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Posted: Wed Apr 13, 2011 4:43 am
by jackssmirkingrevenge
jor2daje wrote:Havent test fired it yet but based on throwing it around I have pretty high expectations.
Looks very promising :) a suitable sabot shouldn't be too hard to conjure up, looking forward to your results. Will this be for range or penetration?

Posted: Wed Apr 13, 2011 8:13 am
by dewey-1
jackssmirkingrevenge wrote:

I do however think that a spring loaded mechanism triggered by impact would be beneficial, separating the tail unit preventing it from being buried in the ground. I'd love to draw some diagrams but access is fairly limited at the moment.
An idea I have been pondering about for a few days, is to to use a miniature lightweight pengun with the barrel end towards the tail.
The Schrader valve would pilot on impact and would release the dye/powder and the tail section giving a colored "blast radius".

Should need only 100 psi in micro pengun. To prevent misfiring, a spring/foam cushion may be placed between nose piece and pilot end of pengun.
This would allow firing due to impact only.

I figured JSR would have come up with idea 3-4 days ago.

Posted: Wed Apr 13, 2011 8:21 am
by LeMaudit
I already considered something similar in this thread (page 13), and think it's a suitable solution. But maybe a bit complex to implement (which is only more fun to build after all)

Image

Posted: Wed Apr 13, 2011 8:46 am
by dewey-1
LeMaudit;
You posted that suggestion while I was drawing the 3D version of the original. While drawing it, I considered using a CO2 cartridge but thought it was to heavy.

I think this is the simplest/cheapest solution to a locating device.
Fantastic machining on the Mini Boy.

Do I see a Mini Boy v2 in the near future with air/co2 ejection?

Posted: Wed Apr 13, 2011 8:52 am
by ilovefire
i had an idea kinda like that but probly even more hard to implement, it was to have a mini pen gun in it that shoots a little red flag that has been rolled up with a pointy weighted bit on the tip

Posted: Wed Apr 13, 2011 8:53 am
by jackssmirkingrevenge
dewey-1 wrote:I figured JSR would have come up with idea 3-4 days ago.
He sort of did ;)

I was trying to keep things simple though. Looking at LeMaudit's projectile literally brought a tear to my eye, there is NO way I would shoot that little gem if I hadn't made it myself. If this is going to be practical, projectiles need to be reasonable to produce in a batch of 5 or 10, not incredible one-offs. At least, if the person pulling the trigger has any heart at all ;)
ilovefire wrote:i had an idea kinda like that but probly even more hard to implement, it was to have a mini pen gun in it that shoots a little red flag that has been rolled up with a pointy weighted bit on the tip
Does it say"BANG!" :D

Posted: Wed Apr 13, 2011 8:56 am
by LeMaudit
Thanks :)

I would like that someone confirm that shooting a piezo destroy it (or not) as it was suggested in this thread. If a piezo survive, a v2 could be made with some loud sound. If it's destroyed, the die would be my second choice. An embedded CO2 cartridge inside the shell may have some appeal. I don't think it would be too heavy.

[edit] :lol: Don't cry people.. I promise the next one will be less shiny... well, I'll try anyway...

[edit2]
it was to have a mini pen gun in it that shoots a little red flag
You know, I also considered having not a flag, but a long ruban that deploy on impact.

Posted: Wed Apr 13, 2011 9:15 am
by mark.f
What type of piezo are we talking? I don't have a high mix hybrid to test it with, but I could launch from my pneumatic at around 350-375 PSI (once I pick up some replacement o-rings for my pump head and some silicone grease).

Recovery is going to be tricky. Obviously if it impacts something the test is void, but firing straight up at those pressures would be a good way of sending a piezo into the next zip code with a little bit of a breeze. :P

EDIT: I just realized you were talking about a speaker piezo. :oops: Edited.

Posted: Wed Apr 13, 2011 9:22 am
by LeMaudit
My bad... my english is not very precise... more on the fuzzy side :lol:
Yes, speaker piezo... the one like in a wrist watch, of better any small think working around 6V-12V voltage that you can find for a couple of $ in an electronic shop.

I found a very loud one 20mm diameter with modulation tone, but I have no way to test if something like that will survive the Gs. On this thread it was suggested it would not and the internal crystal(?) would crash. One shoot with the piezo parallel and one shoot perpendicular to the barrel would be helpful. I'm guessing parallel would limit a bit the stress.

Posted: Wed Apr 13, 2011 9:34 am
by Lockednloaded
What about a nose cone that punctures a 12g Co2 cartridge to expel either a payload of streamers, dye, or even just the tail section so that it doesn't get buried?

Posted: Wed Apr 13, 2011 9:35 am
by jackssmirkingrevenge
Given sufficient movement and shock absorbtion in the projectile's line of travel (eg putting it in a tube with foam/springs/etc. on each end) as I suggested in my projectile diagram many pages ago, there is no reason why a piezo and its associated power circuitry shouldn't survive the shock of both firing and impact.

Posted: Wed Apr 13, 2011 9:37 am
by MrCrowley
As for a piezo-electric buzzer, D_Hall says they should be fine even under pressure as "extreme environment accelerometers and pressure gauges are piezo-electric" so an electric buzzer still could work.
jackssmirkingrevenge wrote:At least, if the person pulling the trigger has any heart at all ;)
:D

Posted: Wed Apr 13, 2011 9:40 am
by jackssmirkingrevenge
Lockednloaded wrote:What about a nose cone that punctures a 12g Co2 cartridge to expel either a payload of streamers, dye, or even just the tail section so that it doesn't get buried?
cough

cough

Posted: Wed Apr 13, 2011 9:46 am
by LeMaudit
there is no reason why a piezo and its associated power circuitry shouldn't survive the shock of both firing and impact.
If someone can validate that with experiment that would be great. I didn't go that road first because of the bigger diameter needed, around 25mm for the shell. I found a piezo loud enough with a 12v small battery or a few lithium ones that I could use, but the smaller piezo I tried just were not powerful enough. So, going to a slightly increased diameter for the next try may be a good idea. It will also help retrieving the thing :lol: And make a BIGGER paperweight!

But I now do like the CO2 embedded cartridge idea too... hmmm....

Posted: Wed Apr 13, 2011 9:59 am
by jackssmirkingrevenge
LeMaudit wrote:I now do like the CO2 embedded cartridge idea too... hmmm....
Heck, why not have a piezo ignitor on the nose of the thing and fill the body with a hybrid mix :D

Again, I think a simple hefty spring is more than enough to fling the tail section/streamers/ribbons etc out, and it would be more easily reusable.