Stell frame cnc 1500X1000. Adjustable table your opinion please

[Boyan Silyavski]

It will work both with 100x100x3 and 80x80x 3 or 4mm. Depends on how strong would be your gantry, what spindle you will like to mount and how further you will like to push it.
I suggest you make your gantry from 2 pieces of the same profile you will use soldered together, hence 200x100 or 160x80 or do it from aluminum, the way Dean makes his machines, with a ball screw hidden in the gantry, depends what means you have.

The drawings look very good. Now if you aim at certain weight or to be able to pass through normal 1m wide door, don't make it higher . if you want to make it higher and at the same time light, just make the legs longer. Also if length, weight is a problem, you can lift the 4 lower beams to the middle of the M , and remove the middle leg below this point, this will not compromise the strength.

If you aim aluminum and hard stuff mainly, maybe a gantry like Jonathans will be better, look at his exemplary build

[ba99297]

I suggest you make your gantry from 2 pieces of the same profile you will use soldered together, hence 200x100 or 160x80

The gantry will probably made as you say from 2 pieces of 80X80 or 100X100 profile, covered with 10mm laser cut aluminium plate just for acuracy for the holes distances. This plate will be bolted on the gantry box section and may be adjustable in order to achieve paralelism with the table.

depends what means you have.

As for the means, i dont have mill i dont have lathe

maybe a gantry like Jonathans will be better, look at his exemplary build

I have read many times Jonathans thread. So many in order to understand what i am reading. NO COMMENT. What else can i say. I cant follow this plan beause it is out of my budjet, and i dont have the means and the knowledge to do such job. For now the only think i can do is design 4-5 type of tables and ask the polite guys of mycncuk to give me their advice and make their corrections

[ba99297]

After hours of design i come back with 3 final (!!!!) plans.

Plan A
( i have already post it but i repost it near the other two plans )
It is the most simple within the other two and also needs the less steel




Plan B
It is the heaviest within the other two
The difference with A is that the beams of the cutting table are lieing between the two X axis rails support beams. It also have extra 40X40 beams for reinforcing X rails beams





Plan C

This plan combines A with B. The beams of the cutting table have been welded as plan A and the reinforcing of X axis beams is as plan B

All plans are made with 80X80 box section steel. Plan B and C also have 40X40 diagonal box section between X axis rails support beams
I am waiting for your advices
Thank you

[EddyCurrent]

Plan A must be strong enough for this size machine. I know that silyavski likes to have the horizontal beams supported at 2 points like your end view but you loose the triangle in the middle and that is not good.
Also where there are no diagonals or triangular pieces on the cutting table to stop it twisting.
Having said that it will still be very strong if you make it like the drawing.

[ba99297]

I know that silyavski likes to have the horizontal beams supported at 2 points like your end view but you loose the triangle in the middle and that is not good.

If you notice all the three plans carefully you will se that the x rails supported beams have contact with the ground at 3 points not 2. It is possible you get confused between the side and the front view.
At the side view you can see that every pair of supported rail beams has straight contact in the middle with the groun as my plan have 3 ( red ) foot at every side.
From left to right i upload Isometric-Top-Front-Side view for every plan

Also where there are no diagonals or triangular pieces on the cutting table to stop it twisting.

You are right about the diagonals. I will put them to the plan. Thanks for your advice