MGF/TF seat brackets to mount aftermarket seats

[Rob Bell]

There seems to be no aftermarket seat bracket that fits directly into an MGF/TF available off the shelf, so I am resigned to making one, or have them fabricated.

What I'd like to do is to solid mount a pair of bottom mounted seats (Cobra Clubmans in my case) into the car, but the bracket I envisage could be used to fix a pair of universal seat runners and almost any chair of your choosing.

MSA stipulate that mild steel seat mountings are acceptable, and need to be made from 3mm sheet, so that is what I've gone for here:

Seat mounting proposal

seat_bracket_proposal.jpg (59.78 KiB) Viewed 7535 times

I am going to ask a local (to me) firm of sheet steel suppliers/ fabricators to have a look at this and provide a quote if they feel that they're able to do it.

Just wondering whether anyone else has experience in this sort of thing, whether the above proposal is doable, and whether anyone else would like a set if I can get them made?

[artful.codger]

Am I right in thinking there are one of each of the pieces shown above for each seat Rob? Are the passenger side a mirror image or the same as the drivers side?

My son works in sheet steel, I'll ask if he could make them in 3mm stainless.

[Stan_B]

I would stick with mild steel, Stainless may be too hard for this application and fracture rather than stretch in a crash. They will not be visible and wont see too much weather so a coat of black paint should work. They look like they will go through a folding machine OK as well.
ps, you can get galvanised mild steel sheet as well, probably ex stock

[dfv8]

I'd concur with the advice about sticking with mild steel. Stainless has a propensity to work-harden. Now I'm not a 'sheetie', but that end of your diagrams with the 10mm rise would be a nightmare to bend in 3mm in any material (11 SWG but 10 SWG the closest commercially available).

fortunately I've found one pretty close to me

And they are??? Seems that this topic would make a good sticky for the forum.

[Rob Bell]

Am I right in thinking there are one of each of the pieces shown above for each seat Rob? Are the passenger side a mirror image or the same as the drivers side?

My son works in sheet steel, I'll ask if he could make them in 3mm stainless.

Yes, I'd need another pair as a mirror image to the two shown above Rick

I was going for mild steel rather than stainless - and the Guy's thoughts on the material properties makes me think that this is probably right. Also, black paint is perfectly acceptable for Project Shed!

I'd concur with the advice about sticking with mild steel. Stainless has a propensity to work-harden. Now I'm not a 'sheetie', but that end of your diagrams with the 10mm rise would be a nightmare to bend in 3mm in any material (11 SWG but 10 SWG the closest commercially available).

fortunately I've found one pretty close to me

And they are??? Seems that this topic would make a good sticky for the forum.

The 10-35mm fold is the bit I am most worried about. If the seats I had were side mounted, I don't think that it would be a problem, but for base-mounted/ seat runners, you need a little height for the bolt heads over the stiffening member across the car. Plus, the angle so that the seat squab angle is comfortable. Making the height higher will make you feel as though you're sitting on rather than in the car, so this is a toughie.

Will post details of the company if they think they can help out.

[sniperpenguin]

Hi Rob,

I know a couple of people who have achieved 3rd party seats, and they have all done it a different way - by modifying the existing runners rather that fabricate from scratch.

They sacrifice a little height this way, but they maintain the adjust-ability of the seat. All it requires are donor seats (FINALLY, something MK1 cloth seats are good for )

Final build goes Old Runners > Adaptor to universal fitting > 3rd party seat

[Rob Bell]

Thanks Nigel - yes, there are a couple of people who've done this, with what appears to be terrific results from what I've seen on .org

This may be ideal, but actually I was going for a fixed seat, since both myself and partner in crime, Tim Woolcott, have similar length legs, and I suspect that we'll be the only ones driving it. So no adjustability. Plus, with no welds, the folded steel will actually be stronger and less likely to fail.

BUT....

Just got the quote back from the local steel fabrication company. I don't know quite why, but they think that this is going to set me back £220 quid for the pair. Excluding VAT and delivery.

I think they're on cloud cuckoo land - or they don't want the job. Unless I am being unrealistic about material and labour prices??? I have asked what can be done to reduce the cost. I'd be happy to change the design to a side - mount to simplify the fabrication. Can anyone help?

[Reckless Rat]

I hear DFS have got a sale on if you're looking for something comfy... but I'm not sure if a 3 seater leather sofa with recliners will fit.

[Matt Parker]

Not bad Rob, my runners were originally for MGZR/R25 and all I had to do was to weld on extentions to both front mounts as the mounting points were about 1.5" further forward, and I removed the rear centre cross bar section due to the shape, other than that they go straight in, you just have to remember to pull the seat belt pre-tensioner wiring forward when bolting in so you don't pinch the wiring with the rear of the seat subframe as they sit on the floor

you can still use the seat manufactures sliders so I can move the seats back and forth if required.

[Rob Bell]

I hear DFS have got a sale on if you're looking for something comfy... but I'm not sure if a 3 seater leather sofa with recliners will fit.

Just typical. DFS weren't putting the lightweight MSA approved seats on sale. Only the nasty corner set that clashed with Project Shed's colour scheme

Not bad Rob, my runners were originally for MGZR/R25 and all I had to do was to weld on extentions to both front mounts as the mounting points were about 1.5" further forward, and I removed the rear centre cross bar section due to the shape, other than that they go straight in

Thanks Matt - I may investigate this further, as the runners from a scrap R200 is going to yield something much cheaper than a bespoke bracket laser cut from mild steel.

I spoke to the chap at the steel fabricators. Apparently much of the cost is in cutting out the shape (as it isn't a straightforward rectangle, unfortunately), but there is a contribution from the bends. I may try and simplify the design by going with a side-mounted design - but I am not really prepared to spend more than 100 quid on this.

So chaps, is my expectation of getting four seat brackets made for the princely sum of less than 100 quid completely unreasonable? Can anyone help? How much can 3mm mild steel sheet actually cost???

[Reckless Rat]

I would be tempted to try a cockle something together on my own. At the end of the day you're not going to see them. It's amazing what you can achieve if you set your mind to it. You can make your own sheet bending mandrel if you've got a decent bench & vice. I can lend you a nice hammer & dolly for the complicated bits. (mind you you'll have to come to France to fetch them). Now the schools & colleges are going back, there might be some night classes available for such a project.

By the way, Rob... a lathe can come in handy. I have a nice little Myford lathe for turning the odd replacement part for my extensive collection.

[Rob Bell]

As it happens I have a neighbour who collects old machine tools - including lathes, as well as old clocks and is chairman of the local clockmaker's club (or whatever they're called). So potentially have access to this facility, although I would hate to break one of his precious machines!

I've never attempted to bend 3mm without a bending machine (and even that was when I was at secondary school - ahem, I shall deny knowing how long ago that was). I have my old grandfather's British made vice on top of a bench made from kitchen work top, but will it be possible to get a decent bend in it? Done it with nice thin sheet readily enough, but 3mm? Need a bigger hammer...

[Reckless Rat]

I'd be tempted to cut it straight & then MIG weld the joint rather than trying to bend 3mm. Piece of cake if you've got a professional hydraulic plate former, but at home you'll never get a very tight radius. Unless you've got a warm spanner as well.....

[Stan_B]

I would get these made at a local metal stamping outfit in High Wycombe called Jeffark. They have a full set of kit and are always happy to help out on a sports car.
I think your local outfit didnt want to tie up a skilled man doing the job.

[Rob Bell]

I would get these made at a local metal stamping outfit in High Wycombe called Jeffark. They have a full set of kit and are always happy to help out on a sports car.
I think your local outfit didnt want to tie up a skilled man doing the job.

Stan, you're a star. I'll drop them a line.

As a complete coincidence, the company I approached has it's head office in High Wycombe... are there a few fabrication companies up there?

[Stan_B]

Rob, thank me when they agree, and ship you some working parts. I have been trying hard to remember the owners name, but failed. He is a bit steam age, likes drawings by fax! So a phone call will be best. Yes High wycombe used to be quite an industrial town in light engineering. There are still a few survivors one of them part owned by a WAMGOC member, but they dont do what you want.

[J13UTM]

Rob

If you send me some more detailed info on the design I could knock you up a proper CAD model?

[Rob Bell]

Thanks James. What would you need? The basic measurements are in the cartoon above. All angles are right angles - although the rear bolt mounts (the flaps at the rear of the mounts) are more acute. I need to measure these, and can certainly let you know.

Been a bit tied up these last couple of days and so haven't followed up a call to Jeffark - hopefully might get some time to do this tomorrow.

[J13UTM]

Only thing I would need would be the rear bolt mounts, though i can adjust the model with this later.

Ill get to work once ive got latest Solidworks downloaded, should be about 3/4 days.

I can also produce a tech drawing for it too, nice piece of kit is solidworks

[Rob Bell]

That sounds awsome James

The rear bolt mounts are those tabs (35mm deep). I've not marked the hole positions, as I reckoned I could save some cost and have some adjust-ability if I simply drilled these myself.

There needs to be an additional pair of these brackets made as a mirror to those shown. If I get a quick moment over a cup of tea, I shall see whether I can do something...