Stell frame cnc 1500X1000. Adjustable table your opinion please

[EddyCurrent]

I like the look of that but it looks weak where it joins the bottom plates. All that weight is hinged off the bottom face of the lower beam. I feel it needs something like this added each end;

[ba99297]

Eddycurrent thanks for your answer
As i said the plans are not accurate and mostly i want an opinion about the 120X60 box tubes arrangement
If it is ok i will go on with the triangulation support that will attach the C shape gantry to the carriages
To be honest i was thinking something like what you design but a little bit more complex. As what i have in mind will be influenced from the gantry shape, that is why i didn’t design the left and right parts of the gantry
Thank again
Vagelis

[Boyan Silyavski]

Looks Nice!

It would be even better if you could design it so that the motor is inside the gantry. may be with some door plate that bolts to the sides. I assume you will use any way belt from the motor to the screw, not drive it directly?

[ba99297]

Silyavski thank for your idea but thiw is not possible as the motor wont fit in the gantry.
I am working now with the plans so i can show to the forum 2-3 different ways to attach the gantry to the carriages.
Thanks for your time

Vagelis

[ba99297]

Hi guys here is some progress

My basic question if this arrangement is suitable for such a machine
The green colour is 1,5 cm aluminium and all the others steel.
The rectangular tube is 120X60
At the beginning i was planning to use 3 120X60 rectangular box tubes in order to make a C shape gantry but finally i change the plans
I will also like to hear your opinion about the way i attached vertical pieces of the side parts of the gantry to the horizontal parts
Finally i would like to know if it is better to bolt or to weld the rectangular tubes to the sides of the gantry

Thanks for your time

Vagelis

[JAZZCNC]

Hi Vagelis,

My basic question if this arrangement is suitable for such a machine

This design will be fine I've use a very similair design on machines but with all aluminium construction.

I will also like to hear your opinion about the way i attached vertical pieces of the side parts of the gantry to the horizontal parts.
Finally i would like to know if it is better to bolt or to weld the rectangular tubes to the sides of the gantry

The arrangement of vertical and horizontal looks ok but with the lower Horizontal base plate you may want to think about how your going to attach to the X axis ballscrews.? It may be better to have the lower plate extend out the side and attach screws to it's under side.?

Regards welding or bolting then NO I wouldnt weld it has you'll have very little room for adjustment. I've said it many times but I'll repeat because it's so important to a Good DIY machine.!!. . . . .ADJUSTMENT ADJUSTMENT ADJUSTMENT . . . . Welding solid is OK for some areas like the frame but for a Gantry then I'd only weld the minimum if at all.!

Also realise because your planning to use Steel for the Gantry sides and base plate it will twist and warp while welding so you'll need to machine the lower face of the Base plate which sits on the Linear bearings. For this reason I wouldn't Use Steel in this area and have Aluminium gantry sides/base plates and bolt together. Still use Steel for the cross beams just bolt it all together.

I would also have 2x brace supports between top & bottom cross beams across the width at the rear. This will help reduce resonance.

[ba99297]

Dean how thich aluminium plate do you suggest?
Is 20mm ok or i could go on with 15mm
Firstly i was planning to have all the gantry welded BUT the front plate ( green color at the above photos ) would be 15mm aluminium true leveled.
Also ( as the y axis rails would be at the same plane) i would use two plates to attach the gantry to the carriages . They would be connected each other with bolts ( one bolted on the carriages and the other welded one on the gantrys sides ) so i could adjust the vertical position of the spindle. I will make a plan and i will come back

[ba99297]

Some progress so far




































The red colour (at the gantry ) is aluminium plate 20mm bolted together
The green gantry plates are also 20mm aluminium plates that will be bolted with the carriages. Under that green plates will be attached the ballscrews
Distance between y axis profiled rails ( centre of rails ) 200mm
Tell me first your comments and i will then ask my questions
Thank for your time

Vagelis

[ba99297]

No one out there for any advice?

[EddyCurrent]

It definitely looks strong and at the same time good looking. The green plates, they are wider at the back so are you putting the ball nut near the back ? maybe it would be better to have it central or in line with the spindle collet ?