siddus74

Dave - my sentiments exactly . . . the additional step is an extra wedge of 1/4 sanded to blend, it brings the step just aft of the recommended CG, it's enough to cause disturbance in the water/air.

Nigel Wyatt

Hi Guys
Hope you all had a good Thankgiving over there.

I am also wanting to build the Sid Morgan 108" span Catalina. I am currently awaiting deliver of the plans, but have a question in the meantime. does anybod have the cowl diameter measurments.
I know from comment and for research that .61 2 strokes will fly this plane but would prefere to go down the Gas route. What sort of AUW have you come up with? I know I build a little on the heavy side (my Ziroli Corsaitr turned out at 34lbs) so I may have to compensate wit bigger engines.
Any help would be much appriciated.

Kind Regards to all
Nigel
(Over in the U.K.)

Bowmaster

Hi Nigel, The cowls are 120mm in dia. I can't answer the question on the gas engines, because I haven't played with them at all. There isn't much room in the cowls, the drawing show only a length of 80mm on the cowls. the cowls that I recieved from Vintage are about 120mm in length before trimming so you could stretch the length to help hide the engines.
Dave

Bowmaster

Thanks Siddus, I'll write a note on my plans so when I get around to building the smaller bird I'll have the information. Dave

Bowmaster

Siddus, I forgot to mention that the pix of your bird are great. It really makes me want to get in the air. These pix are a good insentive to keep me working on my bird so I can go fly her.
Thanks again Dave

siddus74

Dave,

I know what you mean about the motivation, I am struggling with my Sunderland periodically . . . Other peoples finished examples can do wonders for renewed interest and motivation. Just trying to work out a suitable platform for the stabaliser - seems like 3 steps forward and 2 back half the time is wasted checking and rechecking for squareness.

I would so like to build a larger PBY - I have 2 OS 61FX on the shelf doing bugger all as well. Thing is storage and transport as well become a factore when you get to the larger stuff . . . Have you seen any of the Ivan Pettigrew plans and models?

Siddus74

dbkvn

I am about to start this build so I have a MILLION questions...Has anyone figured out how to make the "clam shell" type of nose gear doors work, I realize that they "operate" in a "wet" well...I am going to power mine with two OS.91's, lots of power to fly off water and land here in "mile high Denver"..Attended a float fly here recently and power requirements are VERY HIGH...Also I have seen questions about fuel, because the nacelles are small...Will probably use the Century Jet Model retracts...Has anyone tried to couple ailerons (mixing flaps) to slow this beast down on landings...Interesting to note that the full scale PBY-5As wing tip floats RARELY touched the water? Along that line how does the retract system work for the wing tip floats...I told you that I have a MILLION questions...Many thanks for reading and any help generated is much appreciated !!! Regards...Kevin in SNOWING Denver

Fast Freddy

[8D] Hi Kevin, Have you ever thought of going electric? All of the issues concerning multi-engined planes including altitude, one engine out and engine synchronicity become meaningless with electric power. There are electric motors and the batteries to power them equivalent in power to .91.'s. Yes, it is more expensive, but if I were building a 9 foot PBY I'd want some kind of insurance against the above mentioned multi-engined problems. Just a thought, but you might want to look into it.

Fast Freddy

Hi Sid, Fancy meeting you here again and that's a beautiful PBY you built.

In reference to Ivan Pettigrew's plans I have started the 72" Short Sealand. I have temporarily shelved it after frustration with the plans as there there are quite a few inaccuracies. From what I've read in other build threads on www.rcgroups.com this is common. Don't get me wrong, Ivan is a great designer and his planes all fly beautifully, but there is a certain level of angst and frustration one must go through to get to the final product. It truly becomes a labor of love. I also have his 72" PBY and Grumman Albatross plans. Some day I'll get the Sealand finished.

siddus74

Freddy,

Funny you should talk about the 72" Short Sealand plan, I have that upstairs . . . What inaccuracies are you talking about? I have looked at that plan a couple of times it does look quite complicated, I can see scope for errors in it. I also have the Mini cat plans from Ivan if I build any of them it will be either that or the Short Solent (after my TN Sunderland is done) . . . Also if I build the minicat it will be powered buy 2 x .25's.

If you can reply with a link to your Seland build please, I would be interested to follow your progress.

I agree with you comment on twins being electric and all, as the benifits apart from cost and sound are unquestionable. The Budd Chappell at 66" although alot smaller that the Catalina in question flys without consequence if one engines stops as the engines are so close together, also I always put a out 4 degrees of out thrust in anyway. Im dreding experiencing one out on my Canadair, ill just stop the other if I catch it in time.

What else you building @ the moment?

Siddus74

Fast Freddy

[8D] Sid, I don't have a build log on my Sealand , but I can direct you to a few. I have quite a few photos, but no build thread. This first one is quite good and its from your area.:

http://www.sopwithmike.mudefordsc.or.../catalina.html

Another:

www.rcgroups.com/forums/showthread.php?t=683121

Ivan Pettigrew's planes as put together by Luke in the Ian Pettigrew Hall of Fame. Everything about Ivan can be found here:

www.rcgroups.com/forums/showthread.php?t=710485

Good luck!

Nigel Wyatt

Hi Dave
Thanks for those diamentions.. I think if i go ahead with this I would like to use gas engines possibly the new Zenoah 20cc. But this will mean I have to scale the plans up by around 40%. I think this should give me around a 7" cowl diameter and a 12' 6" wing span.
Has anyone done any scaling up of plans? or know a good method of doing it.
Kind Regards
Nigel

goirish

I take my plans to the local printer and they enlarge them whatever % I want. Just did this with a set of plans that was a 40 size and had them enlarged 120% to make it a 60 size. I have done this on several plans. Figure out what WS you want and then you can get the % from that.

bear 57

Fast Freddy, what would you suggest as an electric motor, battery and esc combinmation for the PBY by Vintage?
I have one 3/4 finished with OS 61 two strokes. I have been wondering if I should have gone electric with it.
I am thinking brushless motors. I could still easily make the change.
Looking for some advice as I have limited experience with electrics, none with twin electrics.

Lorne

Mustang Fever

My Feedback: (2)

Just signing on, here. I'm looking a making a PBY my next project, and want to go with the 9 footer, CJ retracts, etc. The only thing I'm not going to do is buy a 7 channel radio. I'll just switch the servo wires at the Rx, depending on whether I'm flying from water or land. I think a pair of OS 75 AX would be a good power choice.

I want to model it after this one, that flies out of Duxford in the UK.

Bowmaster

I just saw what looked to be a 108" PBY on youtube that had a pair of four strokers on it, and boy did that bird sound good. A very low throated sound. It reminded me of a pair of round motors, just scaled down. It had retracts on it, Wheels and wingtips that looked great in operation. I wish there would have been some info. on it.
Dave

Mustang Fever

My Feedback: (2)

Dave:

After reading your post and thinking about it some more, I'm wondering about using a pair of Saito 3 banger radials. Either the 90s or the 170s. I suspect the 90s would be enough off water with no retractable landing gear, but probably wouldn't be enough off grass with the scale, CJ landing gear.

Any thoughts on this guys? I have no idea what this bird would weigh or what the wing loading might be.

siddus74

Dave,

Here are some pics for your reference. I left the original step as per plan as it wasnt until half way through the build my fellow water plane mate Simon pointed out problem, then after that everything I had been hearing from other people that had built it suggesting that it would not take off started to make sense . . .

I agree with build it light, I substituted the the light ply undersheeting for 1/16 balsa then medium tissue with dope, the balsa was easier to bend as well. mine was 4.6lb RTF.

I love it, it my best flying water plane by a long long way . . .

Siddus74.

dbkvn

In reference to the step being moved (how much) then would one assume that this would work for the 108" size as well...Just one of the million questions...Kevin in Denver

Bowmaster

Sid, Thanks for the pix of the steps. I'm knee deep in sawdust, I've been sanding down this planked hull and shaping the nose and wing pylon blocks on this 108" bird. (Turning alot of balsa into a lot of dust and shavings.) I'm getting excited, it's starting to look like a pby. I'll post pix soon.
Dave

Bowmaster

Well after looking at Lorne's wing I decided to deviate from the plans and make a three piece wing that unbolts from the pylon. I used carbon fiber fishing rod blanks that I picked up on ebay for next to nothing. they are very strong and light. they are 3/4"dia. at the large end. they slide into each other very nicely.

siddus74

Bow,

Looking good, any chance of some close ups and a pic of it all together? Really curious to so what size yours it compared to mine. . Have you decided how you are going to mount your tip floats?

Scott.

Bowmaster

Hi Scott, I'm not sure how I'm going to mount the tip floats. Got any good ideas? I was thinking about using the large 3/16" Robart hinges with the removable sockets. I would like to keep it looking some what scale. I found this drawing on the net of the real thing.
Dave

siddus74

Bowmaster,

I love the Catalina scale tip floats, but I have my own take on time floats that although very practical and work very well up until now to ensure no wing damage and water loops often come at a scale sacrifice . . . so if you want scale tip floats I am not the best person to ask. However I have a the Ivan Pettigrew MiniCat pland which details the tip floats.

This build thread details them quite well [link=http://www.rcgroups.com/forums/showthread.php?t=412146&page=2&highlight=ivan+pettigrew]http://www.rcgroups.com/forums/showthread.php?t=412146&page=2&highlight=ivan+pettigrew[/link]

This is Ivan's home page [link=http://www.geocities.com/ivansplans/index.htm]http://www.geocities.com/ivansplans/index.htm[/link]

This is a link to his videos, the Catalina one shows them in operaton, I love his desings - I have 3 sets of plans now . . .
[link=http://gvillette.rchomepage.com/]http://gvillette.rchomepage.com/[/link]

Bowmaster

Scott, Thanks for the info. and the great links. You're correct about water loops, but I need to make them scale or semi scale just because they look cool.
Dave