Hi everyone,

So, I've started my build. I've been lurking here for a while but the day came and I've started.

I'm going for a mainly book chassis with alterations to use mx5 donor parts. I intend to use Saturn design wishbones other the rear upper which is a bridge I'll have to cross when I get there. I'll also use the talon diff parts to fit that.

I've bought the bare steel and I've been using the mill I currently have use of to prep the ends.



I've also elected to tig it all together as I've always wanted a tig welder and this was a perfect excuse!





I would have done more today but only half the steel I ordered arrive. Does 32m of 25mm box and about 12m of 20mm box steel sound about right?

I'm hoping to have the chassis ready to go in the next couple of weeks. I've been acquiring mx5 bits as well and have a gearbox, diff and prop. I pick up an engine and all 4 uprights tomorrow.

Wish me luck!

Champion, will be watching with great interest. Some nice toys in the garage there!

Keep the updates and pics coming.

Steve

I love a scratch build


I must get my finger out.

Good Luck

I tig welded all my chassis as well, took some time but was very satisfying.

nice start, keep the pics coming and good luck
Gary

Nice to see another scratch build, not manny people seem to bother these days, nice garage to!

Thanks for the comments guys.

I completed the front frame yesterday. I don't like the front frame. Its a hateful piece of metal!

I've got a couple more days off this week so hopefully more will rise up from the table. I found some spare cash to buy all the necc metal so its all down to me now.

Can I ask what tig welder you have and how your getting along with it?

I'm thinking of buying one for my chassis....

And, what's so hateful of the front frame?

quote:

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Originally posted by coozerAnd, what's so hateful of the front frame?

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It's a TigMig TM200HF eBay special. It's an inverter type tig/stick unit.

Is it any good? Seems so however I'm no welder and this is the only tig unit I've used. Seems like it's good for the job.

Yes the compound mitres. Once I clicked the mill allowed me to get them spot on. The rest I made a mess of.

Some more progress.







That'll be it until next week. I'm hoping to have the chassis complete the week after next.

looking good! i think it starts out easy and just gets harder lol

It's probably a bit late now, but did you read the revisions for the Haynes chassis, in particular around that front frame? If you've not seen them, I suggest you head over to;

http://www.haynes.co.uk/forums/showthread.php?t=2430

There's also a slight twist required that Talon told me about. The way it's built up in the book doesn't present a flat face to the suspension bracket, it's very slightly off.

Hi guys,

Yes I found those a few days ago. In the end I made the frame from six pieces and machined the ends. It went together perfectly after. It's then I realised the angle bracket faces. I guess people are putting small shims between the brackets and bars to mount them flat?

quote:

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Originally posted by Mudchute
Hi guys,

Yes I found those a few days ago. In the end I made the frame from six pieces and machined the ends. It went together perfectly after. It's then I realised the angle bracket faces. I guess people are putting small shims between the brackets and bars to mount them flat?

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what i ended up doing was getting all of the chassis tacked together, then when it came to fitting the suspension brackets using the jig, one side had a gap and the other didn't so i un tacked the top frame and tweaked it out a little to close the gap, if i remember right it was only 1-2mm but made the fit on the bracket loads better

Rosco

Some more progress, all the diagonals are in and I've released the chassis from the build table to assemble the rear end. I am however in two minds again as to how to arrange the diff/suspension.

I was going to assemble the rear as per the book and mount the diff with the TMXR diff cover but thats money I can't afford to spend.

This then leaves the Saturn version with its short upper arms which bothers me. Has anyone here driven both versions?

The front suspension mounting tubes have confuszzled me. I can't quite get my head around the drawing in the book which shows where the tube joins the upper frame rails.



The above is mine (its the same both sides), does it look correct? If so I'll neaten it up and join them to the frame rails. I got a bit carried away tacking the bracing tubes together there and completed those two joins. Tig welding is seriously addictive!!

I'm hoping the main chassis will be done next week and I'll then start mounting the engine. I would crack on with the wishbones but that'll have to wait until payday. I can make the assembly templates before then.

I do have some parts to refurbish which'll keep me busy and I pick up some OE 15" MX5 wheels tomorrow as well. If everything goes swimmingly it could be sat on its own wheels next month.

This build bug has really bitten into me, I can't leave it alone.

[Edited on 15/5/15 by Mudchute]

Ah, some other questions for those in the know.

The diff will be mounted solidly to the chassis whether I go TMXR or Saturn. How will this be affected by the engine and box on their movable mounts? I was thinking of mounting them both on polybushes...

Also, one of the lower side to side tubes and bowed slightly meaning the its sticks out under the car by a couple of mm (its the one you chop the centre part out of to accomodate the trans).

I think my build table isn't as flat as I thought. Everyhing else is square and dimensionally correct but this got me thinking about an acceptable tolerance. So far I've been lucky enough to mill the correct angles and overall tube lengths accurately (to within 0.5mm or 0.5 of a degree) but I accept its likely to go out in places once welded or pefore so, is there an accepted tolerance people work to?

[Edited on 15/5/15 by Mudchute]

I hate to be the bearer of bad news but looking at your chassis pics you have made a huge fundamental error....







The tea mug is on the chassis...a metal surface.........the tea goes cold far too quickly

All joking aside, I have been suffering from cold tea syndrome lately. I put it down to my frantic efforts to get as much done as quickly as possible and forgetting about it however, your theory has weight...

The vertical one on mine has the outside corner going directly into the top rail, it's not sticking out at all. From memory the book is wrong on that one, it quotes the wrong corner as needing to be in line with the edge of the top rail. I believe the amendments quote the right approach.

Solidly mounting the diff won't make any difference to the car. Sierra diffs have been mounted solidly for years and never suffered any ill effects. Just make sure you're consistent, either mount the arms and the nose all via bushes or all solidly. Don't mix and match.

I think front to back mine has about a 2mm 'curve', with the middle slightly higher than the ends. There's no twist, or at least nothing I can measure.

Thanks Slimy, I'll revisit the front tubes and see why its different and I'll ensure the diff is either completely rigid or bush mounted all round.

I think the tube thats slightly out will partially correct itself once I chop out the bit that isn't needed. We'll see.

Does this steering wheel look sva friendly?

Ebay MX5 steering wheel

Is 1.5mm walled erw round tube ok for the wishbones?

quote:

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Originally posted by Mudchute
Is 1.5mm walled erw round tube ok for the wishbones?

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quote:

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Originally posted by Mudchute
Is 1.5mm walled erw round tube ok for the wishbones?

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Ah that's what I needed to hear, thank you.

Hi guys,

I'm now thinking about my cars body electrics and I want to be sure I have the correct number of switches in mind to order.

1. Side lights
2. Dip beam
3. Main beam
4. Main flash
5. Rear fog
6. Hazards

Re indicators, I'm tempted to make some sort of column mounted switch arrangement, one for each side. Would I correct in saying that so long as they are marked as indicator switches, are visible from the drivers seat and they illuminate to show they are working then I'm good to go?

[Edited on 25/7/17 by Mudchute]

How are you sorting your Steering Column?
If your steering column has some of them, you may not need that many...

I am using a Pontiac Matiz Steering wheel.
I wonŽt have wipers, so IŽll be using The Wipers switch to power a Fan Override.
Then, IŽll have everything on the column mounted Stalks except for the Hazards.
HTH

Hi guys,

Could someone critique my intended hazard light switch circuit please.



This is almost identical to how I have it atm but the hazard relay is fed by an ignition feed and there is no diode.

I thought the pictured circuit may work as if I give the hazard relay a battery feed I don't want it then feeding the standard indicator circuit with 12v say if I left the indicator switch engaged to either side and using the hazards when the ignition is off.

Also, Does anyone know how I'd wire up a standard mk1 3 wire mx5 alternator if I wasn't using a warning light? I understand I'd need a resistor and diode in the exciter wire but I'm unsure of what rating resistor if there was no lamp involved.

[Edited on 7/7/18 by Mudchute]