- March 22, 2017 at 5:47 am #29973
Just thought I’d post about my MPCNC build. Selection of photos attached.
I’ll mention good material sources I’ve found in the UK for any Brits interested.
It took me about 2 weeks of non stop printing to print all the parts on my rather old, pretty temperamental Thingomatic. Sadly the build area is rather miniature so some of the larger components were printed in two halves, then fixed together with a combination of superglue, acetone and friction welding [guide to friction welding here]. However this hasn’t seemed to cause any problems.
I use PLA from Faberdashery
Having printed the parts I bought 25mm conduit from Screwfix which measures exactly 25mm with calipers.
This cuts fine with a chop saw [with multi purpose blade]. I used the Vicious calculator and [due to space restrictions] went with what I thought was a 700mm x 700mm cut area. This ended up as more like 680mmsq due to me deciding to use endstops [which I’ll justify in a bit].
I ordered the kit from Vicious. I found the price fine [including the 50 quid postage] given the ease of not having to track all the parts down, and the pre flashed Arduino. If you’re ordering from the UK it’s worth noting that you’re going to be hit by a £50 customs charge which is a pain.
The kit took under a week to arrive and came just in time for my build.
The build was pretty straight forward. I found the instructions on the website very helpful. Obviously use a socket wrench for the larger nuts. Otherwise it’ll take forever and you’ll go mental.
I tend to be heavy handed, and I had a few unsettling cracks when tightening parts. When it says “These can get snugged up, don’t crack the plastic, just snug.”…that’s good advice.
If you use the Screwfix conduit for the Z the nutlocks will need a bit of a shave on the sides and a good whack with a hammer, but they will go in.
With the analogue parts assembled I wired the machine, and discovered that the cables were short for X + Y at my build size. I spent a tenner on 5 x 20cm extenders. I’m not going to list these because it’s a waste of money. Just clip the ends off and solder and tape in extensions [which I ended up doing after one of my extenders melted]. Much cheaper.
Otherwise wiring was really simple with the wires in the kit. Ignore the colours, but pay attention to the clip orientations.
I was a foot short on belt. Amazon sell it for 5m for a good price.
All wired up I ordered a Large LCD from Amazon which was plug and play with the pre-installed firmware. It all worked straight off which was great. Tested with a pen and great results. Setup a grid to test accuracy which was spot on.
My next step was wiring endstops. I know that these are frowned upon by some, whoever I want to be able to mill multiple passes with different bits so intend to use endstops as part of my workflow. Long story short. If you use endstops and you put your clips in the wrong way round, you will short your GND and 5V and fry your Arduino. Which I did.
If you do this then you can get a nice kit from Kookye on Amazon for about £30 with a new non-arduino but perfectly fine Mega, Ramps, LCD [which I didn’t use], stepper motors and endstops. This is a great option if you’re not buying the Vicious kit.
Loading the RC7 firmware on here was fine once I’d tracked down the right LCD library, however I was having issues with manual control off the LCD. This was moving in 4x increments eg 40mm, 4mm and 0.4mm instead of single increments. This hadn’t happened on the old Arduino [now with a knackered power output], so I used AVRdude to clone the old drive. If anyone is interested in doing this I can give you a rundown.
With everything fully wired up and working I printed brackets for my Katsu router. If you use these mounts, beware that the router will clash with some nut head’s on your Z axis. These will need grinding right down. Bench grinder will do this nicely. Don’t rip your Z assembly apart like I very nearly did. Otherwise a very solid mount.
Took a while to get used to Estlcam, but it’s a great piece of kit for free. If you’re working from DXFs you do seem to be limited to 2.5D.
I’m an architect and intend to use the machine for milling complex surfaces for concrete formwork etc. so I need to be able to import 3D models. If you want to do this I recommend using the ‘Block Machining’ option which has the benefit of holding tabs and the ability to better define your workspace.
Briefly on feedrates. I’m using a 1/4″ / 6mm collet. My router is set at 17.5k rpm.
For MDF after some testing I run my flat end mill at 1mm plunge depth @ 45mm/s feedrate.
For the ball end finishing passes I run 0.25mm plunge @ 30mm/s.
2mm plunge @ 15mm/s was fine. 3mm was not good. There was no difference in finish between 1mm@30 and 1mm/45 so this seemed like the fastest option. I haven’t tried any faster as it seems fast enough.
That’s it for now. Sorry for the essay but hope someone finds this helpful.
1 user thanked author for this post.March 22, 2017 at 5:49 am #29978
Attachments:March 22, 2017 at 6:02 am #29983
Attachments:March 22, 2017 at 8:32 am #30010
Very cool. Your printer looks creepy, like a crime scene investigation 🙂 . I like how you have the parts just casually sitting on a plotter. Obviously the plotter gets a lot of use :).
@vicious1 will have to comment on the firmware, but the firmware you have might be the RC8Bugfix, which actually obeys the config values for the LCD knob steps. Glad you were able to copy from one to the other with AVRdude. I knew that was possible, but I’ve never tried it.
I don’t live in the UK, and I already have a working MPCNC, and I’m getting close to having a working LowRider, but I read every word. Thanks for sharing.March 22, 2017 at 9:13 am #30014
A low rider is the dream. Could do with one to make a cabinet to sound proof my build. Which is what I’m about to start doing. Mustn’t upset the neighbours!March 22, 2017 at 1:22 pm #30033
UPDATE: cabinet built. Need to rewire the router and test noise reduction. Slightly concerned I’ve just built a reverb chamber!
Attachments:March 22, 2017 at 1:38 pm #30035
I also have the encoder issue with my v7 firmware (4 steps for ever turn). Here is a quick fix posted by P3DCNC here on the forum
Here’s how to fix the knob issue(Configuration.h):
// This option overrides the default number of encoder pulses needed to
// produce one step. Should be increased for high-resolution encoders.
//#define ENCODER_PULSES_PER_STEP 1
#define ENCODER_PULSES_PER_STEP 4 // p3dCnC
// Use this option to override the number of step signals required to
// move between next/prev menu items.
//#define ENCODER_STEPS_PER_MENU_ITEM 5
#define ENCODER_STEPS_PER_MENU_ITEM 1 // p3dCnC
build looks awesome man!
NeilMarch 22, 2017 at 1:45 pm #30037
Great stuff Neil. Took the long way round and cloning the arduino from vicious, but looks like that would have solved it!March 22, 2017 at 1:45 pm #30038
That is in my firmware, what firmware are you using?March 22, 2017 at 1:48 pm #30039
I was using rc7, that you link to, on my replacement mega but my knob issue may be down to the lcd library I used? New to this but solved the issue by extracting the firmware from the board I bought from you and writing it to the new board.March 22, 2017 at 2:26 pm #30041
You say that change is in your v7 firmware? Maybe it’s my hardware but I am using a fresh flash of your v7 and having each turn register as 4. I was going to look into making this change myself tonight.
I may be thinking of my laser machine which is running V8 (still need to get the fixed version). I’ll check
NeilMarch 22, 2017 at 2:41 pm #30045
I should point out that this wasn’t affecting printing accuracy. The machine knows the dimensions it’s moving. It’s just the movement when controlling by lcd.
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