MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Personal Build Histories > MechMates already cutting
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #451  
Old Wed 08 October 2014, 06:36
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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!!
Reply With Quote
  #452  
Old Wed 08 October 2014, 06:42
lonestaral
Just call me: Al #114
 
Isarn
Thailand
Send a message via Skype™ to lonestaral
Well done #122
Reply With Quote
  #453  
Old Wed 08 October 2014, 07:06
Fox
Just call me: Fox
 
Amsterdam
Netherlands
Congrats ! Feels great doesn't it to get those first cuts out of the way !
Also working on the dustfoot .. this weekend I hope.
Reply With Quote
  #454  
Old Wed 08 October 2014, 08:44
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
Congrats Bruce! Pretty fancy first cut!
Are we going to see that dino assembled?
Reply With Quote
  #455  
Old Wed 08 October 2014, 15:02
Duds
Just call me: Dale
 
Canberra
Australia
Awesome Work, Congrats on your machine Bruce!
Reply With Quote
  #456  
Old Wed 08 October 2014, 15:12
wiifm
Just call me: Dennis
 
Cairns
Australia
Congratulations!
Reply With Quote
  #457  
Old Wed 08 October 2014, 17:34
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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
Reply With Quote
  #458  
Old Wed 08 October 2014, 19:16
clarson66
Just call me: Chris & Leon #100
 
Adelaide
Australia
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..
Reply With Quote
  #459  
Old Wed 08 October 2014, 20:40
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
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.
Reply With Quote
  #460  
Old Wed 08 October 2014, 23:12
hennie
Just call me: Hennie #23
 
Roodepoort JHB
South Africa
Congratulations one more no. then my Mech Mate is a classic.
Reply With Quote
  #461  
Old Wed 08 October 2014, 23:12
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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
Reply With Quote
  #462  
Old Wed 08 October 2014, 23:13
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Thanks Hennie,

I think Fox will be the next number so you won't have long to wait
Reply With Quote
  #463  
Old Wed 08 October 2014, 23:13
hevertg
Just call me: Hevert
 
maracaibo
Venezuela
congratulations
Reply With Quote
  #464  
Old Thu 09 October 2014, 04:02
Tom Ayres
Just call me: Tom #117
 
Bassett (VA)
United States of America
Welcome to the club! Congrats.
Reply With Quote
  #465  
Old Thu 09 October 2014, 04:51
Andrew_standen
Just call me: Andrew #109
 
Dorset
United Kingdom
Congratulations.
Reply With Quote
  #466  
Old Thu 09 October 2014, 08:10
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
winner...winner...chicken dinner! Great job.
Reply With Quote
  #467  
Old Thu 09 October 2014, 14:13
Fox
Just call me: Fox
 
Amsterdam
Netherlands
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.
Reply With Quote
  #468  
Old Thu 09 October 2014, 14:47
servant74
Just call me: Jack
 
Nashville (Tennessee)
United States of America
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!
Reply With Quote
  #469  
Old Thu 09 October 2014, 20:07
jhiggins7
Just call me: John #26
 
Hebron, Ohio
United States of America
Thanks for the dimensions, Bruce. I've updated the Builder's Log.
Reply With Quote
  #470  
Old Thu 09 October 2014, 21:19
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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
Reply With Quote
  #471  
Old Thu 09 October 2014, 22:59
KenC
Just call me: Ken
 
Klang
Malaysia
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.
Reply With Quote
  #472  
Old Thu 09 October 2014, 23:22
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
Bugger, thanks Ken. Off to source parts for the boxes....
Reply With Quote
  #473  
Old Thu 09 October 2014, 23:40
KenC
Just call me: Ken
 
Klang
Malaysia
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.
Reply With Quote
  #474  
Old Thu 09 October 2014, 23:46
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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.
Reply With Quote
  #475  
Old Thu 09 October 2014, 23:59
KenC
Just call me: Ken
 
Klang
Malaysia
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.
Reply With Quote
  #476  
Old Fri 10 October 2014, 01:54
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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
Reply With Quote
  #477  
Old Fri 10 October 2014, 03:44
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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?
Reply With Quote
  #478  
Old Fri 10 October 2014, 04:37
Fox
Just call me: Fox
 
Amsterdam
Netherlands
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.

Last edited by Fox; Fri 10 October 2014 at 04:43..
Reply With Quote
  #479  
Old Fri 10 October 2014, 05:01
racedirector
Just call me: Bruce #122
 
New South Wales
Australia
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.
Reply With Quote
  #480  
Old Fri 10 October 2014, 07:55
KenC
Just call me: Ken
 
Klang
Malaysia
@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.
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Ordering Parts - Sydney Australia Bazza Construction started, but not cutting yet 43 Thu 13 August 2015 20:20
Belt Drives, Control Systems & Machining islaww The Market Place 2 Fri 18 July 2014 12:25
12/14 free machining mild steel Quadro Cutting various materials - bit selection, feeds, speeds 8 Tue 02 October 2012 22:31
New Sydney Mech Mate, 3700x2100 G30ff0 Introduce yourself and start planning 8 Fri 08 October 2010 08:33
Machining of the rails jeff Archives 23 Wed 20 June 2007 08:43


All times are GMT -6. The time now is 03:34.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.