For my first build, I figured I would go big and build something that I would really enjoy. I have had a fiberglass hull for an Iowa class for many years but it is of poor quality and has kept me from really getting involved in the sport. The sides are uneven in length, the front is crooked, and it is just not that good (though I may throw it together for a fast gun build if I ever get the desire to use that format) My wood working skills, though not BAD, my perfectionism and lack of symetrical plans has frustrated me and has been cause for a lot of false starts and scrapped builds. Having become somewhat proficient in CAD, and always wanting to build or buy a CNC router, I figured this would be a perfect project to mate with the technology. With out further ado: I imported the blueprints that I found on line to SolidWorks and traced out the top deck and side profiles to give me the overall dimentions. Started with the skeleton outline. Taking some measurements from the BDE plans that I have (though there are two centerlines drawn.. nice.. lain I drafted the few (18 ribs on a 6' long boat..) ribs starting from the middle and moving forward. Eventually filling in the gaps (Ignore the top deck, it was just put on for show) A few weeks went by and this box arrived: Got it all assembled over a weekend: And last night, was finally able to test out the CAM of the F ribs (they make up the bulk of the center of the boat) on some scrap 1/8" luanne that I had. The ribs are going to be 1/4"x1/2", so this was just a test of the design. I still have to tweek the tool paths. As you can see the first cutting attempt was too shallow (guess who forgot to tighten the collet, so the bit was just pusing into the tool instead of cutting the wood...) and the speed was too high so the gantry was being overthrown and it could not keep accuracy (in some cases the gantry would over travel by a quarter of an inch because of inirtia). The second cut was much nicer (now that the collet was tight ) but while the CAM is supposed to go from Z=0 to Z=-.25 (or -1/4" travel) it did not cut through the 1/8th board. So some recalibration of the Z axis is in order.
Nice looking router. I wish my CNC had a bed that big. Once you get it dialed in, you need to get some 1/16" bits like these: http://www.ebay.com/itm/Miniature-C...0660547954? The small bits allow you cut tight corners yet they still are pretty strong.
Thanks! The cutting surface is only 12x12, but I can get longer rails and make it bigger. As it is, I will have to do some fun working to make the cap rail. I might build a custom moving bed, or cut the drawing into 12" sections. Ive already bid on those bits Good looking out.
Here is how the draft currently sits. I have already started adding ribs to stock so I can get as many on the stock as I can to waste as little as possible. The wooden parts are about 95% complete. Some stringers need to be added to the subdeck, and that needs to be broken down into 12" sections to fit it on the machine bed. Everything that is still gray is a work in progress. I am also waiting on my 1/16" router bits to arrive so I can start letting the wood chips fly. If anyone has any suggestions, or thoughts, please chime in.
Perhaps, add a cross beam or two to help support the deck and SS better? So instead of lifting the entire deck off you just lift the portion you need to work under.
I am doing the cross braces a little differently. No matter where you put them, they seem to get in the way. So I modify the side rail to have an "ear", in this ear I put a threaded insert. A corresponding hole is drilled in the top deck. So the top deck acts as the brace. You could also do this by making the sub deck brace removeable. Just a thought.
Have you thought about making the sub-deck a little wider? It will make mounting caprails easier, plus have an edge for the deck to sit on. And if you use magnets, you'll want it to be wide enough for the magnets after you have the caprails on.
I could easily make the subdeck larger. That would be beneficial for me as well for my cannon design.
Make that subdeck nice and fat. I would recommend about an inch. That gives you lots of room for caprails, magnets, a good deck seal, power switches, pump outlets, and anything else you may want up there.
Still waiting on my router bits to arrive.. The snow storm really killed progress this weekend.. However, I am getting a nice tax return so the next purchase will be a 3D printer. The cap rail is now 1/2 wide and will have magnets embedded in it (obviously not shown since I un-hid the top decks)
Well, the large opening will be under the super structure. The other two will be fore and aft of the turrets. Not totally done with the design of the decking structures yet.
IT HAS BEGUN!!! The feed rate is turned WAY down for better accuracy. This costs a lot of time and the 6 ribs will take about 7 hours to cut. Being my first set and the first thing I have cut on the router I wanted to be overly cautious to not miss steps or over drive the router bit and snap it.
Wow, that's slow. Hopefully with a little tuning of the drive system you can get some more speed. Don't worry about the bits, they can take a lot. I run mine at 10,000 RPM (max for my spindle), cutting 0.1" deep each pass, and at 25 in/min.
The 6 ribs I cut turned out very nice (one is a bit wonkey, but easily fixed with some sand paper) Today however, something went horribly wrong and I have NO idea what happened. Thats some good wasted plywood right there. It only did it in one direction (all of the skinny/distorted sides were facing the same direction on the stock) I made no changes to the machine and only increased the speed (though it still only wants to cut at 4.8in/min)
Realy bad backlash or a loose mount on one axis? That is an unusual error pattern, I don't believe I've ever seen anything like it.
Well I am talking to the guys on the ShapeOko forum and we are suspecting my driver board running at 100% amps is causing too much noise on one axis, in one direction. The anomaly side was on the Y axis negative travel when tied to an X axis movement. Before I buy a more expensive (and better) controller, it was suggested I run the motors at only 75% amp. You can kind of see on the bow rib (solid rib on left) when the noise would clear up on the straight cut across the top, loop the tongue, cut the side correctly, cut the notch, and as soon as the Y had to start traveling back down the axis tied with the X movement it would crap out, under cut the side, under cut the tongue, but then clear up as the noise in the line would dissipate again.
How many times did the tool go around the outline of the shape? If you are losing steps I would expect it to get progressively worse -- so even the correct parts of the outline wouldn't be right on the second pass. You can try programming it to cut a circle, but keep the z axis above the material. Mark where zero xy is when the tool starts, run a few passes and see if it ends up at the correct zero.
