Hi Ryan
Another 2 questions for you.
1 The chinese spindle comes with a 48v power supply, can i reduce the voltage from this to say 24v for the stepper motors?
2. Can I use the the software to control the spindle speed, or should i use the pot supplied?

 

How do people find these Chinese spindles compared to things like the Dewalt router? I know they are heavier but quieter, you have more collet options and can control the rpm down to a lower speed ( I know you can get speed controller for the Dewalt ) but in real world terms are they much better?

 

Thank you. Re reducing the voltage I actually intended to keep the output at 48v for the spindle and then make a voltage reduction circuit to connect to the power supply for the stepper motors. I have now bought a 24v power supply now though.

 

Mach3 CV settings can be a pain in the butt at the best of times. Running them on and bumping up your accelerations in the motor settings helps. Also try some tests using ALL the settings in general config turned off and put it into CV mode. If you are still not getting good results try adding a small value into the CV tolerance DRO on the settings page and see if you get smooth but on target cuts. To be very honest how mach3 deals with CV is one of its biggest draw backs IMHO...

I have spent the weekend tuning up a rig that has 1.5m long double belts and still seeing a hair of backlash... may upgrade to steel core belt and trying to find a better method to glue the second belt down too.... I have a 800w water cooled spindle and found I could push my rapids to about 8m/min and accel up to 1000 ( about 0.1g) and getting good results.

To the people double belting, are you taping/gluing the belts down? I remember reading CA glue is the way to go but is a little thin... I have run out of the roll of super strong and slightly thick double sided tape i was using and cant find it any more

@Ryan Lock, I have been meaning to call but due to some family matters I have had to move my focus the past few months. It has been a long road to get things back on track but I will be calling you soon with some ideas!

 

@Jestah CA glue! I have some experience with that stuff. I've had it used to glue on v-rails for a laser cutter. The glue itself is great but it's not good at low temperatures. I have a workshop down the bottom of the garden and find that once you get down to 5 degrees it can randomly give up its bond.

 

In case its useful, this is how I wired up the TVS and 15amp fuse for the xpro v3.

fuse 15amp on xpro v3 by biglouieuk posted Jun 12, 2017 at 9:44 PM

TVS on xpro v3 by biglouieuk posted Jun 12, 2017 at 9:44 PM

 

I found a route through the frame, others may find useful, i could probably fit 6 cables (@22AWG) through here.
Hope the picture is clear enough.

 

Jetsah

Could you post a pic of what settings you have in general config on mach 3. Still getting some "wavy" issues!!

Is distance mode IJ mode an issue ?

Marcus

 

Could you please expand on what you mean by wavy? In the cut, in the machine movement, cut shapes off size from expected/programmed?

I have attached an image with the key points marked.
General Config
Motion mode - CV
CV Control - All off

Now push your machine acceleration till you lose steps or it becomes unstable and back off 20%. Do a test cut to make sure your happy and not losing steps under load and your done.

You may end up trying Stop CV on angles (read up on this as I remember last time I played with this I found it behaves backward to how it reads but this MAY be an issue with the smooth stepper in the system)

Then if you need you can try using CV dist Tolerance but I find this makes for some jumpy machine moves and have not had much luck with it. Avoid plasma and G100 modes unless you know why you need them

I would also stock up on toads eyes, raven feathers, sacrificial chickens and/or goats as tuning CV can feel like black magic with mach3.

@Ryan Turner thanks for the tips on the CA, I don't think my workshop gets cold enough to worry about it letting to... if it did I would be giving up working as well! I was more worried about the overall height making the engagement of the two belts too lose.

 

Jestah

Many thanks - I will try your settings. I am no good at Black Magic and there are to many variables, I need to cut down on what systems are causing errors.
Do you mean acceleration or speed?

Here are some pics of my issue....

 

@Marcus1 Before you go smashing into real work take some time out to do a test pattern. For CV tuning I start with a hole 2D, 4D, 50mm and 100mm and no CV check boxes and low acceleration (don't worry about motor speed as in small holes with sub 5mm bits you won't get any where near it)

Cut it and try and see if you have any mechanical backlash and where it is coming from. Change ONE thing and then recut the SAME gcode. I usually start my pushing my feed up to the tool sounds good then start increasing my acceleration settings to the point it starts showing up as flaws in the cut. I will note each change with pen and then get a clear idea exacty what is working and what is not. as a tip you can set your post/cam to leave the cutter head at the part furthers from 0 corner so when it finishes you can just zero out the axis DRO in mach3, make your one change in the settings then regen and cycle start.

This is us tuning in our latest build with double belts, 2mm per pass, 3.5m/min roughing 1.5m/min finish with a 6mm tool. Having the "history" of your cuts really helped us get more of a gut feel where out issues actually were too!




The other thing to know is that small flaws like what your seeing COULD also be the stock lifting up or moving a very small amount. With hobby style machines you need to think a little more carefully about your lead in/out to try avoid chances of little nicks like your getting. I usually rough out a part in step down passes using ramp-s with 0.5-1mm left on the part then do a last clean up profile on the target size using an arc lead in, over cut and arc lead out to hide any small hiccups you can get on start points.

 

Jestah

All very good advice - Thanks

I am roughing out and then finishing this with a 1 mm finish pass. Leading in I am using angles 30deg plunge. Arc lead in seems to nick the top edge. Using Vetric do you know how I lead out. I cannot find how to do this.

 

The top could be marked if your spindle is not trammed so the tool is tipped over in the finish but also this can be caused by even the smallest belt stretch issues too. Arc in and outs are nift when you don't want to see that ramp angle on the finish cut but are harder for a machine cope with.

The lead out is under the lead options as a tick box that says "do lead out" and overcut distance.

 

Jestah
95% of my routing is straight cut all way through material. I have a home made vaccuum table to hold the part down. At opposite corner retainers to stop any slippage (side to side) as the vaccuum is reduced through cutting out. Tool is 3mm spiral compression cutter

At the moment my cutting strategy is as follows.
Roughing - 3mm depth ramp 30deg angle 3/4 passes to full depth with 3mm tabs on last cut.
Finishing - 1mm left for correct profile, full depth ramp 30deg cutting through tabs
These passes are then merged
The reason for the above strategy is that large cut pieces can be ejected from the part causing inteference with the spindle and step loss. The tabs hold the position until the finishing cut and as this cut is offset from the "loose" piece, there is less likleyhood of this being ejected.

Do you have a strategy that helps with arc in and out leads?

 

@Marcus1 start by making sure you have no backlash. From your photos your very small wobbles look like they could be belt stretch or movement. The smallest backlash will show up in any finish cut as they are only as good as the weakest link in your drive train.

also try leaving a shallower finish pass to help ease up on your cutter loading and see if this helps. Also leave your parts tabbed in for the full cut. Use a table router with a bearing follower bit to clean them up super fast but keeping your stock solid up to the end is just as important as having no backlash. You could also try a cut that has much lower feed (reduce your RPM as well to maintain good chiploads) and see if this helps your issue.

The method I suggested before is how I run my arc in and outs but it took a lot of sorting of the belts to lower my backlash enough that it didn't show up in my finish passes noticeable. The other thing to remember is that these are hobby machines, amazing value and a very low cost way to learn CNC but it is fair to ease up on the expectation that they give perfect results. My Ox cuts like a dream but it has taken me a long time of tuning and also easing up on my cutting methods as compared to the cutting style I ran when programming for a commercial cut shop on a one tonne router pushing around 13KW of spindle.

So to recap.... Check your spindle is nicely trammed, reduce as much backlash as possible and make sure to be taking a very light and slow finish pass that eases the cuter into and out of the cut.

 

Jestah

Getting better results now thanks to your advice. Circles are nearly there, just a slight over cut in X on both sides. Hopefully this will be solved by gluing down the bottom belt when I have some time. Still cannot think of a decent cutting strategy including an arc lead in/out that does not disturb the loose part as it is impractical to use a table router for clean out as most parts contain hundreds of them!

I resurfaced the spoilboard and the tramming is indeed out slightly, but surprisingly its not out in the plane looking directly at the spindle head on, its in the plane looking sideways at the spindle, suggesting that the X beam is not vertical.

Build -
1500x1500 OX - standard, no beefing up (Yet)
double belted - bottom belt not fixed (Yet)
3 Zone Vacuum table
2.2Kw spindle air cooled controlled through Mach 3
Mach 3
ESS

Any Mods, fettling pointers would be appreciated.
Cheers

Marcus

 

I am looking for some help.

I have bought the OX cnc and i am having difficulty in connecting it to my laptop.
i have downloaded the universal G code sender v1.0.9 and the windows driver from ftdichip.com/drivers/vcp.htm. Baud rate set to 115200 and firmware is set to GRBL, but i only get the message "grbl has not finished booting". I can normally sort most things out, but this has got me stumped. can you offer any advice.



thanks

Andrew

 

I thought I would see if anyone else a problem on their 1500 x 1500 machine and I hope someone can help.

I recently double belted it and dropped the bed.

I'm using the x pro 2, fast decay, plentnof current.

If I make a small cut it's accurate. Say up to 300mm on my y axis. If I try doing a 900mm cut it will be over by about 12mm. Recalculating the steps per mm will make it right but when I go back to cut 300mm it's 275mm.

I tried all of this with a pen on the router with the router off and got the same results.

All my belts are tensioned nicely, the x axis performs fine, the machine is square, all grub screws are in place. It's not backlash because it returns to zero perfectly. It's just this weird 'drift'.

I've tried it through chillipeppr and JSON, direct connection with USB and UGS platform. Nothing changed.

I tried switching to 16 microsteps. On the y axis. Nothing changed.

I'm leaning towards the x pro misbehaving at the moment and the only thing I can think of is the pulse width for the motors on the y axis is a teeny bit long.

Then I've been scratching my head over this for days and I can't see the wood for the trees.

Thanks for any help. If I don't solve this it renders the machine useless for accurate big cuts unless I change the steps per mm each time I switch.

 

Hi Ryan,

Still no luck, tried both the 1.0.9 UGS build and the 2.0, both with the same result.
I have deleted and reinstalled the ftdichip drivers, this has not helped either.
Tried it on a second and third laptop, and changed the USB cable, still no joy.



anymore thoughts?

Andrew

Just read one of the reviews of the controller board from your website, and it says "I have followed the instructions to protect the 12v input with a TVS Diode as I suspect a back-EMF surge did for my previous board. Recommended". Which diode is this? and should i have fitted it?

Andrew

 

Hi, guys, my current setup has only been up and running for a week, 1000X1500 OX with the ooznest router mount and Dewalt router 61200 (i think) running on Mach3, I did a few test cuts/programs in ply and it is looking good, This weekend I milled some MDF…. For the love of god, I was covered in dust, even though I was holding the shop vac hose near the cutter, resulting in the expected static shock every now and then.


Are there any plans/files for a dust shoe that would fit this setup including how to mount it, I'd like to get the Ooznest one but regardless of how good it is, the cost is prohibitive .


Any suggestions would be appreciated.

 

Lees 76

I printed a shoe that seems to work ok. I have different attachments that I change depending on job. All mounted using magnets

 

@Lees75

I am designing my own dust shoe at the mo, its a work in progress. I've attached the screenshot of it from Fusion 360.

A lot of dust shoes have a fixed height and I only know of one that keeps in contact with the surface despite the router moving up and down. It doesn't fit the OX!

Here is my version. As you can see the shoe will naturally drop down when adjusted due to gravity and I installed the springs to just provide a dampening effect.

I don't know how well its going to work yet, but it should work ok as you don't want the bristles to deflect a great deal and get caught in the router and sucked up by the vacuum.

If you look at my other posts I have bought a cyclone separator and I have a 5m hose end of a hetty plugged in to it, the other end, the screwed end, I plan on attaching to the dust boot, so I can screw it on and unscrew it. This part, I plan on 3D printing.

Its mainly made from 20mm HDPE, 6mm bars and some Acrylic sheet, I plan on putting some magnets in to hold the sheet in place somewhere and then figuring out how to attach the bristles later.


Oh! By the way! An earth wire should be easy, Have a look on you tube and get any long piece of quality cable. You could either connect it to the earth of the vac or an earth spike.

Here's the cyclone separator. Works really well!




Only the existing dust is in Hetty now.

 

Ryan T.

Thank you for sharing your design, it looks fantastic, regarding dust extraction my plan at the moment is to run 60mm waste pipe around my workshop from my extractor to a 50mm flexible hose near my CNC machine, I 'll try and design a temporary dust shoe (using aspire) similar to what Ryan Lock suggested above (thanks for the suggestion Ryan), and carve it out of hdpe or similar.

If that doesnt work i'll pick up a cyclone extractor and do that. It's incredible how efficiently they seperate the dust.

Thanks for all the suggestions, thay ALL help a newbie such as myself.

Lee.

 

Helloo from another newbie

I am still undecided on this cnc from ooznest , i mainly want to cut through alu up to 6 mm thick alu , and not sure if this machine fits the bill . Wood will also be on the menu , but i think engraving in wood and alu as well as cutting holes in those sheets .

any advise is greatly appreciated , also from the mnf

many thx
Benny

 

I think the Shapeoko is generally a little more robust but unless you have a very expensive machine or put upgrades in yourself you are always limited to shallow cuts in aluminium. I think it's much of a muchness tbh.