waldemar Posted March 13, 2012 Share Posted March 13, 2012 Early days, but here's the plan: I've got access to a Shopbot CNC router, a nice chunk of wood (I don't know what species, but it's solid, seasoned and pretty hefty...) and a vague idea of what I want. [attachment=102351:wood_01.jpg] [attachment=102350:wood_02.jpg] [attachment=102352:tj.jpg] I've attached a mock-up, but the chances are that this will change - especially the finish. I doubt that the wood grain will be attractive enough for a burst finish (it's also glued down the middle so there's little chance of it looking as nice as the walnut burl in the pic) so it might get finished opaque, but very possibly oiled. We'll see. The stock is only 30cm wide, so the bass is going to be a little longer/narrower than my initial stubby designs. You can see that I was having issues getting the bridge to fit on the body... [attachment=102353:initial_designs.gif] The 3rd option above would have just about accommodated a standard issue Fender BBOT, but hardware wise it's looking like a Babicz FCH4 - a substantially bigger bridge. Electronics are likely to be a passive MME Bartolini with a switch or blend pot, I haven't really looked at this part in any detail, so I'm not that clued up on my options with these pick-ups, but the simpler the better as far as I'm concerned..! Hmm, maybe an additional J-pup at the neck. If anyone's got any suggestions in terms of what's been tried and tested then give us a shout. I've always owned P's, J's or P/J combos, so an MM is new territory for me, although I've managed to place it in the 'sweet spot' I've heard tell of (29.5 inches from the nut apparently...) I'm still shying away from making my own neck. I'm sure I could pull something together but at this stage the reality is that I'd be making a less than decent copy of something I already know, like and use. Yep, a ready-made Jazz (or maybe P...) neck. Who knows - a decent Korean or Japanese copy with a quirky head-stock may show up in the meantime. That's all I've got for now, but will post back once things get moving. w./ Quote Link to comment Share on other sites More sharing options...
gary mac Posted March 13, 2012 Share Posted March 13, 2012 Good luck with it and keep us updated. Quote Link to comment Share on other sites More sharing options...
Kiwi Posted March 13, 2012 Share Posted March 13, 2012 This is really interesting. How are you calculating paths? I've played around a little with this as well...free CAD software [url="http://www.emachineshop.com/"]http://www.emachineshop.com/[/url] Quote Link to comment Share on other sites More sharing options...
waldemar Posted March 14, 2012 Author Share Posted March 14, 2012 >How are you calculating paths? Hiya Kiwi. Not entirely sure about how I'm approaching this just yet. I need to talk to the guys who run the Shopbot and maybe ask a few questions over on the Shopbot forum. In principle my approach is quite straightforward: design everything using Adobe Illustrator, import the vectors into PartWorks and from then on the software takes care of the sharp end, like working out the offset for the bit depending on whether it's cutting inside or outside of the profile. There's some more info here: [url="http://wiki.fablab.is/wiki/Shopbot"]http://wiki.fablab.is/wiki/Shopbot[/url] It's essentially a slab body so in theory all I'm asking the CNC machine to do is cut out the shape and then I'll set the plunge depths manually for the p-up and control cavities and also the neck pocket. I'm considering second and third passes along the outside front edge with a rounding bit and possibly a ball-end bit to create an edge contour like this: [attachment=102523:countour.jpg] Although, of course, this maybe entirely unfeasible... At this stage I'd like to keep it as simple as possible, but the other option open to me would be to model the body in 3D using sub-divisions, then triangulating the resulting geometry before saving it as an .stl file. This approach would enable me to add more complex contours. As I understand it, in both cases the software will work out the tool paths depending on the bit etc. In either case I'll be using a 1/2” bit to cut the body and the pocket (there'll be less flex in the bit and should prove to be more accurate) and a 1/4” bit for the pup cavity to allow for the tighter corner radii. I'm totally brand new to this so it's a bit of a learning curve, but hopefully the complexity of the project won't get out of hand. w./ Quote Link to comment Share on other sites More sharing options...
Chimike Posted March 24, 2012 Share Posted March 24, 2012 Hiya, It pays to plan in how you will hold the workpiece, and register it when turning it over, so that everthing lines up correctly when machined. Much easier if you plan ( and draw it ) early in the process. Mike. Quote Link to comment Share on other sites More sharing options...
sprocket123 Posted March 25, 2012 Share Posted March 25, 2012 Always like looking @ these built threads Quote Link to comment Share on other sites More sharing options...
apa Posted March 25, 2012 Share Posted March 25, 2012 Good stuff My 4peneth......... The hard bits ar the initial design and modelling. Your machine paths should take care of them selves. You just have to tell it which ones to use. Large flat (20mm dia) for roughing out (Getting rid of the bulk of the wood you dont want). Large Ball Nose (20mm* dia) for second pass (Getting the actual shape cut out) and finish pass (The final finished surface) (A big bit with a small step over will give a nice smooth finish) *20mm dia assuming your minimum dia in your model is greater than this. If youve got smaller then use a bit a few mm smaller. This is only in the X and Y axis not the Z. There are lots of different types of paths depending on ypur software. Just remember to 'climb' with your cutting. That means the bit cuts into the wood rather than gouges it out. In principal that means running your path in a clockwise direction if working from the inside out. The most important thing in all this is our ZERO (X=0, Y=0, Z=0). Make sure that when you zero your first bit to your stock you can then zero the second. I.e. dont zero on a face your about to machine away!! Also when you flip your piece over to do the other side. Three ways of doing this: 1. Machine over half way but leave 'spru' just like on models so the piece is still left in the stock then flip over and machine past then cut the spru. 2. Machine just before half way then flip and machine up to half way and cut out by hand. 3. Hold the piece down with clamps on the actual body, machine out but avoid the clamps with your path. Move the clamps then machine out remainder. Flip and repeat. This one you can do if your software has that facility. Ways make sure the piece is in the right position when fliped is to either use dowels on a base on the CNC bed or machine two straight edges in your stock and butt them up to reference faces on the CNC bed What you dont want to happen at the final moment is the piece to start juddering and flying about!! And dont over tighten your clamps. The stock will warp as the piece is machined out. Finally. Measure twice, cut once I hope this helps A Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted March 25, 2012 Share Posted March 25, 2012 looks like an exciting project. Part of me is thinking for a one off a band saw would be easier- but what do I know? Quote Link to comment Share on other sites More sharing options...
sprocket123 Posted March 29, 2012 Share Posted March 29, 2012 Look forward to this thread Quote Link to comment Share on other sites More sharing options...
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