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Weird?...Yeah, we can do weird...

Posted: Mon Apr 08, 2019 5:12 pm
by BradyWatson
A lot of 3D projects have come my way over the years. I probably post less than 0.5% of the things that I do...but I thought this project might be of interest to some. A couple months ago a customer contacted me because he was doing a custom-resto on a motorcycle and wanted to do some parts on the bike in wood. (He was referred to me by a member of this board - so thanks for that) He already has a custom hand-tooled leather seat and grips done (really stunning) and adding some wood to the bike was part of his vision.

Since the bike has a 6v electrical system, he wanted to take the 12v LED lights from one plastic fairing (the violet one) and the battery pack mount from the back of another (the red one) - and mix them together in a thicker version of the original injection molded fairing.

I started by scanning both plastic fairings and set off to modify them and extract geometry needed for the newer, thicker wood fairing. I wound up using Rhino to visualize everything, including how it was going to mount in relation to the forks, bars etc. Because the headlights needed to be shooting forward and not up/down/left/right, the plane that the lights mounted on was established as the 'master plane' of sorts, so that it was perpendicular to the Z. This way I could precisely machine a pocket for the light's O-ring gaskets and light assemblies to fit in there - without worrying about blinding any of us on the road at night. :D

Since I had to maintain that plane 'normal' to the Z, I needed material that was at least 3" thick. I wound up getting a 3.25" maple glue-up from my supplier and set out to do all the toolpathing in Aspire, using the 2-sided setup. Since there were parts of the model that had major differences in Z height around the perimeter, I was unable to get the control I needed just doing 'Selected Level' for the 3D machining, so I had to jump through a few hoops to keep the tool from falling off the sides by using vectors to constrain things to my satisfaction.

The front side was pretty straightforward, but the back required about 15 different toolpaths to do the general 3D machining, to flatten/pocket critical areas, drill spots for the stainless insert hardware and undercut the battery slot so the tabs on the battery pack could slide right in the slot made by the keyhole bit. Everything worked exactly the way that the previewer said it would 8)

My methods differ from most...for hold down I used some toe clamps that I 3D printed solid in conjunction with 3/16" slots I put in the sides with a hand router. They sat up about .02" and that turned out to be the perfect amount of spring to clamp everything down and keep things from moving as stresses in the material were relieved. I've never been a fan of using dowels on 2-sided projects, so I just rolled with what I've always done. The material was prepared precisely at 14 x 14 x 3.25". The front edge of the sacrificial board was 'kissed' with an end mill to create a qualified surface true to the CNC. Then a fine mechanical pencil was used to trace around the outside of the material. When it came time to flip, I just aligned it to my qualified front edge and to the inside of my fine pencil marks. The flip was *perfect* - as witnessed by the 2nd side profile cut not digging in where the front side profile was.

I sent pics to the customer - he is absolutely stoked. The only thing left is to do some matching bar-ends in maple and he's on his way to completing his resto-custom dream.
MockUp.jpg
AspireFront.jpg
AspireBack.jpg
3DPrintedToeCLamps.jpg
Front.jpg
Back.jpg

Re: Weird?...Yeah, we can do weird...

Posted: Mon Apr 08, 2019 9:31 pm
by Savannahdan
Glad you posted this. I used a similar hold down method by gluing tabs onto a barely large enough board one time. Advantage of yours is you only need to cut the small insert slot and the toe clamps use the same size screws regardless of project. I really need to get a 3d printer for making things like the toe clamps.
Thanks for sharing.

Re: Weird?...Yeah, we can do weird...

Posted: Tue Apr 09, 2019 12:21 am
by BradyWatson
Dan,
Thanks for the kudos.

In the meantime, you can easily machine clamps similar to these in any material (including plastic or aluminum) right on your CNC.

Cut a long strip with the step in it (pocket or profile TP), then cut them to size on the chop saw. Drill as required.

Re: Weird?...Yeah, we can do weird...

Posted: Tue Apr 09, 2019 12:08 pm
by Savannahdan
Brady, that just won't work. The idea is to get that new tool. Ha.

Re: Weird?...Yeah, we can do weird...

Posted: Tue Apr 09, 2019 12:44 pm
by scottp55
NICE job of integrating the scans, and then doing such a beautiful carve Brady!! :)
Any idea of what he plans for the finish?
Going to be a NICE custom bike!! :)
scott

Re: Weird?...Yeah, we can do weird...

Posted: Tue Apr 09, 2019 4:16 pm
by BradyWatson
Thanks guys. He's totally excited after seeing the pics.

Also really happy with the bar ends I did last night. He only really wanted the ones in the middle (that emulate the red ones) but I couldn't help giving him a few extra to play with...Everybody likes a little extra :D

This piece of maple was a bit hairier than the fairing block...but that's how maple is sometimes. Even different areas of the same piece of lumber can be dramatically different.
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