8x4 router build. Steel base & Aluminium gantry gantry

**JAZZCNC** · 22-11-2014

Over complicated derek with not enough support for the bed. The spacing of the cross beams is too far apart and I would make them full width and support from under side.

Less is more.? Go bigger on the steel structure but have less of it. Check this out to get an idea what I mean.

**D-man** · 22-11-2014

Now. you have really threw a spanner in the works! after seeing that i just want to buy one outright! haha

In terms of not enough support, shall i just run the crossmembers striaght through as you say? i had planned on putting an Ali extrusion bed over the top of this also...

**D-man** · 22-11-2014

Is this what you had in mind?

Ive turned the bed supports vertically to give a little more support and transfered the long one to the bottom to support

**charlieuk** · 23-11-2014

Very keen to see how this goes as I'm thinking a 8'x4' machine could be my next build and have probably enough steal kicking around to build one. What are you designing it to cut?

Are you not tempted by ball screws for the long axis as well?

I'm thinking that by the time you do all the rack and pinnion stuf ball screws would probably not be much more?

**D-man** · 23-11-2014

Hey Charlie thanks for the interest.

I would live ballscrews but can't be chewed to sit and design the rotating nut for the screws. I already have the rack and pinion drives so it's not a problem just a case of getting some longer mod1 rack.

The toughest thing I plan to cut is ali. But the machine will mainly be for wood and acrylic.

**D-man** · 23-11-2014

Unlimited supply of tea and coffee and access to on site cafe if anyone wants to venture down to help hold this thing together while i weld it up haha

**charlieuk** · 23-11-2014

Cnc4u have 2500mm x 20mm screws which I was wondering about using although I do also have enough mod 1.5 rack here that needs a home or selling.

were about's are you?

**JAZZCNC** · 23-11-2014

Originally Posted by D-man

Is this what you had in mind?

Ive turned the bed supports vertically to give a little more support and transfered the long one to the bottom to support

Yes and No. Yes to one piece supports but the spinal beam needs supporting from below not just fastening under the bed supports as that's doing nothing really.!

**D-man** · 23-11-2014

Originally Posted by JAZZCNC

Yes and No. Yes to one piece supports but the spinal beam needs supporting from below not just fastening under the bed supports as that's doing nothing really.!

Yeah pal there is 3 pieces under the spine as per drawing 1. I ain't so quick with solidworks just yet so thought I would see if that's what you meant first.

It's a shame your not closer Charlie, could of welded them both up in one shift haha not bad for the steel either. Total cost of just under 200 notes.