Build Tolerances?

[Airhead]

Just a quick question. I started cutting and tacking my metal together today; overal I am really happy with it but I was wondering what sort of tolerance is acceptable with regards to gaps between the metal? I am having to cut my metal with a hacksaw and have never been great at it so as the thing fits together, especially at the front with the angled rails, there are tiny gaps where my angles are out by a half a degree or so (about 0.5mm over the width of the tube (25mm)).

Any advice is appreciated.

Thanks

[drury318]

Hello Airhead, welcome to the forum. If the gaps are as you say they are OK, a small gap when welding is not a bad thing so long as you don`t let it get out of hand and sloppy etc.You need to keep the overall measurements of the chassis really accurate though, if the plans say the chassis should be a certain length or height at a certain point then concentrate on that more than the gaps. When you come to fit the suspension brackets etc you will be really pleased you did, it makes life MUCH easier!

Dennis.

[spud69]

Just as Drury says, firstly, welcome to the forum for another new builder and his first post.

Good luck with your build and if you have cut everything to 0.5mm and half a degree then you've done really well. You certainly wouldn't get that accurate with a chop saw.

All the Best...AndyH

[Enoch]

I had small gaps on mine in a few places, it's no big deal if you are a fairly decent welder. I am quite new to welding and found that I blew a few holes where there were largish gaps. I soon learnt to fettle the tubes so they fitted as tight as possible and then to look at the joint before I started to weld it. By the end I got quite good and could modify my technique to still get a good weld if the joint was less than perfect. My advice would be to just take your time, make the joints as good as you can, practice welding first if you need to (don't know what your experience is) and most importantly, enjoy your build.
Welcome to the forum, there are some seriously hlepful and experienced builders on here, I would be nowhere near as far as I am with my build without their help.
Best and all that,
Enoch
www.deepfolly.co.uk

[HandyAndy]

Welcome to the forum :)

As others have said, if your cuts are that accurate you are doing really well , As Dennis has said, making sure the chassis is correct in the dimensions is really what to aim for, with strong welds at each joint too,
keep checking the dimensions against the book spec on each phase of the chassis build up & you,ll end up with a really nice chassis.

Enjoy your build & any questions just ask, this forum is a wealth of knowledge in every part of the build.:cool:

cheers
andy

[Airhead]

Hello everybody.

Thanks for the replies!

I have been checking my measurements regularly which raises an interesting point about laying out. I used a marker pen with a 1mm tip but the line it lays down is anout 1.5mm thick, as there are two lines this could cause deviation of up to 3mm on the plans so I have always used the center of the outside line - just a tip if anyone ends up in the same boat.

My welding is pretty good now, I have built a number of beach buggies so had to learn to create a safe weld as the chassis has a 12" (or so) section chopped out of it.

Finally my build is slightly different in that I have an MX5 as my donor. This raises interesting issues over the suspension geometry, engine mounting etc - I'd be interested in finding any other Roadster builders that have followed this route... I will be using Andys (Saturn) body panels so if anybody wants to put me right with regards to planning for brackets etc it'd be great - I have already found the thread re the rear tub so am happy that I won't be wasting time following the book there.

Do people post up build threads here? If so where abouts?

[Trophy Blue]

Do you want me to pop over and take a look? Bonzo may be interested too, he is not far away!

[Bonzo]

Hi welcome to the forum.

I completely missed this thread & in particular did not notice your location :o

Plenty of sound advice has been given but i'll echo Trophy Blue .... More than happy to pop over & have a look at your buid, less than 10 miles from you here in St Hilary :cool:

If you want to pop over to look at my chassis at any time, just give me a shout .... It may be helpfull if you need to measure some of the chassis reference points to assist with your MX5 conversion ;)

Yes, there are quite a few build diarys & blogs to be found on this forum.
I am sure someone will point you in the right direction & put some links in for you.

Enjoy your build :)

[Trophy Blue]

MG Trophy Blue is the colour of my car in case you had not sussed who I am!

[gingea1pom]

Airhead,

Welcome to the forum, nice to see your location is up already.

I think your questions have been answered already .

As to build blogs well my build diary is just a click away in my signature, you might need an hour to read it.:D

Enjoy Ginge

[Airhead]

Aha - Mark! Yep you are both welcome over - Bonzo what a small world; the inlaws live in St Hilary!

Matt

[Bonzo]

Aha - Mark! Yep you are both welcome over - Bonzo what a small world; the inlaws live in St Hilary!

Matt

Tis indeed a small world :) :)

I hope you enjoy your build :cool:

[Airhead]

A picture or two of how things are looking:

http://www.images.spiderwebdesign.co.uk/seven/chassis1.jpg
http://www.images.spiderwebdesign.co.uk/seven/chassis2.jpg
http://www.images.spiderwebdesign.co.uk/seven/chassis3.jpg

And the partially complete framehead:

http://www.images.spiderwebdesign.co.uk/seven/framehead1.jpg

[HandyAndy]

nice pics :cool:

there,s nothing wrong with those cuts at all , especially the 74degree cut in BR8 & BR9 :cool:

front frame looks very nice too..:cool:

cheers
andy

ps..... i,m intrigued with your signature "there,s no place like " what is it?

[Headshot]

its a geek thing

http://what-is-what.com/what_is/127.0.0.1.html

Google is your friend :D

And I hope beyond hope my cuts are that good!

[Airhead]

Thanks for the positive input. :)

I sent you a mail or the such Andy which I guess you didn't recieve 'cos it had the explaination to the 127 thing; the link above is technically correct but you need to take it one step further - as the loopback address or the address of the local machine it could be loosely defined as "home"...

Right - off to finish the framehead and get the chassis into 3 dimentions...

[Hoybi]

Hello Airhead,



Unless you buy the good flat pack, you better cut the tubes when you need them.
Start off with a truly flat table and take your time to draw the plan as good as you can. Then you start building. Once the general structure is there, the tolerances are "self explaining". Too long and it won't fit, too short and it's not possible to weld.
Good luck with your build.