Friday, August 7, 2009


Not sure what happened to all the pictures. I'll have to go back and add them back in. I think that photobucket has corrupted them.

P.s Still waiting on the Smooth-on to glue this baby up.

Monday, July 27, 2009

Tip wedges

Made a couple of tip wedges over the weekend. I had never heard of tip wedges before, until reading a post about power lams and tip wedges over at the Pirates of Archery. Basically the tip wedge will add a bit of stiffness at the ends. The same goes for a power lam (which I'm not using here on this bow) which is placed at the ends of the riser and changes the dynamics of where the working portion of the limb will be i.e closer the the riser or further out in the limb. Experimenting with this, a bowyer can get the most efficiency and performance from the limbs.

I however, have to get a working bow completed before I can start experimenting with these different applications. Some of the guys I have spoken with will make several bows of a particular style before they achieve the right balance of flexibility, material and design which ends up suiting their needs for a smooth, fast and quiet bow.

I had a concern that my longer than average draw length of 30+ inches would be too much for a 62" take down. I consulted with Sixby, whom I've mentioned before and makes some fantastic looking (and shooting)take downs, and posed the question to him.

His response was that 62" is a good overall length for T/D's and that my concern with the draw length could be solved with the addition of tip wedges. These wedges, he said, should eliminate stacking to at least 30". His advice was to make them 6" long with a thickness of .040" tapering to 0" and to have at least 5 inches extending from the string grooves into the limb.

I had some left over bamboo flooring scrap and thinned that down to about .050 and then placed a small piece of scrap under that, which had a thickness of .040". I made a small sled just like the one I have for making the tapered lams and put it through the sander several times until I came close to my desired shape and thickness.

From that point I pretty much played it by ear, trying to get the tip as thin as possible and the taper as even and gradual as I could. The end result shown at the top of the page came out fairly well I think, with the tips being very thin. The measurements I took showed that thickness along the length of both wedges is fairly consistent and the thick end coming in at .040"

So that's it for now in terms of making the components that make up the bow. The next step will be to do a mock up or dry run of the glue up and then the actual glue up it self. I'm going to have to wait a couple days to get the smooth-on, but I did manage to find a distributor close to me which should help reduce cost by saving on shipping.

I'll do the mock up this week and if everything looks good, the final glue up early next week. Stay tuned!

Wednesday, July 22, 2009

Kicking glass

Had a big surprise yesterday. My black glass arrived from Kenny McKenzie over at Kenny's Custom Archery.
Man that dude is fast! Talk about customer service. I better hurry up and get some Smooth-on and grind those tip wedges!

Here's what I got so far. I know my bench is a mess. But I clean it like every week!

Limb wedges

Limb wedges are sandwiched in between the limb laminations and add thickness at the fades. This part will be the least flexible part of the limb. My Bingham's plans call for an 8 1/4" wedge. Mine will be made out of purple heart to match the rest of the bow.

I at first planned on making a jig for this until I ran across an excellent post by Sixby on the Pirates of Archery web site. His method for making wedges calls for cutting a 10" piece of stock diaganally with 5/8" on the thickest side and 1/16" on the thinnest.

So here (kinda hard to see) I marked 5/8" on each side. One side from the bottom and on the opposite side from the top, and drew a fine line with a small sharpie (As Sixby so aptly recomended) and took it to the band saw.

Slowly and carefully I cut on the line that was drawn and ended up with a pair of rough wedges.

Now we take these two wedges and put them back together but this time we do it with the newly cut surfaces on the outside so we can sand them. A drop of super glue in the middle will hold them together and I clamp it for a couple minutes to let it set.

I then run the whole thing through the sander to get all the saw marks smooth and that thin, 1/16" side will get down to a nice feathered edge. After that pop the two wedges apart using a twisting motion and your ready for sanding the individual wedges. Sixby makes some nice take downs and like his wedges to have a flat section that his limb bolts can sit flush against. Since he's the expert and I know snot about making bows, that's what I'm gonna do. (So there!)

Run them through until you get your desired thickness and a flat spot of a couple inches. Not having the complete build instructions I'm not sure how thick it's supposed to be. I think it's 3/8" and in Sixby's tutorial they were .250 I think. I kind of shot for the middle and ended up with .310 or so. Hey I'm improvising give me a brake.

Next I cut them to length, 8 1/4" on the band saw.

And viola! wedges are done dude! Next up are tip wedges and then I think we're about ready for glue up.


Laminations of varied material make up the limbs. This is usually a combination of wood with an outer layer of fiberglass but the core can also use carbon or special foam. My laminations will include a tapered lamination of bamboo flooring, a parallel lamination of the same and black fiber glass for the back and belly.

The thickness of the laminations will determine the draw weight of the bow and the taper will help define the curve of the limbs. Using the Bingham's draw weight chart, for a 1 3/4" width 62" take down recurve between 50 and 55 lbs. I need a thickness between .256 and .262

My .002 tapered laminations will come in at .120 in thickness at the thick side. The taper of .002 denotes a rate that for every inch in length the thickness will decrease by .002 inches. How to do that. Honestly I had no idea in hell as to how. But luckily the boys over at Pirates do and they showed me how. Thanks to J. willis there with his explination of the lam sled.

I'm sure those with a firm understanding of math and some nice shop tools could whip up some tapers from scratch, I have neither so I took the easy way out. First get a template or in other words buy a .002 tapered lamination. So I drop a line to Kenny over at Kenny's Custom Archery and he hooks me up with a .002 and a .001 lamination to use as templates. Quicker than you can say "you've got mail" they arrive.

Now what to do with them. If you said make a sled, your correct. The sled will allow us to put a square piece of stock on top of the taper and after running it through the sander (lam grinder) it comes out with the same proportions.

Look at my highly detailed schematic of this concept which is actually a rip off of a much more experienced bowyer, Sam Harper you can see that as the two laminations are run through the grinder, the top (non-tapered)lam gets gound down to a oposite mirrored profile of the template. Pretty cool huh? I thought so anyway.

Sam's site also gave me the concept on how to create the lam grinder as he had the same type of belt sander as I did. Thanks Sam!

Basically it's a table that that sits in between the raised arm of my belt sander and the motor housing. The front end (left) has a bolt with a nob on it that can be turned to raise the platform thereby pushing it closer to the sanding arm. In use I generally run a piece of stock through, flip it, run it through again etc. Some times I'll run it through twice per side starting at different ends then flip it and do the same to the other side, turn the nob 1/8 to 1/4 of a turn and reapeat until I get my desired thickness which is checked with a set of digital calipers. It's not pretty but it works pretty well.

Some guys have some pretty nice set ups using drum sanders for their lam grinders, like Jim Willis over at Pirates, but I'm a garage ninny and have to make use of what I have.

Now for the sled. Jim clued me into this set up where he used double sided tape to secure the template to a piece of material (wood, aluminum what ever) I used a scrap piece of aluminum that was straight and level, then tape some 150 grit sandpaper on top of that to keep your square stock from moving around. The whole thing goes through the sander as one piece.

This is a picture of my sled in the grinder. The thinest side is in the front (left) with the thickest side to the right. When I put a piece of square lamination on top of that and run it through the sander (many times) my newly created tapered lamination will have its thinest end to the right and its thickest to the left or front of the sled.

The prallel laminations are put through the grinder without the use of any sled until I reached the desired thickness.

Next up are the limb wedges.

The riser

While not absolutely necessary, some power tools make this endeavor much easier. I say not absolutely necessary because there is one person that comes to mind that made a couple of fine take downs using a hand saw, hand drill and his only power tool was a sander. I am speaking of Mr. Hera in Taiwan and you can find one of his build alongs here. Truly excelent craftsmanship.

I on the other hand can use all the help I can get, and even then I have trouble at times. Over the course of time I have aquired tools for the project that are basic for cutting and sanding. Being on a tight budget and a garage ninny I bought or was given tools that are on the lower scale in terms of price, these include a Craftsman 10" Bandsaw, A tradesman 10" tablesaw, a 6" belt sander from Harbor freight and a drill press, also from harbor freight.

Be aware that you get what you pay for and higher end tools with increase to a degree your accuracy and ease of working, but these have suited me fine(so far) for my entry level work.

These tools will be used in a variety of ways but to prep the necessary materials I need to cut/rip my 3/4 piece of Jabota wood so that I can make a riser that is 19" long, 1 3/4 thick and 3 3/4 tall. I'll add an accent strip of Purple Heart as well but first I must cut the Jabota. Of course I don't have a picture of this but I will mention that because of budgeting concerns I bought the best board I could find for the least amount of money. This meant that I had to plan out my cuts not only interms of length but thickness to make sure that I could get the dimensions I wanted.

Cutting out the pieces for the riser were done on the table saw. As I said I also wanted an accent strip to make it more interesting (pretty). This was done by cutting 1/2 pieces of purple heart and jobata and sandwiching them in between two thinned pieces of bamboo florring and glued up.

These cuts were done on the tablesaw and really should have been done on my band saw. The glue lines aren't all that great and I think part of that is due to the quality of the cuts to the small pieces. At the time all I had was an 1/8 blade for the bandsaw which is totally inadequate for my use. Since then I have put on a 1/2" blade which works much better.

I then glued it all up and clammped it together with Urac-185 which is a good glue and doesn't need to be baked but does have a brown color to it. The rest of the bow will be done with Smooth-on which is clear.

After the glue was cured I cleaned up the riser with a sander on the drill press as well as the belt sander.

Next I had to cut the angles for the riser fades. For this bow the plans call for a 20 degree angle. I made a jig for the tablesaw that would create this cut. I don't have a picture of the jig but I do have a picture of the result.

As you can see I totally jack up that cut. I can atribute it to a couple of problems that were not only avoidable but were due to a complete lack of planning on my part. The jig I made, while positioning my riser at the correct angle was tested with a small piece of MDF (press board) cut to riser size. What I didn't acount for was that the small 7" blade I have on my table saw was not big enough to cut completely through the riser. With some advice from the guys at Pirates of Archery They advised just re-cutting and adding in the thickness lost with another piece of wood.

Ok simple right? Just change blades to a bigger one that will cut all the way through. NOT! I tried for a couple hours to remove that old blade. I sprayed it with WD-40, pulled on it with the supplied wrenches, said prayers and ended up curled in a little ball of sweat on the garage floor admitting deafeat and crying for mercy!Nice to know I'll have that blade for the rest of my life.

OK plan B. Table saw is out of the question unless I want to make two jigs for one cut. I don't, so I'll try with the band saw. My concern with the band saw is, one, that it is a small band saw and wasn't sure it was up to the challenge and two, that the hardness of the purple heart would dull my blade real quick. Let's give it a shot anyway.

First a jig. Using my template riser made from MDF I glued up the angles for my jig.

As you can see the board holds the riser at (in this case) a 20 degree angle to the side of the jig. Here's a picture of the cut riser in the jig.

With this small of a band saw it was important to cut slowly and not force it through. A small piece of steel stock was clamped to the edge of the table to ensure I pushed the jig through straight.

Next I glued on a couple of pieces to the fades to make up for the extra cut I made and the loss of width.

Lastly in talking again with the Pirates, the glue lines were a concern and they suggested that I fill any gaps with sawdust and super glue. I did that and sanded it all smooth.

I really hosed this riser and made a mistake at almost every step. But hey, I learned a lot and hopefully it comes out ok in the end. Next step making laminations for the limbs.

Tuesday, July 21, 2009

In the begining...

I originally intended to start this blog in the winter of '09 to follow the progression of my first attempt at a laminated bamboo bow or tri-lam. This particular bow had been sitting in the garage for, oh.... three or four years, orphaned to a shelf at which I would occasionally peek at and say, "one of these days."

Long story short; I picked up the bow again after removing a lamination that had been damaged in a tillering error and tried again. I thought that I was actually going to get a shootable bow but alas, during a pull on the string during tiller "CRACK!" You can see the damage here on the back.

While I was dissapointed, I wasn't real surprised. Heck the conditions in the garage, ranging from 20 degrees to close to a hundred with humidity levels at times through the roof, over the course of a few years probably didn't help much.

What I really wanted to make was a nice fiberglass bow, but the whole idea was (is) somewhat intimidating to a novice. Over the course of the next few months I started looking at build-alongs on the net and soaking up as much info as I could. I already had a set of plans from Binghams Archery for a takedown recurve (absent the process for actually making the thing) so Ithought I'd go that route.

Starting here I'll post my progress on making this bow and the problems encountered. This is all a learning experience so technically, the more mistakes I make, the more I learn.... at least that's what I'm telling myself to justify any mistakes.

So sit back, relax and let the show begin. If nothing else you might get a laugh out of it.