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21

Thanks mate.

I was watching the machine closely to see if I could notice any rough/uneven movement and it seemed (by eye) to be butter smooth. I think I’ll try the same file again but reduce the feedrate to see if I can get a cleaner finish, and maybe generate some different versions of the g file to see if estlcam settings affect anything. I haven’t even started playing with settings or feedrates at all so I think still some scope for improvement. Not to mention the bit used was pretty cheap and nasty.

I’ll measure the height of the gantry relative to the work piece and let you know, rather than hazard a guess. Pretty close though. I have the legs set pretty short currently to minimise this distance.

As far as the logo goes, I like the current one. A bit cheeky/whimsical, and let’s be honest, what’s life without a little whimsy ;-). That being said from a professional/commercial standpoint the corporate one might be a better option. Personally I say to hell with conformity but, perhaps make both available for sample and put it to a community poll?

22

Height of gantry relative to work piece approx 100mm (measured from bottom of ‘middle’ assembly)

Also. Small issue I was hoping for some advise about.

I was playing around with the machine (just moving along axis at different speeds and testing travel limits) as I noticed the belts walking around on the bearings on the roller F’s. Depending on the position of the gantry the belts are trying to walk off the stepper pulleys (if that makes sense?). Only seems to be an issue on long travels. For small back and forth movements the belts tend to centralize.

I was thinking of installing a second panel washer (the big ones) on the inside of the bearing to act as a guide. Do you think this should work. What other solutions are there to the belts “walking” like this? I tried re-positioning the pulleys on the steppers but it didn’t really help.

Thanks.
Justin.

23

Your belts might be too tight, or the ends might be a little off axis. If you are using my stock ones with zip ties they should be pretty dead on any other tension system who knows. At the same time moving a little should not be an issue.

24

All parts are stock IE at the moment. I looked again and it seems the bets are out of alignment at the ends (cable tie) I’ll redo the cable ties and try to achieve better alignment. It could well be excess tension on the belts too. I opted for the white PU belts with the steel reinforcing (zero stretch) and they require a lot more tension than the rubber/glass fiber belts. I’ll play around tonight and post back with any solutions I can come up with.

Thanks for the advise mate.
Justin.

25

Belt alignment was indeed the issue. Thanks for the pointer. I redid the zip ties and got the belts in the correct position and they run true now, no walking around.

26

Hi again. Quick update.

Couple of quick videos. First one is of my MPCNC decking a small waste board I setup to get the working plane closer to the gantry. Its now only about 70mm away.The cut is rather deep, approximately 2.5mm. Much deeper than I would normally attempt, but there were reasons (namely I stuffed up half way through a previous cut). The machine seemed to handle it quite well. No chatter and the finish was as consistent as my shallower cuts were. Bit was 1/2" flat twin flute, feed rate was 1200mm/minute.

Second one is rather boring honestly, its the last portion of cutting out a test panel of the electronics enclosure I’m putting together. The final enclosure will be out of high quality 3mm ply. The test panels are just cheap mdf to check for fit and finish.

This is a quick render of the enclosure I’m halfway through designing. Haven’t settled on a design for the top, or finalized the interior layout yet. But this gives you a rough idea.

The finished piece after a quick clean up with an soft sanding block.

https://drive.google.com/file/d/0B2nobe1HZXsEeTF2MEdiMnBrU3c/view?usp=sharing

There is a 1.5mm * 1.5mm step at each end, so the walls lock together.

https://drive.google.com/file/d/0B2nobe1HZXsEUDZ6QkVyZm1VWms/view?usp=sharing

There was some inaccuracy in the slots. The machine seems to flex on vector changes (I’m thinking causes by the weight of the Makita Router) so for my final cuts in the ply I’ll decrease my feed rates to maybe 800mm/minute or even 600mm/minute?. Question for the more experienced users out there. Are there any acceleration/deceleration settings that I could tweak as well?

https://drive.google.com/file/d/0B2nobe1HZXsEejBIWnp0cnNWNWc/view?usp=sharing

Over all though, I quite happy with how the machine is performing. Looking forward to spending some more time learning and experimenting.

Cheers.
Justin.

27

Neat design for the ramps box. What bit did you use for cutting the pieces?

The second video is set to private.

28

Try out the beta firmware, I adjusted the accelerations. https://www.v1engineering.com/forum/topic/need-some-beta-testers-for-some-new-firmware-stock-machines-only-please/

29

Thanks mate.

Design is not set in stone, just V1.0 so to speak. Further refinements to follow

The bit was just a simple twin flute 1/8" routing bit. Seemed to do a reasonable job.

30

Not sure what happened with the second video. Failure to upload. I’ll follow up when I get home tonight.

31

? I’ll give it a go tonight and report back. Thanks for the advice.

32

Update.

Heat is still causing me some grief! Since my last post about some of the parts of my MPCNC deforming due to heat, the rest of the parts have gone to hell too. Everything is loose/sloppy and many parts have cracked.

It has to be either heat, poor quality PLA (this is a definite possibility, more on this later), or my printer was not dialed in correctly (poor layer adhesion or something). Bottom line is I need to reprint everything.

Not all doom and gloom though. I looked at this set back as an excellent opportunity to experiment with printing different materials, and perhaps improve the stiffness of my machine. Win, win I think?

Now I mentioned before about poor quality PLA. The three spools of black PLA I bought specifically for printing the parts for the MPCNC were cheap, like really cheap. I didn’t know any better at the time, but I now understand that there is a HUGE difference between cheap/nasty china PLA and quality PLA, seriously… chalk and cheese!

I initially didn’t know what to reprint in. Nylon? ABS (I HATE printing ABS), PETG looked good on paper, some PLA blends? Poly-carbonate? There is a lot of cool stuff out there if you go looking.

After a lot time on google I had it narrowed down to Taulman Alloy 910 (Nylon), Taulman Tech-G (PETG) or Polymaker Polymax (Some sort of PLA blend). I ordered a roll of each and got my print on.

I wont go into too much detail of each material (there is a wealth of info on all three products online) but I will say that all three printed beautifully! The Tech-G (PETG) in particular is an absolute joy to print! My new favorite filament!

PETG is immensely strong (no more cracking parts), has a much higher glass transition temp than PLA (no more deforming parts), has very low elongation under tension (this should help with rigidity) and its translucent, purely cosmetic I know, but being able to see the inner structure of your prints is hella cool!

Behold!

I still have a lot of printing to go, but rest assured that I will update as the RE-build continues.

One quick note before I go. I was intrigued as to just how strong the PETG was compared to regular PLA. The first part I printed was a replacement mount for my makita router. Here is the part that failed in service, with the bolt only “nipped” up (just snug)

With the new PETG part in place I deliberately tried to over tighten the bolt to “stress test” the new part. This was the result of that experiment!

Yes the part deformed/streched, but it didn’t crack or break and while looking a little worse for wear, it is still perfectly serviceable. I’ve actually being using it to mill with for the last week!

Sorry for the long post. I’m not sure if anyone else has had issues with PLA parts deforming/stretching? Maybe it was just the el cheapo PLA. Who knows.

Peace.
Justin.

33

Very nice parts with the petg. Maybe I should try some. My parts were all printed with hatchbox PLA. I haven’t had any problems, but as you noted there are many factors to consider. I’m glad you’ve found a material that will give you quality parts.

34

PET is also my favorite, the price is pretty high though.

35

Thanks mate.

I think the quality of the PLA is more the issue. If I had for example printed the original parts in the Polymax, I doubt I would have had issues. As far as PLA goes, its epic stuff.

The PETG is proving excellent so far. I’m printing the parts for the ‘middle’ now. It will be a good test of rigidity.

36

It’s such a lovely material to print. I’m especially impressed by its layer adhesion!

Price wise I found it quite reasonable. Au pricing was $49.95 per 1kg for the PETG $59.95 per 450g for the nylon and $49.95 per 450g for the Polymax.

Bang for buck I think it’s some of the best value filament available. I probably would have gone with the alloy 910 if the price was better, but so far the PETG is performing admirably.

I still may print some of the higher stressed parts in nylon (middle assembly and motor mounts maybe) as I still have an almost full roll on hand.

37

PETG is about on par price wise with PLA from what I’ve found. I primarily use Esun’s PETG at around $25 - the black is nearly opaque, and the blue is just beautiful.

I don’t know if anybody has any experience with Makergeeks, but I’ve been thinking of trying out some of theirs too (they are having a sale with it down to $16.50 for a roll). I know I can trust Esun though (I had a bad roll once and they lived up to their promise and gave me a full refund immediately), and there aren’t a lot of reviews out there about Makergeeks.

38

I hate to say anything negative but the MG filament I tried a few months ago had vary pale color other than that it seemed great. If you try some put up a picture, I would love to go back to them. Right now I am getting ohfila because it prints with a matte finish instead of gloss. Kinda cool.

39

I switched to MakerGeeks PLA shortly after Joshua announced he was making his own filament. I really like the product and love the idea of supporting a small business that makes their product in the USA! Plus he offers free shipping on all orders.

40

Hmm, you might try this for more vibrant color: https://www.youtube.com/watch?v=nwqjz5nxOw0