SFX-100 "silent" driver case build

[scornflake]

I've been building a case for the SFX-100 servo drivers which aims to make them near silent.

For refernce as to why: https://www.racedepartment.com/threads/simfeedback-ac-diy-motion-simulator-10khz-research.175829/

Thought I'd share some pics of the build so far. This will be publicly available via OnShape (or I can post a bunch of STL's). It's a mix of 3D printed parts, carbon fibre and some custom panels which I got done (will get done!) locally.

First, the final CAD idea:

The idea is to build a case that:

1. Takes 240v direct
2. Is switched, itself
3. Remove 240v 30a relay.
   1. Has a remote, so I can leave it switched on, and press a remote from my seat to turn it on.
4. Includes a FN2070 16a EMI filter
5. 240-12v supply for the fans
6. Includes mounting for the Arduino
7. Includes 40mm polyester fibre accoustic insulation (I'm affected by the 10khz tone these things emit)
8. Has sufficient airflow given (6)... that I'm covering everything up
9. Stands against a wall and can be tied to that wall (I live in NZ, Earthquakes).
10. Doesn't take up much floor footprint. My office is cluttered enough as it is.

There's prob more, but I forget

The case is built primarily out of pla. Some parts might be better done in PETG (clamps over carbon fibre scaffold, for example) so that they can flex a bit more. The idea is there.

The design allows for the wrapping of accoustic material around the carbon frame all the way up. Lower and upper accoustic barriers are hangled by way of "fabric retainers", basically platforms that hold fabric. IT's hard to spot these in the drawing above.

Anyway; there's room for about 40mm of p.fibre around all AASD drivers, and that includes space for venting.

The lower base holds a 120mm fan directed intowards the case for +ve pressure. The fabric surround the drivers acts as a guide for this air, taking it past the heat fins of the AASD units. The extractor at the top is a 140mm fan.

I'm currently building/printing the unit. I'll post some more pics as I go!!!

 

[Peter Koslowski]

 

[scornflake]

re Temp: I've got in mind to try a temp probe, but notice in the pics theres a carbon fibre lattice/frame surrounding the drivers? Thats ~8mm away from their sides, on all sides. There are fans lower and top (lower one blows upwards, top one extracts from case), with vents down below. Finally; we hardly drive them *hard*. So I'm quite confident there will be no heat issue.

 

[scornflake]

Peter, love the little base your drivers sit on (made from extrusion) and the little handle!

 

[Peter Koslowski]

It is only the seat for 9.99€, I love it, like karting!

https://www.ikea.com/de/de/images/products/skalberg-sporren-swivel-chair__0724658_PE734557_S5.JPG?f=xxxl

 

[Insert Coin]

re Temp: I've got in mind to try a temp probe, but notice in the pics theres a carbon fibre lattice/frame surrounding the drivers? Thats ~8mm away from their sides, on all sides. There are fans lower and top (lower one blows upwards, top one extracts from case), with vents down below. Finally; we hardly drive them *hard*. So I'm quite confident there will be no heat issue.

I meant the servos, not the drivers.

 

[scornflake]

I meant the servos, not the drivers.

Didn't think they got that warm. Do yours get 'hot'? Guess I should put a temp prob under there. I dont run my rig above about 40% power atm.

 

[Mascot]

More power to your elbow, @scornflake. This project could be the Basílica de la Sagrada Família of sim racing but I admire your tenacity.
Personally, I gave up trying to solve the coil whine issues a long time ago but will be following your project to the bitter end and wish you all the success in the world.

 

[scornflake]

Thanks @Mascot . I'm pleased to say its mostly been a success. The case itself, in its current form, is a PITA to work with (small. tight tolerances. no space to move hands). But it works. I'm currently designing a sheet-metal-bent variant. Larger. Easier to work with. Removable sound absorption panels. Aaccomodates 6 drivers (traction loss and belt tensioner), but those are not required.

So... all learning I guess. Happy with the rig in it's current form. With poly fiber accoustic treatment, it still emits *some* 10k noise; but it's not baaaaaaad. I have the motors wrapped in about 35+mm polyester fiber. The drivers; prob about 30mm (ish) on all sides and about 35mm on top (with slots for fan, as shown in drawings). No wrapping UNDER the drivers; but I they are sitting on 10mm foam + carpet.

All of the motors are wrapped in >30mm (prob more like 35+mm, some more, some less) poly fibre cloth. I'm printing motor enclosures now that provide 42mm clearance/space for poly fibre fabric. I've *stuffed* all I can into their bases, and have worked my way upwards.

Pics!

 

[Mascot]

Thanks @Mascot . I'm pleased to say its mostly been a success. The case itself, in its current form, is a PITA to work with (small. tight tolerances. no space to move hands). But it works. I'm currently designing a sheet-metal-bent variant. Larger. Easier to work with. Removable sound absorption panels. Aaccomodates 6 drivers (traction loss and belt tensioner), but those are not required.

So... all learning I guess. Happy with the rig in it's current form. With poly fiber accoustic treatment, it still emits *some* 10k noise; but it's not baaaaaaad. I have the motors wrapped in about 35+mm polyester fiber. The drivers; prob about 30mm (ish) on all sides and about 35mm on top (with slots for fan, as shown in drawings). No wrapping UNDER the drivers; but I they are sitting on 10mm foam + carpet.

All of the motors are wrapped in >30mm (prob more like 35+mm, some more, some less) poly fibre cloth. I'm printing motor enclosures now that provide 42mm clearance/space for poly fibre fabric. I've *stuffed* all I can into their bases, and have worked my way upwards.

Pics!

Crikey! The motor enclosures look fantastic. Love the screw-on design. Genius. And nice flat tops for resting bottles of Scotch.
This is a real obsession passion project..!
Have you any actual acoustic readings before/after? Very interested to know what the objective (as oposed to subjective) results are so far.

 

[Insert Coin]

Where did you buy the poly fibre fabric?

 

[scornflake]

@Insert Coin I don't have readings of the full; rig, 4 motors, drivers, no fabric. I had *intended* to do some, science and all. But. Meh. Didn't. I will try to do some tho. I'd be interested myself to know what that same software/hardware/mic combo picks up for the entire rig. Of course; it'll depend where the mic is.

All I can tell you right now is that the audible noise (10khz) of all four drivers + all four motors is the same, if not less, than a single driver + motor unit on the floor when I was doing my original testing. Aka: It is SO so "so" much less than 4x uncovered.

btw: My brother has done the same, and has the same feedback (he's done motor covers only, has his own solution for the drivers). His comment was "When I put the last cover on. Ahhhhhh. Silence. An end to the pain".

All 4 drivers. with 4 motors, was I.N.S.A.N.E. Immediate headache. I wondered if I'd been an idiot starting the project. I thought: Oh crap. I don't know if what I have in mind is going to be *nearly* effective enough.

Turns out it was. The initial research still holds. It is not 100% silent. There is some noise, still. But it takes the noise/pain from "oh CRAP" to "oh, I can live with that". My wife says the house shaking due to the motors / rig moving is more of a prob that the 10khz whine

I conclude that I'm "seriously affected" by the 10Khz. That to me, it matters. A LOT. So. If I have found a partial solution (becuase I always want to think and believe there is room to improve) that makes 4x drivers+motors "livable", then I have met my original goal. Mostly.

Still gonna prob build a metal case for the drivers tho

 

[scornflake]

@Insert Coin For me, Warehouse in NZ. Was some kind of black cover throw couch thing. I was looking for the finest polyester fiber most man made thing I could get You want something with zillions of fibres. More attenuation.

 

[scornflake]

btw: if anyone wants STLs, happy to post. I personally printed them using 0.8mm nozzle, 0.4mm layer height. That gave a decent tradeoff between outside finish/thread quality/time. You can of course do 0.2mm lh. But expect each half to take 30hrs.

 

[scornflake]

Here's some STL. Intended for 0.8m nozzle, but prob doesn't matter if you use less.
Important thing is clearance between the parts, which with these STLs is 0.6mm. Lots.

Dropbox

www.dropbox.com

 

[Prickles]

Thanks for your efforts a cornflake. I just finished my build and the 10KHz whine is terrible - luckily for me I can't hear it with my headphones on (open back, even with nothing playing in them), but my family can also hear it.

Looks like maybe I should try your motor covers. Just gotta find myself some of that polyester fibre stuff

Edit: any issues with motor temperatures being fully covered like that?

 

[Onii77]

Just some subjective input: if you can get them hooked up to 110 instead of 220 (i.e. step up/down converter), I had a substantial drop in 10khz whine. subjectively 50% or more.

All of that said, I am not particularly affected even when running on 220 so take my note with a grain of salt.

Again subjectively I THINK there is a small change in the intensity (I like my profiles very intense) but it's really hard to tell. for the last week or so I have been toggling back and forth to see if I can REALLY feel a difference or if it's just confirmation bias.

 

[scornflake]

Here's some STL's for just the motor covers. Intended that you print with a 0.8 nozzle.

Dropbox

www.dropbox.com

 

[JoeyD23]

Wow your case is bad ass!

I’ve been working on my SFX100 driver cabinet. I am just assembling this system so not sure how loud the noise is. Im hoping with the thanks and 110v that it won’t be too bad.

I started with a used 9U cabinet I found on offer up and got for $75.

I then wrapped it in Carbon Fiber vinyl and was going to just cut the section around the perf on the front door but started to punch holes. About 5HRs later I’ve got this someone cool albeit random design going on.

I have the 4 drivers mounted to a 9U mounting plate leaving tons of room behind the drivers for storing cables and other devices that hopefully won’t interfere noise use.

I installed 4 120mm RGB fans, 2 top and 2 bottom and also added 5v LED strips around the interior. Im thinking the backlighting with the driver screen and LED’s should look pretty cool.

Let me know what you think. Still a work in progress.

 

[JoeyD23]

Some pics! The case is 'brown' because I havn't taken the protective film off the acrylic panels yet.

Also interesting, I need to re-do the motor coverings. The cover needs to come down as far as possible. Noise is emitted well into the 3D printer motor mounts. It's not enough to cover JUST the motor. It's also emitted right out the top, so the covering must be good there as well.

Covers you see in the last shot are of course "testing" style, do you like my packing tape?

If you’re interested in selling I’d gladly pay for a copy of any parts you print or make for yours. I know 3D parts take a long time to run so understand either way. My actuator motor to profile parts are just black but I took would love red. I’ve been trying to find someone who makes anodized aluminum pieces to replace the plastic altogether but I’ve been striking out. ERacing lab has a killer looking set of actuators but their profiles I am not sure are compatible and it would take a full conversion that I don’t really want to do.