Simple clamping base jig for the Handibot

Relatively new handibot owner here still having fun learning the ins and outs of the machine. I appreciated the base jig for dimensional lumber included with the machine, but found it awkward to use for clamping smaller pieces of flat stock that couldn't extend out beyond the outside of the machine for clamping. I made a simple clamping base out of MDF and 2 quick clamps and wanted to share it here in case anyone else found it useful. Unfortunately, the forum is not allowing me to attach any SVG, PDF, or JPG files right now, saying that they are incompatible types. If anyone knows a way around this or would like me to directly send them just let me know. In the meantime, here's an album of images: [imgur.com]

The jig is 2 halves in the shape of the handibot base. The left hand side is intended to be bolted directly to the base, and has vectors to cut recesses for t-nuts or washers in the bottom for that purpose. The right hand side is supposed to be free-floating under the base, and is clamped around your stock on the edges using a pair of quick clamps front and back. This way both parts become an effective giant clamp flush with the base. The loose right side allows for some irregular-shaped or angled stock to be used without a problem. The left clamping side should line up with the X=0 mark on the machine base. The entire thing is then put on a spoil board for use. Hopefully the attached pictures make it clear.

I've found it easy to leave this base attached to the handibot even when using other clamping mechanisms... for example moving it over my bench vise to cut keyholes or box joints in the end of machined pieces. I used 3/4" MDF for mine, and you could theoretically cut several and stack/bolt them together to achieve a taller base with more Z contact for thicker pieces.

Thanks to this community for the prompt and quick support... This was a big part in convincing me to pull the trigger and buy one. looking forward to making a lot of things with the Handibot!



Edited 1 time(s). Last edit at 03/29/2017 12:33AM by Josh Gunnar.

Josh,
A brilliant idea!
I can download the imgur images and scale them (if required) to suit, or the whole shooting match is easy enough to draw in VCarve Pro or Coreldraw. If any one is reading this, don't export out of Coreldraw using dxf or dwg formats as they create way too many nodes. I have found exporting to Vcarve Pro using eps format is far better.

Excellent idea! I was about to make something similar, but frankly much inferior...

Did you make this on the Handibot itself? If so, care to share those .crv or Fusion files?

Any problems with needing "down" force, or is the left/right clamping force enough?

Josh.
I am so very impressed with this. it is similar to some stuff the handibot team did early on but different in some significant and useful ways.

It is just days too late to be useful to me but hopefully, I can utilize the concepts on one for the Extended Y-axis. (Yes, I just outed myself as the EYA beta tester)

This forum software has always had problems with attachments, it does recognize links quite nicely though so if you have dropbox or the such you can post a link.

Also, there is my Handibot owners' group over on G+, it handles photos fine but files still need to be linked. If you use Gmail you already have cloud storage you can link to or it just takes a few minutes to set up a free dropbox account.

Anyway, thanx for posting this. I've said several times that the handibots biggest downfall is the lack of owner sharing and you just decreased that significantly.

Thanks all! Glad it might be useful. I've uploaded the svg, dxf, and vcarve files here

I've started using this clamp in a kind of manual assembly line process for small projects out of 3/4 boards. I have some things that take 8" of vertical board space and have toolpaths that require 3 different endmills, so I'll take a 7' or 8' board out and mark on the left edge in 8" increments (plus a small margin for error and to leave enough material between to withstand clamping pressure) all the way down the board. Each mark will take a few turns lined up at the origin point. I'll put in tool #1, line the board up at its first mark with a mark I made on the left clamp that corresponds to Y=0 (the clamp side is always on X=0.. shift it over in fabmo if you need to for larger bits), clamp, run job... unclamp, move to mark 2, clamp, run job... unclamp, move to mark 3, run job... etc down the board. Then switch to tool #2, line it up again at the first board mark, clamp, run job... unclamp.. etc down the board again. 1 complete pass of the board for each endmill for any number of parts (or boards for that matter). That way I only have to change each endmill once. Having that custom Z-zeroing macro mentioned earlier in the forums and an aluminum plate makes precise zeroing to the top of the stock really easy too.

This suffers from some accuracy loss between tools because of the sight aligning with the Y=0 mark. A lot of my cuts are fine with that level of accuracy, but I have an idea to improve it pretty easily for others in the near future.

Also, if your endmill edge moves beyond your stock in your toolpath, just stick some same-height spacer strips as left and right spoilers between the clamp edges and the workpiece. I cut a bunch from my MDF scrap from making this. Remember to shift the X origin right by the width of the spacer in fabmo before using though.

I'll try to answer the questions:

I did not make this on a handibot, but don't see why you couldn't with the large material jig. Actually, I was cutting a large material jig on a shopbot alpha and used the time I had on the machine to crank one of these out too. See the crv in the link above... but it's not tiled - definitely change up your job parameters. Also - you might consider a rabbet on each clamping side edge for sawdust. I didn't because I usually blow it out anyway when changing things and I wanted the option to do very thin aluminum plates or even PCB boards down the line. The file is bottom facing up, so they'd be easy to add.

Regarding downforce, I've only been using square, jointed stock so far. With that, there is absolutely no problem. I have to apply downward pressure when applying the clamps, because if it's floating just a little bit, it's nearly imposible to push it vertically once clamped. Seems like it could get to be an issue with live or very non-square left and right edges. In that case I'd probably use a couple of wood or aluminum downclamps on the spoilboard top and bottom, then use the clamp left and right.

Really interested to see more of the extended Y-axis. I backed the Maslow CNC project thinking it could be a good cheap machine for those rare (for me) large sheet projects, but if that doesn't work out then the extended Y gets a lot more tempting.

Have spent a few hours of a quiet afternoon creating files for Josh's jig.
Dropbox link for CDR file: [www.dropbox.com]
Dropbox link for EPS file: [www.dropbox.com]
Dropbox link for CRV file: [www.dropbox.com]
I have not created toolpaths in the CRV file, Also,I have made the MDF 3/4" thick, you might prefer to change that.
And check the positioning of the mount holes (there might be a little too much bourbon involved).

Having seen and compared the files created by Josh the originator, I have taken mine down, so the links will no longer work.
The CRV file of mine has a few dimensions that don't agree with his, and we know that his are correct as his photos prove.
I look forward to seeing the mods that he refers to.

This is very clever and elegant! I will be building one in the near future.