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"In the world of spuds today"

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Unread postAuthor: qwerty » Sun May 01, 2011 2:48 am

Good to see you decided to go down the hybrid route. You'll be quite happy with the power.


And i might have allready cocked it up :)
I have epoxyed it all together but have forgotten the spark gaps :roll:
Anyway, as i have no access to the schrader anymore, how should i go about making a spark gap. I was thinking, just use some screws with a gap of about 1.5mm and epoxy them in. But then i thought, wouldn't i get a shock instead of the spark jumping? So i am thinking of wrapping the whole thing in electrical tape. Would that work?

EDIT: Nevermind, problem solved :) More epoxy is curing. I should get some results tomorrow.
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Unread postAuthor: saefroch » Sun May 01, 2011 3:12 pm

Good to see there's a lot of builds coming in, and hybrid to boot!

I'll hopefully be doing some drill press work to start making my piston tonight.

In the two weeks that I've had my tubes of epoxy, I've managed to fix three things around the house with it. :roll: Sure is some awesome stuff.
And yes, it's amazing for making things for the girlfriend.
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Unread postAuthor: jackssmirkingrevenge » Sun May 01, 2011 3:34 pm

moar hybrids yay!

In the two weeks that I've had my tubes of epoxy, I've managed to fix three things around the house with it.


Welcome to the dark side :)

And yes, it's amazing for making things for the girlfriend.



Waste of high spec adhesive.

;)
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Last edited by jackssmirkingrevenge on Sat May 07, 2011 6:22 am, edited 1 time in total.
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Unread postAuthor: saefroch » Sun May 01, 2011 4:19 pm

jackssmirkingrevenge wrote:Waste of high spec adhesive.
Only when you have to pay for it. :wink:
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Unread postAuthor: saefroch » Thu May 05, 2011 7:32 pm

ITWOST: I almost got a drill bit stuck in epoxy, trying to drill through it. I was attempting to fill in the rather large scratches on the inside of the spacer I'm using for my piston, but upon drilling out the epoxy, there were still significant ridges... help?

Is there significant DDT danger for an air-propane hybrid chamber 28" x .5"?
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Unread postAuthor: mark.f » Thu May 05, 2011 8:36 pm

You could mitigate it with multiple ignition points... as far as a definitive geometry which would induce DDT, I can't tell you exactly, but propane/air isn't the best candidate for the transition.
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Unread postAuthor: Technician1002 » Thu May 05, 2011 11:06 pm

When drilling epoxy, it is important to use low speed. Epoxy expands as it heats. This causes expansion into the drill bit. When cooled, the spots that was hot are now grooves. Use a sharp new bit. A dinged up bit will leave grooves.
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Unread postAuthor: Zeus » Thu May 05, 2011 11:46 pm

Well I've got a syringe now, fueling math is done, I just need to iron out the bugs in my ignition circuit and I'll have a 15X pistol hybrid.
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Unread postAuthor: jackssmirkingrevenge » Fri May 06, 2011 6:01 am

Technician1002 wrote:When drilling epoxy, it is important to use low speed. Epoxy expands as it heats. This causes expansion into the drill bit. When cooled, the spots that was hot are now grooves. Use a sharp new bit. A dinged up bit will leave grooves.


Hear hear.

Zeus wrote:Well I've got a syringe now, fueling math is done, I just need to iron out the bugs in my ignition circuit and I'll have a 15X pistol hybrid


Finally, looking forward to seeing it work :)
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Unread postAuthor: saefroch » Fri May 06, 2011 12:00 pm

Technician1002 wrote:low speed
Guess I'll be trying again, thanks!

Spark gaps in parallel a good idea?
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Unread postAuthor: qwerty » Fri May 06, 2011 1:48 pm

ITWOST Qwerty's Micro Hybrid....7X mix.....7 burst disks.... 105psi.....Click.....BOOOM!!!!.....Inspect Target.....Minimal damage.....Missed?......Did you put the pellet in the barrel?.....No....

:oops: :lol:
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Unread postAuthor: jackssmirkingrevenge » Fri May 06, 2011 2:19 pm

qwerty wrote:Did you put the pellet in the barrel?.....No....

:oops: :lol:


Happens to all of us sooner or later ;)
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Unread postAuthor: ramses » Fri May 06, 2011 6:46 pm

If you put the ignition points in parallel, only one will actually see a spark. You must put them in series.

Also, I now have a milling machine.

And I still need advice on a bumper for a 4" toolie valve. I was thinking multiple tennis ball halves.
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Unread postAuthor: saefroch » Fri May 06, 2011 8:20 pm

My advice: Rubber and strong construction to be able to take the impact.

OOO! Can you model your valve in GGDT for me and take a screenshot of it?
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Unread postAuthor: Technician1002 » Sat May 07, 2011 12:28 am

And I still need advice on a bumper for a 4" toolie valve. I was thinking multiple tennis ball halves.


Same thing you would use for a 2 inch valve except scale the diameter up for the new larger area and scale the thickness up for the longer travel and higher mass.
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