MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Structure & Mechanics > 10. Base Table
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #61  
Old Tue 27 January 2009, 06:40
Art
Just call me: Art #2
 
Lancaster,Texas
United States of America
Tdc

Normally I cut about 1" off top dead center. This one is being cut so far off TDC because I don't have enough Z travel to get higher.
Reply With Quote
  #62  
Old Tue 27 January 2009, 08:29
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Then this stabiliser rod should work:


The idea is to disconnect the y-motor so that the y-car can ride a little, as controlled by the swing arc of the stabiliser and the plunging of the Z.

For the ends of the stabiliser, use ball joint rod ends, suggest McMaster 6072K185, and put all thread between them with locknuts. Arrange it so that the rod is being pulled (tension) to resist the cutter force.

Attach one end to the z-slide, or even the router bracket. The nearer to the cutter the better.

Attach the other end to the gantry (10 20 450) between the v-wheels, in line with the cutter, as low on the x-rail as you can go.
Reply With Quote
  #63  
Old Sat 31 January 2009, 15:16
HomeMadeCnc
Just call me: Tim
 
Calgary, Alberta
Canada
I'll have to move this over a bit more but I think it will work well here. The last bed rail will have to move too I think. Any other opinions/thoughts/ideas on this 4th axis?
Attached Images
File Type: jpg 4thAxisWEB.JPG (38.3 KB, 1120 views)
Reply With Quote
  #64  
Old Sun 09 August 2009, 14:10
bfauska
Just call me: Brian #30
 
Seattle, WA
United States of America
Just as a way to clear this up in my head... is it mandatory to have x,y,and z axis + the a axis (rotational) or can you build an indexer with x or y and z and a? I am asking because sometimes in theatre (our machine is being built so we can build scenery and props more easily) there is a requirement for the type of things an indexer would be great for and we don't need production level speed, but I purchased the G540 which will only drive 4 motors. If I run an indexer parallel to my y axis and use one of the x motors (and disable the other) I would have enough motors for my needs. Also, do Mach3 and the vectric software packages handle indexers to anybody here's knowledge? It looks like people are modifying their gcode directly, but that seems like it would be a rough approach to something like a spiral cut spindle.

Thanks for any input, I probably won't try to set up our MechMate as an indexer for quite sometime but I'm sure that when we find out we could use it we won't have much time to implement the system.
Reply With Quote
  #65  
Old Sun 09 August 2009, 17:14
smreish
Just call me: Sean - #5, 28, 58 and others
 
Orlando, Florida
United States of America
Brian,
Since you are using the G540, your options are pretty few. With the prewired configuration of the G540 you are allowed x, y, z and a. x and a will be the x axis gantry motors, y - the cross car, z - being z. Mach will slave a to x in your setup.

For you to add an indexer in the future my suggestion would be to purchase a second BOB, like the PMDX 122 and add a second parallel card to your PC and then an extra driver.

Cost for the aforementioned will be about:

-88$ for the PMDX
-20$ for the Parallel Card
-147$ for a high current Gecko Driver (you will need at least a 4.5A output to do the job well at your voltage)
-250$ stepper motor to do the job

(also, if you happen to find a indexer unit like mine on Ebay, it could be servo driven with encoder feedback to the amplifier with the same setup but purchase the appropriate Gecko DC servo amplifier card.) It's not TRUE closed loop feedback, but the servo reacts to step/direction control the same as a stepper)

Mach 3 will easily address the indexer and second parallel card. Don't be concerned about Mach 3.

The biggest challenge you will have when your ready to jump to true 4th axis cutting will be the CAM software package.
I am a recent "expert" on purchasing a 4th axis package and entry level is about $2500 for the most affordable and usable package from RHINO CAM or Visual Mill (Same vendor) The price quickly goes up by thousands from here.

You can do simulated 4th axis in the 300$ range and is about as accurate depending on what level of column, prop skull/statue etc. your trying to achieve. Vectric has a very good 3d carve program that does 4-face machining in the indexed mode and will cut in 90 degree rotations. Very affordable, very easy, very quick to learn.

Your welcome to give me a ring on the phone if you want to discuss in detail.

Sean

Last edited by smreish; Sun 09 August 2009 at 17:19..
Reply With Quote
  #66  
Old Sun 09 August 2009, 20:53
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Brian, I think the reason that the indexer people need so many axes is because they alternate between cutting with the tip of the cutting bit (better detail?), or the side of the bit (smoother finish?). If they were only using one strategy, then there would be an idle axis.
Reply With Quote
  #67  
Old Mon 10 August 2009, 10:50
Art
Just call me: Art #2
 
Lancaster,Texas
United States of America
Indexer

At http://turningaround.org/MechMate/Mechmate.htm you will see my indexer. I am updating site and if you have any questions please ask and I will add to site/reply. A indexer can run with as few as 4 motors representing X, Y, Z and A. A fifth motor, B, can be added as a slave to the X. I have it on very good athority that X and B can electronicaly be slaved on the controler by Campbell shown on my site. I will be confirming this within the week and will post results. The problem is that if Mach has a slave axis on Reference All the slave will also try and go to a limit switch. I don't need a limit switch to true the gantry on the slave side so if I electronicly slave the motors Mach doesen't know that the slave exists. As to software 90% of the stuff I do can be done with the wizard listed on my site. Best $75 I have spent. I am beta testing the new version which is even better.
Reply With Quote
  #68  
Old Tue 11 August 2009, 11:26
Art
Just call me: Art #2
 
Lancaster,Texas
United States of America
Indexer software

Also there is a write up and examples of some examples of work done with Rich'e wizard.
Reply With Quote
  #69  
Old Tue 11 August 2009, 12:18
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Art,
The writeup on the wizards looks great. Cant wait to get a machine and indexer running.
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


All times are GMT -6. The time now is 04:24.


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