BarracudaHockey

My Feedback: (11)

No I have one of the original rectangular tanks I was going to sell, people keep asking me the capacity and you only list the tapered one on your website.

jcpl

Hola Carlos,
Will be ordering soon, Mini Avanti and Mini MB339
Regards from Peru.

Claud4900

Bonjour,
Après battant en électrique avec mon Avanti, j’ai juste rejoint le monde de Kero avec l’achat d’une turbine Kingtech 45. Le package est sur le chemin.
j’ai besoin de savoir le diamètre de sortie interne et externe de la buse de Grumania.
Merci d’avance et ont un bon vol.

sharam

My Feedback: (2)

Claud4900

Bonjour,
What diameter grumania nozzle output inside and outside?
Thank you.

BarracudaHockey

My Feedback: (11)

Huh?

wfield0455

My Feedback: (7)

I have a Grumania pipe for the K45 in my Mini Avanti. I took some quick measurements but the light was poor and my eyes are worse so if these don't make sense I may have made a mistake.. ID ~62mm, OD~ 67mm Bell mouth ~110mm dia.

Hope I got these right.

Claud4900

Hello,
You who have been flying for a long time, how much fuel you burn for a five-minutes flight.

Thank you

Aussie1

With a one litre tank I set my timer to six minutes with the K45, and it has about 2 minutes left when I land. I also tried my K30 in the little Avanti and set timer at 7 minutes with a 700 ml tank. Once again, at least two minutes fuel remaining, after landing.

Claud4900

Thank you for your response.
UAT or no UAT.
Difference in empty or full tank behaviour?

Aussie1

No uat, just a Honda felt clunk, and jet obviously performs better as fuel is burnt off.

cmjets

MikePS

Just finished my conversion from 10S powered JF90 to K45. Hoping to (re)maiden tomorrow. Had initial start up yesterday with zero problems. Balanced right at 145 with UAT filled and about a half inch fuel in the tank.

Aussie1

P20 install, this tank was too big, so replaced with one half the size.



K70/45 size versus K30


K45 plus one litre tank.


K30 versus P20


K30 plus 700 ml tank.
I make all of my own tanks and aim for a minimum 6 minute flight with one go-around circuit in reserve. My Avanti started out with a P20, then a K30 and now finally the K45 and in my opinion the best combination is with the K30 and 700 mls of fuel, no header and a felt clunk. These small engines sip fuel and you can get away without a header, as long as you use a quality felt clunk, which I buy from a lawn mower shop. In all my installs, I use Grumania pipes which are light and efficient.

T_CAT

Great pictures! The side by side comparison of the K30 to the other turbines and installed pictures help to truly see the size difference.

I'd love to see a video of the Avanti flying with the K30.

Aussie1

I have some hat-cam videos of it flying with the K30, but not worth showing. One day, I'll get someone to film a flight properly, but all I can say is that the power/weight ratio with the K30 is perfect! I like experimenting, and while it is way overpowered with the K45, it flies well, but feels heavy, because it is. It is a full 1.2 kgs heavier at take-off with the K45 compared to the K30, and same wing, so you get nothing for free!!

T_CAT

No doubt about that. For a plane that's built primarily for aerobatics, it's nice to keep things on the lighter side.

BarracudaHockey

My Feedback: (11)

Thats 2 1/2 pounds for us Yank's, thats a nice weight loss on a plane that size and I thought mine flew great on a 45.

Claud4900

With the K45, centering at 145 empty tank, how does it fly when the tank is full. Not too picky because the tank is not at CG. Centring before

MikePS

Remaidened mine this weekend. After having flown most flights as an edf (JF-90, HET 700-68-1200 on 10S, though had a dozen flts on 12S), the difference using the K45 was extraordinary. So much more thrust and top end. Really a different experience. 9.5lbs with full UAT (2oz MAP) and around a half tank (1.5L total capacity). Can't wait for more! Hope to have some pics soon, our club professional photog (BarracudaHockey) hopefully got a few good snaps.

extra 300

My Feedback: (3)

Hello,

I am assembling the Mini Avanti and trying to fit the Grumania pipe (not an easy task...) how did you guys solve the issue? did you grind the rear ply former to have the bellmouth behind the rails? i hate to have to cut the grumania bellmouth though...

Thanks for your help
Regards,

MikePS

See my last pic in post #738. No need to grind any formers. The bellmouth fits past the former if turned 90 degrees. once past the former, turn the bellmouth back and slide the pipe in place. the tricky part is securing the pipe to the bellmouth. Some glued the nuts in place before hand on the outside of the pipe, I didn't use nuts at all, rather used Hysol 9642 and glued the bolts in place on the outside of the pipe. Only 17 flights so far, but no signs of any problems.

extra 300

My Feedback: (3)

MikePS,

Thanks for your input. Do you mean that I have to remove the belmouth from pipe to slide it in?? Not very practical solution, as this will surely make the operation of fitting back the nuts to attach the 2 pieces a nightmare. This is definitely not a drop fit item.... I also would not trust gluing bolts/nuts as a permanent solution due to extreme temperatures in this specific area....
Will have to brain storm for a permanent and serviceable solution.

Regards,

MikePS

Will be eager to see what you come up with...

Aussie1

I managed to get my Grummania pipe in without removing the bell mouth by just flattening it slightly and sliding it in. Being spun aluminium, it is easily

One litre tank is good for 7-8 mins, because jet is quite overpowered with the K45.


Grummania pipe, tight fit but it does fit!


Honda whipper snipper felt clunk.
formed back into shape. Then refit engine and tank.