BenWlson

I am considering building this airplane from plans I found on the internet. It claims to be a modified Sea Master (.40 size) designed by Ken Willard. I was just wondering if anyone has built this version from these plans and has any pointers, suggestions, pictures, praise, or criticism about this design. This will be my first seaplane, and it looks like it will be a very stable, slow plane. Almost looks too slow... I was wondering if the suggested .40 size engine may even be too small. The plane should have about a 66" wingspan and weigh about 5.5 lb.

The free autocad plans are available here for anyone who would like to see them:

[link=http://www.balsadust.net/thomas.vogel/Files/Plans//RC/Sport/seamaster40mod.zip]http://www.balsadust.net/thomas.vogel/Files/Plans//RC/Sport/seamaster40mod.zip[/link]

I'm am also very curious if this is the same as the SeaMaster ARF/KIT that everyone is always talking about. If so, then I think it will be a great plane as the modifications were to decrease the weight and increase some wing area. I've finally had the chance to really look over the plans, and I've discovered than one important piece of info was missing: Where is the center of gravity?

BenWlson

I've discovered some more information about these plans. The original was a kit designed by Ken Willard. These plans were modified by Glenn Morris. Here is a list of notes he made about the modifications.

Once again I ask, does anyone have anymore information about this kit or a recommendation as to where the center of gravity should be as this seems to be the only piece of information missing.

jrf

My Feedback: (551)

The CG should be right in the main spar. That's 28 % according to the drawings.

Jim

Dan Taylor

My Feedback: (2)

is this the Sea master as arfed by ACE
Great Plane

BenWlson

That has kind of been my question all along. It looks VERY similar.

jrf

My Feedback: (551)

The Ace Seamaster is heavy and strong. The modified one is light and delecate. (According to the modifier's statement above.) Aside from the changes in materials and the larger wing on the modified version, they appear to be the same.

Jim

BenWlson

Thanks for the info. I would still really like to know, has anyone ever built this modified version?

I like the idea about it being lighter. My only concern is that the plans say don't use anything larger than a .40 engine in order to not risk having to pod break off and sink. I plan to follow this and use an old SuperTiger 40 that I've had laying around for about 20 years (fired up no problem - gotta love the durability and life of those little engines). I'm trying to design some method of safeguarding against the possibility of losing my engine. Anyone got any ideas? I'm sure someone has thought of this before. Like I said before, this will be my first seaplane. I was thinking about making the pod out of foam, or perhaps attaching some sort of extra safety wire from the engine to the hull so if it does break off, maybe it will take enough wood with it to still float.

mjolnaren

Does anyone have teh building instructions for the Seamaster or do one not need them to scrachbuild the plan`?

Best regards / ANders M

Irish R.Seer

My Feedback: (1)

I have built the Seamaster from these plans. You will have to modify a few things on the plans to make everything fit right. The wing is no problem I built it as per plan, but the fuse and the pod are something else. I built the fuse in two halves on a central crutch. You will find some of the patterns for the fuse formers and sides are wrong, so it is advisable to check the dimensions before you cut the parts out. I covered the front bottom of the hull with 1/32" ply and glassed the hull bottom from front to back for strength. If you have the know how to make a fibreglass molded pod it will save a lot of time. I made mine out of ply formers and balsa planking, with an access hatch for the tank and throttle servo, then glassed the whole pod to strengthen it. I made the boom out of 1/4"hard balsa sandwiched between two pieces of ply doorskin. I then put a triangular piece of 3/8" ply under the front of the pod and against the boom, for strength under the engine. I cut a couple of lightening holes in the 3/8"ply.
I used an MDS 58 in mine and it is too much power, I'm sure your 40 will be sufficient power for this model.
I balanced it under the main wing spar and it is very easy to fly, although it wants to climb on full power, and a bit of down trim was necessary on mine. If you need any more info or if I can help in any way let me know as I found this model hard to build from these plans. I've attached a pic of my boat!! Good luck with yours.
Bill