450x300 Aluminium extrusion build from scrap/used parts

[Nealieboyee]

Well 50x50 does not sound like a lot.
webbed in the bed it could be enough.

If you decide to go 50x50 at least make sure it is 4 or better 5mm wall thickness, much easier with tapping threads.

For the size i would go 80x80x4

The main thing is your total footprint.
It is 1000x700 right?

When you can run FEA on your design you know.

I did some basic checks on my design.
Quickly went for 80x80x4 bed and 80x120x4 gantry parts.

Get end caps on the box section.


I think you need to make the gantry as rigid as reasonably possible.

I went with the 50x50mm because it was free for 7.5m length :). If I go to 80x80mm, I will have to shrink the height due to the cost. The new 80x80mm design would look like the one attached. What do you think? I've also increased the free space between cutting bed and spindle to 130mm. My gantry is already 120x80mm.

[driftspin]

I went with the 50x50mm because it was free for 7.5m length :). If I go to 80x80mm, I will have to shrink the height due to the cost. The new 80x80mm design would look like the one attached. What do you think? I've also increased the free space between cutting bed and spindle to 130mm. My gantry is already 120x80mm.

Well free is the magic word :-)

Just make sure ther is enough meat to tap threads in for the linear rail bolts.

Also you need at least 4cm of width flatsurface to pour epoxy on the steel.
Make sure you have that.

Grtz Bert



Verstuurd vanaf mijn SM-A320FL met Tapatalk

[driftspin]

Well free is the magic word :-)

Just make sure ther is enough meat to tap threads in for the linear rail bolts.

Also you need at least 4cm of width flatsurface to pour epoxy on the steel.
Make sure you have that.

Grtz Bert



Verstuurd vanaf mijn SM-A320FL met Tapatalk

Btw,

Why are the the z carriages up that high?
And close to gether?

Move those to the top and lower horizontal plates.

So top Z and Y and bottom Z and Y carriage are really close to gether, assuming X is the bed.

Grtz Bert.



Verstuurd vanaf mijn SM-A320FL met Tapatalk

[Nealieboyee]

Btw,

Why are the the z carriages up that high?
And close to gether?

Move those to the top and lower horizontal plates.

So top Z and Y and bottom Z and Y carriage are really close to gether, assuming X is the bed.

Thanks for your comments.

I did that because the further I move them apart, the less z height I have, because I have only 300mm rails for the Z axis.

Here is the machine at the moment. The z axis is at the lowest point of its travel. I've modelled the ballscrews and rails etc exactly as they are. They arrived a few days ago. Still waiting for the second ballscrew for the x axis.

My only problem was trying to keep the z axis as close to the Y as possible, so that there is less overhang or twist forward on the gantry. So I had to move the ballscrew to the back of the gantry. Not ideal, but with everything being 16mm and 20mm alu plate, I figured it wouldn't pose too much of a problem. Thoughts?

I have now sourced 80x80x5mm steel box section, and I got it through a friend at work for £76 for a 7.5m length. Not too bad!

I've also ordered a 2.2kw water cooled spindle, 425oz motors and drivers. I'll be buying the transformers and caps soon for the power supply. Any idea what control board I should use?

Note I haven't modelled the second ballscrew for the x axis. Its basically a copy of the right hand side one.

Please let me know your thoughts?











Cheers
Neal