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Jim Barry

Scratchbuilt 1/24 Grumman F8F-1 Bearcat

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Hi Jim,

 

Tried to give a couple of “likes†on the engine and LG but no luck. I'm guessing I need to have a few more posts before I can do that.

 

Cheers

 

Dennis

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Thanks Dennis and Harvey. The engine is "pretty good" and very attractive, but I've just started another radial engine project (after many many more hours learning CAD) and now look at this one's shortcoming and go "shucks". It might redo it!    We'll see. As you know the limits of accuracy are not exactly bounded but at some point you have to call things "good" or you'll find yourself in a rubber room. This is especially true in CAD because you can draft  anything down to the mircon.  

 

As for likes, make sure you are logged in (maybe)?

 

Cheers,

 

Jim

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More stuff coming out of the JB parts factory:

 

Today I thought I'd do some tests vacuforming the canopy. Super pleased that it just took two trials to get it right and right enough for it to probably be final. Good news. Credit to advice here about putting the form up on a block of sorts. Key here.  The Fury's center fuselage was vacuformed so this is my second time at this. Classic scratch build stuff. I love it. Lots more detailing to do so I'll try not to get too excited. 

 

0L1d6y.jpg

 

 

S92DFo.jpg

 

eGTE4b.jpg

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Hi Jim

 

Just curious, what did you use for the canopy and how thick was it?

 

Cheers

 

Dennis

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To be honest I'm not sure what it is. I picked it up in the hobby store in the materials section mostly for the the RC guys it seemed.  The sticker on the sheet says  .008.  (must be inches?). That's .2mm. 

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Way to go JB - vacuformed canopy and windshield.  I must say, for my 1/18 P-47 project that you are familiar with, the most disappointing item is going to be the windshield and canopy - the toy versions are out of scale (mostly just too large, but some other issues as well).  I would love to devise am improved bubble canopy (I think I could scratch build the windshield and frame OK, as I have done on previous efforts.  But - I have no vacuform, no experience with same, and importantly I have no master and could probably not produce one close enough to be a significant improvement over what I have.  Therefore, I am going to make do with what I have.   How did you produce the master mold?

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Thanks. So far so good but the frame and detail is still intimidating and likely to lean toward "reasonable accuracy" as there is just so much going on functionally and so little  room to be messy and sand your problems away. I think I might pull another canopy just to protect this one while under construction. 

 

I made my own vacuform box and frame and would call it pretty easy (the hard part was doing it a garage on a -10 below zero F day!) . I can describe it further if you want. The master mold was a three piece thing. The center was thin 1/26th balsa in the exact side profile and glued two thicker pieces a bit larger than the master profile such that the whole thing was a touch wider than the expected contact points on the fuselage .   Then I just sanded it until it looked like Bearcat canopy. The dissimilar center balsa told me both where the center was and where I needed to stop sanding. Never sand that thing!  I made a piece of plastic the shape of the front windscreen flat part front and center and glued that on the mold. Then I primed and sanded some more until is was pretty damn smooth. I glued a small block underneath it all to allow for the plastic sheet to get sucked under the mold and maintain the  the bubble. 

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Hi Jim,

 

Still following with interest. In fact I went back to page one and started all over again. The CAD stuff and printed parts I still find pretty amazing. Who'd have ever thought only a few years ago that printed parts for modelling, among other things, could become the norm for scratch building.

 

Your method for making the buck/mould? for vacuum forming the canopy was interesting also. I use a slightly different method. If you go to my BM F8F build, page 1, post 18 &19 it is more or less self explanatory. I use clay (Super Sculpy Firm) for plunge moulding and general pattern making. Pretty versatile material.

 

I've provided a link that explains why using a certain kind of clear plastic is the ideal kind to use for vacuum forming canopies. Just thought you might be interested.

 

Cheers

 

Dennis

 

 

http://www.ipmsstockholm.org/magazine/2002/08/stuff_eng_tech_moulding_canopies.htm

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Great stuff Dennis. Thanks. I love Sculpy. It was actually the material that kicked off scratch building. I made a 1/16 German soldier with it and a little 1/144 F4F Wildcat . I was just about to make the mold in Magic Sculpt and it's a great material but just felt wood would do. MS demands a lot of work to sand and I wanted to make quicker work out of the task. 

 

Last night, though a swallow invaded my studio like a bat and would not fly out of the door, I did manage to craft this frame from thin malleable aluminum. It was actually a disaster for a while with no real idea what I was doing and then suddenly it fit. I dabbed some clear testors canopy cement on it and the capillary action was just perfect to bond the two surfaces. Whew. May be able to create the front frames too with it but we'll see. Plastic could work as well, I think. No curves. 

 

Thanks for stopping by

 

9tbzUU.jpg

 

SLLrgk.jpg

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Well anyone concerned I might lose the love for the Bearcat while launching the XP-50 project, fear not. I'm still at and slugging through the tough stuff. More frames today. I like the work and think it's par, but I think with another go I might have a better canopy. I'm surprised a first pass came out this good, but can see where I'd like to make some corrections. I'm out of town for most the week now and can ponder my next step. 

 

0JBHzD.jpg

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Hi Jim

 

Pretty impressive for a "first pass".  Not sure if you are building a -1 or -2 but just thought I'd mention that there is a subtle difference in the angle of the windshield.  the -2 having more of a slant..... but I'll bet you already know that.

 

Cheers

 

Dennis

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Yes, that's true. My plan drawings have been a -1 all along but did note in reading “Bearcat in action†that there was more slope to that version.

 

I'm having a blast this weekend in Charleston, SC. The USS Yorktown is a floating museum and just had the best time exploring it. 28 military aircraft to drool over. Grumman galore: Hellcat, Avenger, Wildcat, Tracer, Tracker, Cougar and a Tomcat. No Bearcat but it was nice to be with family!

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Thanks, Gaz. Just need to redo and reduce the errors but I think I have the basics going now. Not a lot of adverse forces on the gluing, and the front frame is aluminum tape. There's some chance the success here is due to wizardry. The aluminum is from Peter Airscales' stock!

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