Requesting some feedback on steel frame design.

[JAZZCNC]

I wouldn't weld the plates to frame.! Brace the frame using normal triangular methods and bolt the sheet/plates to the frame.
This will reduce chances of heat from welds pulling the frame plus be easier, quicker and more flexible regards building enclosure. The bolted sheet will still add strength and allow better access for working on etc. Also you'll be able to dampen the sheet to lower noise and resonance by using rubber gasket between frame and sheet.

[Misc]

Thank you for the feedback, the design has been redone from scratch. I have decided how the gantry should be mounted, but not how the gantry itself should be built. A slim gantry is not easy to design (if at all possible) while also being inflexible.


I am planning on adding a center tube to support the middle of the bed in the front.





The bed is supported by 3 tubes of 50x50x3 tube in the middle section, the sides rest on a 5mm thick piece of angle iron.





Steel tube sizes are as follows

• Green: 50x50x3mm
• Yellow: 80x30x3mm
• Pinkish: 70x70x3mm
• Plates: 10mm Aluminium on the carriages, not sure if i should switch to steel?

At the moment the gantry has 500mm travel are the linear carriages are spaced so they are 230mm end to end, I read later that these should be a minimum of 250mm. So maybe i should widen the gap?

As you can see the wall thickness is 3mm all around, I am considering 4mm to make it stronger; But it is already quite heavy, so is there any parts that will benefit more than others from extra wall thickness?

[JAZZCNC]

Looking better but I'm not a fan of ballscrews being up above the rails due to being easy to damage thru leaning on or when loading material etc.

Also if those black things connected to the screws are steppers and your thinking to mount them like that then your in for massive troubles.?
Try to build in some adjustment for things like ballscrews to ease alignment.

The bearing spacing isn't too critical when using twin screws so your size will be fine if it fits better. Thou more won't hurt if possible.

[Blackrat]

your bracing can be much smaller , as the forces are compression and tension
also try brace into the very corners as this maximize's the strength of the brace , and makes welding easier as there will be even less warp

just a comment :D

[Misc]

Looking better but I'm not a fan of ballscrews being up above the rails due to being easy to damage thru leaning on or when loading material etc.

Also if those black things connected to the screws are steppers and your thinking to mount them like that then your in for massive troubles.?
Try to build in some adjustment for things like ballscrews to ease alignment.

You are correct, they are 280oz Nema23 steppers. I will change the mount for the steppers to something more "traditional". Is there ready made adjustable ball screw mounts or is this simply achieved by drilling oversized holes for a simple mount?

The bearing spacing isn't too critical when using twin screws so your size will be fine if it fits better. Thou more won't hurt if possible.

Okay, ill keep it as is for now then.

your bracing can be much smaller , as the forces are compression and tension

This makes sense, I will lower the dimensions where possible but since Im forced to buy the steel in sections of 6 meters, so I will change what i can to lower dimensions.

also try brace into the very corners as this maximize's the strength of the brace , and makes welding easier as there will be even less warp

Do you mean like this?


I was under the impression that this approach would distort the joint more as that small section is subjected to more heat and will also have more weld material causing contraction?