Waste Board Dimensions

[woodworkerbob]

Have the dimensions, including cap screw hole locations, been released? I plan to create a single piece waste board designed to for T-nuts. My current idea is to mill the top for the metric button head cap screws and the bottom for 1/4x20 T-nuts. I have access to a large CNC router until mid May when school shuts down for the summer.

I wanted the single piece waste board with the T-nuts when I started initial assembly. Don't want to assemble twice. What can I say, I'm just that lazy.

Thanks,
Bob

[WillAdams]

No, on my way out the door or I’d measure them. Edward has said he’ll release the plans — hopefully he’ll find time soon. Aren’t there dimensioned drawings in the assembly instructions?

While one could do one piece, not sure that it’ll really help — the machine is incredibly solid, also one wants to protect the surface of the waste board since it is a meaningful part of the structure (prevents lozenging if nothing else) and has metal fasteners pretty close to the surface. That said, I wish it had four additional holes at the corners to fasten a sacrificial waste board (and regret the engineering decision which resulted in it being such a lean purposeful machine that there’s no room beneath the Y-axis motor plates to run the waste board or stock — wonder how much stiffer, thicker and more expensive the end plates would’ve had to be to make that work — would it be possible to’ve stiffened the end plates further by putting vertical bends along the risers which hold the Y-axis extrusion?)

Thoughts on this (probably one wouldn't’t want to use all of these ideas (and some run counter to others), but it would be great if we could have a list of all the possibilities in one place — add the below to http://www.shapeoko.com/wiki/index.php/Workholding ?):

- add holes for mounting a sacrificial waste board
- maybe make it a two / three piece system --- middle piece has a recess for the top one which is sized to perfectly match the cutting area and is milled as a pocket in it by the machine, thus tramming it
- put T-nuts in the middle piece, low enough to not be reached by the machine, high enough to be reached by not obnoxiously long/ expensive fasteners
- use plastic bolts from the plumbing section for fasteners
- rather than a grid use a spacing system based on phi (Golden Ratio) --- draw up in advance, even out the spacing to integral units, use a smaller initial measure along the short axis (or what will be the short axis when the machine is expanded) identify which sets of four corners match the work stock sizes one typically uses and assign work coordinate systems to them
- at each hole location put a right angle array of three holes spaced at say half-an-inch to allow one to use wedges for work holding
- arrange / align all holes so that one can use a piece of pegboard for the sacrificial piece so that one can just drop on the pre-cut piece and have the holes line up
- include holes for a centering / flip vise centered at the array (anyone have good plans for one?)
- include holes along the radial center axes left-right and front-back

Any other ideas?

William

(who still has to scrounge a sacrificial waste board, but had strange dreams about geometric shapes and proportions)

[edwardrford]

Wasteboard

Have a dimensional drawing for a one piece wasteboard been released?

I'm on sort of a deadline. I have access to a large CNC machine (plans to cut wasteboard there) but only until mid May, when school ends. I could measure the two half boards, but I would prefer a better source (than me) for the correct dimensions.

Thanks,
Bob

I will try to get something released today. You want a dimensional layout of the area to place another piece of 1/2" or 3/4" MDF (or other material)? Correct?

edit: download file here -->http://bit.ly/1Fh5lJ5

-Edward

[veng1]

Will, when you return, could you look at the waste board and see if it could be mounted on the bottom side? Then the sacrificial waste board could be on the top without any loss of height by stacking.

Note that this is pulling the PEM nuts in the wrong direction and it may require hex nuts on the end of the screws to avoid pulling the PEMs out.

[WillAdams]

...look at the waste board and see if it could be mounted on the bottom side? Then the sacrificial waste board could be on the top without any loss of height by stacking.

Note that this is pulling the PEM nuts in the wrong direction and it may require hex nuts on the end of the screws to avoid pulling the PEMs out.

I actually considered that arrangement while I was assembling my machine, but stopped 'cause I wanted to try the stock configuration first --- it seemed to me that one could put the bolt in from the top (it'd have to be full-thread, not a problem at these lengths), pulling the PEM nut tight, then tighten _only_ the nut from the bottom while holding the bolt from the top which seemed to me to be a royal pain.

Also, one would have to preserve the orientation of the boards and the countersink would (should?) fit the PEM nuts and the bolt ends and hex nuts (w/ washers) would be projecting on the plain side --- while I used larger silicone bumpers I didn't have enough large enough to accommodate that.

This would be something for someone who's building a torsion box to consider.

[woodworkerbob]

I will try to get something released today.

edit: download file here -->http://bit.ly/1Fh5lJ5

-Edward

Really nice drawing. The Y dimension of the 2 horizontal holes right in the middle of the board should be about 290 mm? My guess of the locations would be (340.87,290) and (380.87,290). I couldn't find position information.

Bob

[edwardrford]

my mistake for omitting those dimensions. You are correct.

The file has been updated.

[woodworkerbob]

Just created a 1/2 inch thick single board version in Aspire. I'll cut an MDF test version early next week.

Bob

[newtothis]

What is the advantage of having a single waste board vs the 2 halves supplied with the stock SO3?
Is there any functional difference other than personal preference?
I know the reason for 2 parts is an advantage for the packaging/shipping.

[achartthatflows]

The biggest advantage for a single piece wasteboard I can think of is the lack of a joint in the middle of the table. If you're trying to get a really precise locating fixture the seam between halves of the wasteboard could be a source of frustration. Taking a finish pass over the table could help, but you're still going to have a gap to collect debris/moisture. Source: years of woodworking experience.

Edit: After posting that, I started wondering if there could be an advantage to an HDPE "bottom" board, with a wasteboard above. McMaster has a 2'x2'x5/8" sheet for $62.62. Slightly expensive, but it would be nice to be able to cut aluminum without worrying about the bottom board soaking up cutting fluid.