Interesting concept... looking forward to details.

 

I was really impressed by the formply gantry I saw built in NZ. Really nice balance between weight and stiffness.

Looking forward to seeing more about your build!

 

I wish i did but the builder requested that I not take any photos while I was installing a Mach3 controller to his build.

The build made good use of tabs locking into slots. This located the parts well and locked every together once it was assembled. Much like this:

http://kavasmlikon.wordpress.com/2012/11/21/laser-cut-enclosure-box-for-your-rfid-project/

I forgot how he screwed it together as I am not sure how well the end grain of the ply will hold a screw but I don't think he used a captive nut like the link above.

 

Looks good, so far!

 

This is very good looking, I'm glad some people are also looking into a larger/beefier gantry design. I think its required if you want a 750mm+ x gantry

 

Going for a 1500mm X gantry with some issues, I would say yes. At least have the back 20x60 (third, some suggest as 'optional') needs to be horizontal rather than vertical like the other two. But that requires modifying the Y plates. That requires a CNC machine, which I don't have yet as I'm building it. So it might not be a bad idea to start with a smaller design, even if just for having a machine to do parts for the bigger design(s).

 

Well said. In my case, I figured the cost was mostly made up of everything but the V-slot, so might as well go for the big one right off the bat.

The trick would of been to buy a few extra length of V-slot to make a babyOX - scaled version of the big 'one'

All that is needed is 1 extra 20x60 1500mm cut in three equal parts for the X beams, 1 extra 20x80 1000mm cut in two equal parts for the Y beams. The 20x40 for the base can hang long during the experience with a babyOX, unless one is ready to spring an extra 15$ or so to cut 1 extra 1000mm into two parts equal to the X beams. Pre-cut 500mm length are now available (when in stock) from OBPS.

No need to buy everything else in double ...

In any case, its only about 50$ of extra material (reuse the screws and rest) without the 20x40 or 65$ with it. It represents a small fraction of the total cost of a large OX. One could even resale those bits of V-slots for the next guy wanting to give it a go. Kind of pay it forward, get an other person hooked on DIY CNC mill/router.

 

So true. So you could get away with just cutting one extra length of 20x60.

We forgot some GT3 which could be 'wasted' ... depending on how it's clamped down on the babyOX. At worse, just a couple of feet will be wasted anyways.

 

Weight should be fine for those nema 23's .... my last cnc i constructed out of 150mm 'c' channel (metal -- shelving i utilised) ... can't remember the exact measurements but i'm sure the gantry was wider than 1.8 metres , x axis was more than 2.5 metres .... ran it on a belt system similiar to the v-belt system .....here's a you tube link ...

 

SLEW .. my last one suffered a bit with the belt system i employed vs weight , had a set up similar to the v-slot but due to the length + weight ...( and even thought the belt i used was reinforced with steel cable ) ... it stretched over time. Tension it too tight and you put load on the motor (they heat up quite a bit anyway) ..too little you end up with backlash and slippage ....maybe think about installing a spring loaded tensioning timing pulley in the set up ??? Busy with my next machine now 3 meters by 1.5 meters... employing a rack and pinion style system .... getting an open ended timing belt and 'glueing' this to a length of steel ... let the pulley run on that ... you can keep an eye on my progress ... its still a WIP ... just started today ! ( its under CNC cardboard box cutter ... something like that) ....