Yesterday I test flew my new starjet with RAM 500 power and it was supurb. I have fitted the Wren supplied fadec ECU and the combination is perfect, the model weighs 13lb 6oz dry and definatly the quickest RAM500 or MW54 plane I have seen and it lands at walking pace. Im well pleased

Hi Jason,

Glad it worked out well ! Post some pics. I'll eventually get my Starjet done but I first have to tackle my RAM problems. I'm going to replace the turbine wheel and perhaps the ECU. The saga continues....

Hi Marc,

Is the Reaper grounded till the engine dramas are sorted?

Any pics of the model all finished and together?

Regards,
Garrett

Hi Garrett,

I'm trying to get this engine to be something other than an expensive paper weight ! It has some serious issues so the recently completed Reaper is indeed grounded until I can get a reliable powerplant in it. I've been sitting on an MW54 kit for 17 months and I didn't appreciate the fine workmanship of the kit until I took apart the RAM 500. I started the MW54 kit today and will be going full speed ahead on its construction over the next few days so hopefully the Reaper will fly with the Wren soon.
I'll post some pics of the Reaper tomorrow after I get some nice outdoor shots.

I'm thinking of going BMT for a bigger turbine. It seems like Andre is a perfectionist. That would be a refreshing change !

Marc,
Finish the MW54 kit and you wont be dissapointed man! I sure hope you get the ram 500 problems sorted out, I was thinking about it all day today after our talk! I am sure it will come out all right after some reworking. I sure hope so anyway!

Jason,
Can we see some pics of the starjet?? Please!?

AJC

heres the starjet

and another

Jason,

Well done ! It looks great ! I gotta get mine built. I'm working on the MW 54 today. Things are going well and no screw ups yet. Oops, I probably jinxed myself...

How did you finish it ? Some installation pics would be great.

Nice looking plane indeed. WHo carries that model in the US or Canada? I have seen ads for it in RCJI but not much info other than a small photo.

AJC

Malcolm Kay is the US importer.

Hi Guys,

I have to say I'm not a huge fan of the Starjet's appearance ( that's kind of funny coming from a Reaper flyer), but they are a very, very impressive performer from what I have seen.

Anyone out there see an Exocet fly with turbine power?

Garrett

The exocet is very fast and flies really well but requires alot of modifications to convert to turbine. There are alot of good aircraft out there that require less work and fly as well

Yes I had a exocet with a sophia a couple of years ago and it flew much the same as the starjet as it has the same or scimilar wing. Still a very quick plane dispite those massive inlets.


jason

Hey 747,

Why do you need to change your 500's turbine wheel? Is it damaged? Just curious...

Kelly

Hi Kelly,

While doing a bearing change after a very small number of runs, I saw that the turbine wheel had been bored off centre. The LE face of the turbine wheel was ground away to try to bring it into balance thereby comprimising its efficiency, balance and safety. I've decided to replace it with a wheel supplied by Wren. After that issue is sorted out I'll try to figure out my flaming out problem. Maybe a new ECU....

OK, that's a good enough reason... The original 54mm wheel came from Wren in the first place you can't really do any wrong here.

Are you sending the engine to WREN for professional balancing? If not there are a few guys around Canada that can help you out if needed... Ed M, myself, and a few others I think. Internationally, you could send it to Carlos, Wren, ChrisM in Australia, etc. After the smoke clears, my system will be able to detect a felt pen mark on the shaft... Being that the imbalance function is parabolic, its critical on a 160K RPM engine! Its well worth it to send it to Wren or someone with the equipment, your bearings will thank you.

As far as the ECU is concerned... I'd recommend the manual / full auto FADEC by Gaspar, The GB Hobby unit, or our new TEMS ECU. I can have a full auto TEMS tailored to fit the 500 quite easily as it is almost exactly the same engine core as the PST J600. The PST just has a slightly higher mass flow because of a different compressor wheel. AMA approval for the 500 might get a bit sticky though. We plan to eventually have the TEMS approved with a bunch of 3rd party engines. Don't know the story for the GB or the FADEC.

Good luck, sorry to hear about your misfortune.

Kelly

Just couldn't resist to respond here. Amazing to see the turbine wheel balanced that way. Is this the original that came from RAM or someone balance it afterward? Aerodynamic on the turbine wheel is critical and any turbine manufacturers know this.

The PST J600 and TEMS should be with Tom Cook very soon if not already there for AMA approval.

Regards,
B777
Kraivuth S.
PST Jets Thailand

Amazingly enough, this is how it came from the factory ! The asymmetrical grinding of the wheel was an attempt at making the wheel usable after it was bored off centre and crooked. It amazes me that it ran !

Kelly,

I'm using the static balancing method endorsed by Wren to balance my kit MW54 and the RAM. Is your balancing rig working ? I could pop out to YVR to have it done right if you're offering the service.

747, I would be more than happy to help out, just one hitch.

As it sits right now, I am set to maintain all parts of the engines we distribute, except for operations that require balancing. I have a system that I am comfortable using on KJ-66 derived homebuilts but I would not consider using it to offer services because its nowhere near capable of getting a repeatable 3 mg-cm balancing tolerance. (that's what our engines are built to)

On the other hand... I have the shaft mounting hardware for the new system I described earlier and this is easily adaptable for any current turbine design. Right now I'm still sorting out the electronic components, which should take another month and a bit. (didn't think I would need them yet...) Once I have verified the accuracy of the new unit I will be offering this service for our own warranty or 3rd party engine owners.

Here's how things generally work out. The shaft assembly is completely removed from the engine and the bearings are replaced with a set of inner races from another set of high tolerance steel bearings. The inner races ride in Teflon V-blocks on the balancing apparatus. The shaft components are then given phase markings, dynamic balanced, disasmantled again to reinstall the bearings, and reassembled inside the engine with the markings in line. I'm not familiar with the interference tolerances used in the 500's bearing fit on the shaft so it may or may not be easy to get them off. I will see what I can find out.

What I'd suggest you do is go with the WREN procedure for now, but just try not to run it on an hourly basis. With one of the ECU's I mentioned, you will probably want to...

If you are still interested, I'll let you know when I have things sorted out here and we can go from there.

Good luck,
Kelly

For what its worth, I balanced my Wren MW54 kit as per the Wren instruction, and have run it over 5 hours in the past two months with no problems (so far!). My max RPM is 160,000 and it is super smooth at all rpms' other than a very, very slight vibration when passing through the 85-100 thousand area. I attribute that to some harmonic vibrations as it is only at that rpm range. So far my bearings are as good as the day they were installed and I have not heard any squeels or whathave you.

I am interested to see what lifespan I will get from mine, and compare it to the life of a factory balanced rig.

What do one of you guys here in Canada charge for a balance?

One note here before I forget: when I got the kit for the MW54, there was a small white paint mark on the compressor. I left it on when I did my initial balance. Then after running the engine for the first 6 to 10 runs (approx 5 to 6 minutes per run, maybe one hour running time total) I noticed the engine was not as smooth as it was originally. After inspecting the parts, I noticed that most of the paint was gone off of the tip of the compressor blade! This small amount of weight was very noticeable indeed, and I had to strip down and rebalance - getting back to my original smooth runnings where it remains. Just somrthing to look out for anyone who is building one..

Andrew Coholic

Hi Andrew,

True, it can be done in the technique you guys are using on the Wrens and they will run fine. Statistically, I am betting that you will see a difference over time with the appropriate customer base though. There's just no way around it, dynamic balance is always better. As an example, that's why the SimJet kit engines are sent back for final balancing before the ECU software allows full throttle...

I will release the price sheet for the balancing and other services when I am ready to take shipments.

Thanks,
Kelly

Kelly,
No doubt about it, I would assume that a professionally balanced rotor will outperform a "home" job. I wouldnt dispute that! I am interested how long my bearings will last, and after I have to replace them I would be interested in a balance job for sure. Then I can compare that to my first set.

One thing, the machine is only as good as the operator, and I have had one BAD experience (allmost deemed my turbine wheel unuseable) with the dealer that first balanced my wheel. Needless to say, I had to do it over and barely had enough material in the raised portion of the wheel (that ring where you remove material) to undo what was done on the botched job! Luckily I got my $$ refunded.

Thats why I ended up doing it myself in the first place.

It would be really nice to have someone in Canada to deal with in the future. Keep me posted..

Andrew

The drill and tap version of the MW54 went together almost perfectly over the last 2 days. I only have to do the balancing this evening and then final assembly which won't take too long. It's a very rare occasion when I find a kit that EXCEEDS my expectations. There's a lot of junk out there that you pay a lot of money for. If I don't get called to work, I expect to do my initial test runs tomorrow and start installing it in my Super Reaper.

Andrew,

Did you use any type of sealing compound between the case and case rear? Mine fits very tightly as it is.

Time to get out of the basement and get some sun for a few hours...

Hi Marc,

I used an exhaust joint paste to seal mine and it seems fine.Got 6 hours on mine with a hand balance with no vibration at all.
Good luck with the test runs (not that you will need it).

jason

We have our Wren turbine balanced by Wren themselves seems to be running ok.