Originally Posted by horsefeet

t cat thanks pls do

and weigh it also if you can

Not a problem at all. In roughly a few hours, I’ll be able to get that done.

The Sebart double walled pipe is roughly 5.6oz in weight and 18.5” long including the bell mouth.

I purchased mine from RC-Castle a few weeks back.

Originally Posted by T-CAT

The Sebart double walled pipe is roughly 5.6oz in weight and 18.5” long including the bell mouth.

I purchased mine from RC-Castle a few weeks back.

I checked my Grumania pipe on my mini Avanti, and it weights 118 gram and is only double walled for the last 6-7 inches, pretty well only under the fin. It runs very cool and a perfect combination with my K30

Originally Posted by Aussie1au

I checked my Grumania pipe on my mini Avanti, and it weights 118 gram and is only double walled for the last 6-7 inches, pretty well only under the fin. It runs very cool and a perfect combination with my K30

It looks great! That’s a 1.4oz difference. Not too shabby. I wonder what the weight of the Sebart pipe was when it was a single wall. Overall, the Sebart turbine conversion kit seems not too bad for the price.

Henke, what’s roughly the weight of a HAB pipe in the size mentioned for the Sebart mini Avanti S?

found henke post for hab pipe 40mm here back on page about 23 or so



"Wow, good input. I do not know what Sebart is doing? My 40mm tube is 47grams, thats 1/3 of the sebart. I know Sebart usually mounts the turbine where the EDF used to sit also.

Even if choosing the easy route mounting the turbine at the stock EDF position it makes no sense adding weight behind the engine LOL.

I would never get that kit. But people do, because sebart is sebart and should know how to do it.."

henke
now the question to henke is this a single wall pipe and does it require forming mounting rings to keep it away from inside of fuse and allow air flow around it to exit out the rear......

and t cat yours is 158gr and that is getting way more than hab pipe but i need to consider cost as well as weight................will see what hab replies to my email for price

if not then grumania will be the way i go.

All of that is for sure a factor....cost, weight, quality, ease of install, overall value, etc. It would be interesting to do a price and weight comparison for the same length pipes from various manufacturers (although that would vary also with single vs. double wall) such as Tam Jets, Sebart, Grumania, HAB, etc. I haven’t messed with opening the rest of the packaging that comes with the Sebart conversion kit such as the fuel tank and fittings. I’d think without the extra items, the Sebart pipe would be even less expensive (probably not by much, but some nonetheless, ha-ha), but it’s only sold with the extras.

The TamJet pipes are being sold again and appears some for Sebart jets. https://www.rcgroups.com/forums/show...of-sabart-jets

My single wall Grumania was 62g at 32cm, think 6" longer for Avanti you would be looking at 90g at most.

Might try a Hab pipe for my next project to compare myself, I also like to test.

Never realised Sweden was part of the European trade union Henke, always thought it would invite customs charges to UK so that certainly makes it more viable.

Originally Posted by T-CAT

Henke, what’s roughly the weight of a HAB pipe in the size mentioned for the Sebart mini Avanti S?

46grams for the tube. I have a picture of it some where, can fand it now...

also remember it's about tuning the setup. the 46mm takes power away the 40mm lets you GAIN power.

Various testing 46mm tube. Notice that at it's best the 46mm makes equal power as with no tube at all in the 25-30N use case.....

HAB Electronic test and tune bench (1 min 45 sec)

I happen to have a K30 sized engine too making more power, look here

Lambert T50 thrust test (3 min 46 sec)

And then with the 46mm tube, GAINING power.... So the 46mm tube is more suited for higher power around 5-6kg then 2-3kg.

T50 with 46mm thrust tube (1 min 45 sec)

The 40mm can do 24" with no losses at 3.5kg!!



...but what do I know...

Originally Posted by horsefeet

henke
now the question to henke is this a single wall pipe and does it require forming mounting rings to keep it away from inside of fuse and allow air flow around it to exit out the rear......

Tube hangs on two small pins in the front and a simple ring in the tail.... Keeping it simple and light. Remember, all parts we are looking at are behind CG.

Originally Posted by Aussie1au

I checked my Grumania pipe on my mini Avanti, and it weights 118 gram and is only double walled for the last 6-7 inches, pretty well only under the fin. It runs very cool and a perfect combination with my K30

Why do you use a tube when tail mounted is lighter??

henke two questions

how will you deal with heat on the vertical fin of the 3m fox glider made of foam

with the taft valkyrie i see the turbine inside the tail tube several inches is that just foil tape on the foam inside or rings of thin metal

got the info from hab on the pipe

We have what you need, is a single wall pipe, there is no mounting kit because all fuselages is different size. If you give me which outer dimeter in metric millimeter we can make rear mounting ring for you.



Price for pipe 90 Euro

Shipping to USA 20 Euro

Pay Pal +5%

Custom mounting ring 10 Euro


around 145.00 us dollars


BR

Amir Rahimi

+4637280444

www.hab.se

Originally Posted by horsefeet

henke two questions

how will you deal with heat on the vertical fin of the 3m fox glider made of foam

Nothing... just fly?!

Originally Posted by horsefeet

with the taft valkyrie i see the turbine inside the tail tube several inches is that just foil tape on the foam inside or rings of thin metal

Yes?! Turbines are not particularly hot. People make assumptions which often are wrong. You will be amazed what you can do when starting to test.

Look at my A6 and the Yak 130....

Originally Posted by henke

Why do you use a tube when tail mounted is lighter??

I bought this jet locally complete with the pipe. At first, I flew it with a P20, but now have the K30 in it and the little Avanti flys even better! I have done five conversions on foam jets using the tail mounting technique, and all have been successful. I start by cutting two slots in the foam around the tail and epoxy two lengths of spruce into the slots, and these support the engine. I then cut a hatch over the engine and cyno paper hinges on one side, this allows access to the engine. When done properly, the hatch is hard to see. I also make up a small aluminum half tube made from a beer can mounted above the hottest part of the engine. I don't know the weight of all of this necessary mounting equipment, but probably around 60 grams? All of my jet installs are different and for me they all work well. As an example, my Skysword didn't have the required diameter at the tail to do a tail mount, so a made a 6 inch long dual walled thrust tube from a crashed 80 size tube that I had lying around. Had to use rivets and screws as no access to a welder, but it works well. Also, a couple of local members have K45's in their mini Avanti's, and although heavier, they still fly really well! Here's a couple of pics of just some of my installs, and while I agree with you about turbines not being overly hot, a wet start with flames will soon show you how well you have protected the foam!!

LOL, the end of your post cracked me up. That’s a great post, and I love seeing data thrown into the mix to help make decisions on the matter. Thanks for sharing this Henke.

Originally Posted by henke

46grams for the tube. I have a picture of it some where, can fand it now...

also remember it's about tuning the setup. the 46mm takes power away the 40mm lets you GAIN power.

Various testing 46mm tube. Notice that at it's best the 46mm makes equal power as with no tube at all in the 25-30N use case.....
https://www.youtube.com/watch?v=adO9NiI7edA

I happen to have a K30 sized engine too making more power, look here
https://www.youtube.com/watch?v=0Z6QpSgwWoQ

And then with the 46mm tube, GAINING power.... So the 46mm tube is more suited for higher power around 5-6kg then 2-3kg.
https://www.youtube.com/watch?v=MhqKZHIKFx8



The 40mm can do 24" with no losses at 3.5kg!!



...but what do I know...