Cracked sport seat hinge gearbox - first prototype ready

E28 technical advice asked and given! Troubleshooting, modifications and more.
tn535i
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by tn535i »

And isn't it interesting that it's still worth the effort of finding solutions to problems you would never have encountered if it wasn't worth keeping the car going for so long in the first place.

Just last night in parking lot (Harbor Freight btw) some guy said to me, "I had one of those cars once and loved it and should have kept it".

:)
Pattonky
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Pattonky »

I am interested in this as well.
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

There is so many great fixes and mods for this car that got started on this board.
If there is a problem that can't be fixed easily and parts are hard to find, somebody will get so annoyed that he will start looking for a new solution. This is what happened here.

I don't think this will happen to a lot of newer cars in 20 years.

We are still working on the program and figuring out the details but I should have a cost estimate within the next two weeks.
Yojedi
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Location: Orange County, CA

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Yojedi »

BenGerman wrote:There is so many great fixes and mods for this car that got started on this board.
If there is a problem that can't be fixed easily and parts are hard to find, somebody will get so annoyed that he will start looking for a new solution. This is what happened here.

I don't think this will happen to a lot of newer cars in 20 years.

We are still working on the program and figuring out the details but I should have a cost estimate within the next two weeks.
:up: :up: :up:
jon roll
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Location: Northern Baltimore County Md.

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by jon roll »

I'm interested
Brian O
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Location: Portland OR

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Brian O »

Cant wait to see these available. I need two!
BenGerman
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Location: MA

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

:alright:
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Pauly Walnuts
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Pauly Walnuts »

This may have been asked but I'm assuming the passenger and driver's side are the same?
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

They are both the same. There is a left and a right piece.
Brian O
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Location: Portland OR

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Brian O »

Any chance you will be doing the other half of the gearbox?
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

We have thought about it, but it requires quite a bit more machining.
The integrated gear set would be hard to do for a reasonable price.
I have an idea how to avoid it, but I will not have time to take care of it before later this summer.

So the answer is: maybe, but not in the beginning.

Do yours break in the back, where the transfer cables attach? Do you have a picture of the defect?
Brian O
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Joined: Mar 12, 2017 11:59 AM
Location: Portland OR

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Brian O »

Yes it is where the cables attach and turn the plastic gears. I would love to hear a workaround :D I'll post pics tonight

Here is the pic of one of the broken ones. [img][http://s44.photobucket.com/user/Brianeh ... ml?o=0/img]
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

I mounted them on the seat last night, super easy.
Will do the same thing in the car next week and check how they work.

There should available capacity on the machine by late April.
We also have a pricing figured out. I will make that official as soon as the plates have been tested on the road.
Is not a super cheap fix but way cheaper then buying the whole assembly or getting a used seat for it.
Plus you won't have to worry about them braking again.

They will by anodized dark grey or black.

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duggi
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by duggi »

Consider me impressed! When this thread first started I'll admit I was a bit skeptical, but damn, nice job! My driver's seat had this issue at some point before I got it, as it has a replacement gear box on it already with a more modern BMW sticker, but I'm sure the others will need attention eventually.

Now..next problem: is there any effort being made to reproduce the plastic covers that hide these boxes? :laugh:

(fwiw that was a total joke, you've done more than enough just doing this!)
tn535i
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by tn535i »

Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.
Yojedi
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Location: Orange County, CA

Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Yojedi »

tn535i wrote:Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.
That's a really good suggestion. Since the 3D model is now available would the OP mind getting a quote for 3D printing? Could be a "possible" low-volume, low-cost option but don't quote me.
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

Thanks guys!
It still needs little adjustments here & there but thats why they are prototypes.
tn535i wrote:Very very nice work by the OP.

I guess those plastic covers can be 3D printed by someone.
Yojedi wrote:That's a really good suggestion. Since the 3D model is now available would the OP mind getting a quote for 3D printing? Could be a "possible" low-volume, low-cost option but don't quote me.
I think we are talking about two different things here. The actual gearbox plate that I machined and the plastic covers that go on the outside to cover the gearbox. (who would want to cover some shiny aluminium anyway, haha)
I was thinking about 3D printing before but I don't think a material that will be strong enough is actually a lot cheaper than machining it.
Maybe I will find some time later to contact a couple places. For now we have all the soft jaws made up and everything in place to machine them.

Potentially by the end of summer/fall there could be a solution for the back side of the gearbox as well.
Yojedi
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by Yojedi »

BenGerman wrote:Thanks guys!
It still needs little adjustments here & there but thats why they are prototypes.

I think we are talking about two different things here. The actual gearbox plate that I machined and the plastic covers that go on the outside to cover the gearbox. (who would want to cover some shiny aluminium anyway, haha)
I was thinking about 3D printing before but I don't think a material that will be strong enough is actually a lot cheaper than machining it.
Maybe I will find some time later to contact a couple places. For now we have all the soft jaws made up and everything in place to machine them.

Potentially by the end of summer/fall there could be a solution for the back side of the gearbox as well.
BenGerman, nevertheless kudos for undertaking such project. As most of parts for E28 are already NLA these 3D models you are constructing will be invaluable to the preservation of these fine German specimens and our community. :clap: :clap: :clap:
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

Negotiations with the machine shop are completed.
I started a group buy thread here:

http://www.mye28.com/viewtopic.php?f=4&t=143376

I will keep this thread updated with pictures and a install video.
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

We got 14 pieces together, I'm about to place the order with the machine shop.
If you still want one, let me know until 8pm ET tonight.
tn535i
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by tn535i »

I was looking at the gearboxes on my 6er's driver's seat last night which is out of the car and they look perfect to me. I'm unsure how the box gets so much stress to crack but I trust you that they can. I remember my driver's seat somehow the two sides were clocked wrong when I got the car with one side leaning forward of the other. It really bugged me and felt different than the passenger seat until I discover and fixed that. I'm thinking it was mostly due to things being loose.

This part is so well executed I almost want some for that reason alone. I will take a much closer look at mine tonight and decide.
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

Thanks for the compliments again.

If yours are not cracked, that's awesome! It probably also has to to with the previous owners: how often it was used, weight,...
I will send everybody that was initially interested a mail, since I would like to close things by tonight.

Raw material is in stock and there is a slot in 2 weeks on the machine that I would like to use.

The final part will be black anodized.

I will bring some with me to the Vintage.
cek
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by cek »

I have aluminum over this (that's like wood, but more metal).

Take my money! Seriously.
BenGerman
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by BenGerman »

cek wrote:I have aluminum over this (that's like wood, but more metal).

Take my money! Seriously.
I can make you one out of wood for your money?! ;)
ElGuappo
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Re: Cracked sport seat hinge gearbox - first prototype ready

Post by ElGuappo »

This is sofa king cool.
I love these modern solutions to old problems.
For a while it seemed like everything had been figured out on these old girls...
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