Mike's Build Log

[Mike Everman]

Hi guys. I decided to take another shot at the little 2" diameter (what I used to call "pockey lockey")

This one will get a tuned expansive tail after I get some time with the straight pipe version.

It has a removable head and telescoping intake (that's a .010" sleeve in there with a nice snug, but sliding fit.

I've got a raging cold, so didn't go out to the shop to run it today, but put a rossco in it int the garage, just enough to know it's going to go, and it's gonna.

[Purki]

Nice and small! Best of luck! dont let the cold keep you from running it!

[Jim Berquist]

Mike , Whats with the Bolt up CC? Variable?

[Mike Everman]

Oh yeah, I forgot to post some progress! And no, the bolt on is so I can change fuel hole number and diameter. (Fueling is set up like most of my motors; outer distribution volume and holes in the intake flare at the CC)

I ran it the other day. Went really well, and ran right out of the box. I could tell I didn't have enough fuel jet area, as I was not able to over-fuel it.

The oddest thing happened, as I ran the throttle down to go low. It spit the intake out. It still ran, though, with a 2" long intake with no flare! The intake and exhaust are both 1" od, .035" wall. That's going from about 4.5:1 to 2:1 on the intake aspect ratio.

The frequency jumped way up after spitting out the intake, but it wasn't "howling mode". I wish I'd been doing thrust measurements and taking video at the time.

Hopefully Sunday night I'll get some video and thrust, then move on to adding the tuned pipe tail I'm planning. I want to shorten the sliding portion of the intake so I can adjust below 4.5:1 ratio as I cannot now.

[Jim Berquist]

Cool! I just moved out of the dark ages and got my self a DSL service. All I need now is a video cam with sound. Haaaaaaa! Then I can post some of the gooffie stuff I do!

[Mike Everman]

Oh, God, NOoooooooo! ;-)

[Mike Everman]

Well, that was sure the best test ever. I'm starting to reap some benefit from my acoustic model, and that is very satisfying.

I drilled a couple more .028" holes in the fuel plenum, and this motor pulled 3.3 lb stable, running rough at 3.5. Or, surging to 3.5 from 3.3, I can't remember. Over 2 was going to be good, 3.5 is dancing time. OK, I'm easily amused. ;-)

I'll attach a walk around vid, and post some vids at 1 lb and 3 lb thrust for sound analysis folk.

Also, I'm attaching all the dims. Kind of self explanitory, but not a very convenient format.

I'm so stoked about the thrust!

Pockey Lockey 2 (I've got to think of a better name.)

29.74" long
2"OD x .035 wall CC, long rear cone
1" x.035 intake and tail tubes

[Mike Everman]

1 and 3 lb videos.

[Irvine.J]

Pockey Lockey 2 (I've got to think of a better name.)

THE POCKET ROCKET THAT ISN"T A ROCKET AT ALL!
EVER-LOUD! EVER-POWER! man, with a name like Everman sky is the limit!

Man that thing is great, just so cool, so stable, really loud, great build too mike. I'm dancing here for ya. Great stuff.

[Eric]

Nice, see the intake flame curving down to the low pressure zone created by the tail exhaust

Eric

[Mike Everman]

Yeah, and the orange out the tail, but blue out the intake.

[Graham C. Williams]

Dear Mike.
Thanks for pointing me to this. This motor asks a lot of questions! Nice build and plenty of power.

Can't wait to see the next stage build on upon these results.

As always my Best Regards to you and the family.
Graham.

[Mark]

I really liked the two colors Mike, that effect would be fun to strive for on other pulsating combustion toys - add two or more spectra to the show. My computer makes the flames look orange and green. Maybe you could turn the lights down low and put on some soft music. Or just turn the lights down low to see the pretty colors better. ha
Good observation there Eric about the blue flame being drawn down.

[Mike Everman]

guess I have to add a copper tube on there so we can have blue, orange and green.

[Mike Everman]

So I've been noodling out a scaling process, and now I feel that before I move on to the tuned tail for the 2 incher, I want to do a quick build to see if the scaling works.
The driving factor is the u-bend I can use, that is 1.5" OD x .065 wall. The 2" motor had a 1" u-bend.

So the results of my scaling are thus:
CC dia: 2.631" from 1.93"
Length factor: 1.539x
Diameter factor (on all but CC): 1.473x
Max Thrust (with 3.3 lb used from the 2 incher): 7.16 lb.

It certainly wouldn't be the first time a theory falls, if it does, but oh what a thrill if I get the 7 lb and prove the scaling.

I only theorized the scaling last night, so I haven't got a lot of ego wrapped up in it. It fell together far too neatly to be true, ha.