Thread: CNC TTU Build
25th Dec 2008, 08:33 PM #1
CNC TTU Build
Sitting down letting my Christmas dinner digest over a stubby of cold amber fluid, I've decided my CNC Router needs to be bigger.
Well actually, my youngest son and I were putting together a small model boat today that has been CNC cut from ply (commercially bought kit). This is all good fun. The boy asked if I could make him a kit for a bigger model race boat. My CNC is too small as some parts need to be around 1100mm long.
So now it's Time to Upgrade (TTU). Well time to start nutting out design and parts list anyway.
I've been pretty impressed with Rod's latest build so I will probably plagiarise (steal) some of his ideas.
Here are my initial thoughts:
- I would like to have a table that will cut a 1200 x 600 sheet of ply. So I guess the table would need to be slightly bigger.
- Water cooled spindle is on the list
- smoothstepper and gecko drivers.
I don't think I'll be able to order any parts until around March so I've got a bit of time to work the shopping list out.
Time for some Christmas Pudding
25th Dec 2008 08:33 PM # ADSGoogle Adsense Advertisement
- Join Date
- Advertising world
25th Dec 2008, 10:49 PM #2
You know about the ebay seller right?
You can get all your slides and ballscrews from him, motors and power supplies from MS-motor, gecko drivers from gecko directly (best price I have seen but I bought mine when they were on special)
Just wondering but wheres the best place to buy a smooth stepper if you know?
25th Dec 2008, 11:01 PM #3
Not sure if I have the right ebay seller for ballscrews and such. Is it the same guy who sells the watercooled spindles?
There is an Aussie store selling smooth steppers http://homanndesigns.com
26th Dec 2008, 12:04 AM #4
26th Dec 2008, 12:13 AM #5
It is a funny thing but most of us build a machine then see how to improve on that and build again. I keep building and doing other projects because my wife works at night, son has left home and the old faithful mut and me don't like watching the idiot box.
Yes the ebay seller is the one who supplies the spindles. Just send him an email and
he can supply anything mechanical for CNC. I got the square rails through him and so have a couple of others so don't be limited by the round rails he lists.
Peter Homann does supply the smoothstepper and other boards at competitive prices. He held the pre-aussie dollar drop prices for a couple of weeks so he is very fair in his dealings.
As far as sizing your machine if you want a finish cut of 1200 by 600 then be generous on rails and other sizes as you loose at least 100mm on each axis for the trucks.
One of the best tips I can give you at this stage and your experience is to design in protection for the screws and rails. These elements can clog up quick with sawdust so prevention is the best cure.
I too had a great xmas and over induldged so had better be a good lad for a while.
Sorry Chris repeating your information - I'm too slow on the keyboardCheers,
26th Dec 2008, 09:32 AM #6
26th Dec 2008, 10:14 AM #7
The square rails have radial stability whereas the round rails have no radial resistance. Square rails are more expensive though. If the design of your machine is good you can get away with round rails so it boils down to preference.
Probably don't need to go 300 over size but ordering 1200 rails and screws will not get you a cutting length of 1200. It depends on your design and I usually allow 100 to 200 over for the rails depending on the connecting axis.
The ballscrews are not as simple and your design will determine the length.
As a general guide I allow 50mm for machining the ends plus the length of the ballnut. The screws can become a problem if your design does not allow for full travel of the screw - ie the nut is fixed to the connecting axis plate in a way that does not allow for it to travel to each end of the ballscrew. Keep your ballscrew length shorter than longer as it takes more motor torque to drive it.Cheers,
26th Dec 2008, 10:48 AM #8
26th Dec 2008, 12:00 PM #9
I am guilty of plagiarism myself.Cheers,
8th Aug 2009, 09:36 PM #10
I spend way too much time procrastinating on things
Anyway, after I blew my pocket money on a new boat earlier this year, my build got put on hold. Then I was thinking of being lazy and buying a Chinese already built machine. Bugger it, it will be more fun to make my own.
At this stage I'm leaning towards using the ITEM aluminum extrusions like Crocky did on his machine. Any tips Bob?
Now I need to work out the chicken/egg thing. Do I get the frame made first and then get the rails/ballscrews to suit? Or do I get the rails/ballscrews and then get the frame made to suit?
9th Aug 2009, 01:05 AM #11
9th Aug 2009, 01:48 AM #12
I always gather all the parts well ahead of a build. I like to start a machine and finish it without waiting on parts to arrive. It is handy to have the rails or at least the trucks so you can design mountings and spacing as you go.
I never sit down and draw any of my machines and they evolve with the ideas in my head. It does cause the odd muttering in the shed every now and again when things don't quite work out but I enjoy the challenge of doing it on the fly.
You are well equiped to make a decent machine so look forward to seeing your machine build.
I just ordered some G251's for a mid sized machine that is in my future plans. I would hold off on a smoothstepper for the moment - he has not done any work on it, it is still in Beta mode and he has abandoned his own forum. Not bad mouthing the guy but it does place a question mark about the future of his poroduct. I have seen a few of these projects fire up like the smooothstepper then fade away.Cheers,
9th Aug 2009, 06:31 PM #13
9th Aug 2009, 07:59 PM #14
Here is quick mock up of the basic structure.
The Legs and Bottom Rails/Beams are 40x40
The Top Side Rails are 40x160
The Top cross beams are 40x120
The idea is to have castors on the base and enclose the sides. Maybe steal Rods idea of a dust chute?
Just wondering if this configuration is going to be rigid enough with the size extrusions?
9th Aug 2009, 10:55 PM #15
By scottyk in forum BOAT BUILDING / REPAIRINGReplies: 69Last Post: 25th Jun 2009, 02:12 AM
By Misterwippy in forum MUSICAL INSTRUMENTSReplies: 24Last Post: 6th Jan 2009, 12:01 PM
By xray in forum MUSICAL INSTRUMENTSReplies: 2Last Post: 27th Aug 2008, 09:52 PM
By bennylaird in forum NOTHING AT ALL TO DO WITH WOODWORKReplies: 10Last Post: 16th Nov 2006, 08:26 AM
By oges in forum WOODWORK - GENERALReplies: 17Last Post: 27th Sep 2005, 10:38 PM