New project, metric dimensions ansd welding

I

i_ll_be

Hi,

Thanks for welcoming me, discovering all these exciting projects !

Planning a trike or a recumbent on my side, I would probably start with a "spirit" bike.

First question, I am in Europe, so what profile do "metric" builders use ? The dimensions given would convert to roughly 40mm x 1.6mm. Do you use 1.5 or 2mm sections ? I guess the 2mm would be easier to weld and a bit stronger.

Second question on welding : 1.5 or 2mm is relatively thin for stick welding, what technique do you use ? "Stitch" welding ? I guess 2mm diameter stick at roughly 75A ?

Thanks !
 
1.5mm is generally enough unless you're very heavy. You are right that 2mm will weld easier with a stick. You can get 1.5" 16swg or 38.1 x 1.5mm too. I've also used 40 x 20 used vertically. I'm a mig user and keep the stick welder for the heavy stuff but it can be done.
 
i_ll_be said:
Hi,

Thanks for welcoming me, discovering all these exciting projects !

Planning a trike or a recumbent on my side, I would probably start with a "spirit" bike.

First question, I am in Europe, so what profile do "metric" builders use ? The dimensions given would convert to roughly 40mm x 1.6mm. Do you use 1.5 or 2mm sections ? I guess the 2mm would be easier to weld and a bit stronger.

Second question on welding : 1.5 or 2mm is relatively thin for stick welding, what technique do you use ? "Stitch" welding ? I guess 2mm diameter stick at roughly 75A ?

Thanks !
Click to expand...
BTW, all the builds in all of the AZ plans were done by Brad with a simple stick-welder. ;)
 
Mainland Euro here too. And dedicated TIG. So wall thickness doesn't bother me related to welding. (but your 75A is schoolbook accurate, about 30A per mm)

The strenght of a box section/tube comes from the dimensions, not the wall thickness. (look at ali bike frame sizes) On the other hand, the wall thickness makes point stresses more easely absorbed and mounting points simpler.
 
Worth looking at the tutorials.
A little difficult to find sometimes until you go in to the plans section, which you wouldn't unless buying or perusing.

I only TIG at the moment. I would say I've used full runs no stitch welding.
No long welds to speak of, so no heat distortion really.
But small runs to control the heat is useful, but I rarely do because I use a foot controller for the amps.

Martin.
 
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Thanks a lot for your replies !

I think I will simply invest in a welder and use the trial & error approach... the best for learning.

Last question about welding, I have read here and here that AC old style generators are better suited than smart DC inverters for thin metal ? what is your experience please ?

Thanks
 
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