Chris's new build of an MX5 based car

[CTWV50]

Great news Andrew, are your flat packs seamless tube or ERW? Don't want to sound dramatic but I'm putting my sons life in this car and I want to do the best by him. If bike frames are made with seamless surely a car frame should be made with seamless, or does the mount of steel used in conjunction with triangulation resolve this. Sorry just a bit worried about frame strength. Some one at the local suppliers said it would be a good idea to tig weld it for strength while someone else has suggested purging the tubes with inert gas to improve the internal weld strength. I'm sure some of the above is unnecessary but just need some reassurance really as to the details. The saying "A little knowledge is a dangerous thing!" springs to mind.

HELP!

Matt, I am so tempted to I really am. Can't imagine my son being to keen to help cut steel by hand/grinder.

[CTWV50]

OK so I gather seamless is pretty much unavailable after speaking to a few companies so I guess ERW is the only and a safe option. I guess the book meant "seamless" as in, you can't distinguish the seam externally? :shruggs:

[spud69]

Hi Chris,

Just seen your post, had visitors for last 2 hours - comes with the sun i suppose.....

The car is designed around ERW box section and as you say the triangulation gives it its strength. What HandyAndy does is to cut and put together the chassis packs in 2mm walled box, unless otherwise asked, which gives the frame a lot more strength and stiffness for not a great deal of extra weight.

Andrew

[CTWV50]

Thanks for the reply Andrew. I have decided that taking a chassis kit from HandyAndy would be my best option, it's a great price he's selling at considering how expensive steel is and the cost of equipment and time to cut it.

I have built my build table after flat planing many bent bits of scant and discovering quite how out of level my garage floor is. So after many hours being quite particular I now have a perfectly flat and painted build table.

I started marking out but then stopped as I decided it would be easier to do when the steel has arrived although I did manage to get BR5, 6, 11, and 12 marked out and after checking diagonally I was maybe 0.6 mm out iirc! Which I thought was quite good.

I have spent most of the weekend either asleep or in the garage, that build table started to look very comfortable and inviting. Oh also this weekend I managed to knock the passenger side wing mirror off of my donor by letting the build table fall on it! Oooops!

[HandyAndy]

Originally Posted by CTWV50

I have decided that taking a chassis kit from HandyAndy would be my best option, it's a great price he's selling at considering how expensive steel is and the cost of equipment and time to cut it.

I have built my build table after flat planing many bent bits of scant and discovering quite how out of level my garage floor is. So after many hours being quite particular I now have a perfectly flat and painted build table.

I started marking out but then stopped as I decided it would be easier to do when the steel has arrived although I did manage to get BR5, 6, 11, and 12 marked out and after checking diagonally I was maybe 0.6 mm out iirc! Which I thought was quiet good.

I have spent most of the weekend either asleep or in the garage, that build table started to look very comfortable and inviting. Oh also this weekend I managed to knock the passenger side wing mirror off of my donor by letting the build table fall on it! Oooops!

Hi Chris,

Cheers for your kind words, with the amount of steel that I purchase it helps to keep the costs down

Nice work on marking out your build table so well, 0.6mm is barely the thickness of a fine tipped marker pen , the time taken at the early stages will really benefit the build later on.

I,ll reply to your PM

cheers
andy

[CTWV50]

Originally Posted by HandyAndy

Nice work on marking out your build table so well, 0.6mm is barely the thickness of a fine tipped marker pen

Ahh that's why it wasn't spot on, too fat a line. I'm joking!

These tools helped, iphone apps for your haynes build!

[CTWV50]

Well I never! Never buy those disposable 60 liter (950cc @60bar) halfords bottles of weld gas they are such a rip off! I have only bought one and it ran out very quickly. After a little bit of brain power I have worked out that you get.....wait for it.....at a gas flow of 10 liters/min.... a total of..............6 whole minutes of weld time!!!! I couldn't believe it! No wonder you can just throw away the bottles! Jesus!

Just got myself a 2,420 litre bottle (10.5 liter@230bar) with a proper reg and some 2 mm walled box for practice. Should keep me busy with 4 hours of trigger time!

[CTWV50]

This weekend I've managed to mark out my entire table, all modesty blocked out and decided to involve the children aged 4 and 7 by jacking up the mx5 on axle stands and removing all the wheels for cleaning, obviously I ended up finishing the job and my eldest decided he wanted the wheels painted gold, not my first choice for a red car but hey-ho!

[CTWV50]

Today I finished the house re-pointing (a nasty boring job) and other odd outstanding jobs. Don't want anything slowing me down once my steel arrives!!

Oh and found a dead half eaten rat in the garage! Now it's all clean and nice I guess they thought they'd have a bloody party! Literally! B'stard things!

[CTWV50]

One successfully 450mm narrowed mx5 seat. Once I'm happy with the recline angle, I'll remove the adjuster and use it as a template to make a 3mm plate bracket instead. Bit baggy on the base but hey it was free! Oh and it weighs only 9.5kg without all the extra brackets and gubbins.


DSC00002 by CTWV50, on Flickr