Finally got to do some preliminary testing on my extreme FOC cedars. Fly great, and seem to hold up quite well.
Here's the scoop. Started with 11/32 cedar shafts, 9-inch tapered to a 5/16 Bohning classic plastic nock. About 28 7/8 inches to back of point, spined 70-75#. Fletched and untapered, they weigh about 425 grains. Four control arrows weighed 580-584 grains with a 160 grain field point, yielding an FOC of 14.5%
To get to extreme FOC, I tapped another set of 4 almost identical arrows with a 3/16 inch drill, using a jig to hold the shaft perpendicular under a drill press drill bit. I drilled the shaft 2 1/2 inches and epoxied in a three-inch section of 3/16 inch steel rod, then cut the rod and sanded it flush with the end of the arrow and finally tapered the arrow. A 125 grain field point, yielded arrows of about 674 grains and 18.5% plus FOC. With 160 grain field points, the shafts came out at 708 grains and 20% FOC plus/minus a few tenths.
Shot them out of a 62# Howard Hill at a 3D course today. They flew well. To test their durability, I shot each arrow into a 1-inch plywood back stop. In each instance, the arrows bounced back from the plywood undamaged. Unfooted arrows usually break when I try this. I also shot one shaft into a live oak tree (intentionally). It stuck with no damage to the arrow. I did manage to break one shaft by glancing it off of another large oak tree trunk (unintentionally). The internal footing stayed intact inside the point, but the shaft split nearly it's entire length.
Obviously, more testing needs to be done, but my initial impression is that these arrows shoot very well and they're about as rugged/durable as one can get out of cedar. The steel internal footing seems to strengthen the shaft behind the head, preventing breaking there. The steel internal footing also yields more FOC than external wood footings. Wenge footings, on the same spine, diameter, weight and length shafts yield 15%-16% FOC with 160 grain broadheads.
A couple of notes re construction. Despite using a jig, made out of wood, I was not able to get the holes perfectly straight in the shafts. I have since devised a steel jig that could be used with a hand drill that will yield perfectly centered holes, but I will need a machinist to make it.
In epoxying the steel rods into the hole in the shafts, I applied too much epoxy to the sides of the hole, which was forced to the bottom of the hole as the steel rod was inserted. In three out of the four cases, when I pushed the rod home the last 1/4 inch, the epoxy broke through the shaft wall. (A 3/16 hole in an 11/32 shaft leaves only 5/64 of shaft surrounding the steel footing, if the hole is perfectly centered, somewhat less if it's not.) Regardless, I expect the cured epoxy rendered the area sound and strong. However, less epoxy, or perhaps none at all, or perhaps drilling a 1/64 hole perpendicular to the shaft at the base of the hole to let excess epoxy escape, might be better approaches.
This isn't a new idea, of course. Others have talked about increasing an arrow's shafts weight and strength by drilling out the end and inserting a nail of one size or another. The 3/16 steel rod, available at hardware stores, is just a tad larger than a 16 penny nail and weighs about 48 grams per inch. My 2 1/2 inch internal steel foots weighd an average of 122 ounces. Many hole diameter and length options are possible, and likewise, other materials such as brass, threaded rods, etc.
Kind of fun for those who want to mess with it. I think it yields a pretty good arrow to boot. Looks like we woody shooters won't have to switch to carbon to get extreme FOC. Have at it. :bigsmyl:
TTT
Good job Orion-lots of great details.
I'm very interested in high FOC woodies, thanks for your hard work! :thumbsup:
How do you do your point taper, just make it shorter?
How about a smaller hole with lead wire to prevent blowing out the sade and allow more slop? I suspect the epoxy isn't necessary.
Wow! You were busy this afternoon Jerry! Pretty interesting stuff. Are the 70-75's stiffer than normal for you? Or did you move up?
Jerry,
You are on the track of the method I THINK will prove the easiest and most practical method of getting Extreme FOC on the woods. If you could still get Forgewoods, a modification like that would probably get you up into the mid-20% FOC, and YOU should ALSO be able to do that by adding it to a footed shaft that had a light-weight rear shaft.
Ed
TGMM Family of the Bow
Slo Mo: I taper the same way as normal on a sanding disc. Take it right down to the diameter of the steel. Taper is just a little shorter than normal, probably 7/8 inch plus. I normally taper about 1 inch.
Steve: Lead would definitely increase the weight, but wouldn't do much for strength. In fact, since it would contribute very little to strength, and given that one is drilling out part of the center of the shaft, it might actually weaken the shaft. Epoxy would help stiffen and strengthen it.
Joe: I usually overspine by 10-15 pounds on all my bows, so this is what I shoot out of 60# bows. By the way, the footings did not change the spine.
Ed: I think adding the metal internal foot to a hardwood footed shaft would yield another percent or two FOC. By changing from a 125 grain to a 160 grain point, I increased the FOC 1 1/2 percent. Best I can tell, a standard length hardwood foot only adds about 20-30 grains. A fairly heavy cedar might run 14 grains per inch; hardwood, about 19-20 grains per inch. Given the tapering on both ends of an 8-inch hardwood foot, one probably ends up weightwise with the equivalent of about 4 inches of hardwood, which is substituted for four inches of cedar/softwood. In short, one is replacing a piece of wood that weighs about 56 grains with one that weighs about 76-80 grains. Of course, the hardwood foot could be made longer. And, even though the weight gain isn't that much, the hardwood foot would be stronger yet.
Jerry,
Yes, what I had in mind was a longer hardwood footing with a dense wood, such as ipe or ironwood, and a light weight rear shaft; something like silverwood, then your steel rod and a heavy BH up front. I'm believe that a heavy single-bevel BH, designed specifically for getting higher FOC on woods, is in the design stage.
Ed
TGMM Family of the Bow
QuoteOriginally posted by Dr. Ed Ashby:
I'm believe that a heavy single-bevel BH, designed specifically for getting higher FOC on woods, is in the design stage.
You're such a tease! :biglaugh:
Tim, I have to amuse myself some way! :bigsmyl:
Ed
TGMM Family of the Bow
i think orion is working on making your standard cheap shaft into a extreme foc shaft. which i find interesting cus at the price for footed shafts who can blame him, orion what about some allthread so you could screw it in and out. I bet with a stiff enough shaft with a little steel rod making it probably a little stiffer you could put on a heavy enough head to get a pretty high percent.
oh and dr. wonder if you could put in a good word for this new one to be in lw
Ed: Weren't they in the design stage a couple of weeks ago? Should be in production by now. I'm anxiously awaiting their arrival. :D
jr: I think threaded rod would work. I experimented a little with 1/8 inch threaded rod. As I remember I couldn't find it in 3/16. Maybe my hardward store just didn't carry it. 1/8 was pretty light. My shooting partner just took a fine thread long machine screw and screwed it in, after drilling a hole first, of course. I think 5/32 would be the ideal diameter for a 11/32 shaft, but I can't find much in that diameter. If you try it with threaded rod, will need to keep the tap hole almost the same size as the outside diameter of the rod. Otherwise the threads will have a tendency to split the shaft. Drilling the hole the same size as the threaded rod, and then putting some epoxy on the threads would make a helluva bond.
Jason,
I've put my 2 cents worth; both!
Jerry,
Patince, grasshopper, patience! I'm hoping they make it by fall but, as I told them (?), better to take the time to get everything right than to rush one onto the market that isn't up to sniff. Hope they heed that.
Ed
TGMM Family of the Bow
who is making this broadhead? and will they make it in standard to heavy weights 150 160 or so? ive been looking for some like grizlys i think tuskers are probably the closest but it would be nice to have some available in the usa.
sorry kinda off thread topic
Jason,
If I tell you WHO, they may be forced to kill you! :p . There MAY even be more than one potential maker. :D
As I understand it, plans are for a series; from somewhere around 160 grains on up.
Ed
TGMM Family of the Bow
:bigsmyl: :bigsmyl: :bigsmyl:
I had a video (not sure where I put it right now) that showed how to home-make a jig for drilling out the end of a POC shaft. It then went on to show how a short length of alum. arrow shaft could be slid over the end and a standard insert glued into the end inside the wood shaft. Wouldn't this increase FOC, beef up the insert, and allow for screw-in BHs all at once?
I will dig around for the video. Seems like it was a how-to sort of deal. Showing how to make arrows and flemmish twist strings. It was a big fella with a beard doing the instruction. Maybe I can find it.
OkKeith
whoa there doc, thats a long shot for one of those telephone poles you shoot to reach me up here in ak, haha whats the harm in spilling a little of the bean, if you pm me i promise i wont tell, anyway they sound like just the ticket.
Jason, note that I said "THEY may be forced to kill you". You just might be in range too! :saywhat:
Ed
TGMM Family of the Bow
If you want to foot a shaft with aluninum it`s easy. For a 11/32 shaft use a piece of 22 size al. shaft,I like 2216. Taper the wood shaft back about an 1/8" and just start twisting the al. piece on the wood. As you are twisting you will note it is cutting off it`s wall thickness from the wood. Keep turning the al. piece till you`ve cut it back about an inch. Hot melt the al. piece onto the wood, add any weight you want inside the al. piece, glue your insert in and your ready to go. You will notice that the fit of wood to al. is perfect as both the wood shaft and the 2216 shaft are exactly the same dia. For 23/64 just use a 23 sized al. such as 2215.
I`ve done this for a long time but not for FOC but to repair broke shafts and add weight so screw in Judos weigh what my broadheads weigh. Hope this will help you out as it is easy to do. Bob
Great research Orion! Thanks for sharing the results of your work.
I'd bet I'm like a lot of folks here... trying to find a way to get the high FOC without giving up on my wood arrows. Looking foward to what is to come...
-Vig
Orion your numbers are right on.......I got some footed cedars-Wenge and Purpleheart-FOC was 14; but they are very pretty and have some additional strength where it counts. Keep us posted on the iron rod developments. That idea has got legs!
What I meant was FOC was 14 including a 160 Grizzly.