Laminated Longbow Build Along

[Cupcake]

Hello Tradgangers,

I have been itching to build my first bow and am now proceeding to do so.  I got a shipment from Bingham Projects so now I have all of the stuff.  I have been gathering tools since last December and everything is in place.  Two weeks ago I spent several hours in Frost Hardwoods in San Diego (what a feast for exotic wood lovers).  My first bow will be simple: maple lams, walnut riser and black glass.

But first, let's start with my garage.  DesertDude will vouch for my being out-of-control; but, hey, you only live once...

Actually, my garage is the Spine-O-Meter world headquarters.  It has been undergoing a make-over recently so let's have a look...

I tore out an old workbench that was not well designed and now have a place for power tools.

 

Next, I had to design and build a new workbench, got carried away...

 

Another bench that serves me well.

 

Next, I need a hot box.  Maybe I will graduate to heat strips someday, but for now this is made from 2x2 and some foam insulation I got at Lowe's.

 

Three 100 watt bulbs did not get above 128F so I put in 3-150 watts and even a little pancake fan and got up to 165F.  The foam is only 1/2 inch thick but the lid and one side are doubled to use up all of the two 4x8 sheets.  I put heat shields, made from soda cans, between the bulbs and lid because experiments showed that the insulation would de-form with the bulbs this close.

 

[Cupcake]

Now I need a bow form.  I am going to use C-clamps for this one instead of the air hose method.  This will be more versatile and allow experimenting with different riser designs.  I laminated two 3/4 pieces of 12 inch wide MDF.  Next time I think I will use plywood - even though it is not truly 1.5 inches - because the MDF is HEAVY.

 

The template is made for half the bow and I will use a pattern router bit to get a good edge on the form and flip it for the other side.

 

The pattern has two holes to pin it to the form when it is flipped so symmetry can be maintained.

 

Here is the form roughed out with my jigsaw.

 

It has momentarily stopped raining so I am going to route the form outside.  Stay tuned for the next episode.

We are having a freak rain here in San Diego the last two days.  It has dropped about and inch.  We have not had a drop since the end of February so it is welcome...unless you want to work outside on your bow making stuff.

[Cupcake]

Dang - it just started raining again.  I need to make a string jig so I guess I will do that.

[KYArcher]

I'll stay tuned.  

[CLK]

I look forward to this build along.  I don't post much, but I too have be collecting tools. I'll be watching an learning.  While I'm at it, I'll trad you a Saxon Kadiak for that ugly yellow BMW in the background.  Looks like it's just taking up valuable space.

[Cupcake]

CLK,
Sorry, no trade.  That machine gets me to work everyday - rain or shine - in So. Cal. it is mostly shine.  I just turned 86K miles and it still runs great.  My last BMW I put 100K miles on.

[kennym]

Lookin good Kevin,how ya like the bandsaw?

[DesertDude]

Cake...  wish I was there to see all this come together. I know you are Way out of control.... Can't wait to shoot your bow.  Hope to see ya sunday......

[Cupcake]

I made some more progress today after overcoming a few difficulties.  I had planned on using a hole saw to cut all of the holes for the clamps in my form.  It clogged with sawdust and started burning.  A reminder that MDF is evil on a lot of cutting tools.  After trying a few things I settled on drilling holes at the corners of a square and using my jigsaw.

 

After that I used contact cement to glue a 1/16 inch aluminum strip to the form.

 

After sanding, Scotchbrite and wax the form is now ready.

 

Next I set up to re-saw some maple for the limb cores.  A bought a 1/2 inch, 3 TPI, carbide tipped blade for my Grizzly bandsaw and set it up similar to articles I have seen in woodworking mags.

 

Kenny, I like the Grizzly.  This re-saw set-up worked way better than I expected.  I sawed a strip then ran the wide piece through my drum sander to get a clean edge and then sawed another strip.
 
 

I got nine of ten strips cut successfully.  I may have to reject a few due to the knot you can see.

I plan on using three parallel, full length laminations in this bow.  I am still trying to understand the use of tapers.  I don't see many longbows with a thickness taper over the length.  I have a recurve with a taper.  Beside being able to adjust limb thickness easily by using reverse tapers can someone tell me if they taper the limb thickness.

Maybe more tomorrow after shooting in the morning and seeing Indiana Jones in the afternoon.

Kevin

[DesertDude]

Way to sweet Cake.........  I can't wait, I'll see you in the morning.....Mark

[onemississipp]

Nice setup, keep going!

[TimZeigler]

Your garage is way to clean   :eek:  

Looking good so far, will be following along.

[BMN]

Looks great! Let me know how that MDF works out. I'm planning on using it for my first form.

Bill

[Holm-Made]

I'd try tapering the limb .002" per running inch.  I wouldn't use all parallels with that design.  Chad

[kennym]

I'm with Chad on this,.002 taper will lighten/limber up your tips and add a little strength to your fade area. JMHO

[mmgrode]

One thing I notice about your shop...it's so clean!!!      
Looking forward to the rest of this thorough buildalong.  Cheers, Matt

[mmgrode]

Ahh, I see you are an engineer...that explains things    My brother is one of your kind     Keep it coming clean and precise!  Matt

[Cupcake]

I am all ears on the use of tapered limbs but I still am confused.  If I taper the limb .002" per inch that will be over .040" difference in thickness from the fade to the ends.  That seems like a lot to me.  I have looked at a lot of longbows and have not seen one with that much taper.

I had hoped to glue my first one this past weekend but had a few difficulties - no point in rushing.  I was having trouble getting the fades to cooperate but I think I figured out a better approach this evening.  Maybe tomorrow I will have enough energy to work on them.

Sorry about my garage condition.  Since it is the only place in the house that I have control over I am doing things my way.

Stay tuned.

[ghost rob]

Cake, I've built some mild r-d longbows (kinda like the Great Northern Critter Gitters) and I ran a .006" taper. This made it smooth to draw and snappy too.I have noticed that on the hybrid bows there seems to be less taper and I think its because they're not as thick. On a 62" bow I used 2 lams of glass .05" and 4 lams of wood with a butt thickness of .085". I used an 18" riser also.

[Holm-Made]

The last 10" on a bow limb bend very little as most of the "strain" is near the fadeout.  Putting tapers in the limbs lighten the tips and get them bending a little more.  It also beefs up the fade out area as Kenny says where there is more strain.  If you use all parallels then the limb will only work from midlimb to fadeout.  

In a nut shell:  Tapers add more beef where the limbs need it and take more material away where the limb doesn't need it making for a more efficient working limb.  Chad