[alfshooter]

Thank you very much, Mr. Henry great information and input from peers fantastic, I learned a lot.
greeting

 

[Alex Jacob]

Blinking flip, mother! This formula works a treat. I've tried a few dimensions either side but 4:3 inches gives a smooth, accurate and fast shot. Should be as it's fairly close to the golden ratio, which would be about 4.3:2.7 for a 7 inch brace height.

I found I had to really strangle the tubes to avoid slippage though. I tried tying the loops with bowlines but getting them the same length is as tricksy as Bagginses. I've settled on a small overhand knot in the tubing to stop the twine from slipping and it's working fine so far.

 

[qute10]

Any chance of those draw weights henry?

 

[pgandy]

[sub]I got my first 1745 rubber yesterday. I still haven't completely explored the 1842 putting it on hold until I could get more 1842. Being satisfied with the results of the 1842 I decided to save what I had left until I could replace what I had used before more experimentation. I have more enroute out there somewhere. [/sub]
[sub]As for the 1745 I like it and find it more powerful than the 1842. I found one 1745 band set that gave the same energy as the 1842 that I use for general purpose. As a comparison; the difference was that I was stretching the 1745 388% vs the 1842's 517%, leaving me to believe longer band life and less expense. The trade off is 21# pull vs 15.5#. I consider the 21# pull good PT. When stepping it up to about 25# I zipped hex nuts through tin cans with no problem. One can is pictured below.[/sub]
[sub]That is about max for me and I don't care to shoot it many times. I can pull more but the fool frame of that Dankung bites into my hand. Also I began having trouble holding on to the pouch and needed large balls or double hex nuts. Perhaps in time I can build those finger muscles up. [/sub]
[sub]The Dankung is now my most used slingshot, but only because of the way it carries. And I like the quick band change ability. Having said that I feel that I should say: My PS slingshots will out shoot it and are more of a pleasure t shoot. They certainly shoot smoother. I get the same accuracy at 40' with my PSs as I do at 30' with the Dankung. I get the same power with the PSs as I do using the Dankung with several band sets requiring 18-19# pull compared to Dankung at 25#. I think that I haven't found the right Dankung formula yet. Band life is shorter with the PS in the upper ranges though. After wearing the second hole in my pocket with a PS I started leaving them home in favour of the Dankung that I can easily conceal under my shirt. For an afternoon of shooting fun the PS has it beat, hands down in my book. [/sub]
[sub]

[/sub]

 

[pgandy]

Here's a photo of a coconut made after the above post with the 1745. One shot nearly halved it. And I haven't reached its maximum potential yet.

 

[Henry the Hermit]

Here's a photo of a coconut made after the above post with the 1745. One shot nearly halved it. And I haven't reached its maximum potential yet.
View attachment 15962

No surprise there. My son put a .50 cal lead ball through the husk and shell of a green coconut with double 4:3 taper 1842s.

 

[Henry the Hermit]

Any chance of those draw weights henry?

Sorry I took so long. 4 strand 1842 pulls 16.5 pounds at 32 inches. I have to make up some more 4:3 sets.

 

[qute10]

Thanks henry be interesting to compare the 4/3 draws to the 10mm multi strand pseudo tapers (tbg) that i am currently obsessing about.

 

[Henry the Hermit]

4:3 1842 pull weight = 10 pounds 1 ounce at 32 inches.

 

[qute10]

Wonderful thankyou henry its too cold to chrony here at the moment and i havent rigged up ir leds to chrony inside yet but have great hopes for these 10mm multis very smooth and feel/SOUND fast by comparison to my own dankung tubed 4:3 setups.Mine run at 12.7 but i think they are 1745s (cant get 1842 at a reasonable price at the moment without going to dankung anyhow).

 

[Alex Jacob]

If 1842 tubing is potentially faster than 1745, how does it compare to 2040? I've been using this for straights (simple loops), cos there's less hand-slap than with 1842 and keeping the 1842 for tapers.

 

[Henry the Hermit]

If 1842 tubing is potentially faster than 1745, how does it compare to 2040? I've been using this for straights (simple loops), cos there's less hand-slap than with 1842 and keeping the 1842 for tapers.

If you're getting hand slap, you need heavier ammo or a different frame. I was a bit disappointed with early tests of 2040. I expected more velocity with light ammo, but actually get a bit less than with 1842. Maybe I did something wrong. I still have almost 10 meters of 2040, so plan to do some more experimenting.

 

[Henry the Hermit]

I think I have discovered the reason my bands are breaking at the tie points. I use hemostats to clamp the tubes while I stretch and tie them. I finally (yeah, I'm a little slow.) noticed that the edges of the hemostat jaws are a bit sharp. I now have covered the jaws of a small set with 2040 tubes and will see if that resolves the problem.

 

[August West]

Henry, mine are breaking in the same place, right in front of the tie. I use hemostats as well, I will try the tubing too and see if it helps. Thanks, Chris

 

[Henry the Hermit]

Henry, mine are breaking in the same place, right in front of the tie. I use hemostats as well, I will try the tubing too and see if it helps. Thanks, Chris

Chris, today I used a very skinny hemostat to put an 1842 sleeve on the tie point. I'm hoping that will protect the tie from the string. Not my idea, just following up on a suggestion made earlier.

 

[August West]

Right now I am trying something a bit different to see if I can improve the longevity. I am using a closed loop chained to a double loop to try still have the tapered effect. I have went down to 20/40 tubes since I am doubling them, so far it seems to be working well but I am not that many shots in. Chris

 

[Alex Jacob]

2040 plain loops are what I use as backup to the 1842 tapers as both handle M8 hex nuts nicely. When it's a bit warmer I'll get some casting kit and brew up some .36 and .50 ammunition (cheers Charles for the buckshot mould - as we limeys spell it - info) then it's back to testing various tube sets.

To stretch the bands prior to tying, I've been using a couple of strong tarp clamps strapped to my knees (in lieu of morris dancing bells for 'tis all great folly). Not my idea - cribbed it off a youtube vid but can't remember who's. I've filed off the jaws a bit and put a layer of gaffa/duct/Jesus tape on the end. The clamps aren't themselves strong enough so I put a ring of low-stretch cord around them and pull via that. Doing so tightens the jaws.

It works well enough and only cost a few bob and a couple of minutes to assemble but the elegant solution would be a jig like the one I saw on another vid I can't find again. It consists of two spring-loaded doors and posts which wedge shut against the pull of the bands. A couple of yacht cam cleats on a board might do the same thing.

 

[August West]

Henry,
How are your longevity tests going? I have started using cuffs of 17/45 with my constrictor knot directly on top with no prestretch. Been shooting this set up for 3 days or so and so far am really liking it, I have had zero slipping, I haven't been keeping count of my shots but I am still on the original set and have been shooting pretty heavy, so far so good. Chris

 

[Henry the Hermit]

Henry,
How are your longevity tests going? I have started using cuffs of 17/45 with my constrictor knot directly on top with no prestretch. Been shooting this set up for 3 days or so and so far am really liking it, I have had zero slipping, I haven't been keeping count of my shots but I am still on the original set and have been shooting pretty heavy, so far so good. Chris

I got kinda side-tracked into power bands for a week or so, but I have one set of single 2040 that I use with .30 lead and it has several hundred shots on it. I get a very consistent 200 fps with an ear anchor with this combo. I have not started testing the pseudo-taper 1842 set with cuffs yet.

 

[Henry the Hermit]

Here are some of the results of yesterday's testing. I shot single 2040 and 1842 tube sets in several sizes of ammo. I also shot pseudo tapered and doubled 1842 sets, but won't post those results until I have done the same with 2040. I shot a series at each weight over the Chrony first at 30 inch anchored pull and then at my maximum pull of about 39 inches. I did not test 1745 tubes because I don't like the way they feel, and I get all the speed I need with the softer tubes. Here are the first results.

.30 cal lead ball (39.7 grains)*
2040 single - at 30 inch pull, average velocity 208.80 fps, at full draw 254.95 fps
1842 single - at 30 inch pull, average velocity 202.88 fps, at full draw 247.93 fps
Interesting to note that at this ammo weight, 2040 is faster than 1842.

.363 cal lead (74 grains)*
2040 single - at 30 inch pull, average velocity 176.80 fps, at full draw 214.83 fps
1842 single - at 30 inch pull, average velocity 188.12 fps, at full draw 216.48 fps
At this weight, the heavier bands work better. I plan to shoot some 3/8 steel later today and am betting that performance is nearly identical at that weight (53 grains)

*Note - I weighed 5 balls and divided by five to get an average weight.

Here's a picture of the band sets, 2040 at the top.