First CNC machine

[kev]

Hi everyone,
this is my first post, basically im building a cnc machine for my college project,
so far this is what i have got and made,






Its made from 45x90x1000mm aluminium profile,
i have used igus drylin linear bearings and rails
and thats about it really.

its about 1090mm x 965mm and i should be able to get a cut area of around 800mm2.

im planning on keeping the y axis as close down to the x axis as possible, and then making a long z axis so it will cut below its frame so i can raise it up if needed and cut bigger things.

i will be using 2 steppers on the x axis with the screws running along the top of the rails.

but now im a bit stuck on where to go from here, im trying to design it on autocad but its not going to well.

so suggestions are much welcome

Thanks.

O and how do u keep the pictures big? they look realy small on this post?

[Tom]

Hi Kev,

Looks good so far - should be nice and rigid with those large alu sections.
You have an interesting concept with the Z reaching to cut below the frame, do you have any sketches?

Next you need to decide where to put your y axis gantries, and how to mount your leadscrews and steppers.

When does your college project finish - a deadline is healthy! I wish CNCs were around when I was at college! :) (actually they were, but you fed code to them on punched card, not usb keys!)

Keep it up and keep us posted!

[irving2008]

Welcome Kev...

Rather than insert your pictures inline using the IMG tags, attach them using the 'manage attachments' button below the edit box... this will put thumbnails in the post and will auto-enlarge them on mouseover.

[kev]

Looks good so far - should be nice and rigid with those large alu sections.
You have an interesting concept with the Z reaching to cut below the frame, do you have any sketches?

yea its pretty solid, bit of a pain using the connectors tho.

with the z axis i got the idea from here

basically its going to be used for sign making but if i want to put something tall inside it then i can raise the machine up on a stand im going to make, thats why im planning on having no obstructions in the cutting area.

i will post up some autocad drawings that i have made so far tomorrow.

with the y axis im thinking of using some more rail, perhaps mounted on the top and bottom of another piece of alu box section. or perhaps top and side.

My deadline is around june time.

[kev]

Hi,
right just made some stuff up on autocad,
im not sure how heavy the z axis will be tho as it uses a lot of 10mm plate.
Any thoughts?
thanks

[irving2008]

Hi,
right just made some stuff up on autocad,
im not sure how heavy the z axis will be tho as it uses a lot of 10mm plate.
Any thoughts?
thanks

thats easy... work out the total surface area of the 10mm plate used in square millimetres (just work it for each piece then add them all together), multiply the result by the plate thickness (10) and multiply by 0.00275 will give the weight in kg. (weight of aluminium is 2750kg per cubic metre)

[Ross77]

Hi Kev.

just 1 observation. Are you only using one rail on the y axis? if so then the 250mm travel + the distance to the rail + the length of the cutting tool will put quite a bit of force on it!

Good luck with the build.