Welding the chassis
 

Hi everyone,

Just a quick question that will probably cause huge amounts of controversy, does the chassis all have to be fully welded in one go? Or can it be fully welded at stages, and more tacked on?

The reason I ask is for moving and storage, I need to be abe to move the table/frame to stack it away when I'm not at home, and don't want to risk knocking partially welded parts askew.

what i was planning was to maybe get the base frame fully welded, then proceed with the rest when I have more time.

Any advice greatly apreciated.

its ok to tack the chassis together and weld in stages, as long as you doulble check all of your angles are correct when you come to fully weld it, especially if you intend to move it around. Your idea of fully welding the bottom rails first seems like a good idea. It would also be best probably to weld what you can with the chassis sat flat on the table to prevent any warping. Oh and remember to weld oposite sides and allow bits to cool to stop warping also.

nathan

I've been following these forums for a couple years now, so fully prepared for banana chassis...

Dad's trying to talk me into constructing a miniature chassis out of offcuts to see how it will behave. Nice idea and would probly tell me a lot, but its a lot of extra cutting...

I had nightmares about about my chassis performing all sorts of contortions but it didnt happen. Its not perfectly true but its good enough for me:)

Oscar,
I never dared fully welding the chassis stage by stage, but I think it is not a bad idea, if you are sure everything is OK before. For example, the front frame and U1-U2 have to be in the perfect position before you fully weld them, and it is hard to know if everything is fine before placing the suspension brackets (which comes at the end), even if you respect the book's instruction. For example, some people place these tubes using the suspension brackets jig, you will find threads about that on this forum.
Personally, I had to remove them and make them a second time at an advanced stage of the building. so I would have been in the sh... if I had fully welded them in the first place. So I think it is just a question of confidence in your skills, measuring, welding and double checking as shh120m says.
Concerning making a smaller chassis, I did the same, and I'm glad I did it. I built the fist stages of smaller chassis (scale 1/2, see the picture), to practice and try different things. As I couldn't hold the tubes vertically with the bolts-brackets assemblies, as I did for the big chassis, I got distortion. (I used 20x20 tubes for the small chassis, and the holes in the brackets didn't match this dimension, so I couldn't hold the tubes with bolts, as I did with the 25x25 tubes of the big chassis - see pictures).
I haven't fully welded the big chassis yet (but soon !), but I expect the bolts-brackets assemblies to help avoiding distortion (I haven't invented this, I found it on a blog of a Locost builder). So this could be an idea.
Hope this could help.
Good luck.
Cheers.

Small chassis :
Attachment 1323
Big chassis :
Attachment 1324
Small chassis finnished
Attachment 1325

Please tell me your going to finish the mini roadster, put a lawnmower engine in it or something!!

I have to confess I'm thinking more and and more about that too !

I'll be making a few of those 1/2 or 1/3 scale chassis soon. I don't have the room for 2 full size display chassis plus what ever else I'm making. They will be used to help design a few roll cages and hopefuly a few full bodied designs that will probably never get made.

That is a very impressive mini-roadster. I think you owe it to the entire forum to finish it!

Any idea roughly how much steel it took?

It is scale 1/2, so half of the lengths needed for the big chassis (I let you make the calculations !) with 20x20x2mm tubes. It is only the first stages of the chassis, up to page 39 of the book.
Thanks for the comments, and I promise to keep you informed of the small chassis evolution :) But for now, I'm quite busy with the big one ;)