The 20x40 for the z axis, is it open/no plate at the bottom?
I ask cause the RC spindle I'm making will bolt to the bottom of a 20x40 with m5 screws
Here's a pic, still putting it together

 

As crazy as dreams tend to go, I was thinking of using dual spindle on the same drive!!!
Humans tend to associate beauty with symmetry - if your left-right facial features are symmetrical then you can be a model! So, I thought if I had dual spindle doing mirror image of a pattern on the same carving things can shine a bit.

The reason to RAISE the gantry is to see if I can do some cylindrical carving using a rotary axis below--

You guys are the doers at this point and I am happy to be part of this.. Retirement can really push you into some crazy thinking modes - you know the saying about idle mind..

 

This is kinda what I was drawing out while my mill did the cutting I think it will work out.
As they say ya don't know till you try

Please excuse the art skills lol

Enough with the pics I'm going to spoil the build lol

 

Thats what Open builds is to me man, a place where my mind can grow and feed off all the great minds alike here.
OPENBUILDS Rocks!
Cant wait to have an OX flinging chips
I may also go with ten tpi leadscrews that I came accross, 500mm thread travel

 

Looks great! All good designs start on the back of coffeeshop brown knapkins.
Have you thought about using the PM rotor and stator coils cannibalized from brushless RC outboard motors?
Also, keep in mind of lateral chatter/resonance at high RPM... but I would be the last person to suggest paralysis thru analysis!

 

Hey. Is it possible to get the files to the new OX CNC Plates?

Thanks

 

Looking at routers for ox, ran into this one:

http://www.amazon.co.uk/MAKITA-RT0700CX4-Inch-Router-Trimmer-240V/dp/B00B48Z01G/ref=pd_cp_diy_1

http://lumberjocks.com/reviews/3178

Looks like 110/220 both available, and seems lighter weight but better built than a colt. Plus variable speed.

 

Mark, have you looked at these from a company called ITEM.



As everyone else here, waiting to see when the plates would be available from the parts store. Being slightly on the impatience side, I have already ordered the V-slots, other structural mounting plates and ordered six 270 oz-in Nema 23 steppers and two spindle motors (300w and 800w with E11 collets).

I do have a question though, do you really thing a dual NEMA23 for the y is necessary? For my application I need eaqual x-y force at the spindle. I was thinking to split the two 20/60 on the gantry and two belt runs with the z installed in between-any caution from you?????

-Gopal

 

I forgot to mention: On the drive electronic side, I have the TinyG 6axes bord (https://synthetos.myshopify.com/products/tinyg) interfaced to tgFX drive software (the latest build is at https://www.dropbox.com/sh/huiupgemipv8f4q/X2l_1EH-gx for Windows - it runs fine on Win7 x64 although the s/w is for 32bit).

For me TinyG allows me to map A/B/C axes to X/Y/Z thus use two spindles with steppers slaved on X and the two Y steppers also slaved. The interesting part of these two H/W & S/W combination is that they can be run on OSX as well and hopefully an iPAD with wireless interface. DREAMS!

Gopal

 

I have to admit im with you Gopal. I have ordered all the parts for the OX minus a few little things and also cant wait to get the frames cut or templates and might try to just cut them out without CNC. Just last night i got my Hobbycnc board hooked up to my computer and got all the steppers running. Just got me that much more excited to get this machine built.

 

The RT0700C has been replaced with the RT0701C. You can pick it up at Home Depot for $99.00. I like that it has a electronic speed control range of 10k-30k rpm. May be ideal for harder materials.

 

It's been only a few months since I jumped into this hobby (!) and my findings on the net may all have been seen by most of you. So my apologies if my postings and ideas are blasé to many of you.

The difference I think between Mechmate cnc and mine would be that mine would have TWO independent spindle with two steppers on X axis running code but operate in mirror fashion - don't know if I am all wet here! The x axis will be a single belt-pinion drive à la except the steppers would run in opposite sense. Might have to use wider belt just in case.

But all these are just buzzing in my head. I am anxiously waiting for you second part video on the OX and the optimizations you will certainly do. Being new to all this, I will first try to put your design first before forking off to my craziness!!!

So, thank you for publishing all these and it won't be long before you turn me also into an expert like you - but for now I am an ardent follower of you.
Gopal

 

Sounds great mark can't wait to watch it

 

Dude, are you in India? I'd love to see someone take this there and get a distributor for parts. Maybe even get some fair trade going and cut out the corporations, just go person to person. You know, free market something like that. Plus India has so many EE and CS people now it would help us a lot.

 

So sorry.. I am in North Carolina - have been in the US & UK for the past 40years - I am 68 now.... Not been to India in a long while!!!

 

Good news is Singapore is a cross roads for India, we have a good size of India Population, and people regularly come to Singapore to buy and bring back. I'm almost thru getting setup for being a OpenBuiilds Distri here.
Planning on OX kits, and fully assembled.

Have to checkout and see if there's a maker fair in India.

 

Mark,
I have some material that - I'll happily use to Alpha test any part files you have for the side plates

I am looking for motor packages and am trying to decide between a NEMA 23 that seems in line with a 2'x4' machine or your thoughts if this can handle much larger motor package? I think I recall you mentioning a desire for 23's for the side plates in your Part1 video?

Based on your experience with Routy and Ox what do you think is sweet spot for motor size?

185 oz-in
http://www.ebay.com/itm/321284383152?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

287 oz-in (Nice clean enclosed driver board)
http://www.ebay.com/itm/221344427902?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

428 oz-in - this is one option if looking for more than 3A from the stepper driver. Would this be overkill for an Ox based mechanical package???
http://www.ebay.com/itm/140902769594?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

For whatever it is worth, I have heard that (not used personally) the controllers based on T6560 have some reliability problems. Besides the interface is parallel port - check if you have one on your computer!

I use TinyG ($130) which has 4 axis drive with the 4th axis mappable to the other three. It is fully self contained (can take any Gcode sent via USB and drive the motors) It can drive up to about 2.2amp/phase without any heatsink (the chips are rated for 2.5amp max but I hate to use max rating on anything!!). Synthetos who makes these suggest fan cooling than use any heat sink. And they claim to have tested this board with 17 & 23 motors. By the way, they also have an Arduino shield if you prefer that route. And , best of all, its open sourced.

But if you want to try ebay look for controllers with TB6600 chips. Interface (USB or Prallelport) should be decided by what computer you have). You can instead buy the steppers on ebay for about half that price, and use US built TinyG. (I have only had some critical discussions with Synthetos so please don't assume that I have any vested interest in the product except that more people end up using the TinyG the better the product will eventually be)

As for sizing the steppers, higher torque means faster movement of the axis. This also depends on the load you have on the X-Y axes (defined by friction on the bearings - minimal for the OX) and the spindle motor and the work you want to do. If you want to do deep cuts @ high feedrate on hard material then you do need the 270 0z-inch motors. Also keep in mind that at max roll out, the belts also tend to stretch. Zaxis on the OX is safe as it has an acme thread where you do get some mechanical advatage of the leadscrew.

I am certain Mark can explain this better as he has personal experiece with belt-pinion drives. I DO NOT!

Sorry for this all hypothetical cautions - I am a physicist and this comes out of being one.
Gopal

 

Yes indeed! stay away from TB6560 boards.
I myself had many issues and the z axis chip exploded.
I ended up salvaging the parts and building my own controller from the remaining TB6560 IC's.


In the end it cost me more to get the junk I was sold to work nice but also learned to make my own PCBs.

 

G-code logger idea, nice.

With my designs i just would code this with the Atmel chip so it uses a I2C LCD to show the current G-code in operation.
Arduino rules. I have a GertDuino that sits on-top of my Raspberry Pi with HDMI & USB & Ethernet all for £30

SD card provides the G-code card input. So no PC required.
Plus the designs can be locked on a SD card.
This way you make SD cards for the shop once, then lock them down.

This helps separate the CAM process & the manufacturing side.
Very handy when working with people whom don't understand computer systems.

 

Thanks for the feedback guys.. I have been reading up on the TinyG board at the forums and am considering it for sure.

Robert your board work is inspiring.. I'd love to know how to do that kind of work

 

Ty, it's not that hard at all just takes practice and a lot of reading.
I just got so mad I said to myself if they can make it so can I

I started out with the iron technic and got ok results but success rates where low. Here is a video of me making my little girls nightlight


I built an exposure unit using an Arduino Uno and put the code together using bits and bites from many different sketches.
I know very little when it comes to programing, just a good hack lol
This allowed me to get fine traces and 100% success etching boards

I'm about to dive into SMD PCBs to make my own Arduino based controller for my OX build.
Should be fun and in the end I hope to have a solid 4 axis 4.5 amp GRBL based controller.

 

Want 8 amp try this

http://openbuilds.com/threads/high-voltage-compact-pwm-control-circuit.322/

http://www.rmcybernetics.com/shop/PWM-OCm Price: £19.99