sounds like your pump is too weak for this motor.

But it's flightworks 400B which is same as in other similar motors(good upto 40lbs).

Thanks.

Scratch what I wrote. Flight works 400 pump no issue but do make sure it does not have crud in it. You said you just bought this used, correct? Make sure the pump works well. I am trying to rule everything else out before you start to look at the engine. Maybe PM me.

Andy

Hello Andy,
I currently don't have other pump to try.
Can you suggest a fuel pump for this.

Thanks.

Hi... I really don't have any suggestions here. I think you need to have some alternate parts to start out. Make sure the propane and fuel inlets are not mixed up as that would cause you some issues but i doubt you'd reach 75k with the inlets mixed up. Without a known to be good pump, and real working knowledge of the engine you might be chasing your tail.

Try flushing the pump and running fuel through it circulating it for while. if it seems sluggish take it apart. there are only two screws but be careful not to lose the gears the pin or the o-ring in the cover. I would use 5volts to do this. I don't know that I lean toward the pump here but this is all guess work and I am a mechanic so I take known to be good parts and rule things out so you can deduce what is wrong without guesswork

Andy

Hi Andy,
I have the working knowledge of the gas turbines as I have been making micro gas turbines since like 5 years now. Made around 6-7 working engines on my own (just that they were not for RC purpose) but for power generation.

I haven't quite worked with this micro pumps as I never used them so that's where the problem is.
To me the pump seems to run fine without any sluggishness. And the fuel lines are surely not mixed up as the engine will surely not reach 75k rpm with 1 lb propane can for extended duration.

I am quite sure that its not the pump but in order to be 100% sure I need to have a reference point to compare it with. If anyone can provide me any symptoms of a failing pump. Flow rates or power draw at priming etc.)

Just some calculated guess work here.

Thanks.

it could always be an old pump / weak motor or similar.

Hello Dazz,

Are you spinning the rotor with compresses air or with a motor drive and is your cradle sensitive enough to reach such low values and if re calibrate are you finding the same results? what Hz are you spinning ?

I,m builded the cradle with bearings support , still playing around to get better results , I must say its fun to actually reach better specs each time

I have made a solid aluminium cradle, balancing comes close to 2mg now.

Roughly I balancing the rotor first but then balancing the whole engine ,more accurate when bearings are seated in the shaft

I was wondering who sells the Regal ECU? I have need to replace a ECU on one of my Wren 54 turbines. Any assistance apprecieated.

dave

That would be a discontinued ecu now so not availabble new but any of the older gasper/xicoy fadecs will work as well like the AU504 or AU605 probably the later AU10 can also be configured, lots of turbine brands use Xicoy ecu, kingtech jet central so other suppliers repair places might have one knocking about try turbine solutions in uk he does repairs on wren or email gasper and ask does he have any old ones lying about

Hi everyone, sorry to resurrect an ancient thread. If there is a better place for advice, let me know:

I've got an old JJ1200 KIT that I got in probably 2007. It has the "semi auto" Regal ECU. I start it with a blowtorch and an air compressor. If the firmware is update-able I have not done it. I ran it a few times back when I first got it, I recall feeling it had ECU issues, I shelved it and only picked it up again recently. I am having an issue with it flaming out when I approach the high end of the RPM range. The ECU reports speedlow then flameout. I strongly suspect the problem to be the hall effect sensor. After running it, it is commonly reporting an RPM of 6600 with zero rotation. It continues to detect rotation, just is then wildly wrong. I think when I approach the high end of the RPM range a glitch in the RPM signal is causing the ECU to sense an impending overspeed so it cuts fuel, and way too fast, causing a flameout. Or possibly the sensor glitches to show a momentary zero rpm and it detects that as speed low and flameout. I'm not sure, but I am pretty sure its not ACTUALLY flaming out as it cuts out instantly and I don't get that tell tale white smoke trail of unburnt jet fuel for a few moments. Interestingly, when the engine is running the RF interference must be bad as my FrSky telemetry cuts out frequently. I'm running on a 3s lipo, with a BEC providing the power to the receiver, then a male to male servo lead going to the ECU. So I believe my BEC is powering the ECU. Everything is connected to the same 3s lipo. As I'm typing this I am realizing that could be the cause of all the RF interference. Maybe I should try a 4.8v NiCD.

Things I have done:
-Removed and re-installed the hall effect sensor checking for issues. Found a standoff spacer slightly too small so it wobbled just barely. Fixed, now snug
-Applied a strong magnet to the hall effect sensor hoping to make it stop reporting 6600. Did not fix. The 6600 seems to be intermittent
-Tinkered with the deceleration delay from 15 to 25. Problem persists.
-Calibrated my throttle range in the ECU
-The max rpm is currently limited to 140,000 so I don't wildly over speed it if something happens. It only seems to happen near the end of the throttle range, not necessarily approaching the actual 160k limit. I wonder what happens if a value is sent beyond the calibrated throttle range? Would that cause a shutdown? I may tinker to check that.
-I have disconnected the RPM sensor while the engine is running to verify the behavior. A nearly immediate shutdown with a speed low and flameout message, leading me to believe this is definitely related to the speed sensor.

Any suggestions or "must do" items to get this engine running smoothly? Even not related to this problem. I'm not afraid to take it apart, I am very mechanically and electronically inclined. Even building my own ECU is not totally out of the question, but I'd rather spend my time on other parts of this larger project.

Thanks!

Went thru a similar issue recently running everything off one battery , issue went away when each device was powered separately

I powered from an alternate source and still get telemetry warnings, but haven’t run it yet. Interestingly, if I take the Hall effect sensor and place it directly next to the receiver the ecu reports 6600 rpm. I have a strong suspicion this is the issue. I’ll separate everything much further and see what happens. The Hall effect sensor is extremely sensitive.

I separated the receiver from the Hall effect sensor by about 18” (they were about 6” before) and now it runs fine. I think the telemetry was interfering with the speed sensor causing it to either think it was over speeding and reducing throttle to fast or read zero, not sure. It seems to be running fine.

This engine is old and never upgraded in anyway. If anyone has suggestions about must do things to keep it running well, please let me know. Also, I used to start it with some kind of wand, I’m using an air compressor now, anyone know if one of these wands can be purchased today? I think it was called a handy wand.

Thanks!
Ted

Ted, I did have issues with wierd RPM readings on a Wren when the glow plug wires were run along side
the starter & RPM sensor wires. A friend had a Wren 44 which used a 'wand' to start it but quickly changed
to an on-board starter with FOD screen after the rubber insert fell out of the wand fell out & narrowly missed
getting sucked into the intake. A clutch is needed on the starter motor shaft if mounted on the engine.

I found an electric jet starting motor with bendix attached already at DreamWorks RC, I'll just make a new nose housing that I can mount the start motor on to and integrate a FOD screen. Honestly, in the very little time the motor has operated the compressor has visible discoloration on the leading edges, presumably from whatever dirt and grime is in the air. These screens are clearly advised.

Ted

When I bought my Wren the starter fell off on the third flight jamming the engine so I sent it back under warranty.
While it was being repaired I had the new integrated FOD screen/starter holder fitted & I think they sent me back
the original starter holder & the three supporting legs for it which I have no need for.

The Jet Joe was a Wren copy so these parts may fit, if you pick up the postage (from Oz) you can have them if
1/ I still have them & 2/ if I can find them.

A friend had a Jet Joe around that time, I think JJ used something cobbled together from hose clamps to mount
the starter. His engine was never really succesful in a Boomerang intro, replaced with a Jetcat P-70.

Thank you for the info (I had no idea its an MW54 knockoff) and the offer. I'm mostly done designing in CAD a new motor cap and starter motor holder, so if it doesn't work out and I give up (rather possible) I will take you up on that offer, it is truly generous of you. If its an MW54 clone, my understanding was the MW54 had multiple compressor options. I wonder if a simple compressor update would net me some extra thrust....

Ted

Good news, bad news. I have the starter mount & the front cowl but not the mounting legs.
The Wren 54 mounts the starter to the inner cowl section, the Wren 44 to the front cowl (as I have one of those)
but this cowl has no holes where it would have mounted.

The legs appear to be machined from one piece of aluminium with a male thread to screw into the starter holder
at the top & threaded holes in the other end for the mounting screws.

Let me know if you need it, another reader has PM'd me to say he will take it if you don't.

Just order new parts from jetjoe they have everything

Thanks Boomerang, I have it all designed up now and when my new electric motor comes if I can't get it up and running I may take you up on this.

Do you know if there is a US supplier, or is it just jetjoe.com which I presume is the Chinese supplier?

Just from china, I have parts for them all the time, and I did setup programming for jj1400 to make it work perfectly