couple of days
http://www.simtechracing.co.uk/downloads


#13

Raw sincos resolution is 8192. You get 4 clean bits there on top, so 128K. 21 bit simucibe limit gives you 2M - that’s 16 times more. And on top of that - no loss of phasing, recentering issues, no noise issue, no interference. If that works - it’s certainly better. And for any effect except pure torque mode that resolution is really needed to properly calculate effects from acceleration - acceleration calcs at low speed are really bad now.

It’s a pity that Mige didn’t found biss-c that fits existing shaft.


#14

I guess this is a nice option if you are building your first Simucube.
I upgraded to the 2048 SinCos and I did feel a difference. It’s very subtle, but noticeable. Of course, much of this could be placebo with my mind telling me that I’m able to sense loss of traction better than the 10K encoder that I bought with my Simucube build.

That being said, I agree that there’s absolutely no value in upgrading just for the phasing (or lack thereof) part.

Great to see new tech though!


#15

So it means, for all older Mige’s owners, if they didn’t get Sincos by now they will have to live with max 10k encoder or there will possible adjustments for BiSS-C to work with or even some other solutions?


#16

Yes, for older MiGE motors the BiSS-C is not suitable. The issue with the shaft is such that the cone from the motor side is a bit too long, which leads to an issue that the encoder slightly wag/rock on top of the shaft end because the encoder does not sit properly on the shaft end. This may cause issues with the encoder bearing. Other issue is such that the spring plate on this encoder is slightly smaller than on other encoders and the attaching points do not match with the other encoder dimensions that have been used that are also on the motor back end. It is possible to customize the older motor to support this encoder, but due to the amount of work is requires it may not be worthwhile, especially if one does not have professional tools & skills for such modification. Second issue is such that installing an encoder to a motor that does not have suitable dimensions for mounting is troublesome for the customers + troublesome for sellers to provide any warranty on the sold product since it would be installed on a motor that has mounting dimensions that are not designed for it. Therefore upgrading for example from 10k to this BiSS-C encoder is let’s say challenging. However BiSS-C is only a communication standard from the encoder to the drive, some other manufacturer may have suitable BiSS-C or SSI type encoder but I am not aware of such encoder that could be swap-on replacement part for those MiGE motors. Some businesses/companies/individuals may source those and possibly sell those as upgrade parts(?).

For people who want sincos or let say 21bit resolution and who have older motor, it is advisable that they would contact their reseller now and to try to order the sincos encoder now, rather than later, because later (if the encoder is still available) the lead times for an order will be rather long.


#17

Ahh that sounds like it can all be fixed (the Mechanical mounting issues… If someone is willing to send me one I will develop an adaptor set-up… However, the Cabling and of course the Housing would still be issues as My guess is Mige found it cheaper to modify the shaft than the housing… Actually just realized I could fix the housing depth issue and wiring as well I did it for the 1080 Haidenhains I sold… So again if anyone wants to be the guiniea pig on this I will make them an adaptor set-up.


#18

Tamagawa (cough) :slight_smile:


#19

Easiest or straight forward way with good tools to fit this encoder to the shaft is to grind/hone/sandpaper the shaft end a bit shorter on the “old motor” so that the encoder would sit better/perfectly on the shaft. The amount of material that needs to be removed is by an estimate less than 1 mm. However without proper tools it is challenging or even impossible. Of course it is possible to make some sort of adapter as you were thinking. In addition to this issue, one needs to figure out how to attach the spring plate to the back side of the motor. Anyways, this is not something that I would recommend people to do unless they do know what they’re doing… motor manufacturer warranty is void, but with an adapter the good part however is that you likely do not need to modify the motor permanently.

Hmm… as I am aware, Tamagawa does not manufacture absolute encoders that could be used with our drives.


#20

As soon as I have the new stock of motors/encoders we will be manufacturing an adapter to allow the BISS-C to be mounted on the older type Mige Motors