Page 1 of 1

Frame Expansion Methods

Posted: Mon Jun 11, 2012 9:07 pm
by DukeA42
Hi been doing some research for my hackerspace looking into building a new CNC router and really find the ShapeOko/Makerslide design great with a lot of potential. However, we have goals of scaling up the frame to handle a cutting area of 4x8 ft boards. Not original concept I'm sure, but haven't seen any talk about anything up to that large of a size.

1) Does anyone have any attempts at this started? Anything to share? What's some options to try to reinforce the 2040 extrusion?

2) I found the discussion on how the Makerslide (or 2040 extrusion) will likely deflect ~1mm on a 1m length with 5bls in the center. The 2 Y Axis parallels will be easy enough to add both plates to join sections of Makerslide together on the interior and then legs or L-Brackets to the underside to support the extra weight across the 8ft length.

3) Being that the Gantry design has all 4 sides covered by the cradle and in full motion, it's a little unclear how to help reach the 4ft length. My cheap thought is to use expanding foam for just a little more density inside the Makerslide. The other thought was to make taller the 3 motor mount plates and place a 2nd Makerslide directly above the first with another set of rollers on the cradle.

Please let me know your thoughts and that if any of it is feasible.

Re: Frame Expansion Methods

Posted: Mon Jun 11, 2012 9:17 pm
by edwardrford
4' x 8' is way outside my comfort zone. I've never really though much of it because I personally don't have room for that big of a machine, and am jealous of anyone who does :-)

As long as you're comfortable blazing a trail, I'm more than willing to help out with what I can.

As far as scaling x/y goes. You're right. The Y axis is easy. Adding a support to the inside is the simplest way to go. My original thought was to just buy a piece of 20mmx80mm extrusion that is as long as your desired bed (probably slightly longer than 8' so you can cover the entire 4' x 8' work area). Then, doing the same thing with the X would probalby work as well. Instead of bolting the makerslide to the motor mount plates, you could instead bolt the 20mm x80mm extrusion (it too has 20mm end tapped hole spacing) then bolt the makerslide to the piece of 20mm x 80mm. Got it?

Where your problem will be is the z-axis. I'm afraid that with the weight and speed of the spindle you'll want to put on that z-axis, the current design just wont support it, so a modification will have to be made. After all, you wouldn't want a huge machine like that with a tiny dremel bolted to it right? :-)

I have some ideas for a modified z-axis, but would need to model them up first. What are you thinking the z-axis would look like?

This sounds exciting!

Re: Frame Expansion Methods

Posted: Mon Jun 11, 2012 10:28 pm
by DukeA42
.Yeah, I've been just saying 4x8 for reference, but the actual length will likely be closer to 5x9. Too many metric to english conversions :)

I follow how the 2080 would work as a brace for the Makerslide on the Xaxis Gantry, but then I lose how the X carriage will work on sliding across it. Would the two plates expand to go around it? I also thought maybe a second makerslide behind the X motor with a 3rd roller plate would provide both extra counter balance and horizontal support.

For the Z-Axis, the weight appears to be all dependent on the threaded screw, I think that using a slightly larger acme/lead screw would better handle the weight there, but not sure of available clearance - may need more spacers between standard plate and the Z makerslide. Two nuts on the screw would help the rollers against tilt. It may also need to use two segments of z makerslide plated together to fit the outside of the same 4 rollers. That would give a wider carriage to mount to (and we've already picked out a craftsman full-size router). Our length isn't really going to expand on the Z, so current ~200mm is likely fine for plunging.

Many options of course, but just looking for simplistic and cost effective for a bunch of hobbyists to build/use.

The group of us will meet Tuesday ( if I may plug our St Louis group) to plan out further details and purchasing. We'd like to build the gantry/carriage (X/Z) and a smaller table base (Y) first to replace our current model, and then expand to the 8foot table/base (y) that will store vertically on the wall when not in use (but uses same X and Z for cost/space reasons).

Re: Frame Expansion Methods

Posted: Tue Jun 12, 2012 1:05 am
by pourcirm

I don't know what anyone's interest level might be, but I also live in Saint Louis and have heard a bit about the Archreactor space. I'm currently building my ShapeOko from the original kit Edward was selling. I'm waiting on another box from him with a few different goodies in it, but if anyone is interested or curious to see more about the MakerSlide or ShapeOko maybe we could arrange some type of meeting.

Just a thought,


Frame Expansion Methods

Posted: Tue Jun 12, 2012 3:31 am
by DukeA42
Well if you can make the drive our regular meetings are on Tuesdays 7pm-ish. Directions at the website (or PM me). Always looking for new members to share our space with who love the hacker/DIY style.

We (well one guy) are familiar with makerslide atleast, (him) having made an ORD 3D printer and a laser cutter with it. Good stuff. Love to have your input into the design. I got a small team assembling on our forums too. I think we want to see something successful at that size even if it takes a few tries.