50" recurve- Finished pg 5

[bjansen]

Just finished this form this morning for a short recurve and I had to post it.  I got some cabinet grade plywood scraps from a friend and glued 3 deep. The top of the form has a .100 lam of hickory, the whole thing sealed and the top waxed.  I put two clamp holes in the bottom to attach it while gluing up, lam keepers at the crown and I also added some pegs to help taping the lams down prior to attaching the top...I think its the best form I have ever made.  It had a huge riser for a high grip on such a short bow. The riser is also lopsided (the bottom limb will be on the right in that pic). But its back to work tomorrow so might not get time to work on this one in a while.  


   

   

[kennym]

That is a mean lookin dude!!

Back to the real job tomorrow for me too!

[Russell S.]

that thing looks mean...  what are the specs going to be??

[bjansen]

Well, I glued one up today on it...but I dont think I will get to finish it in a while.  It should measure 46" ntn unbraced.  I used .040 ULS brown glass and 2 .050 lams, zero taper for a total lam stack of .180.  I took some notes on some shorter bows I have seen like it and notices they have little to no taper.  I am shooting for somewhere around 50-55#.  The riser I used was green mountain camo S/A.  


I would like to hear any thoughts on taper theory for shorter recurves...or recurves in general.  All of the bingham recurves I built had a total taper of .002.  I think all of the Bear recurves I have seen (58" Grizzly, 52" Kodiak, Black Bear) also had a taper rate of .002 from what I could tell.  But then some of the shorter recurves I saw appeared to have zero taper.

[Apex Predator]

I know nothing about building a bow like this, but plan to after this threads conclusion!  

[Russell S.]

my 48" R/D (1.5" wide) form came out at 15#@24 with that stack.

[bjansen]

Russell,...how long was your riser? and how much recurve did you have...what is your best guess on what this one will come out to after seeing the form.

I might be able to get the bow out of the oven tonight and see.

[adam]

Well i borrowed basically the same bow you are building from a friend b/c i wanted to build one for myself. You are right as far as the taper. The bow i have is all parallels. Its a 48" bow rather than a 50" though. I took some measurements off mine to give both of us a comparison when yours is done. The one i borrowed is 48" and is 27#@28". This bow has a 20" riser and comes out at .178 stack at the fadeouts.

I'm guessing you will probably be a little light but the other 58" recurves i have checked were about .240 or .250 for a 50# bow. When i lay mine up i was going to use a .195 stack. It will be intresting to see for sure. maybe these numbers will help you some.

Adam

[bjansen]

Adam, Thanks alot. That is some excellent data.  What kind of bow did you borrow...was it a bear supermag...or some other production bow or one that your buddy made?  

Well you guys had me nervous on the weight...so I had to work on it tonight. I have some progress to post...but i have a smile on my face.


Here is a pic of it out of the form....quite a bit of excess on the ends.

 

Here I am using the laser jig to get centerline..the laser line is quite precise..but my scribing the line is not.  

 

Here is the initial form template that I made with the specs I drew out.  Perfect fit.  I drew the entire bow out on a sheet of cardboard first, including the riser ends and the string knocks and I transferred all of that to this pine board.  I cut the and sanded the board and then used the router to make the jig similar to how Kenny describes on his website.  I initially came up with a lam stack of .172 to create a 47# bow.  This was based on looking at a bear supermag, a short browning cobra and a 52" kodiak this past fall...some figuring that looked precise but was more of just a guess...of course then I rounded up to .180 to get the poundange up a bit...also a bit unprecise but you have to start somewhere.

 

[bjansen]

 

 

To the bandsaw, then the edge sander to smooth it out and here is the blank

 

[bjansen]

 

 

[bjansen]

Im not getting too far back yet in that pic...but it was feeling pretty good.

I put it on the scale...it is currently 58# at 28".  I think after I finish the limbs and sand it will be in the 51-55 range easy dont you think

I think the pic shows it is a bit bendy at the fades..but look how the tips rolled out.  To finish the limbs I will have to taper them a bit more, so I am guessing that will help.

[sw]

VERY nice!!! Looking at your drawing pic that bow will feel nice on the fingers at 28" of draw!!! Very little string angle at your partial draw.

I use tapers on my 48" t/d bow with excellant results. It lets the tips unwind just a tad but still keeps the angle down for a full 28" draw. I compared two bows one with tapers and the other without and did have a touch of speed increase with the tapers, plus the bow felt a tad smoother - but this was all feel.

I can't wait to see how this one comes out!!!! very nice so far!!!

[bdawg]

thats gonna be a cool little bow!!!cant wait to see it finished.i would love to have one like that for treestand hunting.bdawg

[dutchwarbow]

nice!!

almost looks like a riser with recurves  :p

love your recurves brad!

[Russell S.]

my 48" form is a r/d with 13 degrees of deflex and very slight net deflex. sorry it was 15#@20"  riser is 14" with 10" 0.010 full tapper power lams.  i think its about 27# at 24.  it is a different monster,  i wouldnt try to draw it to 28"   i am very interested in that form,  did you lay it out on a computer??  or can you post layout specs (points of infection angles and distances), or maybe a Super tiller plot?  i would love to have a 50" bow that could be shot reasonably at 28"

[TNstickn]

Very cool!

[bjansen]

Russell, I did not lay it out on a computer, I gathered some ideas and some recurves that I had and then drew it out on cardboard.  How about I take the profile, draw it out on 8.5" x 11" sheets of paper, scan it and send it to you.  Then you can just print them out, tape them together and you will have a full scale profile.

[Russell S.]

i would really appreciate that.  i pm'ed you my email address.

[VRB]

That's looking good.I think your right on the tips,narrow them down and get a little more bend there.It might be interesting to leave an 1" to 1 1/2" more on the tips and move your string nocks up accordingly.It would make the bow 2" longer and give you more tip to open and add to the smoothness,just a thought. Bill