eBay and Chinese made products are very attractive for hobbyists on tight budget. Many of the electromechanical products are quite ok but I would be very hesitant to use built electronics. There is so much fun in doing the electronics as there is with the XYZ tables. Just ask Robert who seems to be enjoying all these. He even dabbles with Laser optics, wow!

If I can get into this sort of play with all thumbs I am sure all of you can and keep it open for others to jump in.

As for me, I am trying to build a 6axis controller using Arduino Mega for the Gcode parsing using GRBL and USB interface and use either VNH2SP30-E (from STMicroelectronics) which is rated at 30A and 40VDC and THB6064. Unlike the TB6560, which absolutely requires logic power be stable before motor power is applied, the THB6064AH can survive motor power without logic power and will not intermittently short on power up. This is a VERY common failure of the cheap TB6560 drives. Besides THB6064 can microstep to 1/64! It can also handle 4.5amps@50V.

Another parameter I would like to point out is the fact that stepper motor load is primarily inductive (the coil) and can produce opposing voltage (back EMF) proportional to the running speed. So if you want to run the axes fast you would normally use high voltage drivers but keeping a constant current specific to motor. I am just passing these on as I am going through the learning and design process.....
Gopal

 

Nice find thanks.

http://www.ecomorder.com/techref/ecomprice.asp?p=416074

£75 for a full 3 axis kit. http://www.massmind.org/Techref/io/stepper/THB6064/index.htm

 

Alternate Gantry Support
Here is an idea for an alternate gantry, more similar to the routy than the existing garolite OX. It primarily uses 2080 uprights, with brackets to hang the bearings and stepper mount. This would seem to offer more rigidity, as well as adjust-ability and expandability vertically for different material thicknesses, the trade off being higher parts count. At least 3 versions are possible, a single flat plate with bearings and stepper mount; two plates one with bearings at bottom and stepper mount and the other with bearings on top so the bearing gap can be adjusted on the 8020 upright, or L angle brackets with bearing sets and stepper mount on each.

Does anyone see a problem with this approach?

 

I am not sure about rigidity of the 2080 over just having the 1/4" Graolite plate OZ design, since I am new to CNC Routers. But is does have some resemblance to the Routy gantry plate design, so someone experienced with that may be able to better answer your question.

I like the second design better using a single plate. This gives me an idea on how to transform the OZ into a CNC/3d printer. By allowing the plate mounted 2080 Vslot pieces to move up and down a few inches, I could raise and lower the gantry. This could be done with a simple dual screw drive or just a move and lock system. Fully retracted for CNC work and fully extended for 3d printing. Of course the Z axis would have to be extended for more travel, but would only use the first 3-4" of travel for CNC work and a full 8-10" for 3d printing. This would allow for larger Z axis 3d printing without sacrificing Z axis rigidity for CNC routing.

 

Mark any updates on the files for the plates and video.

 

I have a rigid 2401 that I use on the binding jig I will post a picture. It is nice because the base is tapped and the mounting is easy I was thinking of using this type of router. Variable speed I weighed it and it is a little heavier than the colt 3.6 pounds. I think you can make it out from the picture.

 

Hi Mark/Robert and everyone else!

I came across this linear actuator design (meant for a hexapod aircraft simulator) but the concept of the belt drive taken to a large scale! Enjoy...

Gopal

 

He should have used Constant force springs, instead of bungee cord. Would have worked much better, as they provide a near identical amount of tension over the entire motion range.

 

Great video mark thanks for taking your valuable time and making this video

 

I have one suggestion. One of the final test items done on the build should be to draw a design on paper attached to the table with a pen/marker attached to the Z-axis. Just tape the pen/marker to the the Z-axis and set up the zero point so that when extending down it just touches the paper. This method is what proved that the 2 motor Y-axis was required because of racking of the gantry on the ShapeOko. It is also final proof for significant others that your time was not a compete waste. Besides I like the idea so that you can frame it and hang it on the wall just like new business owners do with their first dollar. I can prove that it works. It is a certificate of final build completion.

Bob

 

Great video I am a Newbie to this and I learned a lot. I am a retired teacher and I was impressed with the clarify of the build. As it should it left me with the feeling I can do this. The part I find off putting is learning enough Cad and Cam so I can actually make something. Any ideas about places to go on the net to learn this. Remember I am an old guy I didn't grow up with computers just erector sets and tinker tools. I was a builder then to.

 

I just watched the video again and I had an idea about the platform. One way woodworker make a stable panel is to do something called a torsion box. It is a stable way to make a box that is much lighter than a solid muti layered top. Maybe the top layer could act as a vacuum chuck if the box was sealed up air tight and finish to seal it. The valves I showed in the vacuum chuck could be installed at regular intervals. I have to get going on this build so I can try this out. There would have to be holes inside the box so the air could be pulled out of it. Google torsion box to see a lot of good picture. While I was writing this I realized it could be a big vaccum table as well.

 

Yes and if you use the whole table then you could say the it really sucks for the whole project. LOL.. Sorry I just could not pass up the bad joke. Use a torsion box table with built-in suction would greatly increase the utilization of the system and allow for a more stable structure.

Bob

 

I'm planning on doing this with my routy and eventually OX. Instead of ordering extra v-slot for the frame to support an mdf table, I'm making a torsion box and mounting it to the frame. On top of that, I'd like to add a scratch-pad and suction table. I need it to be removable so I can put on a heated bed. Maybe I could make that same suction attachment you posted before and the top would be a sliding piece that can be quickly changed out with a new scratch/suction top or heated bed. Have different tops for different devices. Maybe a laser-proof one too .

 

Im with you Bro ! I cant wait . Will the parts be available in the Phlatstore ?

 

Thought I would share my latest score at my local surplus $5

Not sure of its TPI yet but there is 6 inches of thread. I just need to get another 1602 bearing and I should be good to go