Thanks GrayUK

 

Anyone??? I still need help with how to do the limit switches and where to put them.

 

Hi @greenmonk ,

Sorry for the delay but I have posted a few photos of my way of mounting the limit kits from OB.
​

Both of the long axis have a limit so I can use slight adjustments to the placement of one of them to bring the gantry square after homing.}



The Z switch stop would hit the screw nut if I was to use the full stroke on the Z but as this cnc will only cut thin plate this is not a concern. I like the placement of this switch as it keeps the wiring neat and higher above the dust line than if I was to mount the switch to the lower part of the Z beam.



I have the other axis switch just getting clipped by rear ally plate. Simple but effective



​

I have also noticed that on Ox build the longest axis was called the Y but it has always been my understanding that the longest axis is always the X. What is the correct axis naming convention?

 

I have decided to build an Ox instead of a routy as first planned. I am a distributor and have placed the parts I bought for the routy on my site www.opensourceluthiersupply.com. Check them out I have four stepper motors a power supply and other various parts.

 

Hi everyone,
I am new to this whole habit and have not built a Cnc before or operated one. I have watched the videos mark has made (great job really) so I am now hooked on building an OX of my own. I am not worried about the mechanical part (famous last words) but it's the electrical side that I am concerned about!
In the videos Mark made it look so easy, but looking in the parts list the controller he used is not available anymore, I liked that one because it had no external driver units (I think) or am I missing some thing?
Am I right that the controllers in the shop will need drivers? Why do they not have any listed?

Looking forward to the challenge, keep up the great work everyone.

Paul

 

@Paul Franklin Yes the USBCNC boards will need stepper drivers connected to them. I have heard that the motion is VERY good from this controller

The G540 is a good most in one option that has MORE than enough power for most Vslot projects.

Arduino + stepper drive + shield is also an other option (plug in stepper drives are good if you think you might blow something up....)

 

I really like this design. I do a significant amount of work with 304 stainless (occasionally 316). Mainly what I would like is to be able to cut precision holes and the like - and not have to pay for the laser cutter.

I'm curious if anyone has used it on stainless steel? Are you getting clean cuts? What is the precision?

I'm assuming cut rates of around 10 ipm and .02 per pass.

 

Hello All, I too am a newbie at CNC. I've wanted to build a CNC router for some time; I even bought a set of drawings for a MDF version a couple of years ago. After looking at it, I just could not bring myself to believe that the MDF with roller skate bearings on a aluminum angle would work very well. I found this site about a month ago and every thing just seemed right. I have been ordering parts and working on the construction of my 2x4 OX ever since. Chris Laidlaw has been a great help with parts, he has even made me a custom bracket for a NEMA 23 on the Z(I already had the Nema 23's). After 3 orders from the parts store and 2 orders from Chris and orders from Amazon and Probotix and a few trips to the hardware store, I have everything (I think) but the 8mm lead screw. That has been bought on ebay for a week but has not shipped so I may still be looking.

By trade I am an equipment engineering tech so the hardware and electronics is the easy part for me. The hard part is the software, I have decided to use Mach3 on an old XP based PC with a parallel port. I have downloaded the trial version and have been watching the videos. What CAD and CAM programs would you suggest for a newbie? To start I would like to be able to cut out letters and engrave signs and such to start with then move on to cutting more intricate parts.

 

Hi Paul,

There is lots of software out there to choose from but my choice would be something from the Vectric range; http://www.vectric.com/

Tweakie.

 

Working on my OX build today and discovered I am way short on T nuts, and guess what the parts store is out. Anyone have a second source?

 

Thanks Rick, I have some on there way.

 

Congratulations on your completion yet I have a few comments;
1. Why use 2 separate X axis steppers when using one 500+ in/oz with a connecting shaft would eliminate any error generated by two, plus reducing gantry mass?
2. The use of derlin type bearing tires is ingenious besides reducing metal to metal noise and aluminum track wear.
3. Considering long spans of 6'+ wouldn't a welded truss be more appropriate or additionally base frame levelers?
4. I have found TEE-NUTS seat better and straighter when pulled in place like a pop rivet with short hex head screws and a fender washer and insure useable threads.
5. It's common practice to twist unshielded wires to reduce "crosstalk between pairs" and to use stranded wire where motion is involved this also applies to HF PWM.
6. Stepper noise can be greatly reduced by placing a thin rubber 'gasket' between motor mount and stepper, this also reduces vibration being transmitted to the base/gantry.
7. Did I miss seeing base leveling feet on the BOM?
8. Did you consider debris will collect in the gantry track and under the cogged belt and removal will be difficult since the belt is tensioned?
9. Experience has shown galvanic corrosion occurs using steel screws in aluminum parts especially humid non regulated temperatures. Un-anodized aluminum will also develop a protective oxidized layer which might be detrimental causing increased wear on plastic wheels.
10. AC powered routers will perform considerably better on PWM DC providing greater motor torque, maintaining consistent speeds, with lower operating temperatures, longer brush life, by avoiding AC sine wave voltage swings.
11. As a retired E.T. I'm wondering why your using such puny power supplies? It is common practice to use a power supply that is at least 200% of your maximum wattage. Also why not run at least 24 volts or 36 or even better 48 so your steppers run cooler by drawing less amps. Here's some p/s available on Ebay right now;
12v/58a +5v/2a $13.09 w/free ship - 24v/13a $38 w/free ship, 500w/48v $40 w/free ship, 750w/48 to 58v $60 + $18 ship - 48v/30a $37 + $17 ship - 48v/12.5a $18 + $15 ship
BTW these are server p/s rated for continuous duty and those were on page 1 of 10 w/200 per page. That 48v/30a should put your gantry in warp drive!!!
13. In 49 years in electronics my theory on solid state devices is they are just like us 40F is too cold and 110F is too hot.

 

Try http://www.woodpeck.com/tnut.html $1.10 for 10

 

I think they are talking about a different sort of Tnut @Geek1945

Are you sure you couldn't find anything positive to say about the OX?

 

Hi Geek1945,

Welcome to OpenBuilds - Your years of experience will be of great benefit to us here - please keep up the suggestions.

Tweakie.

 

Has anyone cut aluminum with their OX yet? How thick?
I am curious what materials have been cut so far.

 

My 750 x 1000 OX is about 90% complete. I've agonized over the control but decided to just bite the bullet and my Geckodrive G540 is here. Hopefully another week of evening tinkering and I'll be making sawdust!

If anyone else has used the geckodrive I'd love to see where you placed it, how you wired it etc.. Haven't started on it but not sure how to run all my wires with the gantry system. Any help is appreciated.

Thanks

 

I'm building a 1000 x 1500, and am still agonizing over the same - someone help me

There are nice pre-made G540 "kits" with matched steppers, power supply and simplified cabling. But they're twice the price of buying everything from a supplier in China (with decent Leadshine digital drivers) and doing your own cabling. And the pre-attached DB9 or DIN connectors would prevent me from running any of the cable through the v-slot channels.

What size of NEMA23 stepper is everyone using on their build? Same approximate size as the 175 oz-in units on the OB parts store? Having never built a machine like this before, I don't know where diminishing returns starts kicking in, as you size up from there. If I never intend to cut anything tougher than sheet goods or maybe 1/4" aluminum plate, is getting up into the 350+ range a waste?

Has anyone used a NEMA17 with integrated acme screw for their Z? Seems like it would be one less component that could come loose over time.


I think my biggest issue, is that I see a 4' x 8' machine in my not-too-distant future, and thinking of re-using parts from the OX is over-complicating what I'd otherwise just buy now. I should assume that even if I build a 4'x8' (non-OX) eventually, I'll want to keep the OX for smaller/more-specific jobs, and just buy the components without planning for re-use.

I also wanted to thank Mark for designing the machine and providing such useful assembly videos.

And for anyone looking for aluminum OX parts (gantry plates, motor mounts, etc.), I thoroughly endorse Chris Laidlaw's work - excellent stuff, except now I'm being overly-careful with assembly because I don't want to scratch the brushed finish

 

Everything I've read about the G540 is excellent. It just seems the DB9 Connections are going to limit my options or cause me quite a bit of extra work if I need to disassemble anything.

These are the motors I ordered:
http://www.amazon.com/gp/product/B00F18E69W/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
Ordered on June 16, Arrived June 30.

I'd never seen those before. I already have my Nema17 and Adapter but would consider that if not.

I'll second that. I received my Gantry Plates and threaded motor plates from Chris. Top Notch parts. Thank you

 

Watch out for the nema 17 Z axis motor. It seems that my motor wasn't powerful enough to hold the weight of the router when there's no power to it. The router just go down until it reach its minimum mouvement. Just think about what it can do when your router is spinning... it goes down... and down... and down... you have to find your z axis zero back before resuming the g-code. Long and painful... I'll go with a nema 23 on the z-axis, I just have to find the fitting plate @Robert Hummel ?

 

I will be cutting Z axis plates today, I will mill an extra.

Shoot me a pm with your address again

 

I pulled the trigger (prematurely, as it turned out) on my electronics. Everything is from OMC/StepperOnline, so we'll see how accurate the 3-5 day estimate via DHL from China is.

Since the OpenBuilds parts store was still out of Acme Tr8x8, I opted for the largest NEMA17 I could find that used Tr8x8 (200mm of it - perfect) as its shaft, a 62oz-in. To that, I added four 269oz-in NEMA23 steppers (figuring OB would eventually get Tr8x8 back in stock, and I'd ultimately want something beefier to drive my Z).

For drivers, I picked up Leadshine DM432C units (fairly closely matched to the steppers) and a 5-axis break-out-board. I ended up spending almost the same as I would have on a Gecko G540, so hopefully the positive reviews I've read about Leadshine's digital line bear out. The availability of the Tr8x8 stepper and the simplicity of ordering from a single supplier was appealing.

I had to grab both a 24v and 48v power supply, since the NEMA17 specified something in the 12-24v range, while the NEMA23s could use up to 48v.

So Murphy's Law kicked in, and OB updated their inventory and Tr8x8 was back in stock *12 hours* after I put the OMC order in. So now I have an unneeded 24v PSU and that NEMA17 Tr8x8 stepper. Oh well, onto the shelf with piles of other "for some future project" parts

 

Hi Everybody, I am very new to the world of of CNC. I was producing routed clocks using a laser pen mounted above my router in a table then mirroring the picture stuck to the back of the work piece and followed it with the laser dot, it worked quite well but then I got an order for 32 clocks out of 10mm oak faced mdf and I decided to take the plunge and buy an OX CNC kit supplied by RoboCutters in the UK. The instruction that came with it were nearly none existent and customer support very limited. I eventually discovered the OpenBuilds build videos parts 1 & 2. Part 1 was brilliant and in no time I had the mechanical build finished. However I am now at a loss because on the part 2 video the stepper motors are wired directly into the controller board, my kit came with 4 small boards with cooling sinks on them as pictured together with a CNC USB Controller board MK2/4, can somebody help me with instructions on how to fit these, if they are needed? Thanks,

 

You must decide where to put them and then wire to the mk2/4 board.

I'm using the same drivers soon just building the control box.

You need to wire your step/dir/enable from the mk2 to each driver for each axis.
Also provide power to each driver and bring back a ground from each to one point in your control box "star ground"

 

Thanks will take a look at in the morning, Can I just confirm that my 2 Y-Axis motors are wired into the same terminals but reversed as shown in the OpenBuilds video?