Yup, thats exactly what I was experiencing. I got lots of smoke at one point and panicked all while totally forgetting about the 4 e-stops I have all over the machine :)

Same here on my first cut, got so mesmerized by the sound of the spinning bit that I didn't even consider the rotation. Never had to consider rotation on any of the routers I've ever used.

I even had my reverse wired up ( my software allows for that cause of lathes etc ) untill I realized that was plain stupid with my colletholder :D

I use left-hand compression spiral 1/2" all the time for melamine cutting (bought dozen on sale cheap).
The collet and nut never came loose on the Chinese water cooled spindle. So its safe to use it in any direction M3 or M4

How about pictures to get it a number. Video is even better. :D

Phew, good to hear I am not alone. Should have known better as I had already used the spindle on my other machine :)

Video/picture evidence coming Pete, its just every time I do something I forget to take pics/video! :)

I know that feeling. There is a lot of stuff I would have liked to had on video to post on here.

Okie Dokie.... remembered to take video.... or at least I remembered to get my son to do it while I manned the dust collection.

Cutting out a dinosaur as its first cut per se, did an OK job. Table needs levelling (not happening until dust shoe done) and I have chatter on some circular parts but kind of accept that this will happen with direct drive, meaning I should get my reduction boxes happening soon. All in all happy with the way it ran.

https://www.youtube.com/watch?v=dO-QblvJMPk

Cheers

Congrats on getting her built !!!

Congratulations.

Excellent, I am officially numbered - thanks Mike! I have wanted one of these machine for a very long time.

It's all down to this brilliant website and it's awesome members who helped me through this. And a big thanks goes out to Gerald whose plans are the very best in the business, without them there would not be the number of working and numbered machines in existence.

Cheers to all and sundry!! :)

Well done #122

Congrats ! Feels great doesn't it to get those first cuts out of the way !
Also working on the dustfoot .. this weekend I hope.

Congrats Bruce! Pretty fancy first cut!
Are we going to see that dino assembled?

Awesome Work, Congrats on your machine Bruce! :)

Congratulations! :D

Thanks guys :)

John, nope, dino won't be assembled, purely a test to check a number of things. Off to fix those things as we speak ;)

Good for test cut but I forgot to check the width of the cut outs versus the thickness board despite the file being called "12mm layout" the cut outs weren't so we couldn't assemble ours..

Builder's Log Update
 

Bruce,

Congratulations on completing your MechMate (Serial # 122)

Here is the Updated Builder's Log

Please provide the cutting dimensions for the log.

Also, please review your entry for any changes you would like to make.

Congratulations one more no. then my Mech Mate is a classic.

Hi John

Thanks for the update. My beast has been designed as having a 2400x1200 cutting area although I'll probably squeak a little more out of now and then ;)

Cheers
Bruce

Thanks Hennie,

I think Fox will be the next number so you won't have long to wait :)

congratulations

Welcome to the club! Congrats.

Congratulations.

winner...winner...chicken dinner! Great job.

That depends.. I made the cuts. Just before you did :).. but does it need tot be painted or just have a logo for a number ? A Logo can be made and slapped on the bare metal, but it wont have paint soon. I think in the summer.

Sounds like a good reason to route a sign into wood, a quick paint job then and attach it with magnets! At least for the pix :)

Or not. You have done all the hard stuff. Now the real fun begins!

Thanks for the dimensions, Bruce. I've updated the Builder's Log.

Thanks John, I am very relieved to finally have an entry in the list :)

Now, I have been cutting a few things in 6mm MDF with a 3mm upcut bit. Speed has been 2000 mm/min, 2mm DOC @ 12000rpm on the spindle.

I am experiencing quite bad chatter on anything but straights and it is really annoying me as I expected better from this machine. I am running the machine direct drive, 640Oz-in motors, 30T pinions and 8 microstep. My ESS is set to 125Mhz on all motors and 250Mhz on the main setting.

I have checked and realigned the Z, tightend and rechecked the Z rollers and Z plate and all is tight. All pinions are tight on their shafts, all rollers are tight on the X & Y.

Questions:

What should I be looking at to get rid of the chatter or am I stuck with it until I go reduction box?

Am I running the wrong size pinions for direct drive? Would 20T be better?

Should I be going slower again, again until I go reduction boxes?

Is there a question I am not asking that I should be asking?

Please help this depressed Kiwi in Aus :)

20T pinion doesn't have enough meat on it for the 1/2" motor shaft. using 23~24 tooth is right at the edge. Lesser teeth will improve the chatter a little but it still require sanding.
If you really need smooth, make yourself some belt reduction.

Bugger, thanks Ken. Off to source parts for the boxes....

A friendly reminder.
Please do not expect belt reduction will solve all your misery.
With belt reduction, you still need sanding for very smooth finishing, just lesser elbow grease.

So what is the actual cause of the chatter? I ask because my old crappy aluminium machine with ACME leadscrews didn't have any chatter of curved parts. That was 425 Oz-in Nema 23's. I really expected far better from a superior machine like the MM.

big mechanical ratio. which improve resolution. & the side effect are the torque goes up, but speed goes down.
Lead screw pitch is usually lower than Rack & pinion system. with Mod 1.0, 30teetch means 30*3.142=103.686 mm travel per rev. & a 8mm pitch/lead leadscrew makes only 8mm per rev. that is a 12.96:1 difference... i.e. in direct drive situation, the leadscrew has higher mechanical ratio (built in belt reduction).
24T pinion will give 75.408mm per rev. an it has 1.25X better res then a 30T.

Wow, thanks for that. Looks like I got the wrong pinions to start with, will look into both better ratio pinions and reduction. Spent enough on this thing already, whats a little more in the whole scheme of things :)

Parts ordered for a 3:1 reduction box, T5 16mm belts. Going to build JR's boxes because they fit into the standard MM motor plates. Will make the first ones out of 12mm Acrylic then switch to 12mm aluminium later is I need to.

8 microsteps with 3:1 and 30t pinion will give me 50.93 steps per MM @808.5 rpm. Switching to 10 microsteps will give me 63.662 steps per MM also @ 808.5 rpm. 16 microstep yields 101.859 steps per mm and brings the resolution down to .01mm (.0004 inches). All number from Geralds spreadsheet.

Am I correct in assuming that the Oz-In will increase to 1920 oz-in effective with the 3:1 reduction?

Gearbox: higher reduction (3:1 vs 1:1) means higher torque and mechanical resolution, but lower topspeed (your steppers effective rpm maxes out around 1000 rpm).
Think about your car stuck in the mud vs driving on the highway. Your MM is difficult as it will be doing both many times while it drives,kind of like a rally car which has lost it's gearbox.
So you need to find the sweet spot (choose the right gearing) where it has enough torque and resolution, yet still drives comfortably on the higher speed stretches so to speak.
It does not really makes sense to go higher then 4:1, as you will be limited by other parts of the machine that can not achieve that mechanical accuracy anyway.

With the proper gearbox, I see no reason for big visible chatter that needs sanding, unless you'r pushing the machine over what it is capable in terms of speeds and feeds.
Also look at other examples of people with gearbox vs without at the forum, I am running custom 4:1 reductions, which can be enclosed, I can share the files if you need.

Thanks Fox. I know all about gearing, just driving my wifes Kia Rio makes me want 6th at 100 kph whereas my 6 cylinder Ford Falcon is just getting to a couple of thousand RPM at the same speed :)

I was going to change the files I have a little to cover myself for either 3:1 or 4:1, I would only need to change the big pulley and the belt to switch. I would be very interested in your design, especially the ability to enclose part.

@Bruce, In reality, there are no advantage to go from 1/8 microstep to 1/10. you are better off sticking with 1/8.
If you had attempted designing a belt reduction, you will not bother to go higher then 3:1.
in fact, 2:1 will produce a very sleek looking & compact belt reduction box. Unlike the 3:1.
Anything higher the 3.2:1 will look clumsy & stupid.... & there are no meaningful performance gain.