New build started... Please comment.

[margni74]

Been playing around in sketchup ... I have in my possession 90+% of the parts now to really start building. after over a year watching the parts collection collect dust, it's time to put a plan into action.

Most of the structure has been layed out. I still need to sort out the bits that will be mounting to the gantry structure, but i think this is going to a workable design. It should be 4'x3' or so. The cutting area will be around 30" x 20" x 4-6"

Please point out any weaknesses in this approach, I'm sure there are many things I have overlooked.

[acondit]

I am not sure where your cutting surface will be, but if it is where it seems logical to me, then your lower gantry piece is too low. Your lower crossmember needs to be high enough to clear your thickest cut.

Alan

[margni74]

Originally Posted by acondit I am not sure where your cutting surface will be, but if it is where it seems logical to me, then your lower gantry piece is too low. Your lower crossmember needs to be high enough to clear your thickest cut. Alan

Hey Alan,

Thanks, nice catch.. would have had an 1/2" of z travel.

[acondit]

Catching everything yourself can be hard. I know! I've had to do a few redesigns myself.

Alan

[Coogrrr]

Love it and with the slides you chose it should work great but that much 8020 your gonna be paying thru the nose unless you have some good deal.

Rock on and post TONS of pics of the build.

Coog

[spalm]

My recommendation would be to not actually start cutting 8020 until you know how you are going to mount your motors, screws, and leadnuts. You don’t always have to draw them in, if your cad skills are not as fast as you want, but at least pencil them in as they are a real integral part of the machine and some forethought is needed here. Cad drawings would be preferred, of course.

Looks like you are off to a good start,
Steve

[tahustvedt]

Here's what I would change. I took the liberty of drawing on one of your drawings for illustration.

1. Remove the short vertical beams and mount the traverse underslung beam under the bottom edge of the two longer side beams after rotating it 90°. This should make the lower beam more rigid in the X actuation direction and the connection between the bottom beam and the side frames stronger. It would also make the whole gantry more rigid because the long side of the beam will be better at preventing one side from lagging when you are milling on one side of the board.

2. Raise the bottom Y beam a couple of inches for a little more more work space.


Does it make sense?

[margni74]

Originally Posted by spalm My recommendation would be to not actually start cutting 8020 until you know how you are going to mount your motors, screws, and leadnuts. You don’t always have to draw them in, if your cad skills are not as fast as you want, but at least pencil them in as they are a real integral part of the machine and some forethought is needed here. Cad drawings would be preferred, of course. Looks like you are off to a good start, Steve

That's good advice, I agree. This is one of the reasons I am trying to put in the time and plan it out as much as possible in cad before I fire up the chop saw. I know there will be some "uh oh" moments, but I am trying to minimize them as much as possible.

[margni74]

Originally Posted by tahustvedt Here's what I would change. I took the liberty of drawing on one of your drawings for illustration. 1. Remove the short vertical beams and mount the traverse underslung beam under the bottom edge of the two longer side beams after rotating it 90°. This should make the lower beam more rigid in the X actuation direction and the connection between the bottom beam and the side frames stronger. It would also make the whole gantry more rigid because the long side of the beam will be better at preventing one side from lagging when you are milling on one side of the board. 2. Raise the bottom Y beam a couple of inches for a little more more work space. Does it make sense?

Yup, I see. Your method is better and requires less material as well. I've raised the cross member so I have roughly ~5.5" of potential cutting travel, minus whatever platform i end up mounting in there.. This should be good enough I think.

Here's the latest:



Thanks for the input, keep it coming!

[magick_man]

This newer version looks great.
The only thing I might recommend would be to mount the Y axis on the opposite side of the gantry.
The reason I say this is, The way it is now you will have alot of dead space on your table with the x moved all the way to the left in this picture.


I think it would move your usable table area more into the center.
Instead of being able to use one half and not touch the other.
I am not sure if any of that makes sense or not, I can draw it out if it doesn't.

But regardless it is a great looking machine.

Joseph-

[margni74]

Originally Posted by magick_man This newer version looks great. The only thing I might recommend would be to mount the Y axis on the opposite side of the gantry. The reason I say this is, The way it is now you will have alot of dead space on your table with the x moved all the way to the left in this picture. I think it would move your usable table area more into the center. Instead of being able to use one half and not touch the other. I am not sure if any of that makes sense or not, I can draw it out if it doesn't. But regardless it is a great looking machine. Joseph-

I see your point, I'll probably end up taking your suggestion, it may get me a few more inches of usable travel. The issue I have is that I have sort of a mishmash of odd ball length parts that I bought from ebay. I have a set of monstrous 4' rails, but only a 32" length long screws. check out the size of these rails. talk about overkill!

so with the 16" or so difference between rail and screw length i can compensate by moving the mount points for the screw up towards the front of the machine

[spoiledbrat]

I like your machine. Not only does it look rigid, the design seems to lend itself to adjustment. What I mean by this, is that once you have machined a few parts, your machine will be able to be "squared" to perfection in each axis.

Good luck with your build!

Rob