Posts by Wood Guy

Quote from Tin Man

The UHMW will cut cleanly with very sharp tools, but sometimes you get a little fuzz at the corners. It can be removed with a razor knife and a steady hand.

Alternatively, Wood Guy makes short Delrin muzzle inserts that would fit into a USPS small flat rate box. Not sure what he charges for the inserts, but shipping would only be $5 anywhere in the U.S.

I charge $12 for the dovetailed delrin muzzle guard plus $5 for shipping anywhere in the US. It has an 8 degree x 11/16" wide dovetail. You install it first, then cut the track right through it when you cut the track. Here's what it looks like.

Quote from 808natural

Thank you Wood Guy for all of that knowledge!!
I guess uhmw is out of the question. I dont think its worth the trouble if i can do the same thing with delrin, with half the headache. Im thinking about doing an all wood track and will take your advice of adding delrin to the muzzle. But will it be a PITA to put a coat of epoxy on the wood track. Im thinking that putting an even coat of epoxy will be very difficult. Maybe im just putting too much thought into it.:rolleyes1: Would you give a little input on how you finish your tracks?
Thanks again Wood Guy!!!
Oh yea, Tin Man. I hear a lot of talk about poured epoxy tracks, and the only type of epoxy i use is West Systems 2 part epoxy. What are graphite and microfiber fillers? Do you add these to the epoxy? And what is its purpose? Pardon my ignorance.:D

mahalo bruddah Keoni

I don't build a lot of guns, but when I do I use teak, with an oil finish. I like the way teak looks, and water doesn't hurt it. It's also very easy to wipe a fresh coat on it to restore any scratches the gun accumulates. I just put a coat of oil on before inserting the trigger mech, handle, muzzle guard and other stuff the final time, then do another 3 or 4 coats of oil after assembly. Using 320 grit sandpaper will give it a nice luster. To me, if I'm going to spend $200- $300 on parts, and 30- 40 hours or so in labor building the gun, it's worth the extra $20 or $30 for the wood.

That said, more guys probably use woods other than teak or carbon fiber now than teak, and an epoxy coating is probably now more common than oil, so I'm probably a throwback who is hopelessly stuck in the past. ( Damn it, though, those teak guns sure are pretty!)

I try to look for the simple solutions, and a wood track, delrin or g10 muzzle guard, with an oil finish is pretty simple. I hunt mostly small wrecks in Pensacola Bay and we beat our guns up pretty badly, so the oil just makes it really easy to make them look like new again.

Lot's of guys know way more than me about epoxy coatings, though, so maybe some of them will jump in and go into some detail about how they do it.

I had overlooked the poured epoxy track in my earlier post, Dan, so thanks for bringing it up. Tin man summed up my feelings pretty well on that. It just seems easier to me to go the wood or delrin route, but they all will work if done right. With the carpentry background it would seem like the wood and dovetailed delrin muzzle guard would be less of a learning curve for you.

A wood enclosed track in a wood gun is pretty straightforward- you just cut the track with a straight router for the neck and follow with a ball cutter. If you go that route I would recommend installing an 8" or so piece of delrin at the muzzle to protect the muzzle if you drop the gun or shoot too close. I make the muzzle guards with a dovetail but being a carpenter you could make one yourself easily enough.

If you go with a full length track I would highly recommend a delrin over the uhmw track because of it's machinability. UHMW can be machined with sharp tools, true enough, but try to sand, file, or steel wool it and you'll quickly see why I recommend the delrin. The full length delrin track is just a longer version of the muzzle guard. You cut a dovetail in the wood, cut the delrin in a matching dovetail, install it, then cut the track. After the track is cut you put a #4 screw recessed in the track near the trigger mech to hold it (one end only!) and you're done. You can leave it a little proud if you're shooting metal wishbones, or make it flush with the top.

There is one other option you didn't mention. You can make the track out of g10, which is a resin enclosed fiberglas. While it's a little heavier than delrin, the advantage is that it can be epoxied into the wood. This means you can cut a square slot instead of a dovetail, and just glue the square g10 bar in the slot. You can route and machine it like delrin, although carbide tipped bits need to be used unless you just like to resharpen bits.

Hope this helps. There are a lot of other ways, I'm sure, and differrences of opinion on delrin vs UHMW. I've worked quite a bit with the delrin, and I know it works. The g10 is really easy, however, and being able to glue it makes it that much easier.

Whatever you use, I would open the last 3" or so at the muzzle to an open track to make loading the shaft easier.

As you will find out, building a custom speargun becomes a very personal thing, so listen to it all, then build what YOU want to shoot.

Nice job, Lunker. Thanks for sharing.:thumbsup2:

There are some cameras out there that will shoot at 1000fps, and are moderately priced. Problem is that at 1000fps the definition is at something like 240 x 240, so you need pretty good light, amd things are probably kind of blurry if you blow them up in size. Hopefully there are some spearos who are shooting high speed video now and can share what they are using. With all the stuff out there on u-tube, you just gotta know there are moderately priced cameras that will work for videoing a muzzle or tracking a spearshaft. It's just a matter of finding the right camera the first try.

Ok, Jeff, you knew it would be just a matter of time. Does anyone have any info to get me started looking for a high speed video camera? I don't know the first thing about what frames per second I might need, or whatever else might be important. My sense is price will go up with speed, but what speed would I need to track a spear shaft, and what resolution would I need to get clear enough video to be able to analyze? I'd appreciate any info anyone might have. I tried the search but didn't come up with anything.:confused2:

Quote from Marco

I have a friend in Spain that built a very nice rollergun, and he told me that with thicker/heavier shafts is when you realize the full potential of the rollerguns. He uses a single 5/8 band streched to 3.5 x factor.

I can post some pictures here is you want.

Please do! I've only started tank testing, but the 5/16" shaft seems to get much better penetration than the 9/32". What diam. shaft does your friend shoot?

Thanks, Lunker, but you're making my efforts sound way too noble- I just want to figure out what works and what doesn't, and if a few urban myths can be replaced with actual data along the way that's ok too. As long as we don't stop drinking beer and debating SOMETHING! :toast2:

Quote from Marco

I don't know much about rollerguns, but what I've seen is that with just one band, you get enough power.
Isn't much complication to use 2 bands?

I'll like to see the gun fully rigged though.

You are probably right. Two bands are definitely more complicated than one on a rollergun, and for shooting fish at fairly short range, one is probably plenty. This gun is a learning gun for me, however, so I wanted to experiment with several options, such as hard metal wishbones, or soft, one band or two, does it matter if it's the front or rear band, effect of the compound lever on penetration, etc. I see this gun as sort of a test platform to actualy see in my little test tank whether this sort of stuff makes any difference, or is academic. I understand this is a fairly unscientific approach, but if I keep everything else the same, I can probably draw some conclusions.

When I fire a 9/32 and a 5/16 shaft, for example, I am getting almost twice the penetration into the target with the 5/16" shaft. I get the same results with one band or two, at 7' and 11' (from the muzzle). I wouldn't have predicted so much difference. I fact, before I actually shot the different size shafts I couldn't decide which I thought would have more penetrating power. The 5/16 shaft has more mass, but has to be moving slower, has more drag going through the water, as well as through the target, etc, etc. Being able to make actual test shots helps cut through all the theorietical crap that has an answer so dependent on assumptions that it really doesn't mean much.

There are probably a number of very good reasons most rollerguns have one band, including complexity. After I've played around with this gun (and a few others), I'll probably understand what really works and what doesn't. Then I think I'll be able to build a much more optimum gun for the use intended. At least, thats the idea.

I think I got em all back. I got all cute and was going to organize my photos in photoshop, and severed the link without realizing what i was doing. I re- downloaded from my computer hoping it would recognize and re-establish the link. Looks like it dit.

Two things:
1. Cleaning up and organizng can be bad.
2 Even a blind hog finds an acorn once in a while.

I used a compression spring to make the lever latch engage:

With images of the little chainsaw still in my head, and knowing I would be bumping the gun around in the test tank, I also installed a safety.

Here's how the lever turned out:

In the next post I'll show how it looks rigged out.

Made quite a few changes since I last posted on theis thread.

I wasn't happy with having to move 4 band ends to get the compounding effect after loading, so I decided to install a lever. I wanted to push the lever toward the muzzle so, by having cables run from the end of the bands through a roller and back to the lever I could maximize band length and stretch.

Here's what the underside looked like before the change:

"It's a terrible thing to see a beautiful theory brutalized by a vicious gang of facts!"- Unknown. I really should have thought it through a little better. Pushing the lever forward required placing the other hand on the muzzle over the spear shaft, which was now in the loaded position. The reversing pulley also created additional drag which made it harder to cock the lever. After visions of the pins on the shaft going through my hand like a tiny two toothed chain saw, I scrapped that idea and decided to build the gun with the lever pulled back toward the handle. Much safer. The little gun is now starting to resemble some kind of mosaic with the different colors of teak.

Of course, in order to move the cocking lever under the gun, the line release had to be relocated to the side. I used the same resetting tab at the bottom of the mech, and used the previous line release slot under the gun for a locking lever to hold the cocking lever in place after the compounding lever is in place. Whew!

Here's the handle with the original line release:

Here's the final version (side release).

More in the next post.

Look what I built you, honey! It's a lap pool for koi! I love it. :laughing3::laughing3:

Total length is 24'. The look on the neighbors faces is hard to discern.... fear, concern, confusion? :laughing3:

Quote from Tin Man

I know that look. It's very rewarding :laughing:

Outstanding project. But we can't have you undoing years of drunken speculation by recklessly throwing data around . . .

How about an additional small window in one side, that would allow filming the muzzle reaction during the shot?

Of course, we could always replace drunken speculation with drunken testing- just to maintain the same level of credibility.

I don't have a high speed camera..... yet!

Hi Y'all,

I got tired of waiting for the vis at my dock to get good enough to do some testing on my Dirty Water Rollergun, so I made a "test tank" instead. I tried to keep the cost down since it is really a means to an end (testing spearguns) rather than the end itself. It's not elegant by any means, but since I was after function, beauty was secondary. The shooting end can be seen from the street, and it's got the neighborhood walkers and security wondering what the hell the crazy guy is up to now. I love it! :laughing3::laughing3:

The tank is made up of 3- 8 foot sections that are 16"high by 16" wide. Those dimensions were chosen so I could get a section out of a 4' x 8' piece of OSB. I had 3 pieces of OSB that I had been kicking around the shop for years, so that's what I used. I used 2 x 4's and 2 x 2's for framing the bottom and sides for support.

I tried waterproofing the OSB with elastomeric paint (used to waterproof stucco) but that didn't seal the holes in the OSB, so I ended up using liquid rubber (used on roofs). That did it. A clear 1/4" piece of lexan and some "cabinet gloves" rounded out the ensemble. I had to use liquid tape to seal the gloves, but they still leak like a sieve, so I'll need to go to plan "B" on the gloves. They work good enough to try the tank, however, so I'll revise the gloves later.

The target is a 16" high x 16" wide x 12" thick foam archery target that is clamped down with bar clamps to keep it from floating (Hey, I said it wasn't elegant!).

So, with the neighbors furiously reviewing the neighborhood covenants, and my beloved wife of 42 years muttering under her breath, I commissioned the test tank today. Here are some pics of the tank. Results of the testing will be posted in the "Dirty Water Rollergun" thread as I go along. If anyone would like more info on how it is made, cost, etc, let me know and I'll be happy to oblige.

I'll try to get some more meaningful shots tomorrow.

Price is 748 euros, which is about $1000- $1050 US according to the link I saw.

Thanks. I'll re-try with the larger pics.

If I make em small enough, nobody can see the screw-ups.:laughing3: How do you make them bigger?

Got a few more pics today. I couldn't shoot at a target due to lack of vis at my dock, so I shot a few times into the sand and at least got to see how it fired. No shooting line entanglements, etc. I only shot from the back pin (per Phil's recommendation), but I shot from both the single and 2nd stage position. The solid wishbones worked ok, and I like the sight line they allow along the shaft. I'll probably leave them on and try soft wishbones the next time I have to change something on the bands (Phil mentioned that hard wishbones often cause the tie lines to wear quickly so that might be the first thing I need to change).

Shooting line and bands functioned well and there were no problems with the bands interfering with shooting line, in spite of their close proximity.

Once I have the water clarity I'll see how the accuracy is. I didn't see any problem with how the shaft was leaving the gun, but without high speed photography or a target I can't really tell where the gun is shooting.

The bands lie pretty good along the top and bottom, especially with only one band. I've got 3 wraps on the shooting line right now but I'll wait until I can shoot it in the water and see how much of a pain 3 wraps are before I decide whether to shorten the line or not. If the gun shoots straight and has the power, I might leave 3 wraps on it since it's so short.

Here are a few more pics showing how the bands and shooting line lay. I've got some tweaking to do on band length, but these are the first attempt. The bands are so short a little change makes a lot of difference in the stretch ratio.