Primitive Archer
Main Discussion Area => Bows => Topic started by: Del the cat on September 19, 2017, 07:13:38 am
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Dunno if anyone is interested, but I've vastly improved the lamination planer/taper machine which I made from an old power plane.
The taper sled is made from some 2"x 1" x 3/16"thick Aluminium U channel, it still has a little spring, so maybe steel or thicker Ali' would be better, but this version is vastly better than the mk I
The sole of the plane is drilled and screwed to the plywood verticals so it is all nice and rigid. (Well relatively ;) )
It works pretty well now, as long as you stick the lam's down to the sled with double sided tape.
I've just run a couple of Purple heart lams through it and they have come out nice.
One good thing is it produces chips rather than dust, much easier to clean up.
I'm hoping to do a Boo, Purpleheart, Yew ELB
Del
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That's a clever setup you made! Wish I had the space for stuff like that. Still taper my core lams by hand and purpleheart does take me some time usually.
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Nice one Del, I converted a planer to a lam grinder last year. I use two pieces of 1/4 glass for my sleds, I use wire between the two pieces to establish my tapers
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That's still a pretty sophisticated looking well made tapering set up there Del.Nice!!!!
I always liked laminated bows.I should get into some again.Bamboo backed bows mostly though.Using smooth on glue.I went and bought a hand drawn power planer years ago and used that and it was'nt cheap.It got me close enough to a good tiller when first braced.
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Cheers guys.
BTW, the adjuster screw ( in that notch on the underside) bears up against a bit of thin steel plate, for smoothness and consistencey.
Del
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I like that sled, looks like it won't bend when feeding.
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interesting set-up for tapering, making do with simple portable tools. Of course, we are all now looking forward to seeing the trilams :)
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Del if you use just a parallel base board with a stop at one end and then place a tapered lam on top it will cut out the need for adjustment and reduce the flex. I can grind you some perfect tapers (key!) and send them down to you if you want. An elb needs 0.009" per running inch if you are interested ;) Pyramids 0.002" and parallel limb bows around 0.004" - 0.006"
Although i'm only set up to do 1 3/4 width max.
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Nice idea Del I cant work out how it exactly operates though. Is it for full length lams, or billet lams? Does the plane have a depth stop, or do you do it by eye?
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Nice idea Del I cant work out how it exactly operates though. Is it for full length lams, or billet lams? Does the plane have a depth stop, or do you do it by eye?
It's for billet lambs, but will take a 4' length or you can push through any length if its parallel.
The plane has a depth of cut setting, but I just leave that fixed and just do fine repeated cuts slowly raising the platform until I get the thickness I want (by eye mostly). The wooden platform is screwed up or down by the screw which goes up from the notch under the base. The aluminium sections are the taper sled, which are hinged together at one end, the other end can be opened up to what ever taper you want, the lam is then taped to the sled and becomes tapered as it is run under the plane.
Del
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Del, thanks for posting. This is simple and effective - great, I like inventions like this. I will copy that for sure. Saved your post under favs.
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Del, thanks for posting. This is simple and effective - great, I like inventions like this. I will copy that for sure. Saved your post under favs.
An honour indeed :)
Del
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Do you have any ideas for running bamboo through it? How to back the internodes and how to hold a crowned surface down?
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Very nice Del, that'll do for sure. I am interested in how you are going to approach the bamboo as well.
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Very nice Del, that'll do for sure. I am interested in how you are going to approach the bamboo as well.
I'll just plane the boo' by hand, because of the undulations where the nodes are. It cuts quick and easy as long as your plane has a good sharp blade :) . I've done boo backed Yew before, but never a tri-lam.
Del
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Del,
do all three lams get tapered?
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Del,
do all three lams get tapered?
Yeah, I'll taper the boo by eye, and use the jig to taper the core and Yew billets for the belly, mind the final tillering will be done by hand/eye.
I don't like the look of parallel cores which then leave the belly very thin at the tip... just my thing.
I'll aim for my somewhere near usual 2mm every 6" taper, which then allows the tips to be tapered some more for final tiller.
The limbs will be tapered billets with a continuous Boo back. I won't try for an accurate match of the billets, as the tillering will be done on the finished bow.
I never aim to do it accurately by numbers, just to get it close, well hopefully a bit over weight so I can bring it in to exactly what I want.
Del
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Okay Del, I get it now. Nice idea, especially if you need to work difficult wood like purpleheart, that stuff will blunt a carbon steel handplane blade in no time. HSS on an electric planer is good for abrasive tropicals.
I have toyed with an idea, but have never taken it further than a concept sketch. It relies on an electric handplaner with frictonless adhesive on either edge of the sole to act as runners, and to stop the plane from biting into the form. The plane moves over the form fixed lamination, rather than a lamination being feed into a fixed planer. I believe it is a method used by bambo fly rod makers to rough out tapers, prior to finishing up with a regular handplane.
Food for thought for some guys who have more time than me for bows at the moment.
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I like that a lot! I added it to my list of things to do in my non-existent free time.
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It relies on an electric handplaner with frictonless adhesive on either edge of the sole to act as runners, and to stop the plane from biting into the form. The plane moves over the form fixed lamination, rather than a lamination being feed into a fixed planer.
Hamish,
can you link to or post a pic of that method? I am having trouble visualizing the form.
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Willie, Imagine a plank of hardwood planed smooth, or it could be multiple thicknesses of hardwood ply glued together, which would be more stable. Dimensions 2"(3" would be even better, allows for wider laminations and gives more bearing surface so the plane wont tip) x4" tall as long or a little longer than your intended bow. On the top edge saw with a dado head or rout a groove wide enough for the lamination. Depth of the groove is dependent on what type of lamination you are cutting.
If you wanted a form for a belly slat you could make the groove 3/4" or 7/8" deep. If you wanted to do a core lam it could be 3/16"-1/4" deep.
Mark out the handle/ dip area on the top of the form. From the ends of the board, up from the groove mark up 3/8" if you want to do a belly slat. Connect a line from this point back to the end of the handle area. Repeat for the other end of the form if it is for a full length stave. Saw off this waste, and you have your form. Run a strip of frictionless tape down the each side on the sole of your electric plane, trim the excess from over the mouth so depth of cut can still be set.
Place your belly slat blank in the groove. It could be fixed to the bottom of the groove with double sided tape , or held in place by screws on side, through the walls of form. Just the tip of screw would bite so the slat insn't comprimised.
Set the plane for a fine cut, no deeper than the thickness of the frictionless tape, so the planer won't cut into the form.
Run the plane on the slat as many times as necessary until the taped part of the sole bottoms out on the form.
Hey presto you should now have a belly slat with a flat section as long as the handle, or fade area, 7/8"deep tapering to 3/8".
If you wanted a form for a core lam, you could use 3/16" or 1/4"deep for the groove, tapering to 1/16" or 1/8".
My method gets around you needing to add a powerlam under the backing lam, like you often need to do if you use thickness sanded taper laminations. You can still glue on a handle riser if you are making a deep narrow handle, it won't pop off because the flat area gives you enough thickness so the dips won't flex.
My proposed form isn't very adjustable but minor variations could be achieved by placing a thin parallel lamination of sawn or planed wood on the base of the groove before placing the blank on top.