Laminated ELB question

[Prarie Bowyer]

I want to make one or more laminated ELBs.  I built a laminationg rinder but I havent used it for that yet.  My other bows I just use it as a power rasp belt sander to rough tiller.

My thinking is bamboo back, bamboo core or Ipe core, or some other core, and a Hickory belly.  Questions are:

What sort of taper should I use on the pieces to get real close to final tiller?
should I cover the sled in sandpaper to prevent the actual bow pieces from slipping?

How is bamboo in the core?

I had an aidea for an all bamboo one similar to the robustus style bows only looking ELBish.  Bamboo on the back and belly, bamboo core multiple laminations there also.  Can I use the same taper?

[Ian.]

Getting a heavy weight is all about getting the initial dimensions right from the start. It would help to know what sort of weight you wanted.

I start with these measurements for anything heavy. These dimensions with an Ipe belly should give about 130lb at least, with other woods more like 110lb.


78" long, then go with Centre dimensions of 32mm by 28mm, mark out a 12" section in the middle so 6" above and below the middle point. Basically you don't take anything away from the centre 12".

Then mark a point 12" away from the each tip, at this point the stave should be 25/28mm wide depending on the wood.

Then taper the last 6" down to 14mm, this last 6" taper will look very sharp but the ends carry almost no weight so they can go that thin.

Finally draw a line from the 6" centre marks tapering the belly to 16mm at the ends. You can get them to 12mm when you tiller the bow.

For the woods, I would avoid Hickory in the belly really, unless you need it to be very heavy. Based on the woods you have access to I would opt for Bamboo/Hickory/Ipe or Hickory/Bamboo/Ipe, Bamboo is good just about anywhere.

If you let me know the weight you want, I can alter the above dimensions.

[fishfinder401]

Ian, would these dimensions work for a bamboo/hickory backed ipe?

[Prarie Bowyer]

Ian,

Ha!.... drawing a 130lb bow.  My sides hurt either from the laughter of the absurdity of it or just thinking abou it.  I wouldn't mind making one at some point but these are for a vendor at a ren fair.  So I'm thinking the likley client wasnt up to 40lbs. 

My source of the IPE is spotty.  Hickory I have lots of.  Maple I have lots of but don't like it for bow building.  Bamboos I can get.

[Ian.]

Fair enough, this is the warbow section so I instantly assume heavy. 

My sum knowledge of lighter laminates bows is about 2 bows 6 years ago, so if someone else can help that would be better.



Noel - I personally make Ipe bows shorter (76-74"),  depends how confident you are getting a good tiller. But yes, it should work okay, again depends on the weight you wanted.

[}|{opukc]

70" 30 x 20 mm in center , 25x16mm in mid limb and 10x10 in the tips - It must address a 50lb or so more. Bamboo and middle lam is 3mm but it can go now 65-70lb...
I have exactly that amount and it went 54lb with 2 lams /boo/ipe