Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Turbine Helicopters


Turbine Helicopters Turbine R/C Helicopters


Reply
 
Thread Tools Display Modes
Old 11-08-2011, 03:00 PM   #1
DDragon
Registered Users
 
Posts: 1,329
 

Join Date: Aug 2007
Location: Canada
Default New Tank Configuration for Wren 44

Well, as mentioned in another thread. Here are the pictures of the new tank configuration I have for my Trex744.

As some of you may remember, I originally had those twin (ugly) green tanks on the sides. I decided to streamline it and place a smaller 24 oz. Du-Bro tank below the tail.

The twin tanks were 30 oz with the BVM, this one is 24oz. I was getting 15minutes with the twin tanks... took here for a spin today and I'm getting 8 minutes leaving about 1 oz of fuel in my BVM. It's a little less than I expected. But not bad.

The CG is actually more to the front (even with a full tank) now which I think is strange... but it's not bad. I may be able to even it out more.

Thinking of placing a couple of small overflow tanks on the side to add more time. But not sure how to Plumb it as this stage.

If people can respond with their current fuel capacity and flight time using a wren 44 I'd appreciate it.

Forgot to mention. I have it titled slightly back so that all the fuel drains. Once I get my CNC mill up and running I plan on making a better set of mounts out of CF.

Thanks.
Attached Thumbnails
Click image for larger version

Name:	photo.JPG
Views:	159
Size:	139.5 KB
ID:	265511   Click image for larger version

Name:	photo2.JPG
Views:	139
Size:	110.4 KB
ID:	265512  
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-09-2011, 11:19 AM   #2
cbdane
Registered Users
 
Posts: 4,881
 

Join Date: May 2006
Location: Bay Area, California, U.S.
Default

Oh my, not sure. Looks a little cobbled on, IMHO. Please accept this with the helpful spirit that it is intended.
__________________
Have laser, will travel.
cbdane is offline        Reply With Quote
Old 11-09-2011, 02:56 PM   #3
Aussieheliguy
Registered Users
 
Posts: 179
 

Join Date: Feb 2006
Location: Cairns, Australia
Default

Is that a good idea to lay the gas cylinder on it's side? I would think liquid gas would be more likely to flow out of the cylinder like that.
__________________
MA RAZOR#26-Hyperion brushless,85HV,9S,9252,Vbar V5.3...thrashing machine
Trex844 Turbine (stretched 700), Wren 44 heli, Hitec HV servos, FBL CGY750 1.31, born 01/2010
MAAA: RW25, FW25, Gas Turbine Inspector
Aussieheliguy is offline        Reply With Quote
Old 11-09-2011, 02:59 PM   #4
ppridday
Registered Users
 
Posts: 1,291
 
My HF Map location
Join Date: Mar 2005
Location: Detroit Lakes, MN and Mobile AL
Default

Gotta agree with cbdane to tell the truth. That is where the tank sits on my Pred/Wren and I hate how mine looks. I'd rather have the saddle tanks on mine... Sorry dude... We could all have a if that helps...

Paul
__________________
I love the smell of kero in the morning....
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ppridday is offline        Reply With Quote
Old 11-09-2011, 07:32 PM   #5
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Thanks Paul thanks cbdane

Actually I adjusted it today so it sits higher. Right now this whole exercise is just for proof of concept. If the positioning works out I'll make some better brackets out of cf once I get my cnc mill up and running.

So far it's not bad, but I'm unsure about the center of gravity and I'm only getting 6-8 minutes flight time. I was getting 15 out of the twin tanks.

If this doesn't work out maybe I'll go back to the side tanks. Actually, I saved a set of Budweiser can/bottles I thought those would skew cool fuel tanks.

But this is just another winter project

Hey Paul, forgot to mention, it handles like the wren pred with this configuration... Not sure if I like that. I can see myself going back to the side tanks once I get my machine working... One thing for sure, the side tanks with the PVC brackets may have looked like hell, but it was really well balanced.

Thanks guys, I do appreciate your comments thats why we pst here right?
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-09-2011, 07:36 PM   #6
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Quote:
Originally Posted by Aussieheliguy View Post
Is that a good idea to lay the gas cylinder on it's side? I would think liquid gas would be more likely to flow out of the cylinder like that.
Forgot to mention.... I have it like this on my wrenpred too... Never had a problem.... But I don't fill it up much...just a squirt to get it started. I think if I filled I up more it would cause more problems.
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-09-2011, 08:02 PM   #7
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default New Pic

Just for fun... here's a pic of the tank a little higher... I lifted it about 1 inch. It's very stable and sits well between the rails. But the CG is off and the time still bugs me.
Attached Thumbnails
Click image for larger version

Name:	new.jpg
Views:	83
Size:	119.8 KB
ID:	265816  
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-10-2011, 01:09 PM   #8
lperagallo
Registered Users
 
Posts: 2,225
 
My HF Map location
Join Date: Aug 2006
Location: Westfield, IN
Default

With the Bergen setup of side tanks at .6 liters a piece I fly for 9:30 with a 2:00 reserve.

Tanks sit centered over the main shaft so there isn't a change of CG as it flies.

Lou
__________________
Vector 550 Quad/Octo Multirotors
DJI WooKong Multirotor Controllers
Twin Bergen 44 Magnum Turbines - KERO Start FBL
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

www.circlecityhelis.com
lperagallo is offline        Reply With Quote
Old 11-10-2011, 04:46 PM   #9
MattJenner
Registered Users
 
Posts: 143
 

Join Date: Jul 2011
Location: Kent
Default

Yeah deffinatly would not put gas cannister on its side, it needs to be upright or neat liquid will enter which will expand in the turbine and cook it to near melting point.
On my Longranger where by design the cannister is on its side under the rear seat i allowed this to happen and On a data download i did, my MW54 i had reached 1100oC, thinking the ECU would shut it down i carried on with the startup process.
It was only after a chat to Wren that i found out, that on the startup some of the fadecs dont shut down a high temp,and some do, but they did not know which ones did and which ones didn't, I have a Mark 4, 54.

I stripped the turbine down, and could clearly see where it had really over heated, so after this as turbine was down on power, I ensure that my cannister is vertical on all my turbine machines.

Matt
__________________
Have Fun
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
MattJenner is offline        Reply With Quote
Old 11-10-2011, 10:41 PM   #10
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Hmmm, been thinking. I may pull everything apart and go with the stock tank and position. CG can really make or break the fun factor. And it's not too fun.
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-11-2011, 10:31 PM   #11
rcnz
Registered Users
 

Join Date: Sep 2006
Location: Nelson / New Zealand
Default

How long is the flight time with those using the HeliChris conversion with that big round tank. You might be able to get the big round tank and cut to fit into the standard 700. Looks tidy, Just a thought.
rcnz is offline        Reply With Quote
Old 11-12-2011, 12:57 PM   #12
Laurens
Registered Users
 
Posts: 6,124
 
My HF Map location
Join Date: Apr 2004
Location: Oegstgeest/ EHGR, the Netherlands
Default

I really felt a difference in the whole flight, because of CG issues on my Predator Jetcat with the tanks in the back.
__________________
Team Thunder Tiger Europe
MS Composit, 4RC.nl, Scorpion systems, Scorpion packs

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Laurens is offline        Reply With Quote
Old 11-11-2011, 01:14 PM   #13
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Do most people get two stock tanks, cut them in half and plastic weld them together to make them larger? I may give the a try.
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-13-2011, 03:23 AM   #14
kevinww
Registered Users
 
Posts: 660
 

Join Date: Nov 2008
Location: London
Default

Quote:
Originally Posted by DDragon View Post
Do most people get two stock tanks, cut them in half and plastic weld them together to make them larger? I may give the a try.
Tried that and it worked, apart from if you left it standing with any fuel left in the tank. It would slowly leach out through the joint if it wasn't perfect. Eventually settled on 2 700 tanks side by side in the normal 700 position and hooked up in parallel.
__________________
Trex 600N Pro with Vibe 50 Head and YS91RS motor, Vibe 50 VBar FBL, Trex744 VBar FBL MW44 Turbine, Mikado Logo XXTreme, Mikado Logo 600 12s, Mikado Logo 500SE, Vario UH-1D (Building), Scratch built 625mm Quad, Author of Spektrum Telemetry Viewer App.
kevinww is online now        Reply With Quote
Old 11-13-2011, 10:10 PM   #15
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Quote:
Originally Posted by kevinww View Post
Tried that and it worked, apart from if you left it standing with any fuel left in the tank. It would slowly leach out through the joint if it wasn't perfect. Eventually settled on 2 700 tanks side by side in the normal 700 position and hooked up in parallel.
I thought of the as well, reminded me of my Harley tanks. How did you get around the problem of the right side of the tank not being square? Do you have any pics?

Thanks
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Old 11-15-2011, 05:31 PM   #16
kevinww
Registered Users
 
Posts: 660
 

Join Date: Nov 2008
Location: London
Default

Its not really a problem, you just angle both tanks towards the back slightly.
__________________
Trex 600N Pro with Vibe 50 Head and YS91RS motor, Vibe 50 VBar FBL, Trex744 VBar FBL MW44 Turbine, Mikado Logo XXTreme, Mikado Logo 600 12s, Mikado Logo 500SE, Vario UH-1D (Building), Scratch built 625mm Quad, Author of Spektrum Telemetry Viewer App.
kevinww is online now        Reply With Quote
Old 11-15-2011, 06:40 PM   #17
DDragon
Registered Users
 
Posts: 1,329
Thread Starter Thread Starter
 

Join Date: Aug 2007
Location: Canada
Default

Quote:
Originally Posted by kevinww View Post
Its not really a problem, you just angle both tanks towards the back slightly.
LOL... didn't think of that?!

Thanks
__________________
Cheers, Deron.
Still lovin' it after all these years

DDragon is offline        Reply With Quote
Reply




Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Turbine Helicopters


Turbine Helicopters Turbine R/C Helicopters

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Copyright © 2004-2011 - William James - Helifreak.com