Right , I see . Got yaaa

Thanks fellas

Got the video footage from the other night's start-up, 'Bono.

Unfortunately, my mates HD cam was set to 'auto' so the darn thing looks like broad daylight LoL

Though heaps better quality than the one I took using my little Samsung ES15, its not quite as spectacular.

Soooo....we're going to try again soon, with the brightness locked to standard so the smarts inside the camera don't try to compensate for the lack of light.

....and it should be of the 'twins'....

BJ

For some dumb reason, the 'BETA: Mutli-File Upload with Progress Bar!" wouldn't work at all the other day I posted pics of my JJ-3000. It just kept taking ages and ended each time with an 'internet connection' problem.

So I tried the longer standard way, and it too clagged each time. My files only totalled just over 4mb, and the download page said it was good for up to 6mb - but no go.

So I ended up posting them one at the time.

Any ideas on what might have been going wrong?

Ta.

BJ

Hi guys, I intend to change turbine wheel in my JJ1200. Jetjoe has balanced spare part. How can I do a dynamic balance of the rotor by easy way since I have not balance equipment? Does it work just align the mark on new turbine wheel with the mark on the original compressor? Waiting for your recommendation.

4mb is big really, photos shouls always be resized to no more than 800x600, there is no need to be any bigger, I could post 20 plus pictures for 4mb

Does anybody have an ECU manual or auto for sale ?

Which manual version are you looking for, and when you say auto do you mean you are looking for a autostart ECU

Seamus,
I think he's actually after the ECU itself, be it manual (semi auto) or full auto..!

Cheers,
Smithy.

See that now, funny how your brain reads things depending on the order of the words !

Ahhhh the power of the comma, as my english teacher would say.

Inglesh.... punktuashion and prunanownsiashion is for them "Grammar" boys who read about it and dream about it, but never really get to do any of it....

Here's a few 'commas' on me ,,,,,,,,,,,,,,,,,,,,,,,,,,,, LoL

BJ

WOW WOW Ladies Looks like I ve just started a small scale debate ... lol
 ooops here is my coma for last sentence : ,

LoL...ya dag...

BJ

So Iv been reading thru this thread and also the one over on RCG. From what I am gathering the JJ engines have greatly improved. The only question still nagging at me now is this if you guys are getting the full load of 14 lbs out of the JJ1400?

I'd say yes if they have been assembled properly by someone who knows what they are doing.

Mine at the start was certainly not, I'd say 11lb if that, low egt's alone told me the power was down, it started and ran fine and I flew it like that for about 20 flights.
I then replaced the two piece tailcone with a single piece version and made a huge noticable difference.
Egt's went up and when we done a pull test with a model strapped to a girder with a digital spring balance and the figures my not have been a true reflection on actual thrust, but there was an increase of 3lb.

I have a older wren mk2 which is about 12lb and the Jetjoe would have more thrust so I'd say it is now producing the 14lb.

Dunno about exact 'thrust'...but if pure noise is anything to go by... my '3000's must be pulling about 45lbs each...

BJ

Might have to raise a glass....or three.... today

BJ

Hi BJ
It finaly cooled down enough to spent Sunday (Last weekend) getting the JJ1800 in sinc for the A10. What a sweet sound when in sinc
Probley have to wait till after easter before flying jets here in Perth

stay safe
swampy57

Good the hear Swampy

Er...what exactly do you mean by 'in sinc'? Do you mean getting them to provide the same thrust as each other up through the rev-range so that the aircraft won’t yaw? Your donks would be far enough apart to be able to ‘rudder’ the plane just by subtle thrust variations between the two Turbines, yah?

I had a bit of a mixed-bag weekend - I didn't get to fire up the twin 3000's as I was a bit short on the proper fuel hose. So I used that rubbery silicon 'glow' type tube and had a bit of trouble getting some ends to seal properly. I managed to trash a fuel-pump in the process by giving it a tad too much juice (my fault - I didn't read the max volts for the pump correctly). So I spent this arvo having a go at repairing it, seeing as it was stuffed anyways.

After I took the blue anodised pump off the front of the unit, I noticed that the motor ran fine (this time on some AA's as Smithy suggested instead of the LiPo). So the problem was in the pump mechanism itself. I found that the non-driven toothed wheel was frozen solid - probably nipped-up due to over-revving. I managed to work it slowly loose using the end of a plastic peg (so as not to damage anything further) and some oil. I managed to get it moving slightly, but it was still rather tight. So I put the drive-wheel back into the unit, oiled everything up good an proper, and carefully inserted a small blade screwdriver into the drive-pin notch in the drive wheel, and used my cordless drill to spin it seeing it was still too tight for the fuel-pump motor to budge it. That worked out ok, and I sucked the non-driven cog out with one of those 'pick bolts up' magnet thingies.

I could see a small burr inside the blind hole where the non-driven cog's shaft goes, so I got some Tamiya polishing paste (the one you can polish scale model canopies with - super fine), and put a bit of that in the 'bearing' hole. Grabbed one of those round tapered tooth-picks and snapped it off so the end was just smaller than the hole, and stuck the toothpick in the drill and gave it a good spin to lap the bur out. Seems to have done the job, as the non-driven cog now spins freely when it's back in the pump body. Oiled it all up and put it back together - no go. I could feel the motor trying to spin, but the pump cogs refused to turn. So I played around with backing off the two 2mm Allen key screws that hold the pump to the motor body and I got it to free-up nicely. I noticed that by tightening/loosing the two screws in different orders that the revs of the motor went up and down, so clearly there's some alignment thing going on when you torque the screws up and down. Those tiny cogs inside the pump probably have a fairly critical working tolerance between spinning freely, and not spinning at all.

Still, I managed to get it going again and let it run via a recycling bottle of Kero for a few minutes - adjusting the two screws until the unit didn't leak past the sealing o-ring but where the revs didn't die down too much. There must be some sort of knack to getting it just right (??). I'm ordering a new one as a replacement anyways, and keep this one as a 'spare'.

That's about my lot for now - hope to be able to at least fire them up together some time this coming weekend. Should be awesome

You must be itchin to get that A-10 up in the air…

BJ

Hi BJ
Sinc! Just getting exhaust temps and fuel voltage simular with in reason after some long discussion with my cousin who was a flight engineer (40,000 hours on 727 and 747 for S/African) he suggested to keep those two areas in a reasonable tolerance. I think its me being a little anal as well.
I also had to run one pump to bed it in a little further. Like you I ran it in the loop to the tank.
The original fadec's I tuned them up by giving them a solid thump [:@] with a 2KG ballpain hammer I purchased two xicoy's much better[8D]
One interesting thing I found was that by placing and ajustable valve in the gas line and a bit of fiddling I was able to get consistant starts first spin (like the 200xl)
Sorry to hear one pump gave you trouble. You are correct on the tolerance between the rear plate and the cog if I could find out the correct clearance I could fix a few of my own stuffed pumps.
Good luck with the start up on the weekend
Flying the A10 the way the temp is over here probley wont get to test fly her till after Easter[&o]

Yah - I kinda guessed that's what you were doing. With the two Turbines that far apart on the A-10, I wouldn't be surprised it they started to rudder-steer the plane if they were two far different in thrust at any point in time.

LoL@fixing your old FADEC's with a ball-peen hammer. Guess they're *really* good and fixed now...[:-]

Interesting comment about putting a valve in your gas line - my JJ-3000 starts really easy. I do the gas totally manually - direct from the bottle into the Festo near the Turbine. As soon as I see "Glow Test" on the monitor, I open the valve on the bottle - she spins and goes 'pop' straight away, and really climbs the revs quickly.

One thing I have noticed, though, is that it seems to stay on 'Fuel Ramp' for ages before I finally see "Running" on the Monitor - about 1/3 of a litre of kero. There's probably something/s I can set in the FADEC to get it to ramp-up a bit quicker.

But I'm really happy with my starts these days - smooth as silk and glitch-free. I'm hoping Turbine #2 will spool-up just as easily. This weekend should tell

Fixing the fuel-pump was an interesting exercise. I have always been interested to know what goes on inside one, and you'd be amazed at how tiny the two toothed gears are in there - considering the amount of fuel that thing can squirt when the motor is fairly spinning. I learnt heaps in the process - everything you stuff up is a learning experience IMHO. And each one you fix is a bonus.

Looking forward to hearing both JJ's screaming their lungs out...

BJ

A restrictor in the gas line is always a good idea for reliable first time starts.

You should be able to tighten down the screws of the pump cover, the clearance between the cover and the cogs is what makes the difference in how well/efficiently it pumps, as these two screws also attach to the motor then there may be a alignment difference pushing sideways on the shaft(drive cog) out of the motor.
I would remove screws and look into holes with a torch see if the pump holes are lining up with the holes (threads) in the motor, if not then a slight enlargement of the holes in the pump body might help the screw line up better.
Another fine tune would be to shim between the motor and pump with wafer thin plastic washers, you may find that shimming it out slightly or just one side will cure the problem.

*sigh* - put it all back together on the test-bench and it doesn't want to play ball.

I must have upset it a little when I hooked the fuel-lines back up. Hmmm....'shimming' is starting to sound like a good a idea....

BJ

A few months ago I detailed stripping my JJ1400, it had been sitting about in bits and I eventually got around to rebuilding it again.

I have done a detailed strip, balance and rebuild in another thread [link=http://www.rcuniverse.com/forum/m_9458885/anchors_9463433/mpage_1/key_/anchor/tm.htm#9463433]JJ1400 Turbine Stripdown[/link] some of the stripdown stuff I have taken from my earlier postings here, so you may have seen that bit already.

I used the "Rocking Method" for balance and it has worked really well, very pleased with that, time will tell how good it is on bearing life.
Thanks to anyone who has given me help and answered my questions Smithy in particular.

Lot of stuff has went on about these turbines but I am still glad I bought one as it has taught me stuff I would never have learned if I had bought a P70 or similar at the start.
If anyone has any questions about this turbine I would prefer to answer them here rather on the stripdown thread as I dont want it to be about Jetjoe just a thread on stripping a 14lb turbine. Unless of course the questions are relating to the work that was done.

Hi Xairflyer,
There are a lot of things I can learn from your post even though I stripped my jj1200 many times. Rocking method would be useful to me because the turbine will be changed soon.
Installation of NGV is very difficult to me. On the one hand the position of NGV determines the position of the case which shall align with all screw holes and glow plug collar on the CC, on the other hand, fitting the NGV onto the end of the tunnel affects concentricity of NGV which is very important. So it seems only one position for the NGV. Up to now, I can not get even gap of turbine blades by stripdown many times.

Sometimes it cooled down the turbine wheel was sticky, but I can't find any problem. I think it may be caused by improper gap of turbine blades.