53 replies to this topic

[shmmee]

'Darksircam', on 25 May 2011 - 05:13 AM, said:

Did some testing with hoppers.
Homemade hopper as well, but there's nothing that the dart may catch on. CPVC+PVC slant, glued on the outside only.

I believe it might be the friction from the silicone tip preventing it from feeding fully. It takes two shots to fire from a BritHopp - when shook, it fired in one. But with a normal hopper barrel, I either fired it in one shot or it didn't fire at all. The dart took some persuading to fit into the reamed out barrel.

Tried to test by covering the tip with some material, but the chemical/adhesive resistance of the silicone tips works against us again. Modge Podge (craft glue/sealant, basically school glue) failed - did not adhere to the silicone at all. If that worked, you could just dip the tips and problem solved.

So I made a duct tape cap to cover the silicone. It fired in one shot, same case with three trials. The duct tape cap flew off afterward though - again not sticking to the silicone. This is evidence that the tip friction is the problem.

I also shot a 1/2" slug of silicone from a PETG barrel on a SNAP. It popped out, about six feet of range.

During development (before we discovered the felt backing bond) I tried close to a dozen different glues. Results ranged from absolutely crap-tacular, to moderately crap-tacular. Poke around on the Nrev slugs domes and other thread to get the list of what's been tried. If it's only a tip that's being glued on, a moderate bond strength should be adequate.

The only two things that held moderately well - were:

"liquid nails small projects silicone adhesive" in a blue and gold squeeze tube (not caulk tube!)


And un-cured oogoo.

I just mailed out my main form. (hope to do a new one today) Any chance I could persuade you to try dropping some pre-cut/pre-punched felt discs into the form holes before your next pour? I think If we have them sitting at the bottom of the wells, we can avoid the extra step of gluing padding on later.

[Darksircam]

I was just looking for something that would cover the head like Darth Maker said. Felt heads solve that problem anyway.

Precut felt heads, yes. I've yet to acquire a reliable method of punching holes. Especially with the thick felt. Ah well. For each dart I make, I peel off the felt on one side and use it for the tip of the next batch.

Four of the eight darts turned out well. Examples of the good and the bad. I experimented with just throwing felt pieces in as well - turned out very lumpy. The main problem here is that the felt doesn't STAY at the bottom - might leave some deadspace. You can also use thicker boards with this - I think I'll be getting some 1/2" thick boards for the final molds.

[shmmee]

'Darksircam', on 26 May 2011 - 01:48 AM, said:

I was just looking for something that would cover the head like Darth Maker said. Felt heads solve that problem anyway.

Precut felt heads, yes. I've yet to acquire a reliable method of punching holes. Especially with the thick felt. Ah well. For each dart I make, I peel off the felt on one side and use it for the tip of the next batch.

Four of the eight darts turned out well. Examples of the good and the bad. I experimented with just throwing felt pieces in as well - turned out very lumpy. The main problem here is that the felt doesn't STAY at the bottom - might leave some deadspace. You can also use thicker boards with this - I think I'll be getting some 1/2" thick boards for the final molds.

Awesome! Do they feed any better in hoppers with a felt tip?

[Darksircam]

Darts now feed well - no misfires, I've tested four times with a five-shot hopper.
These should be more durable than slugs as well - foam-felt attachment is more secure and less prone to breakage as the felt bends with impact.

There's still the problem of weight distribution - if the felt doesn't stay at the bottom, lopsided (and inaccurate) darts result.

I'll probably be getting blue foam from Oznerf, as the darts will last much longer and be more visible than grey FBR. Less dart loss = less time spent making darts overall.

[aj1234119]

Do you notice any decrease in range between these felt tipped darts and the round tipped ones?

[Darksircam]

Testing with a barrel-replaced Nitefinder, yes. The felt-tipped darts get slightly less range compared to the nontipped flat gumdrop heads. Slugs got similar ranges. This is due to decreased weight, I'm guessing. Felt is lighter than silicone.

I also tested with a similar weight felted tip, with silicone stuck to carpet tape, stuck to foam. Same as the nontipped darts.

Too windy outside to do range tests with "heavy" blasters (Modded watergun that gets ~90 foot ranges).

[shmmee]

'Darksircam', on 27 May 2011 - 03:12 AM, said:

Darts now feed well - no misfires, I've tested four times with a five-shot hopper.
These should be more durable than slugs as well - foam-felt attachment is more secure and less prone to breakage as the felt bends with impact.

That's great! Poor hopper feeding has been one of the big down sides to these things. Thanks for doing a fix for them!

Here's a thought for getting the felt to stay put while filling:

Use a mold with holes breaking the back surface (drilled fully or at least partially through) Peel off an Avery sticky label (of appropriate size) and stick it to the back of your form. You'll then have a sticky surface exposed at all holes. Stick a felt disc in the bottom (label should hold it in place) attach backer board, and fill as normal.

You should also be able to re-use the label by shifting it slightly to expose some fresh stickiness.

Edited by shmmee, 28 May 2011 - 09:21 AM.

[shardbearer]

Another idea is to put a sheet of felt clamped in between the two boards, but then they would be harder to punch out, because you cannot put the head through the punch prior to punching through the felt.

[shmmee]

'shardbearer', on 28 May 2011 - 7:55 PM, said:

Another idea is to put a sheet of felt clamped in between the two boards, but then they would be harder to punch out, because you cannot put the head through the punch prior to punching through the felt.

This is the first thought to strike my mind when trying to tip the gumdrop heads, but further thought of a mold with felt on top, felt on bottom, and cured oogoo - perma-bonded to both sides of felt cured in the middle - turning the mold into an oogoo sandwich steered me away from it. Individual pre-cut dots are probably the best way to go.

[Darksircam]

I had the same idea, but toyed with it for a while before realizing that punching out the felt also damaged the head/board. A good hole punch is too thick, brass gets dull quickly.

Meh. Even with cutting felt heads it takes less SKILL than the other stefan heads. Here you can just mindlessly assemble the mold while doing something else at the same time, then take a few minutes to stick everything in and then wait for curing. Only part where you have to concentrate is sticking oogoo in the holes.

I see it as a hybrid of the other two - hits like slugs, lasts almost as long as hot glue domes, takes longer to make than either. But for painless (no skin penetration at least) and safe ammo, these will probably be the darts to go with. Indoor/cubicle wars especially - no sharp parts, no real worry of scratching or denting anything, and the small area reduces dart loss.

Edit:
Using more silicone in the ratio seems to bond the heads to the felt better.

My first batch, when pulled, broke at the bond between silicone and felt. A little bit of felt fibers were left, but not much.
The second batch with almost translucent heads... broke off at the foam.

Both were harder to break off than slugs.
No apparent damage to the dart head after firing at a wall seven times, at 15-foot range, with a PETG'd Super Soaker. Felt got a bit frayed, the foam near the dart head seems to be a bit damaged. But it's Home Depot foam.
I once tested similarly with slugs, I remember the head was starting to fall off around nine shots into a wall.

Edited by Darksircam, 30 May 2011 - 08:39 PM.

[shmmee]

I did some more developmental work over the long weekend.

Everything is still curing in the forms, but here's what I've tried doing differently:

Increased diameter to 7/16" (1/4" tall), and a flat conical shape. (increases surface area, and mass)

Tipped the dart heads by dropping a felt disc down each individual head form prior to fill.

Bought a hollow punch set and a 1lb dead blow hammer (plastic hammer filled with pellets that transfer all of the energy into the object it's striking). Tried punching single felt discs out of felt (felt is substantially cheaper off of a bolt from a fabric store. I bought a full square yard for $2.39) It was difficult to punch through a single thickness of felt, but after folding it over into 6 layers, it punched well, with about 4 blows from the hammer. It also made 6 discs per 4-5 swings.

I placed a disc in each head form, but they shifted, and rode up the sides of the wall, so I coated the back of the form with packing tape, and stuck the discs to the tape in the bottom of the form. That solved the shifting, and kept them in place while filling.

Everything else was done as normal.

I'm concerned - due to the difficulty of punching through a single sheet - that it may be difficult to use the punch to separate the heads from the backer felt. I was using a scrap piece of maple floor board to pound on. Would some sort of softer material be more effective as a pounding board? Some sort of rubber, or a pine stump (facing the grain) or sacrificial layer of felt glued to the board help to make punching out discs and heads more effective?

I'll get pictures up when I can. Thanks all.

[Darksircam]

On the hole punching problem: If you're using felt that's anything thicker than a sheet of paper, you can probably peel the excess thickness off one side of the head, resulting in a small amount of felt remaining.
This small amount still sticks to the foam via hot glue, and now you have a pre-cut circle of foam for the next batch's tips.

I also peel the disc off the tip, doesn't seem to hamper dart feed in hoppers.

So you can generally "reuse" felt discs two to three times. Not sure if the extra discs could be used to cap the dart head on BOTH ends, but if that works you can avoid punching holes for one batch.

The main problem is speed. Placing down discs takes slightly longer than pushing down in each dart hole, and that extra time might allow the silicone to dry.

Tested my darts out in war-situations. Let's just say... I'm not using slugs in wars anymore. These hurt so much less with powerful blasters compared to foam-tipped slugs. Especially on exposed skin.

I know I said there was little testing difference, but that was shooting myself at pretty close range. Both hurt. At longer range, the difference is appreciable.

[ChaosPropel]

I tried making a pointy head for form/some darts for the first time last night, and it turned out a bit wacky. I drilled 1/4" into the board (just as the writeup said), using the DeWalt countersink bit (I like the pointy heads a bit better), and my sili heads came out looking nothing like how they looked in the OP. First of all, there was a small dimple between the drill hole made by the countersink and the drill bit itself (caused by the open area between the 3/16" drill bit and the countersink bit (since to adjust the drill bit's location, you have to move the countersink). Also, the heads looked MUCH shorter than those in the writeup (what depth, Shmee, did you use for those heads shown in the OP pics?)I'll try to post pics this afternoon.....

[taerKitty]

Oh, for those who are experiencing feeding problems -inside- the hopper with these - try 1/2" thinwall PVC. Works like a charm. I put 20 rounds through an SVT4B with an EMT conduit bend for the 45-degree portion of the chopper. Misfed once becuase I forgot to tip the blaster forward while pumping it. Aside from that, no problems.

[shmmee]

'ChaosPropel', on 31 May 2011 - 10:47 AM, said:

I tried making a pointy head for form/some darts for the first time last night, and it turned out a bit wacky. I drilled 1/4" into the board (just as the writeup said), using the DeWalt countersink bit (I like the pointy heads a bit better), and my sili heads came out looking nothing like how they looked in the OP. First of all, there was a small dimple between the drill hole made by the countersink and the drill bit itself (caused by the open area between the 3/16" drill bit and the countersink bit (since to adjust the drill bit's location, you have to move the countersink). Also, the heads looked MUCH shorter than those in the writeup (what depth, Shmee, did you use for those heads shown in the OP pics?)I'll try to post pics this afternoon.....

The exact height of my most recent pointy head batch is .280" (a hair past 1/4"), but that includes felt...
Here's a pic of how far out the counter sink bit is (again for pointy heads.)I noticed from the pic that one of the spiral grooves is jam packed full of debris. That made drilling slow, but I guess it also prevented uncut plastic from hiding in the gap.



I remember pre drilling the holes with the center bit extended to a depth of 1/8". With it barely sticking out like it is, it has the potential to slip till it finds it's groove.

Updated op with pic of most recent pointy head darts.

[Darksircam]

I prefer flat-head darts, due to the fact that they're heavier (for the same depth of mold) and still hurt less. I think they have similar hopper performance - much better when felt-tipped though. The main purpose of this is to get a dart design that can be used with equipment most Nerfers already have.


Also more colorful.

And it's much faster/simpler to make flat-head molds. Mark holes. Drill straight through. Repeat.

Just don't get the Irwin "Speedbor" bits and you should be fine. Sure, it looks pretty. But the edges of the drill bit have teeth, which really messes up the drilling a lot. The teeth got stuck in wood, plastic, and PVC, Couldn't get it started again as quickly either. Had to drill in reverse in order to smooth out the weird gradient that happened with the drillbit.

(I edit my posts after submission. It's a bad habit. Bad formatting or jumps in logic most of the time.)

Edit: Saw that part about testing with dryer lint. If you shred it and stick it through a sieve/box with holes in it, you could sprinkle it over the entire mold.

(Theoretical) Still keep the tape on the bottom of the mold, but the sili head should not rip off ALL of the lint, allowing tape to be reused as a lint holder.

Edited by Darksircam, 01 June 2011 - 02:16 AM.

[ChaosPropel]

My first batch of gumdrops that were the shape I wanted (I had tried a batch before that one, but the shape came out screwed up) turned out pretty good-I think the height of 1/4" is just right-any more and the dart will seem TOO long. It still seems, however, that my heads are shorter/subbier than Shmmee's. It may just be his camera angle, though.

I just finished pouring my 2nd "correct" batch (a total of 60). I'll post pics of my first batch later today (they've already be glued to FBR), and my 2nd batch when they're ready.

Some tips for people planning to attempt this (Shmmee and DarkSircam, please feel free to correct me if I'm wrong)
-DEFINETELY do this outside, or in a room with AT LEAST 1-2 windows. The fumes ogoo releases will "burn" your nostrils if you breathe it in. What I do it I mix the sili and starch outside, and then let the board cure outside for the first 2 hours, then bring it in so I can know exactly when they're ready, without having to go outside.
-Instead of using the drill bit that comes with the DeWalt countersink bit, I used a 5/32" bit , since it made less (VERY SMALL) of the aforementioned (previous comments) "moat."
-Home Depot only sells the DeWalt bits in packs of #6, 8, and 10, for about $25. I got this pack, since HD and True Value are the only hardware stores near me. Also, the countersink portion of all 3 bits are the same, so you have 2 backup countersinks in case you need 'em (although I doubt you will).


I think that the pointy heads are a sufficient down-grade for pain-as in they are a billion times softer than traditional glue domes-, so I don't think that cylindrical heads/adding felt padding on top is really necessary. Honestly, you don't know JUST HOW SOFT these things are untill you've made them... Also, the "angled hits" phenomenon that people experience with slugs may happen with the flat head darts, although it would hurt less, it would probably still hurt more than a flat-on hit, which is rare.

Sorry if this post was a bit unorganized-I just have a bunch of stuff I'd like to put out there .

Edit: here are some pics of my mold board and some darts from my first batch (2nd batch/pics coming soon)

Edited by ChaosPropel, 01 June 2011 - 05:07 PM.

[shmmee]

Darksircam, ChaosPropel, Sirs I applaud both of you! Thank you for proving this concept to be reproducable, and even effective.

I just pulled my first batch of 7/16" felt tipped cylinder gumdrop darts from the mold, and I am Giddy with how they turned out! (I mixed too much oogoo and and to smear it in another mold before I could get felt tips prepped and in place, so some are unfelted.





I didn't bother to put felt discs in the deformed holes. That's why a couple are missing a disc.

Thoughts:
-I have no idea how much each head weighs.

-Those 209 heads took 8 squeezes of caulk - about half the tube.

-The cheap $2.50 wallmart silicone caulk with the semi opaque tube and black lettering works just as well as the expensive $5 - $6 3M caulk for oogoo heads.

-To second what ChaosPropel said - they reeked to high heaven! Do this away from living spaces. I was working in my basement, but the smell was still noted up stairs.

-I don't know if the increased diameter or square edges will help or hinder hopper feeding.

-The packing tape backing really helped hold the felt heads down! (I filled the holes with felt, gently turned the mold over, applied the tape to the back of the form, then flipped it back over and tapped the discs down. That way the discs were already semi centered.

Edit:
Punching custom disc heads works great if you stack the felt multiple layers high. I had 6 layers stacked.

-I've offered to send some samples to Vacc so they might be considered legal at Apoc (though I have no chance of attending). We'll have to see how that goes. It may either be vindicating, or condemning.

Edited by shmmee, 02 June 2011 - 08:25 AM.

[Darksircam]

'shmmee', on 02 Jun 2011 - 05:06 AM, said:

-To second what ChaosPropel said - they reeked to high heaven! Do this away from living spaces. I was working in my basement, but the smell was still noted up stairs.

I... still don't smell much of it. Strange. Have you tried using GE Silicone I?

Smell was gone in about 15 minutes, if you came within about a foot of the molds you could smell it for a few hours, about as much as trying to smell the silicone tube itself. Vague vinegar smell that spread pretty far for a short time, but it wasn't that pungent.

Even if it is the silicone that isn't as pungent... it's double the cost for more convenience.
And I suspect it's the smaller amount I'm working with - about three to four squeezes, I'm using the oogoo for other stuff as well, so I just mix it on a cutting board with plastic knives.

The nonfelted tips look almost... edible. Like jelly. And while they might not feed in hoppers, turrets, RSCBs, and inline clips are still fine.

You can fit around 250 darts on an 8x11" cutting board/felt sheet, which means the cost for each dart head... is about one cent.
.6 cents for silicone (Wal-Mart)
.4 cents for felt.
Guessing felt sheets are 25-50 cents for that size? If you're getting it by the yard it's more like 20 cents per 8x11" batch.

Slugs are more expensive (felt dots are 1 cent each?) and they have a tendency to fall apart. The only difference is labour taken to make - hammering out dart heads is harder than sticking felt heads on.

[ChaosPropel]

With 3.5 squeezes out of a caulk gun, and roughly 2-2.5 spoonfuls of corn starch, I was able to make about 45 darts. There was a lot of waste since not every mold hole got filled. I'll have to do a better job at that in the future.

Darksircam-
You said "Have you tried using GE Silicone I?"
Does this mean that you've been using it? If so, I don't have to worry about using my Walmart tubes conservatively, since when I'm out (of my 3 tubes I bought), I can just use GE I.

Shmmee- Those heads look fantastic! I love how neat the uppermost felt looks!

[shmmee]

'ChaosPropel', on 02 Jun 2011 - 10:43 AM, said:

With 3.5 squeezes out of a caulk gun, and roughly 2-2.5 spoonfuls of corn starch, I was able to make about 45 darts. There was a lot of waste since not every mold hole got filled. I'll have to do a better job at that in the future.

Darksircam-
You said "Have you tried using GE Silicone I?"
Does this mean that you've been using it? If so, I don't have to worry about using my Walmart tubes conservatively, since when I'm out (of my 3 tubes I bought), I can just use GE I.

Shmmee- Those heads look fantastic! I love how neat the uppermost felt looks!

Thanks!

My latest batch used 2 spoon fulls corn starch to 3 squeezes caulk. They came out much softer than my previous batch. Darksircam suggested a volume based ratio of as little of 10:1. Your ratio might be a little rich. They look great though!

Edited by shmmee, 02 June 2011 - 08:23 AM.

[Darksircam]

Yep. GE Silicone I works.
I've been getting a lot less odour than what everyone else seems to get, so I was wondering about that.

[ChaosPropel]

'Darksircam', on 02 Jun 2011 - 11:48 PM, said:

Yep. GE Silicone I works.
I've been getting a lot less odour than what everyone else seems to get, so I was wondering about that.

YESSS! I'm so glad, since I just ran out of my first Walmart tube! Woohoo!
Also, today, I tried using less corn starch, and the odor was considerabely lower (I think my previous comination was a little too starch-rich).
I'll post pics of my 2 latest batches (I did 2 pours today ) when they're ready.

[shmmee]

I just weighed the sheet of 7/16" x 1/4" cylindrical heads. the 81 heads weighed 42 grams. Therefore each head should weight about .51grams! (which is even half the max dart weight set for Apoc.) Chalk one more mark up in the safety column! I'm going to go punch them out of the felt now.

[Darksircam]

Drilled out some more holes and made another batch of about 30 darts.
Is everyone using a paint stir stick to poke the oogoo into the holes? I prefer using my fingers... or if possible, a plastic-coated wooden rod about the same diameter as the tip diameter. Makes sure you get the oogoo all the way in, and it's pretty quick. Then smear some more over and repeat.

The amount of cornstarch may also affect the smell... if it acts as a catalyst, more vinegar smell is generated, and it's generated faster.

Edit: On felt: You should be looking for felt that does NOT fall apart easily - fluffy felt makes bumpy/unbalanced dart heads.

Edited by Darksircam, 14 June 2011 - 12:40 AM.