building with steel tubing pre-welded plates with holes doable?

[grain_r]

Hello reefy86
I am making my plates and welding them at present and although I marked the holes out precisely when they get hand drilled it is possible to be a 1/4 mm out and make a problem.

so really I would say it depends on how the plates are created e.g. hand build or CNC'd or lasered will all give you different qualities.

I have made all of the Tapped holes as accurate as I can but then I have made a larger hole for a small amount of movement to allow to get as accurate as possible when setting up.so my M5 bolts have a 6mm Hole on the plates that get bolted to them.

My worry is that it might wander but I plan to do some small tack welds to keep the plates in place if they do and it it ever needs to come apart they can be ground off. but hopefully the won't be any movement.

Thanks

Rob

[Boyan Silyavski]

I think you are missing the point that the most imprecise part in a machine is not the drilling but the welding. I am a maniac and it took a lot of time, so 1200x 600 machine i weld under 1mm in all directions. But it takes time, a lot of time to align and wait for heat... My big machine i did alone by myself and it was even more difficult. All is ~1mm plus one mistake at one end where ~2.5mm. How did i know- judging from channel depth when pouring the epoxy. Epoxy could be only 5mm deep and 3mm min, so machine must be precisely welded.

I doubt where i live / Spain/ a local welder could do that. Have been working in construction so i had to mount fence, doors, etc.

So as a conclusion, if sb welds for you, you have to specify one priority, not seek perfection. If sb welded for me, the priority will be for the top side / under epoxy/ to be in one plane as much as possible. Gantry though i recommend to be as perfect as possible. Z must be perfect /if welded, that means hard stops or fixture/

Anyway, all this said , then what it means is weld the plates, but drill them when on machine and rails aligned. Otherwise all must be machined.

[reefy86]

thanks again boyan, instead of creating another thread ill just ask in here, whats the difference between these 2 motors?

http://www.zappautomation.co.uk/elec...per-motor.html

http://www.zappautomation.co.uk/elec...tor-48577.html

both have same specs just slightly different dimensions.

Ash

[Neale]

Keyway or flat on output shaft.

[Boyan Silyavski]

I definitely prefer the keyway. Flat shaft is a bag of worms. Though a drop of glue works well, + 2 screws .