Model Boat Mayhem - Forum

Dry Dock / Shipyard: Builds & Questions => Springer Tugs => Topic started by: clockworks on August 18, 2019, 06:50:22 PM

Title: Aeronaut Springer - couple of questions
Post by: clockworks on August 18, 2019, 06:50:22 PM
My first build - an Aeronaut springer kit fitted with brushless motor on two 5000maH 2s LiPos in parallel. Skinned in epoxy and cloth, so it's not exactly a lightweight, but I still needed to add a kilo of lead to get it close to the waterline.


It handles quite well when going forwards - as long as I keep the speed down. Turns nicely too, unless I try going in reverse, when the rudder does absolutely nothing! This isn't a major problem when I'm just pottering around on the lake, but it might make lining up to rescue another boat a bit tricky.


Is this lack of rudder authority in reverse an inherent problem with springers?


Just how low at the stern do I need to ballast it to stop it submarining at higher speeds?
Title: Re: Aeronaut Springer - couple of questions
Post by: Gardener on August 18, 2019, 07:20:38 PM
stopped my cratch built Springer from diving by pushing a barge, it handles much better with the barge than light
Title: Re: Aeronaut Springer - couple of questions
Post by: Netleyned on August 18, 2019, 07:25:25 PM
I ballasted mine so the waterline was level, then
moved the ballast aft to give the bows about an
Inch and a half between waterline and water
I fitted a Kort nozzle(steerable) on mine as the
Hull has no longitudinal stability, i.e. no keel so
the rudder has little effect. With a Kort nozzle
my Springer will turn in it's own length ahead
or astern.
Ned
Title: Re: Aeronaut Springer - couple of questions
Post by: clockworks on August 19, 2019, 09:36:51 AM
Sounds like I need to shift a lot of lead towards the rear.


Steerable Kort nozzle - I guess I could do that by extending the propshaft a little so that the prop sits on the rudder shaft axis.