Model Boat Mayhem

Mess Deck: General Section => Model Boating => Topic started by: john44 on November 04, 2017, 02:15:16 pm

Title: Hovercraft
Post by: john44 on November 04, 2017, 02:15:16 pm
hi guys here is one for you technical hovercraft people, my Sirius 600 is digging its nose in
When I try to run it on full throttle even with the lift motor at full throttle.
The drive fan is set at 90 deg.with the deck.  Would it help if I raked the duct forwards?
Or back from the 90 deg setting wich way would lifti the front end?
I am running both lift and thrust fans on 7.4 lipo,s


John



Title: Re: Hovercraft
Post by: Klunk on November 04, 2017, 04:12:58 pm
its being overpowered at full speed. add some weight to the rear and also check for any obstructions to the airflow in the skirt at full power.
like an aircradt the c of g is critical on hovercraft
Title: Re: Hovercraft
Post by: Klunk on November 04, 2017, 04:17:01 pm
just had a quick look at the hovercraft in question. is the duct at the back able to move at all?????
Title: Re: Hovercraft
Post by: john44 on November 04, 2017, 08:31:20 pm
Hi klunk, do you mean the lift duct or the thrust fan? The lift duct could possibly be relocated but would
Mean patching up the holes left.
Title: Re: Hovercraft
Post by: Klunk on November 04, 2017, 11:04:13 pm
The thrust duct. Was wondering if it was loose and moving at high revs.  Im assuming the lift duct was put in vertical at build time.  I know on the fusion 400 and the Griffin tdx that you have to get the c of g correct otherwise they plough or skip at high speed. 
Title: Re: Hovercraft
Post by: Sub driver on November 05, 2017, 02:37:49 pm
Hi.
Sounds like you cannot get over hump speed ie the depression in the water under the craft..


I may be wrong but doesnt the sirius 600 use 11.1v 3 cell lipos.
Hope its of use.

Title: Re: Hovercraft
Post by: john44 on November 05, 2017, 04:50:30 pm
Hi sub-driver, yes 11.1 lipo or 8.4 Niamh I tried 2x 7.4 lipo,s, 1 for lift & 1 for throttle.
I do have 5000mah 11.1 lipo,s so I will try one of them and see how it goes.


John
Title: Re: Hovercraft
Post by: Sub driver on November 05, 2017, 05:02:23 pm
Hi.
You will notice a HUGE difference with 11.1v lipo if you use one for each lift and thrust it should go....once you have it on cussion you can back the lift motor off by more than half...
Cheers
Sub.
Title: Re: Hovercraft
Post by: john44 on November 06, 2017, 08:06:53 am
Hope you are right sub. I will try it wed, weather permitting  :-))