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Hi Mary:

The machine doesn't have "feet". If you are referring to the clear neoprene bumpers for the axes, I guess they technically are feet, but I don't use them for that. They are used as soft bump stops to keep the axis from crashing into the end. I got them at Home Depot.

 

Should be on there. I think the side plates were $180 the x gantry plate set I don't recall. I will see if i can find it for you a bit later.

 

The X gantry plates are these ( you will not need the spacer blocks)
Tall 80 mm X Gantry Plates and Spacers for the OX CNC (seen at Openbuilds) | eBay

I have contacted Chris to get the order numbers for the plate set. I will post it here as soon as I get it.

MG

 

Hey Ronald, Long time no speak, buddy!

Thanks, I've built enough Ox's to know all the tricks by now.

The inductive sensors work well, they seem to be pretty robust. And they are really cheap, almost cheaper than limit switches. Speaking of limit switches, I use the limit switch mounting plates from the OB store to mount them, they have the same hole spacing as the micro switches. The screws they come with are crap, throw them away and use 4-40x3/4" instead. A couple of cautionary things, though.

• They need a 12v power source at least, they will not run off 5v. I add a small wall transformer just to power the inductive sensors, it's a bit of a pain but keeps the wiring simple. Just tie the ground from the 12v supply to the Arduino ground and it works well. I don't think it's a good idea to power them off the 24V supply, because then you have to tie the ground of the Arduino to the Motor supply ground, which is a bad idea noise-wise. Also, the stepper drivers go to all the trouble of opto-isolating the logic inputs from the Arduino, connecting the grounds back together just does not make sense.
• They have a limited range detecting aluminum compared to steel. They are rated at 5mm distance, but that is with steel, with aluminum it's only about 2mm. But, they work well nonetheless. Worst case, you can use a steel screw as a target to get better response.
• With the Arduino Nano, you must add .1uF caps from each limit switch input to ground, or the homing cycle does not work properly. Should probably do this with all Arduinos, but the Nano seems to be more sensitive to this.
• If you use a 12v supply to the inductive sensors, they have an internal weak pullup resistor on the output to the supply voltage. This is not really good for the Arduino to have it's inputs pulled up to 12v, although it seems to have internal protection circuitry and does not blow the inputs. May not be good for the Arduino long term, however, so I usually put a series Schottky diode between the sensor output line and the Arduino input. Cathode towards the sensor output side. Thus the sensor can still pull the line low, but it does not allow the 12V to feed back into the Arduino input.

I can send you some pics of the mountings if you want. I use the 2 hole angle brackets, the OB part store micro switch brackets, and the odd screw and spacer to mount the sensor and a target for it.

Take it easy, man.

MG

 

Hey http://www.openbuilds.com/members/ronald-van-arkel.2417/, how about putting up a build for that machine?

Or at least start a thread with more pix... It looks VERY interesting... You can't just tease me like that!

MG

 

Nice one, getoffmyland. I didn't see this when I was looking. There should be lots of builds like this out there, since Chris has said he has sold lots of plate sets like this.

MG

 

Hey Robert:

Should work now. You are right, there was something wrong with the ZIP file. Make sure to extract the file before you try to run it in SketchUp or you'll get an error.

MG

 

Yes, I have seen this build... Nice work! Yours is an order of magnitude heavier than mine... I just wanted to beef up the Ox a bit to take out some of the flex and fix the really weak Z axis. It's still a belt drive machine, and you can only do so much on a belt drive system.

I really like your back to back c-beams. That assembly should be really stiff.

Why did you make your Z axis so tall? You can only use less than half of your travel before it hits the bed or the front plate...

Something I am going to try - using two of the OB router mounts one on top of the other to give the router itself much more stability. You can't do this with a Bosch, but the Dewalt DWP611 and also possibly your Makita have enough room to fit into a dual mount.

MG

 

I'm posting a sketchup drawing in Concepts and Ideas on the forum...

MG

 

No problem. Perhaps the moderators would see fit to move this to a new thread, as it would be good information for a topic all its own.

I'm kind of tied up for the holidays, but I will post something the first of the week about the schematics.

Merry Christmas, everyone!

MG

 

Since the moderators seem to be all sleeping off their turkey, I will create a new thread in Forums/Electronics/General Electronics called Proximity Sensor wiring.

MG

Prox Sensor Wiring for Limit/Homing Switches

 

Now that's just plain silly. That setup would be about as stiff as a wet noodle. It would have Centimeters of flex.

Multipurpose machines may do everything, but they don't do anything well. They are always a compromise.

Besides, the Ox has gone the way of the mastodon, it's extinct. Belt drive machines are old news.

MG