Reversable armrest + USB

**e31gixxxer** · 02-04-2011, 05:16 PM

Finally got round to fitting my armrest.
I haven’t seen one done like this, so here it is for your scrutiny.
The reason I have done it like this is twofold.
Firstly, none of the original e31 trim is harmed in any way so it can be returned to stock in minuets.
Secondly, by mounting the base/hinge this way up it is the same as in the e46, from which it is taken and so the hinge stops work as designed, so there is no need for extra supports etc.
I have utilised the extra bit tray in the armrest for locating my USB drives for the head unit. You could fit ipod, aux, or your preferred interface instead.
I am not doing a full step by step as most of it is self evident.

Once you have your e46 armrest, remove all the unnecessary plastic that is not required for e31 fitting as in pic.1. The assembly can be stripped easily by removing the springs on the ends, unclipping the centre hinge cover, and then removing the hinge pins by pressing the barbed retaining clips down with a screwdriver. These are the two square holes under the centre hinge cover.

Construct a bracket as in pic.2. This needs to be 5mm - 6mm for strength. Note the tabs on the front and rear are not perpendicular to the base as the hinge assembly is tapered. It forms a dovetail when fitted together and actually held prior to drilling and bolting, as in pic.3. I used M6x75 ss dome heads and tapped the front tab.

Remove bit tray upper section. It pops out.
Mount required interface sockets.
Remove ribs that interfere with sockets.
Drill a cable hole in the end of the hinge pin and bit tray hinge.
Reassemble the components as in pic.4.

Use the e46 cover trim part No. 51 16 8 218 307 (black), and remove the parts that don’t look like they belong in an e31. Use your best plastic welding skills and refit these parts you have cut off in to a different configuration until you have an e31 cover trim. Drill mounting holes and insert metal crush proof spacers.
I had to buy the e46 trim new as I couldn’t find a breakers that would split this from the consol, but at £14 GBP, 2 day, main dealers, not too bad. Paint as required.

Remove the mat from the bottom of the centre consol tray. The holes in your bracket should be countersunk and line up with the existing fixing holes in the tray. Remove the screws and fit your bracket using slightly longer screws to allow for the thickness of the bracket. This is surprisingly ridged. Replace the mat with some length removed to allow for the bracket, or make a new one, as I did so the original parts are preserved.

**e31gixxxer** · 02-04-2011, 05:19 PM

More pics.

**Bryson** · 02-04-2011, 05:42 PM

Best one I've seen yet! I might even make one for myself now...

**DMPrentice** · 02-04-2011, 06:45 PM

LOOKS FANTASTIC !!!!!!

If I can find the correct colors I am going to get on that as soon as the front suspension project is complete...

Once again OUTSTANDING !!!

Cheers

DMP

**mcat911** · 02-04-2011, 07:29 PM

That's excellent, thank you, I need an armrest

**rcrad6653** · 02-04-2011, 07:33 PM

I have all the other elements and have been hung up on the bracket...the UK chap who made the nice one never came up with specs or drawings. I'll pay you for a duplicate bracket, paypal waiting. Thx

**e31gixxxer** · 02-04-2011, 09:04 PM

I have all the other elements and have been hung up on the bracket...the UK chap who made the nice one never came up with specs or drawings. I'll pay you for a duplicate bracket, paypal waiting. Thx

Randy
Apologies for the lack of dims/drawing on my setup, but it was a prototype that ended up working first time and got installed.
You could start with a plate that fits snug in the bottom of the tray. A vertical plate perpendicular to that at the back, about 6mm higher than the top of the consol. Make the rest to fit your cut down e46 rest. Offer it up in situ. and mark it. Tack it. Check it. Nail it. If you want to get started as I know from your posts you are more than capable.
I wasn't looking at producing these, but I have had another request. I will probably remove mine, take some measurements and post the drawing. I may make more, but I am not really setup to mass produce, so they would be labour intensive hand made. Please give me time to sort out as it will be a while before I can get back in the workshop.
Regards gix

**cartoonz** · 02-04-2011, 10:28 PM

keep in mind that ours need to be oriented differently on this side of the pond though...

**ELIBEEMER** · 02-05-2011, 12:48 AM

congrats, it looks great!

**Frankie** · 02-05-2011, 03:18 PM

Originally Posted by e31gixxxer

...I will probably remove mine, take some measurements and post the drawing. I may make more, but I am not really setup to mass produce....

The bracket is the key.

Well done. If the bracket becomes available to purchase I will add it to my write-up on this topic. (For whatever promotional value that may be to you.) With the actual bracket dimensions, someone here with access to a CAD/CNC set-up may be able to produce them.

I've found that my armrest is still a bit weak regarding side loads (twists a bit when loaded over the e-brake), even though most loads are borne directly onto the center console. This is probably due to the connection points in the center cubby - they are in-line, tandem screws. What is needed is two lateral anchor points. I mention this because your bracket will be under VERY strong loads due to the long moment arm from the hinge. Any side load will be magnified, causing a strong twisting force. You may want to consider an additional mounting point other than just the two cubby screw locations.

**e31gixxxer** · 02-05-2011, 03:56 PM

keep in mind that ours need to be oriented differently on this side of the pond though...

Should just be mirrored to fit wrong hand drive

The bracket is the key.

Well done. If the bracket becomes available to purchase I will add it to my write-up on this topic. (For whatever promotional value that may be to you.) With the actual bracket dimensions, someone here with access to a CAD/CNC set-up may be able to produce them.

I've found that my armrest is still a bit weak regarding side loads (twists a bit when loaded over the e-brake), even though most loads are borne directly onto the center console. This is probably due to the connection points in the center cubby - they are in-line, tandem screws. What is needed is two lateral anchor points. I mention this because your bracket will be under VERY strong loads due to the long moment arm from the hinge. Any side load will be magnified, causing a strong twisting force. You may want to consider an additional mounting point other than just the two cubby screw locations.

Cheers Frankie, no extra fixings required. Quite happy with the strength in mine. The load is spread across the whole area of the base, and the screws "sandwich" the tray between the bracket and the centre console. This provides lateral support also.
There is a few mm of flex down if you realy push hard, but only slight and you do have to push HARD, more than resting your arm. I think I could sit on it, maybe. I May test it with some weights.
More detail to follow.
Cheers gix

**e31gixxxer** · 02-05-2011, 04:18 PM

Some more pics. that may help.
You could get the dimentions from your own cars if you want to make a start. Just make the vertical 5 -6mm higher than the top of the console, as the hinge clamping part does not sit horizontal, bur tips down at the front.

**Bryson** · 02-05-2011, 04:36 PM

The base will need a plate that is 8.25" x 2.375" (2 3/8) wide with ~3/8" radius corners. The vertical support must be 2.675" (2 5/8) tall.

I don't have CAD with me at the moment, so I can't draft the parts up, but that should be a good start for the bottom part. I'd recommend a triangular shaped gusset if you're worried about loading. That should move the loads directly downward, eliminating the large moment arm (and virtually any flex) imparted by your current design.

I'll do my best to get something drafted into the computer, but I don't have an armrest to take dimensions of..

**e31gixxxer** · 02-05-2011, 05:12 PM

Thanks Bryson,
a gusset would work as you say, we could also use it as an emergency engine lift then.

It only moves 3mm (1/8" old money) maximum.
You can still use all the space underneath it unobstructed with the Mig weld fillet method, but it is all adaptable as you don't destroy anything, So easy to develop if not happy.
Just going out to sit on it now, got to know.

**Whisky** · 02-05-2011, 05:40 PM

folks who don't drive their cars long distances (time wise) just don't get it..

very nice mod - good job

**MParallel** · 02-05-2011, 06:14 PM

Nice mod. I'm surprised such a car never had the option for a center armrest. Once you're used to one, you can't live without it.

**rcrad6653** · 02-05-2011, 06:47 PM

Originally Posted by Bryson

The base will need a plate that is 8.25" x 2.375" (2 3/8) wide with ~3/8" radius corners. The vertical support must be 2.675" (2 5/8) tall.

I don't have CAD with me at the moment, so I can't draft the parts up, but that should be a good start for the bottom part. I'd recommend a triangular shaped gusset if you're worried about loading. That should move the loads directly downward, eliminating the large moment arm (and virtually any flex) imparted by your current design.

I'll do my best to get something drafted into the computer, but I don't have an armrest to take dimensions of..

Bryson, the two dimensions you need for the main mounting top piece is: 2 1/4" (snug) by 5 1/8".... I cannot say about the front and rear ears. Of course the vertical needs to be mounted opposite

Also, quite awhile back I got these hinge end caps made by a well known member here..... I'll let him speak up if he'd like to produce more. This eliminates the necessity of trying to locate the parts to use like shown. gixxer's are the best IMO but could be a pain to source. I think the roundel is a bit over the top so I'll have these anodized black.

**e31gixxxer** · 02-05-2011, 07:11 PM

Data: Bottled it! Did a good lean across though!

Load test: A weight of 34.2lbs, (15.5kg), a Dell optiplex gx 400, was applied centrally to the rest. The deflection was 1/4", (6mm).
When the weight was removed the rest returned to the original position.

I think that as a diy method anything along this line will be ok. A box section vertical would be nice!

Conclusion: A vehicle with the build quality of ours perhaps deserves something better. Aluminium, carbon, some cnc work, you know, it could almost be more of a feature and not need the plastic trim.

It would be nice if someone could produce one commercially. Nice caps Randy by the way. The e46 rests are readily available here so easy to use.

Had a good run round today, first trip since the bad weather. Not cold, windy, wet. Rest was great position for me. About the same as the door one, but wider and comfier. My hand is on the gear selector. Lift it to get two coffees in the console and then you can still put it down. Suppose that depends on how big your coffee is.

Cheers gix

**Bryson** · 02-05-2011, 08:08 PM

Originally Posted by rcrad6653

Bryson, the two dimensions you need for the main mounting top piece is: 2 1/4" (snug) by 5 1/8".... I cannot say about the front and rear ears. Of course the vertical needs to be mounted opposite

thanks Randy, I'll get on that and see what I come up with.

One last question for you gix,

You said that the top mount isn't level with the floor piece.. the only dimension I'm missing now is one that describes how tilted that top mount really is. Could you measure the height of the front and back of the mount so that I can get that tilt right? Trying to do this without an armrest first, though I realize that procuring one would be the simplest solution

Thanks!

Bryson

**Frankie** · 02-05-2011, 10:43 PM

Originally Posted by e31gixxxer

.....The load is spread across the whole area of the base, and the screws "sandwich" the tray between the bracket and the centre console.....

This is exactly how mine is secured too. But it still twists slightly when loaded on the driver's side. And it's the driver-side which bears the most frequent loads. Again, this is due to the geometry of the two off-axis tandem mounting screws, sandwiching the plastic console. Take a close look at my armrest installation:

Loading the armrest directly over the console (passenger side, front to back) isn't much of a concern. But loading it over the unsupported driver's elbow portion creates off axis (left) twisting moments. This area - where the underside lock is located - will probably be used as a hand/elbow placement point when entering or exiting the car (this is how I use it). Creaking, squishing plastic sounds are the result.

You no doubt noticed how stout the E46 mounting arm was before you cut it for your mod. You may have also noticed its third mounting screw location: off axis, to counter those loads.

Originally Posted by Bryson

.....I'd recommend a triangular shaped gusset if you're worried about loading...

This would only brace on-axis loads. As discussed above, the concern is with off-axis loads, since the armrest's vertical mount does not span the full width of the armrest.

I mention this not to be merely critical, but instead to offer constructive feedback based on my experience, and to address a potential weakness in gixxxer's bracket design due to its greater moment loading.

**e31gixxxer** · 02-05-2011, 10:55 PM

Soz for the lack of info. will provide measurments asap. But top of my head about 1/4" up at the back and a comfy, not digging in at the front. Guess 5 - 8 degl

[QUOTE][Originally Posted by e31gixxxer

.....The load is spread across the whole area of the base, and the screws "sandwich" the tray between the bracket and the centre console.....
This is exactly how mine is secured too. But it still twists slightly when loaded on the driver's side. And it's the driver-side which bears the most frequent loads. Again, this is due to the geometry of the two off-axis tandem mounting screws, sandwiching the plastic console. Take a close look at my armrest installation:

Loading the armrest directly over the console (passenger side, front to back) isn't much of a concern. But loading it over the unsupported driver's elbow portion creates off axis (left) twisting moments. This area - where the underside lock is located - will probably be used as a hand/elbow placement point when entering or exiting the car (this is how I use it). Creaking, squishing plastic sounds are the result.

You no doubt noticed how stout the E46 mounting arm was before you cut it for your mod. You may have also noticed its third mounting screw location: off axis, to counter those loads.

Quote:
Originally Posted by Bryson

.....I'd recommend a triangular shaped gusset if you're worried about loading...

This would only brace on-axis loads. As discussed above, the concern is with off-axis loads, since the armrest's vertical mount does not span the full width of the armrest.

I mention this not to be merely critical, but instead to offer constructive feedback based on my experience, and to address a potential weakness in gixxxer's bracket design due to its greater moment loading.
__________________
Frankie
Austin, TX

/QUOTE] Dude, with respect I am not trying to undervalue your achievements, I respect your opinion, but the OEM parts are very strong and the c/g is low on the fit. I have no issues with it, apart from wanting one made from titanium or other rare earth elements.
Cheers gix:~)

**e31gixxxer** · 02-06-2011, 06:31 PM

Ok got some dimensions for you.

The angle of the top section is not as much as I remembered. The difference is 1 mm lower at the front on mine, so mounting it level should be ok.
I have taken Frankie’s concerns over the screws onboard and modified the metal clips and used M5 countersunk ss capheads.
Easier to fit them now as the rear one, that is awkward to get at can be tightened with a 1/4" drive ratchet.

Rock solid!

Don't forget to reverse the drawing for L/H/D.

**cer54467** · 03-23-2011, 09:36 PM

I got this Mod just about done, I fastend it in the car to check it out to see if i need to cut it apart and redo. It feels right just looks a little high but i am 6'1" anyway. What is the Pn for the E46 hing cover for the passenger side of a LHD car? What is the Of of the round aluiminum hing cver that was made for the othe open side? I have a lathe and mill in my garage. I sanded it but i havent primed/painted it yet.