Henke Torphammar

I just got the first test and tune bench from HAB assembled. This is a test bench meant for the nano turbines such as Lambert Kolibri, Jetcat P20 or any simular turbine. The test bench comes as a kit which glues togeather really fast. Even the 7kg/15lb rated scale are included. It took me about 15min to assemble (Never mind my glueing skills )

The pivot are ball raced for minimum friction, the kit includes interchangable adapters to fit 40mm, 45mm or 50mm thrust tubes of any length. This is where it gets intresting and the test and tune bench comes in handy. A good thrust tube can increase the thrust, and a bad one can easily chew 30% of the performance. By bench testing you can test diffrent diameter of thrust tubes and also the position of the nozzle in the bellmouth of the tube. I se alot of people asking where the tube should be mounted and there always starts a debate... now you can KNOW which is the best for your setup. It's always nice to optimise your setup, but with the nano turbines it's crucial(!)

It's also rather fun to build up your knowledge base trying diffrent fuels and diffrent lubricants, seeing the effect on spooltimes, tempratures and thrust IRL.

Or why not just note the thrust on diffrent RPMs and make a throttle curve for 100% linear thrust.

I never cought the final priceing, but I know it was to sell for less then €100 includeing the scale, ball bearings, and of course CNC parts. ([email protected])

BaldEagel

Interesting stuff, I had a Grumanian thrust tube to test, but was asked to send it on to John Wright before I had fully tested it, my results showed an increase of 0.1lb with the thrust tube not much, but still an improvement, this was with a JetCat P20 would be interested to see if you get the same results with this set up.

Mike

Henke Torphammar

Testing the first engine, a Labert Kolibri T25-HP, where HP means it's a selected engine which runs the best of a 10pcs batch. The normal T25 is rated 2.7kg of thrust and the selected will deliver "more then that" enjoy our testing. Ambient temp was 19degrees celcius / 66F

If you klick the buttons on the scale it said 106oz... what ever that means

[youtube]http://www.youtube.com/watch?v=6-y2Pn1LER4[/youtube]

Henke Torphammar

A standard Koliri T25 tested. Martin promises 2.7kg of thrust and this one also provides that even in the ambient temp of about 19C/66F

I think next week two T15's will show up too, they will ofcause be tested too

[youtube]http://www.youtube.com/watch?v=mESbj4iOXUg[/youtube]

Henke Torphammar

Another T25 droped by and was tested, this time in as high ambient temprature as you can expect in Sweden, 27°C/80F. The engine ran with no strange signs of this, but ofcause a bit lower thrust and higher EGT then expected on a colder day

[youtube]http://www.youtube.com/watch?v=4qaGcTWQl6c[/youtube]


The day before we ran a total of 25flights on these three T25 equipped planes in the same ambient temp with no signs of problems, appart from mosquitos stuck on the FOD guard

Henke Torphammar

Testing is knowing :-) Gaining is hard, reduceing is very very easy!

[youtube]http://www.youtube.com/watch?v=adO9NiI7edA[/youtube]

megafly

The pipe colapsed! Thats bad....

Henke Torphammar

Yeah, now we know the bell mouth is needed :-)

Henke Torphammar

P20SX tested in out test bench. Ambient temprature of about 10 Celcius.

[youtube]http://www.youtube.com/watch?v=t4M6acKtrnI&list=UUXbd6D3PhZhqageOYtpOzOg&index=1&feature=plcp[/youtube]

Henke Torphammar

Another Kolibri T25 tested at the same time as the P20

[youtube]http://www.youtube.com/watch?v=0o8F4F6erms&list=UUXbd6D3PhZhqageOYtpOzOg&index=2&feature=plcp[/youtube]

Henke Torphammar

BaldEagel

The relative compressor size look similar, so is the difference due to compression ratio? or have I assumed the incorrectly and they are different size's?

Mike

Henke Torphammar

To compare the compressors I would have to disassemble the P20 and that I can not do as this is not my engine. The compressor is only one part of many that needs to work well to put out good thrust. The gap between compressor and the shroud was smaller on this P20 compared to the one JC showed on Jetpower. Still the Kolibri has an even smaller gap which is better for performance.

Things I also noticed is that the solenoid valves are exactly the same, JC has only glued who of them togeather. Fuelpump is exactly the same too, but JC has their bus sytem mounted to the pump.

The installed weight of the P20 is 150grams heavier then the Kolibri.







The cone is off center by about 1mm. Again not my engine so I'm not fiddeling with adjusting it. Probably easy to do.

BaldEagel

Thanks for the info Henk, all interesting stuff.

Mike

raptor30se

Is there a make on the lambert valves? Would like to find source to make an extra set for p20 without markup from jetcat.

Henke Torphammar

I'll check that for you in a bit

Henke Torphammar

I only find a Lambert sticker om them, so not much help.

frema

the rotors of the p20 are just a little to small for high trust
you can say that the p20 is a basic engine
the compressor is 36mm , but has only 10 blades,and to small intake
also the tipheight of the compressor is very little so thats why the engine does not produce more then 2,4 kg
i tuned many p20 engines ,and i can get them to 3kg
the kolibri t25 , has larger compressor blades,and more tipheight
also the turbine blades ar longer ,and instead of 21 blades , he has 25 blades, more power
and thats why the t25 can reach the 2,8 ,almost 2,9 kg
its simple ,if you understand turbines
also my jetjoe junior produce 2,6 kg now
only change is compressor wheel

BaldEagel

frema

Thanks for the explanation that makes it a whole lot clearer, do you by chance tune the P20 for other people?

Mike

frema

ofcourse Mike
just sent me a pm ,and i will give you info
Regards
Martin.

Henke Torphammar

Have you too seen an improvement in the gap between compressor and shroud or is the P20 I got just a good one?

frema

yes its correct
they improved it
but still to little compressor wheel
not enough power

Henke Torphammar

More testing done, this time in cold weather and bright day light :-) Some how the P20 did idle at 113000rpm, but I'm sure that is due to human error from our side and not an engine related issue.

[youtube]http://www.youtube.com/watch?v=GkH_ezJU6Hg[/youtube]

Henke Torphammar

Iv'e gotten a couple of PM's and comments about the head to head test and I thought I'll post a general reply here too.

Someone thought it was unfair to compare a P20SX to a tweaked Lambert, but this is not the case. The T25-HP is a shelf product available to anyone. We are simply compareing the high end engines from both manufacturers to be able to make the convertion kit as good as possible. For a review of which turbine to get I would compare a T15 to a P20SX, I think those would give an airplane about the same performance. Need more power, then look for a T25.

Someone also thought our diffrent tests were irrelevant. So might it be, but they are still performed in the exact same way on both engines and there for very comparable. Again to gather data for the convertion kit rather then a review. Looking at the P20 tailcone it's pretty obvious it's hotter then 590°C when glowing red hence checking it out with the external probe. This misstake is also made by RCJI where the list says 621°C an the cone glows red. Looking at the GSU is obviously not a good way of checking EGT. (As there is a pressure drop over the tailcone the exhaust after the cone is colder then inside the cone.)

A youtube comment says that there "must be something wrong with p20sx did not start as clean and way too hot it will be in melt down zone in summer temp". I simply do not know, this is the only P20 I have ran. It starts and goes well, puts out about the thrust it's said to do and looks about the same as the other P20 videos at youtube. Anyone with more P20 experience want to chime in?

Someone also suggested reading the manual closer, well...we only recived a german manuals for the P20SE and another one for the larger turbines, not for the P20SX. Is there an url for the P20SX manual in english?

[link=http://www.youtube.com/watch?v=vkO39Yvz4eQ]www.youtube.com/watch?v=vkO39Yvz4eÂ*Q[/link]
[link=http://www.youtube.com/watch?v=lI7jja8YJxU]www.youtube.com/watch?v=lI7jja8YJxÂ*U[/link]
[link=http://www.youtube.com/watch?v=2FI9oht4qR8]www.youtube.com/watch?v=2FI9oht4qRÂ*8[/link]


This is data from a stock Lambert T25 tested a couple of times during the year.

Kolibri T25 (exact same engine)
2650grams / 5.84lb @ 27C / 80F
2880grams / 6.34lb @ 10C /50F
3250grams / 7.16lb @ -3C /27F

frema

Well i can say i knew it along that jetcat is fooling with the egt probe
i measure it too
they made a big mistake in the engine , but that is something different
i can understand that the t25 is much more powerfull because of the completely different chamber , but also the much bigger impellor and turbine
Martin did a very good job , and jetcat has a basic engine
thats how i see it
congrats on the testing , very nice.
ps, i tuned the juniors
2,3 kg is not bad heeee

Regards,
Martin.