Sketchup is in my eyes, the best program ever for designing. have you considered what parts you are going to use? Supported rail from Linearmotionbearings2008 etc?
I thorughly agree with JazzCNC and Jonathan about drawing out your design with a CAD package. You can see this from my thread here http://www.mycncuk.com/forums/showth...gn-Build/page4 and it allowed me to get good advice from the guys here on the forum who have learnt the hard way! A picture tells a thousand words!! A 300 mm ballscrew does not have a thread length of 300mm - it is about 200 once you take into account the end machining to fit the bearings at either end. On my Y axis, this clearly showed up when I did the drawing. I use TurboCAD Platinum Pro 15 which I got from Paul Tracey http://paulthecad.co.uk/ at the Model Engineer exhibition some years ago for a fantastic price (very much less than retail!!). It does solid modelling which means when you draw the ballscrew, bearings etc, you can "assemble" them together just like real objects. Some of the stuff like the BF/BK bearing blocks, stepper motor couplings I got off the internet already drawn as 3d objects, so it was easy just to use them. Also as CAD is / will be part of my workflow to use the machine i.e. CAD draw object send to CAM software to produce toolpaths and tool selection then to CNC, then for me it is time well spent.
There is quite a step learning curve in using these programs (Google Sketchup is easier to get to grips with) so unless you are in a hurry, it makes you think through every stage. My mantra is "measure twice cut once" so doing the drawings etc will hopefully help me avoid some expensive mistakes.
All the best with you new project!
PS Also got my rails, ballscrews, bearings couplings from Chai at Linearmotionbearings2008 on ebay. Fantastic price and great service. Everything turned up within 10 days and was straight.
Last edited by MikeyC38; 17-01-2012 at 02:10 PM. Reason: spelling mistake!
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I have been playing with sketchup and i can just about get a square on there at the moment. I'm in no real rush for a build as my work shop is basically out side. I'm thinking its best to start with the ballscrews and then design form those, i.e use the set lengths, or is that the wrong way
Sketchup is great. This link will take you to a thread on cnczone of a guy that started from scratch and learnt sketch up. Worth a read.
For a true autocad clone then progecad smart (free) is very good indeed for cad design although only in 2d and rudimentary 3d. There is quite a learning curve for autocad but for simple work it is not to hard. This is the best clone I have seen for free.
Keep asking questions. I do and it is beginning to get me in the right direction. Stick with it here becauce these guys are the best.
BruceThe more I know, I know, I know the less. (John Owen)
Thats fine, you will need a chair to sit and build your cnc.
If you are stuck and cannot find how to do anything on sketch up then just ask.
Sometimes its good to turn of perspective (in the camera menu) and then use the standard view and you will see it like a cad drawing.
On my last post redesign 5-1 is in non perspective.
bruceThe more I know, I know, I know the less. (John Owen)
This is what I ended up doing, as buying the ballscrews, ball nuts, bearings and couplings from Chai's standard offerings seemed the cheapest way. I had a rough idea of the cut area I wanted - had to cut guitar bodies and guitar necks which are approx 575 - 660mm long and then estimate how much is lost from the X and Yaxis due to the gantry.
The guys on this forum were great in advising on suppliers they had used with success and on material sizes. On my x axis (longest) they are 20mm dia supported round rail and 16mm dia rails on the other axes.
BTW I've started playing with Sketchup and found a great set of tutorials here http://sketchupforwoodworkers.com/
I have been following a set of tutorials and seem to be getting the hang of it. Started on the Y gantry and now have the basic shape etc. But I'm wondering if there are minimum dimensions that should be adhered to. The width of the " z plate" and the Y gantry for example.
Also if you are planning on using ballscrews the chances are you will use BK/BF bearing blocks to mount the screws, these along with rail/bearing width will dictate the Z axis minimum width.
If you look around on the net there will be 3D models of BK/BF Blocks, linear rail/bearings etc these make it easier and save some work.
Try to model it close to spec of parts to be used as possible, this becomes more important in areas where it gets tight like the Z axis. It's very easy to think it will fit then find out it doesn't by a few mm's.!!!
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Well i have been searching for over an hour and all i can find are models for the BK/BF bearings. Could you give me a clue where to look please
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