Getting my feet wet again…

[rmorris]

Well it’s been about 7-8 years since I have attempted a bow but my oldest is about to turn 11 so I figured I needed to get back to making some bows and put all the other projects on hold.

Found some nice looking diamond wood at the local big box store, just too bad I had to glue 3 pieces together to get it thick enough.

I will try any post some pictures as I get this new design figured out but I think the last time I posted a picture on here the entire user interface was different!

[Kirkll]

Diamond wood???

Looks like plywood to me….     Hopefully you are going real light weight on this… that looks scary to me….  Kirk

[rmorris]

Kirk, my son chose wood for his bow that was outside of his pay grade. Making a mock up plywood riser to make sure my new templates work before I make an expensive mistake. Glad I did because I am not sure I like the curves not being centered on the riser,  looks I need to go back and make another round of templates…

[rmorris]

I am now very happy I am making a test bow before jumping back in. Made a test limb (no glass) and cut the riser limb pad angle to 23 deg… no idea where I got that number from!?!?

After playing around with an older broken recurve I was given several years ago as I am somewhat modeling this now after that one. I noticed my limb pad angles were a bit off.

Looks like I should be somewhere closer to 17 deg. Don’t judge me but I think I am going to try and reverse glue the cutoffs back on and try this again!

[Roy from Pa]

Hey stranger, how you been?

[rmorris]

Roy, the last 10 years have been some of the most fun and exciting times I have had. Got a great bunch of kids and now that everyone is wiping their own butts I figure I better get back into archery and try to drag a few of them with me as I do it. How life treating you?

Got my scrap pieces glued back on and recut to the new angle. I think I am about out of things to do and may have to dive into making this bow.

[Roy from Pa]

Sounds great, Ralph..

 

[dbeaver]

There a million projects I'd think to do a mock up, I'm really.glad you made a ply riser and a glassless limb, super eye opening for testing visual appeal and if it looks like it'll work.  I comepletely overlooked this as a possibility

[Kirkll]

You will be much happier with 16-17 degree pads with that limb shape. At 23 degrees you’d end up with a 9” brace height once you have your pre load dialed in.

Without having an adjustable riser, I can see doing a mock up. But I would be very careful actually using threaded inserts in a plywood riser and actually loading up a set of 50# + limbs. I’m not sure it would hold up.

I think I would use red oak you can buy pretty cheap at the big box store for mock up risers when actually stringing up your limbs, and use limb pad wedges to adjust preload. That oak will be much stronger and safer on the tiller tree.

.02 cents worth.

[rmorris]

The plywood bow will never see a string and more than likely won’t see a second limb, was making a joke early on when I called it  Diamond wood. Mostly to trying to prototype and make sure all the new jigs I am making will work and that I also remember how to still do this.

The one part I can’t prototype is the limb thickness on the first attempt. I am shooting for 35#@22” for a 62” recurve with an 18” riser.

I am going to shoot for .200 stack just after the riser wedge and that will be with a .002/“ taper using .04 glass and approx 1.6” wide limbs.

If anyone has any better suggestions on that stack thickness please let me know.. I will send the closest guess a nice piece of “diamond wood”!

[Noah70]

You might be a little weak at .200, but that depends on the wedge length and if you include a tip wedge.  35# @ 22” puts the bow at 47 - 50# @ 28”, roughly?  I measure my stacks at 16” from the nock, belly side,  (if all else is identical) and I’d be at .205 +/-, and that’s with a 1.7 width limb.  So add .002/inch back to your wedge, plus a couple extra. Easier to remove extra   My .002 cents worth?
I’ll donate that diamondwood to a worthy cause.   

[rmorris]

Uli,
You saved me and made me do some thinking and re - measuring tonight when you said 50#@28 and I thought no way my 11 years could pull that!

The correct weight is 30#@28 or closer to 18#@22”. Now I am thinking .200 is too much now.

Appreciate the help!

[Kirkll]

I’m going to give you a bit of advise… you can take it or leave it… building recurve limbs at ultra low draw weights can be frustrating as hell because they get too thin up at the base of the hook and want to go sideways on you… it’s really tough to get torsional stability in those ultra light recurves…. And extra width isn’t going to help.

You can use stable core right under the glass on the back of the bow, or a bias weave carbon will work even better. The last ultra light I built I used .015 twill carbon over stable core on the back for a total of .031 composite backing.and the stability rivaled a 65# bow.

If you are just using .040 glass, I’d recommend no forward taper in the limbs at all, or even a reverse taper for a 30@28” set up…. Once you drop below . .185 - 190 limb thickness at the base of the curl, they start getting squirrelly on you and are very touchy and a perfect alignment is critical …..   food for thought….

You know…. I’ve never tried .050 glass on a light weight recurve. That may in fact give you better stability, but it’s awful heavy on such light limbs… just a thought…

Kirk

[Jon Lipovac]

Don’t mean to sidetrack this thread.
Kirk , where did you get the .015 Twill and what did it cost?

[rmorris]

Kirk,
I appreciate all the help I can get on this as this is targeted to be my first successful recurve. I will be going with your advice and getting rid of the taper and will also be looking into the .015 twill. Going to try the first one without it as once I get a weight for this design I should be able to calculate stack fairly easily going forward and that is where I will be interested in the twill.

As always appreciate everyone’s help and will try to post if I make any progress over the long weekend.

[Kirkll]

Don’t mean to sidetrack this thread.
Kirk , where did you get the .015 Twill and what did it cost?

it comes from China... i'd have to do some digging to find the contact, its been awhile since i bought some.  Crooked Stik found him on Face book.. he may have the contact info handy. i''l have to look.
but it was reasonably priced..... it's not the best looking carbon weave i've used, but it sure does the job on stability.   Kirk

[Mad Max]

Mark Tom ???????????????????

[Jon Lipovac]

Thanks Max. That’s the guy.
Chatting with him now.

[Mad Max]

 

[rmorris]

I am interested in the .5MM twil but will take that up on the new conversation.

I got a little work done today of the new bow. It will be canary wood for the back and belly of the riser and black limba for the center section. I am going to do blood wood/ Osage and maple mosaic with padauk and maple accent strips.

I was able to cut enough padauk out of that 3/4 in board to get enough strips for the accent strips and laminations in the limbs. I have used padauk in several long bow limbs and it works well with the exception of all the grain filling you have to do.