jymster

My Feedback: (9)

Thanks Martin, I will have a read. Gotta love Google translate!

jymster

My Feedback: (9)

I think the hardest part is finding a high enough rpm brushed motor for the starter. I think it needs something like 60K-70K rpm to be able to start it. Most starters seem to be around the 30K-45K mark.

frema

you dont need the 45 k, 30k is enough.
use the 2 t motor jetcat use.

Boomerang1

Ahhhh....... No. A friend has a blower start Lambert (what the JJJ is copied from) and the idle speed is 100,000 RPM.

45K is not even close to the speed these little guys need to start. Reconsider the blower start, you will need a method of getting the blower on to the front of the engine though. One thread had a guy with a 90 deg elbow on his blower to reach into a fuselage. - John.

frema

use the motor they show in the forum above.
Then you will have no troubles starting any small engine

frema

on the previus page i mean.
its the t2 or z2 from atomic

jymster

My Feedback: (9)

Do you think so? I am sure I read somewhere recently that the Junior needs around 60K rpm to sustain combustion to be able to start. Not sure where I got it from, will have to go over my recently visited web pages and my emails.

jymster

My Feedback: (9)

Hi John,

Yes, I am sure this is the case too. The JJJ also idles at 100,000 rpm (or there abouts). I will probably make up a 90 degree elbow using conduit or similar.

P.S. You coming to Orange in a couple of weeks?

James.

knobby1

Yeah....The JJJ idles @ ~99-100k, max's out @ 240k. They require ~65-68k to self sustain depending on ambient conditions....however, what Frema says it quite correct, the small Atomic electric motor will indeed start the JJJ. Once the gas and fuel starts to flow it will help take the load off the starter and much higher rpms will be seen.

A good example is the Wren MW54, they self sustain @ ~ 24-25k-ish, their starters will only "free spin" to ~18k depending on the applied voltage, however when assisted by the gas & fuel will easily run up to and over 30k which is where the starter is usually set to cut out via the ECU parameters, then the engine will happily accelerate up to the normal 40-45k idle from there..

I ran an auto-start Lambert Kolibri a few weeks ago and the starter would free spin the engine to ~38k using just 5.4volts, (it had a 6v electric motor setup), so it still had a bit in reserve. It started the engine fine with no drama at all. Great little engine is the Lambert.

Cheers,
Smithy.

jymster

My Feedback: (9)

Thanks Smithy,

I think it was you that told me this in an email. Must be on my home PC. I will investigate this a bit further. Looks like the small bendix clutch from Wren might work. Will have to check the ID of the o-ring.

knobby1

I'm afraid the Wren clutch is way too big, the JJJ compressor nut is only an 8mm hex and the nose of the nut is ~6.5-7mm, so the bendix drive "O" ring needs to be smaller than that.... Martin Lambert makes the only "commercially" available one at the moment, mind you, if you're handy with a lathe you could possibly spin one up in no time..

Cheers,
Smithy.

jymster

My Feedback: (9)

What motor does the Lambert use?

jymster

My Feedback: (9)

I guess it would be nice if Lambert made parts available separately, so that us DIYers can make our own retrofit starters.

knobby1

To be honest..I don't know, there were no markings on it that I could see, although I wasn't looking that hard.

BS.

jymster

My Feedback: (9)

Ok, I will have to see if I can get a hold of a bendix clutch from somebody so that i can see how it works and then I can make my own. Maybe Ausjets have a cheap JJ one I could buy to work from?

knobby1

Mate, I have ~5 of 'em at home, I can send you one if you like....or you can come a pick one up..!

BS.

jymster

My Feedback: (9)

Ok, thanks for the offer Brett. I think I will come and pick one up. i have been meaning to call you and arrange a time to come and see you anyway. Will contact you over the weekend.

James.

knobby1

No probs...although I will not be home on Sunday....am going to the "Nostalgia Drags" at Sydney Dragway.

BS.

jymster

My Feedback: (9)

No worries Brett. Not sure I can make it over on the weekend anyway, was just going to call you t make arrangements.

Boomerang1

I don't want to trot out the old 'illegal copy' line again but it's pretty unlikely Martin Lambert would be happy supplying parts to help anyone trying to get a JetJoe running properly.

Probably about as much chance as getting bits from Wren for the larger engines.

No, I won't be going to Orange but I have been a couple of times, usually a good weekend. Enjoy!

Good luck with your engine - John.

frema

Lambert use the z2 from atomic.
Wow ,then i have a much better junior then you all have
The thrust is also higher 2,3 kg

frema

Sorry guys , i will stop posting, i dont want to confuse you all

idleup1

[youtube]http://www.youtube.com/watch?v=0Kz34qDvMTQ[/youtube]

starting jjr with angled blower

jymster

My Feedback: (9)

G'day idleup1,

I presume that is a Baiojet? I have been looking very seriously at that airframe for my JJJ. Have you flown it yet? I would love to hear how it goes.

James.

chuckels

My Feedback: (25)

James,
have you fired that beast up yet??
Chuck