A stiff Shapeoko as a starter

I spend way too much time, and take pilgrim steps quite often. So my first CNC router for furniture making with particle boards is supposedly some kind of a stiff Shapeoko.

Size: I dimension my stuff by pallet fractions. The final router shall not be bigger than 1200x800mm (as a German I am metric). I want to clamp pieces with a size of a quarter pallet == 600x400mm. This is the first iteration, I want to go longer (I have 2 makerslides in the length of almost 3000mm that I will save until I decide on my biggest furniture piece.)

I have access to a metal workshop with skilled welders; I just learned how to program the Heidenhain 145-controlled CNC mill with CamBam (500x500mx300mm milling space, 2500 RPM (old machine)).
I have "purchase power" there, including a reasonably priced laser-cut supplier.

Software, not craftsmanship is my forte.


So here is my first draft of a table-top frame (vocabulary?) with the following design consideration:
- I can always make another one ;)
- the "long-axis" is the support for the makerslide. Reduction of welding seams as much as possible.
- To not have to draw milling paths for future CNC-router dimensions again this frame "already" consists of 80x80 tube, thickness tbd -- but why not 5mm... Gives me material to mill a support for the makerslide into. I somehow HOPE that I can clamp the frame to said CNC mill to "plane" and level the frame with this groove -- IF the frame is twisted (I should be able to check it on one of those "precision welder tables")
- holes drilled into the "long-axis-tube" give access to the makerslide v-nut profile to screw makerslide and tube together

- I have 3 Pololu stepper motor drivers and a FabScan shield The Media Computing Group : FabScan Arduino Shield . But am willing to invest later.
- three Nema17 stepper motors are also at hand
- an Arduino with grbl is what I want to start with
- to start with the Shapeoko belt drive seems easy to set up.

Because I only have access to said workshop on weekends I can only "sketch up" my thoughts for now. On the workshop SpaceClaim, BricsCAD and "Tenado Metall" is used.

I really only want to get going with all this. I will worry about speed later. To only use the router for 80% foam models and 20% "furniture drilling" would be sufficient for me for let's say one year. I rather want end switches and a tool length "database" than nicer software. As an endurance sports buff I think long-term: In three or four years I want to build a weekend retreat (am otherwise nomadic in my professional life). I want to educate myself to be capable of doing all interieur work (additionally to the domotics stuff that I am _really_ looking forward to).

Neet idea, you should also checkout openbuilds.com vslot. May be more appropriate for what you are contemplating. It uses v wheels in special slots instead of riding on an external v rail like the makerslide. Also the 20x80mm gives you more seperation between the vwheels and may give more rigidity.

http://youtu.be/584Z47gTBRY

A while back I watched a tutorial for a Shapeoko machine and their recommended cutting speed and depth of cut recommendations were extremely slow and shallow. It was something like 50IPM at .125 inch depth of cut. I don't know if it's the rigidity of the machine, flex in the rails, or the belts used to drive it, but I would seriously look more into it before building a machine based off of such parts for cnc routing.

Edit
I just went to the Shapeoko website and looks like their is a version 2 of machine that is stiffer. Still looks a little slow for my needs but to each their own.

The Makerslide as used in the Shapeoko is definitely not designed for anything other than light loads. It's only aluminium with plastic wheels.

I went a similar route when I built my long-distance touring bicycle last year: I started with ricidulously un-suited parts and replaced more or less the whole bicycle during one year. But it was a bicycle that carried me from Frankfurt, Germany to Odessa, Ukraine.
This iterative process produced a better "final" result than a over-thought planning process had, because working with the "bad tool" I discovered what I really wanted.

Quote:

---

Originally Posted by cpr

I spend way too much time, and take pilgrim steps quite often. So my first CNC router for furniture making with particle boards is supposedly some kind of a stiff Shapeoko.

---

I'm not sure a Shapeoko is the way to go here. Defining furniture might help, we could be talking things that sit in a shelf or things that are sat upon.

Quote:

---

Size: I dimension my stuff by pallet fractions. The final router shall not be bigger than 1200x800mm (as a German I am metric). I want to clamp pieces with a size of a quarter pallet == 600x400mm. This is the first iteration, I want to go longer (I have 2 makerslides in the length of almost 3000mm that I will save until I decide on my biggest furniture piece.)

I have access to a metal workshop with skilled welders; I just learned how to program the Heidenhain 145-controlled CNC mill with CamBam (500x500mx300mm milling space, 2500 RPM (old machine)).
I have "purchase power" there, including a reasonably priced laser-cut supplier.

---

If you have access to all of that you are light years ahead of many here. As such it would pay to design the machine to leverage that hardware. This also means that you can design a more robust machine.

Quote:

---

Software, not craftsmanship is my forte.


So here is my first draft of a table-top frame (vocabulary?) with the following design consideration:
- I can always make another one ;)

---

Possibly, no one knows what the future holds. As such I'd suggest making a robust machine that can be useful to you for a very long time.

Quote:

---

- the "long-axis" is the support for the makerslide. Reduction of welding seams as much as possible.

---

Personally if you are going to these lengths to make the frame and other components I'd seriously consider profile rails or even round rails.

Quote:

---

- To not have to draw milling paths for future CNC-router dimensions again this frame "already" consists of 80x80 tube, thickness tbd -- but why not 5mm...

---

There is the basic structural considerations when choosing a thickness but let's not forget the practical. One thing here is screw holding, the material thickness should be at least as thick as the largest screw you expect to drill and tap for.

Quote:

---

Gives me material to mill a support for the makerslide into. I somehow HOPE that I can clamp the frame to said CNC mill to "plane" and level the frame with this groove -- IF the frame is twisted (I should be able to check it on one of those "precision welder tables")

---

A precision frame starts with precision machining before the frame is welded up.

Quote:

---

- holes drilled into the "long-axis-tube" give access to the makerslide v-nut profile to screw makerslide and tube together

---

Think hard about this! How will you reach into the tube to install the nut or screw as the case may be?

Quote:

---

- I have 3 Pololu stepper motor drivers and a FabScan shield The Media Computing Group : FabScan Arduino Shield . But am willing to invest later.
- three Nema17 stepper motors are also at hand

---

The above strikes me as far too small for what you are building.

Quote:

---

- an Arduino with grbl is what I want to start with

---

A very interesting solution! I've been tracking GRBL since I've heard about it a few months ago. Yes I behind the times. It looks like a good basic if lower performance controller.

Quote:

---

- to start with the Shapeoko belt drive seems easy to set up.

---

Easy doesn't mean suitable. When I think making furniture I think of lots of horse power and big chunks of material.

Quote:

---

Because I only have access to said workshop on weekends I can only "sketch up" my thoughts for now. On the workshop SpaceClaim, BricsCAD and "Tenado Metall" is used.

I really only want to get going with all this. I will worry about speed later. To only use the router for 80% foam models and 20% "furniture drilling" would be sufficient for me for let's say one year.

---

You see you have completely redefined your goals here. Foam and hole drilling are a bit different than machining furniture components.

Quote:

---

I rather want end switches and a tool length "database" than nicer software. As an endurance sports buff I think long-term: In three or four years I want to build a weekend retreat (am otherwise nomadic in my professional life). I want to educate myself to be capable of doing all interieur work (additionally to the domotics stuff that I am _really_ looking forward to).

---

Like it or not you have basically defined three or more machines here. One for foam work and light duty. One that is portable and a third heavier machine suitable for home building. You might want to reconsider your design for the first machine to make it portable, at least portable to the extent a table saw is portable. Like a portable contractors saw handles a range of work below a cabinet makers table saw so should your first machine. To be perfectly honest moving big machines around is no fun.

Thanks a lot to everybody for the remarks, I realize I have indeed more than one machine in mind!

I will think about the design, and try to plan towards the "evolutionary split" into multiple machines.

Only one thing right now: To attach a slide on a quadratic tube you just drill a bigger hole on the other side, so you can insert even a "ratchet" (is that the englisch word for the "mechanical screwdriver"?)

I am running under way too much steam at the moment so I will postpone the redesign until a later time. Until then I will follow-through with the "stiff Shapeoko" idea.
But the gantry will change soon afterwards, I think.

I really want a cupboard-board-sized router, but right now don't want ti commit building one (pilgrim steps, that is me).

I was in the workshop 16h yesterday to experiment with the base-"table" metalwork.

An Arduino with grbl is already turning three small stepper motors.

Because the mill "only" does an 500*500 work envelope I had to reposition the 80*80*5 tubes. It worked out allright, there was about 1/10mm that the gauge jumped. This is at the better end of the tolerances in this workshop.

Until about midnight I made a first test pattern for the 4 holes at each end, will continue in this morning.

I tapped two DIN 427 "screws" and "pocketed" two holes for M10 screws. Was a bit off but that can be corrected.

Well, I am off to the workshop. Feel a bit "driven". *g*

The base frame feels stiff enough for a potential 2,07m * 800mm work area. Let's see how the accuracy will work out.

As a software guy who only recently got into the "world of things" some experiments with parametric design algorithms and a (crude) workflow into CAD/CAM were promising! :)
And I really need to come up with an idea for a 30degree clamp to use that cool dovetail software developed by forum membar JerryBurks.

The saw is quite accurate, but I did not dare to measure from both ends of the tubes.
The mill with its work envelope of ~500x500 cannot reach both ends of x and y axis-tubes. So I made a guide from a 8mm steel "plate": With the same hole configuration and additional pockets at 250, 500 and 750mm distance down the axis. The workshop has a CNC probe tool with a 10mm ball, that's why I used a 8mm plate.
With that guide I could easily reset my zero position down the "long axis".

I milled the holes/pockets for the "head" of the DIN 427 thingies: They measured 7,88mm and I milled 7,9mm counterpart-holes. On one tube I got impatient and drilled additionally with a 8mm bit. Now one corner is a bit "wiggly" *grr* Next time I am going to be more patient with the press-fitting connections!

Then I marked and drilled various holes for mounting the Makerslide profiles.
There is no M4/M5 threaded rod around, I need to buy some next week to use small pieces as a guide/marker for the t-nuts.

And finally I put some screws into the whole frame, to get a feeling for the stiffness. I am quite pleased so far, it is the first thing I built and I like the "look&feel" of it.
I did not fully screw the tube with the press-fitting holes together, not sure how hard it will be to take it apart. But already now I have some _solid_, *SOLID* foundation to build on!
It is bigger than I pictured it. Let's see how the 800mm gantry will perform with the double makerslide.

I am not sure how precise the 80x80 tubes are. I noticed quite some fluctuation in the z-axis on the mill, not sure how 1/10mm here or there will affect the final router. But it is too early to make a prediction or measure the frame.

(I cleaned the vise thoroughfully, but sometimes I had to reset the z-axis when milling the holes. Really not sure where those fluctuations come from!)

Now I feel a bit flat, I still have a full week off from work. Quite some parts will arrive monday or tuesday, so I unsure what to do next. I might just spend tomorrow with software and make me some crazy "hello world" gcode file. I am still positive that I will have the router up and running at the end of next week.

Because I did not have a source for the POM leadscrew I had to make my own. In the workshop they had a piece with a diameter of 45mm and 150mm length.
I was somehow under the impression that the leadscrew was fastened with screws and nuts. BUT after I drilled the two 5mm holes I realized that these were supposed to be tapped! *ouch*
So I rammed another 9mm bit in and created a "pocket" for M5 nuts.

This is only the first machine I am building. The last days were such a lot of fun! I already looked at designs of hot wire cutters and such.

Well, this build will have run into problems soon -- I believe. Everything went so smotth so far, it cannot remain like that!?!
Probably I have warped frame and the z-axis is going to be screwed up (or down)…
And the stepper motors with their default configuration are not turning constantly but one is "stammering".

I upgraded the z-axis carriage to something where I should be able to attach a proper screw to, not the M8 rod I am going to start with.
And I made a spindle holder for the Kress Spindel that clamps at the verz bottom of the spindle.

Haha, I have "upgraded" myself to about 3mm of z-axis travel: See first picture.

Solution: I will make tool holder with more space. This is the quickest solution, pending a "z-axis redesign" (I already have a kind of an ACME screw, I believe our european system is different and it is translated literally "trapezoidal-thread spindle".)
But I have no good idea for a design and I don't feel like quickly googling for one.

I have 80mmx10 aluminum and 120x10 and 40x40, all of it in sufficient quantities.
That's why the spindle holder looks as it does, I had to put the radius somewhere in the 40mm workpiece.

Or does anybody have a link to some design that will work with a profile-rail, screw and a NEMA17 w/ 0.44 Nm?
I will upgrade the stepper motor anyways, but I'd like to get a quick working version this weekend.