My baby 15" x 15" machine

[wilfy]

it doesnt have to be done this way, it was just an idea i had to use the rest of the steel what you see in the picture is all the steel end of.. if it doesnt work, i'll just figure out a way to make it work as a desktop machine it might mean that 2 legs are secured to my worktops and with the left overs i will have enough to extend the other 2 legs down to the ground and do it that way and brace as you said like a chair.

is it likely i'll need any adjustment in the feet of the machine??

[Jonathan]

I agree with the earlier post - those strips are too thin to be useful for bracing. Your problem is they need to be strong in tension (which they are) and compression. A strip is the worst cross section under compression as it'll just bend. Angle would be better, or better still more box section. Also using thin strip for bracing is asking for trouble with resonance as the strip can vibrate, just like a rubber band. If the resonant frequency of the strips is a long way from the frequencies induced due to the motors and cutter then you wont have a problem, however calculating that is not trivial. Shorter strips will have a higher resonant frequency, so are less likely to cause problems, but clearly to an extent offer less support so it is is a compromise.. There's some good information on this site, Mechanical Resonance - Factors that Affect Natural Frequency.

[wilfy]

I agree with the earlier post - those strips are too thin to be useful for bracing. Your problem is they need to be strong in tension (which they are) and compression. A strip is the worst cross section under compression as it'll just bend. Angle would be better, or better still more box section. Also using thin strip for bracing is asking for trouble with resonance as the strip can vibrate, just like a rubber band. If the resonant frequency of the strips is a long way from the frequencies induced due to the motors and cutter then you wont have a problem, however calculating that is not trivial. Shorter strips will have a higher resonant frequency, so are less likely to cause problems, but clearly to an extent offer less support so it is is a compromise.. There's some good information on this site, Mechanical Resonance - Factors that Affect Natural Frequency.

sod it then i'll stick to the original plan above and find some other use for the spare metal.. i may cock bits up yet anyway so it's good to have back up i suppose.. plus i can use some scraps to set the welder up properly before i go at my good cuts