Thursday, July 18, 2019

My Shaper Origin Meta Project - Using Shaper Origin to make a worktable to work with the Shaper Origin

I spent the afternoon cutting a multi-function table with a new tool at the Chimera Arts Makerspace: a Shaper Origin handheld CNC router. (New to me at least.)
Completed Multi-Function-Mini table sits on sawhorses and has a rigid aluminum T-slot frame. The front work table is 24" deep and the back extension table can be raised to create a coplanar surface with a field of Shaper Origin tape.

My project is a knock-off of the Festool MFT. I have a genuine Festool MFT/3, and it's a very good, somewhat portable workbench with many clever configuration and clamping options. Its shortcomings are its $600 price and that, at more than 60 pounds, it's not very portable.  

This Multi-Function-Mini project is a simplified version of the MFT using a similar shop dog hole pattern in 18mm MDF that sits on a table or on Kobalt Adjustable Steel Saw Horses (available at Lowes for $35 each).

[photo: Shaper Tools]

The Shaper Origin is a CNC router that you manually move around on a flat surface like a traditional plunge router. The Shaper Origin tracks special tape you apply to the cutting surface. The tape has little domino patterns that Shaper Origin tracks with a built-in camera. The tape is $18 per 150 ft roll. (There are open-source pattern generators such as this one here that will create free printable PDFs with unique domino-patterns for use with the Shaper Origin. You would print them out and glue them to your material.)

The Shaper Origin needs a spoiler board if you intend to make through-cuts. As with all CNC routers you will also need to devise methods of anchoring your material down for cutting. Unlike many other CNC routers you don't need to worry about accidental collisions with your hold-downs with the Shaper Origin because you are doing the rough guiding of the machine with your own hands. The Shaper Origin is handling the fine-level guiding of the cutting bit within the moving position of the overall machine.

When completed, my Multi-Function-Mini should make an ideal workbench for working with the Shaper Origin. It is made from cheap MDF that can be sacrificed as a spoiler board, and the pattern of evenly-spaced shop dog holes afford anchoring the material to be cut with clamps from the underside without too much difficulty. 
A variety of clamps, hold-down and dogs that work with the 20mm MFT-style holes: (l-r) Festool Quick Clamp, Veritas Bench Blade, Veritas Low Profile Work Stop, Veritas Parf Dogs and bolts, DeWalt 12" Large Trigger Clamp

(Irwin, DeWalt and Jorgensen now make quick clamps with easily removable far jaws. This allows the clamp to be threaded through the dog hole and captured from the other side by reattaching the jaw. Festool sells their MFT quick clamps which thread through the dog hole and can be secured with one hand.)

The MDF surfaces of this project seemed like a good test of the basic capabilities of the Shaper Origin. The Shaper Origin had to be able to cut the shop dog holes to the exact 20.1mm size required, and if the Shaper Origin can cut the spacings between the shop dog holes accurately enough, I will be able to use the final Multi-Function-Mini table to make straight cuts with a tracksaw or traditional router using only shop dogs and tracks as guides.

I modeled the table in Fusion 360. 

The model shows the extruded aluminum T-slot frame to raise the extension table. (The legs in the model are simplified representations of the metal sawhorses.)
I exported the table surfaces as SVG files using the Shaper Tools plug-in for Fusion 360.  These files are then imported into the Shaper Origin using a USB thumb drive.

The machine worked amazingly well... mostly. But it is a bit tedious because it doesn't have CAM sequences (i.e. no G-Code). For example, to cut each 20mm-diameter shop dog hole through 18mm MDF I had to make 5 passes: 
  1. cut a pocket with a small offset from the inside edge to 6mm depth; 
  2. continue the pocket cut to 12mm deep; 
  3. continue the pocket cut to 18mm deep; 
  4. do an inside cut with no offset at 18mm; 
  5. do an engraving cut to 0.5mm to clean the edge at the top surface.
(I later simplified the process by eliminating the last router step, and I replaced it with manual deburring.)

That's a lot of work for each shop dog hole. Repeat that 120 times! It's easy to imagine lots of room for improvement. I managed to cut 30 of the 120 holes over my first few hours with the Shaper Origin machine. It will probably take me another day to do the other 90 shop dog holes in the two boards. (Update: it took about 3 hours to complete the other 42 shop dog holes in the larger board. I decided to wait until I have a physical anchor mechanism between the two boards before I cut the holes in the smaller board.)
My first day's cuts with the Shaper Origin

My model also includes a lot of 
smaller 6 and 9 mm through-holes. The 9 mm holes are counter-bored to hold recessed anchor bolts. These holes were all too small for the 1/4" bit to cut. (Cryptically, the Shaper Origin simply doesn't offer any "cut" button on-screen when it encounters a hole it can't cut. It would be helpful if it gave the user a clue in this situation.) I also tried the available 1/8" bit, but that bit was only able to cut about 11mm deep (according to the on-device prompts). So I was unable to figure out how to cut these holes with the Shaper Origin and bits I had. (I did succeed in marking several of the holes' perimeters with the engraving bit.) Perhaps a longer 1/8" bit would work. Alternatively, I may just end up marking starter holes for these holes with the Shaper Origin. Then I will drill them by hand or with another tool. (Annoyingly, Shaper Origin doesn't seem to have any mechanism to mark the center of a circle imported into the machine.)

The dust extraction capabilities of the Shaper Origin combined with a Festool CT dust extractor vacuum were not up to the task of cleaning out the cut holes during my cutting process. (A quick blast of the Festool CT dust extractor nozzle directly to the hole got all the sawdust fine. But this was awkward because each time I would manually operate the dust extractor, the Shaper Origin (which was plugged into the dust extractor) would lose AC power and reboot. I needed to run the dust extractor manually all the time, or I needed two vacuums at the workbench!) 
Update: it turned out the Festool CT dust extractor was very full. The dust extraction during cutting did much better after we replaced the dust bag. It still didn't completely pull all the dust out of the cuts, but it did get most of it.

In order to assess the device's accuracy, I measured the positions of the actual cut holes relative to their intended positions in the model. 

The distance of the cut holes from the long edge at the front of the board was off by an average of -9.6mm (-0.38") with a standard deviation of 0.5mm (0.02") over half the length of the board. Along the short left edge the holes were off by 1.8mm (0.07") at the front, and varying almost linearly (standard deviation from linear: 0.2mm (0.008")), to 4.5mm (0.18") at the back. These errors probably indicate (A) the board isn't square to start with, and (B) systematic problems with how I was using the Shaper Origin. I seem to have had a problem with how I was trying to anchor my design to the edges of actual the board. (I used a method of making a grid on the machine aligned to the edge of the board where the Shaper Origin probes the edge of the board with its bit. But I might have made a mistake somewhere in the process. I clearly need to do more experimentation to learn the process and its limitations. Update: I ran another grid anchoring test with a test board and achieved accuracy of better than 0.5mm (0.02") for the distance of cuts from the board front and side edges. So I must have made a mistake in my first grid anchoring procedure.)

The spacing between the holes should not have been affected by the edge positioning errors. And I measured the between-hole-spacing to be off by an average of 0.2mm (0.008") over the 30 holes I cut. More important, the standard deviation of the error was 0.1mm (0.004"). The most extreme error I measured was a hole that was off by -0.5mm (-0.02").

Hole diameter seems to have similar accuracy. But 10 of the 30 shop dog holes were too small to fit the precisely machined 19.9mm diameter stainless steel Veritas Parf Dogs. (Update: These too tight holes were easily fixed by another inside cut pass with the router.)  

I did not measure overall linearity of the array of cuts.

The overall measured maximum error of my Shaper Origin cuts was +/- 0.5mm (0.02") and was typically +/- 0.2mm (0.008"). This accuracy is impressive considering that I have never used this tool before, and there is some technique to using the Shaper Origin. The Shaper Origin was certainly accurate enough for the intended primary use of this project -- holding down material for woodworking. I will have to do further testing to determine if my Multi-Function-Mini table is accurate enough to anchor square cuts with my tracksaw. I suspect it is. (The Festool MFT/3, on which my design is based, has a maximum error of +/- 0.1mm (0.004") for its array of shop dog holes.)

My subsequent tests showed me I could register material edges relative to the CAD model with the same level of accuracy I was achieving with my cuts in general. My initial grid registration errors were likely caused by mistakes. Additionally, I was able to continue cutting the project over different sessions on different days without loss in accuracy or calibration. Literally, you just return the Shaper Origin to the board you were cutting. Shaper Origin automatically recognizes the workspace based on the domino tape pattern and you begin cutting. Amazing! Further testing will be necessary to determine how difficult it is to reproduce cuts once the domino tape has been removed, and how difficult it would be to recover if the Shaper Origin's internal map of the workspace was lost or reset in the middle of a project. But the overall robustness of Shaper Origin's optical guidance system is truly impressive.

In summary, Shaper Origin is quite capable of cutting one-off projects, prototypes of complicated projects, and small quantities of duplicate things. Origin eliminates the need for physical templates and jigs for many routing jobs. But I can't imagine using Shaper Origin to make more than a few copies of a complicated or lengthy project. Unlike a gantry CNC router, Origin doesn't do sculpted cuts (cuts with continuously varying depths). (I don't see any reason it wouldn't be possible. Maybe Shaper will add that capability in the future.) Because it is handheld, Shaper Origin has the ability to cut materials that would not fit in a gantry CNC router (for example, a cut into the edge of a vertically mounted board). Finally, Origin lacks cut sequence programing (G-code). This is a major difference from other CNC routers, and it ultimately limits the applications of Shaper Origin for production-type jobs.

At $2500 the Shaper Origin is a significant investment. But it's not at all unreasonable for what you are getting relative to competitive small CNC routers. The Shaper Origin is half the price of a Shopbot Handibot (another portable CNC router system), but it's about twice as expensive as an entry-level small gantry CNC router kit such as the Carbide 3D Shapeoko kit and the Inventables X-Carve kit. (Keep in mind those are bare-bones unassembled kits.)

The Shaper Origin machine seems very well made. It comes in a Festool-type "systainer." And, except that it's not green and white, you could be fooled into believing it is made by a company like Festool. Update: In January 2019 the company that owns Festool, TTS Tooltechnic Systems acquired Shaper Tools. Also, the SM1 spindle and the systainer of all Shaper Origins are indeed made by TTS Tooltechnic. 

I owe many thanks to Ariel Stone at Chimera Arts Makerspace for his patience and assistance getting me up to speed with the Shaper Origin.