1/6 Scale Hellcat
10-17-2013, 09:03 PM
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http://www.rcuniverse.com/forum/rc-w...review-17.html
Chad, the fuse is more or less built like a 3 D plane with plug in wings
Chad, the fuse is more or less built like a 3 D plane with plug in wings
10-18-2013, 10:16 PM
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For the tail hook operation you could use a Lado or similar actuator with an extended threaded rod. With a sturdy enough internal track for the hook to ride on, the actuator would continue to turn in either direction until it meets enough resistance to stop. Travel distance is irrelevant since these actuators just continue to turn until they reach a physical limit
-Dave
-Dave
10-30-2013, 08:02 PM
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More Good Stuff!!!
Ok everyone, here are some pics of the cowl and my first pull on the canopy mold. I only had .030 PETG for this first one so it's a little thinner than I would like. I will be making final versions in .040. The clarity as you can see is quite good. I have a lot of time finishing and polishing the plug, but it's all worth it when you can literally see though the results like this. The cowl is absolutely huge! It's 12" at the back edge from top to bottom. I was able to put my 1/6 Corsair cowl inside of it and it is just an amazing difference in size! It really goes to show how much effort went into getting the Corsair's frontal area as minimal as possible with an identically sized R2800. The Hellcat is just big brawny. Just an FYI the I Phone camera distorts the images so some angles don't do the shape proper justice. I held up pics of the fullsize airplane and the cowl looks really well shaped. the inner duct will also be molded separately to be able to replicate the actual depth and shape. More later - Dave
10-31-2013, 11:43 AM
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The cowl and formed canopies look fantastic Dave. Very exciting developments! The cowl should swallow up any number of suitable powerplants quite nicely I'd say. I will be using a G-62 on my prototype and am considering one of Mick Reeves reduction units for it in the hopes of swinging a near scale 3-blader. Still doing some research in that department though.
For those who have never done it, forming high quality clear canopies free of defects can be an exercise in frustration. It requires a forming buck that is just about perfect. Here is a pic Dave sent me of the nearly finished buck to give you some idea.
For those who have never done it, forming high quality clear canopies free of defects can be an exercise in frustration. It requires a forming buck that is just about perfect. Here is a pic Dave sent me of the nearly finished buck to give you some idea.
10-31-2013, 09:02 PM
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While Dave continues to make great strides with the canopy and cowl I am plodding away on the plans. I've suspended the wing design temporarily in order to get the drawings for the tail surfaces finished up so that they are understandable by somebody other than me! I will be cutting the tail and fuselage parts for Dave's build very soon and will continue work on the wing as soon as he's got enough parts to get started building when he is ready. Here's the nearly completed horizontal stab plan.
Last edited by Chad Veich; 10-31-2013 at 09:11 PM.
11-01-2013, 03:27 PM
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@Chad.
I see that you are considering using a Reeves reduction drive. I have tested a few props and exhaust systems on mine, and with the right silencer you will have a very powerful setup.
I´m using a DA canister sold by Toni Clark in Germany, and that provides almost as much power as a KS tuned pipe. Here are my results running open exhaust, canister and tuned pipe.
SEP (Wilga) 32x10 2-blade: 3.800 / 3.900 / 4.000
3W 32x12 2-blade: 4.100 / 4.200 / 4.300
Menz 26x12 4-blade: 4.600 / 4.350 / 4.350
I seem to remember that, at 6th scale, the Hellcat will have about a 26 in prop? If that is the case, you should be able to spin a Menz 26x16 3-blade at around 4.300 rpm, providing fair speed and power. Personally though I would go for a prop with more pitch, 18-20 in, for a warbird.
I see that you are considering using a Reeves reduction drive. I have tested a few props and exhaust systems on mine, and with the right silencer you will have a very powerful setup.
I´m using a DA canister sold by Toni Clark in Germany, and that provides almost as much power as a KS tuned pipe. Here are my results running open exhaust, canister and tuned pipe.
SEP (Wilga) 32x10 2-blade: 3.800 / 3.900 / 4.000
3W 32x12 2-blade: 4.100 / 4.200 / 4.300
Menz 26x12 4-blade: 4.600 / 4.350 / 4.350
I seem to remember that, at 6th scale, the Hellcat will have about a 26 in prop? If that is the case, you should be able to spin a Menz 26x16 3-blade at around 4.300 rpm, providing fair speed and power. Personally though I would go for a prop with more pitch, 18-20 in, for a warbird.
11-02-2013, 04:45 PM
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Tinus,
Thanks for the good information on the reduction unit. This is something I would very much like to try but was hesitant as their does not seem to be a great deal of information out there from folks like yourself with real world experience. I am much more comfortable making the investment based on your report above. Thank you!
Hellcat builders, just imagine the big kitty swinging a 26 inch three blader! Gets me excited just thinking about it. Of course if I go with a Solo Prop or similar then the prop is going to be worth more than the engine swinging it! That part makes me nervous.
Thanks for the good information on the reduction unit. This is something I would very much like to try but was hesitant as their does not seem to be a great deal of information out there from folks like yourself with real world experience. I am much more comfortable making the investment based on your report above. Thank you!
Hellcat builders, just imagine the big kitty swinging a 26 inch three blader! Gets me excited just thinking about it. Of course if I go with a Solo Prop or similar then the prop is going to be worth more than the engine swinging it! That part makes me nervous.
11-03-2013, 04:36 AM
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Vogelsang Aeroscale sells Fiala and SEP propellers in the US, and they should both be able to provide a suitable prop at a lower price than Solo. Both companies will manufacture custom props at a fair price I believe, and I have seen others using SEP propellers with great luck on geared engines.
http://vogelsang-aeroscale.com/propellers.html
Personally I have had good luck with Fiala. The props are very effective, but the props load very little so you can normally use a significantly larger prop than other brands. On a piped, direct drive, G-62 I can easily run a 26x10.
I´m working on a geared 124cc inline using two G-62´s, and that should be able to spin a Fiala 32x18 3-blade if my calculations are correct.
Below you will find a youtube link to a short testrun. I later shortened the header and found around an additional 200 rpm.
http://www.youtube.com/watch?v=PgLFPSkZJRo
http://vogelsang-aeroscale.com/propellers.html
Personally I have had good luck with Fiala. The props are very effective, but the props load very little so you can normally use a significantly larger prop than other brands. On a piped, direct drive, G-62 I can easily run a 26x10.
I´m working on a geared 124cc inline using two G-62´s, and that should be able to spin a Fiala 32x18 3-blade if my calculations are correct.
Below you will find a youtube link to a short testrun. I later shortened the header and found around an additional 200 rpm.
http://www.youtube.com/watch?v=PgLFPSkZJRo
11-04-2013, 08:02 AM
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Thanks again for the further information Tinus and for the neat video. I love the sound of the geared and piped G62, particularly at idle. The 124cc inline sounds like an amazing project, best of luck with it.
11-04-2013, 08:03 AM
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In regards to the previous discussion concerning an operable tailhook please have a look at the link. Pretty slick really.
http://www.youtube.com/watch?v=AnLDpL7rUJA&feature
http://www.youtube.com/watch?v=AnLDpL7rUJA&feature
11-16-2013, 07:07 PM
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I've finally managed to get the tail plans done complete with build notes and labeling. With any luck Dave should be able to build a tail from these without running into too many brick walls! Next up will be to laser cut some tail parts and get them shipped off so Dave has something to do while I finish the wing design.
11-16-2013, 11:39 PM
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Looks great Chad!!! Can't wait to get started. On my end, I now have some completed canopies, finally!!! I will be sending one your way along with your 1/8 scale static prop. As it turns out, I had to end up using the plug in the pictures as a secondary mold instead of the primary. The catalysed primer I used kept off gassing when it got hot, so I made a silicone mold and made one cast from high temp tooling epoxy. The parts are coming off great now. No more work on the cowl mold, I have been a bit side tracked doing a static prop(s) for Brian O'Meara's new 116" Sea Fury. It's huge at almost 38" diameter!!!!
-Dave
-Dave
