Diego, I think you might have chosen the wrong drive for that boat. The intake is still too far forward and will cavitate under high speed. Like Viking said earlier, you want the intake as close to the transom (and as narrow) as possible. The Graupner 2347 (29mm) would have been the correct drive for this 27" boat I believe. http://www.cornwallmodelboats.co.uk/...upner_jet.htmlIf you want a 40mm, then the Kehrer 40 (black unit) would have been most suitable. Graupner makes a larger (49mm) with the short intake (Model 2347) and it is a monster, but too much for this project (my opinion). I''ll stay posted, as I'm planning a similar build with the Kehrer unit. http://www.jet-drive.de/cms/componen...,11/Itemid,17/
Did you and Dirtysouth both build the jet drive riggers? Saw the video, toocool. I did the NQD surface drive rigger mod with 4m flex hardware http://www.rcuniverse.com/forum/m_85...tm.htm#8506113 but it's been too cold to try it out. Soon, though!
Last edited by sundog; 03-09-2009, 12:03 PM.
Reason: added link
Diego, I think you might have chosen the wrong drive for that boat. The intake is still too far forward and will cavitate under high speed. Like Viking said earlier, you want the intake as close to the transom (and as narrow) as possible. The Graupner 2347 (29mm) would have been the correct drive for this 27" boat I believe. http://www.cornwallmodelboats.co.uk/...upner_jet.htmlIf you want a 40mm, then the Kehrer 40 (black unit) would have been most suitable. Graupner makes a larger (49mm) with the short intake (Model 2347) and it is a monster, but too much for this project (my opinion). I''ll stay posted, as I'm planning a similar build with the Kehrer unit. http://www.jet-drive.de/cms/componen...,11/Itemid,17/
That's it...! any more naysayers out there? Fine, I'll abandon the darn project since it will never work and when I get home I'll go Dirtysouth31 / SJFE on this boat & stomp it to pieces. I guess I should have asked all the darn naysayers for permission before I even started because now it won't even work! Oh well, It's just money down the crapper.
I guess it's easier to say "that @!#$% ain't gonna work" than it is to say "you may want to try this (insert suggestion here) since you already started down that path."
Originally posted by sundog
Did you and Dirtysouth both build the jet drive riggers? Saw the video, toocool. I did the NQD surface drive rigger mod with 4m flex hardware http://www.rcuniverse.com/forum/m_85...tm.htm#8506113 but it's been too cold to try it out. Soon, though!
Ya that was us. Dirty could have used a bit of finesse instead of brute force installing the jet to make it perform better. He had the impeller making contact with the suction tube wall, so rather than adjusting, he filed down the impeller.
That's it...! any more naysayers out there? Fine, I'll abandon the darn project since it will never work and when I get home I'll go Dirtysouth31 / SJFE on this boat & stomp it to pieces. I guess I should have asked all the darn naysayers for permission before I even started because now it won't even work! Oh well, It's just money down the crapper.
I guess it's easier to say "that @!#$% ain't gonna work" than it is to say "you may want to try this (insert suggestion here) since you already started down that path."
NO!! Don't get discouraged now!! I have high hopes for this one! And wouldn't mind buying it if Doby doesnt lol....
Sorry about that Diego, I can see I should have used more finesse here. That boat should work fine up to a point. But as you apply more power (in the mod-v hull design), the waterline creeps back towards the transom until at some point it will pick up air. I didn't mean to unmotivate or diss you, I was just sharing knowledge. My apologies, Sdg.
Don't worry. This project will be completed. I was just kidding. I'm just getting tired of all the "it won't work"; "You did it wrong"; Stop wasting your time" type comments. I love some criticism, as long as it's constructive. The video of her run will speak for itself.
The motor is mounted and installed. I just need to get her ESC from Meniscus, so she can get wet!
I can always count on you Meniscus, for... well, I can always count on you.
No hard feelings Sundog. Welcome to OSE! I'm glad you took time away from RCU to check us out!
Yeah, I know what you mean - I've recently experienced some (foks with no imagination) cut my (crazy) ideas down (in an attemp to build themselves up?) Hmmm. But I assure you that wasn't my intention here. I can see this is a touchy subject with you and so I don't mind stepping away... my apologies .:
Please don't step away. This darn boat has been fighting me every step of the way. Your input is appreciated, really! I just can't undo what I've already done.
Hi Diego;
I got my boat in the water the other day and it wouldn't run on 2s. Ran in the air ok but wouldn't start in the water!?
I had a 3s with me and tried that---- too much power !! It spun out with the smallest rudder input ----- Hmmm ----- perhaps a turn fin or two.
What do you think???
Viking
That Viking www.How2RC.com PULSO
Home made 36" DeepVee 50mph
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