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

Hi just wanted to ask if its possible when purchasing steel tubing you can have plates welded to both ends with requested tapped holes? also after reading from an old thread on here i seen some people say to never rely on 3d drawings when it comes to actually putting the pieces together in real world. what i mean is if i can get steel plates made and drilled from my drawings and then welded onto the steel tubing directly from the same company would i expect problems matching those holes to the rest of the gantry?

sorry if this sounds confusing and thank you in advance

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Originally Posted by reefy86

also after reading from an old thread on here i seen some people say to never rely on 3d drawings when it comes to actually putting the pieces together in real world.

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That may be true if you don't spend enough time analysing your drawing. Not for me though. On my 2 builds and other stuff i designed, when i finish the design, i start assembling piece by piece the design in the building order, so i check if all elements are able to pass through and so on. So far had some minor mistakes like very difficult access once for a wrench so i needed my wife's help with her smaller hands to tighten a bolt.

What i said many times here is not to drill or machine for ball screw nut mount, spindle mount and similar from china, as they sometimes have different holes placement than drawings or a molded aluminum, so holes are not on exact place. In general until you have all linear elements / screws, nuts, end machining, etc./ at home to examine, dont start the build if possible.

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Originally Posted by reefy86

what i mean is if i can get steel plates made and drilled from my drawings and then welded onto the steel tubing directly from the same company would i expect problems matching those holes to the rest of the gantry?

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Same as above, and follow Dean's advice to leave always place for adjustment. My advice from experience is if you use steel laser or plasma cut for motor mounts etc., leave all pass through holes 2mm bigger diameter. Say bolt is M6, so pass through hole should be 8mm. As base coat, paint and adjustment will eat that 2mm.

Ash It might be a good idea if you keep all your info in one build thread as it makes it easier for folks to see what you are trying to achieve as some of the questions you are asking are impossible to answer without seeing what you are doing. Have you decided what you are wanting to cut with this 8x4 machine etc. Please don't take this as a criticism. Good luck with the build

thanks boyan really apreciate the advice :)

Ash

Hi clive no offence taken i actually forgot i asked this question once untill boyan mentioned deans advice. my machine will be for cutting wood and plastic only.

Ash

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Originally Posted by Clive S

Ash It might be a good idea if you keep all your info in one build thread as it makes it easier for folks to see what you are trying to achieve as some of the questions you are asking are impossible to answer without seeing what you are doing. Have you decided what you are wanting to cut with this 8x4 machine etc. Please don't take this as a criticism. Good luck with the build

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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

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.

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

Keyway or flat on output shaft.

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