Anything To Do With 500 Series Kits.

[twospruces]

Interesting, you mean you don't expect to get top quality wood in a 12$ kit that is mass production and not intended for contest flight?
Sarcasm aside, you must be pretty good at cutting out parts! It must add a lot of time to do that.

[WIDDOG]

LOL Thanks for the comments TwoSpruces. When I was younger I worked at a Lumber Yard. Long story short I like using the Contest Balsa. These 500 series kits don't even use that much wood... So really the extra cost, to me anyway, is not even noticeable. Also I factor in a "Hey This Hobby Saves Me Money" by not spending money on other hobbies. i.e. The model railroad guys I hear have it the roughest. This might be a good time to address the extra time it takes to cut out the pieces. Like I mentioned before I learned from reading this Forum about sharpening my hobby knife blades over and over again. This maybe does not sound like much but before I read about re sharpening I used to replace the blades when they got dull. It kind of gets expensive to replace those blades all the time. With the use of a nice sharp blade I found that cutting parts from Contest Balsa is really not a problem. I have built a "Laser Cut" kit and yes it was nice in away BUT Even though the wood was "Good" it was not Contest Balsa.

[twospruces]

Cool! Hey, never thought about sharpening. Do you use a whetstone? Or do you use a grinder with a fine stone?
Thanks for the tip.

The problem i have with cutting out parts is my own accuracy and the width of the lines on the plan. Seems i end up with less than correct parts..

[WIDDOG]

I would like to make a correction. I read about sharping hobby knife blades from the book "Hey Kid Ya Wanna Build A Model Airplane by Bill Warner. To sharpen I use a device called a Samurai Shark. http://youtu.be/OAhUS8DoT5U

I understand it sounds like a lot of work. I would just like to mention though that the Contest Balsa cuts so much more easily than the kit wood. I think a lot of people remember the ole Comet kits. i.e. Not Die Cut. I remember clearly as a kid trying to hack away at that wood without much success.

The kit I'm working on now kit 507 which will be my third build of this model. Note I bought about $10 of kit 507 decals, plastic parts and windshields in one order so I can build this kit a few times. Anyway first time I used kit wood, Second I used Local Hobby Shop Wood. This time I ordered online Contest Balsa. With each build I have gained more knowledge and better flight times. I'm at the stage of my build where I still have a shot at under 20 grams AUW. IMHO it is worth it to use the Contest Balsa.

[twospruces]

been thinking about a way to really lighten up the tail of a 500 series.

Has anyone ever laminated thin balsa, and replacing the B formers with what amounts to a laminated stringer that just supports the longitudinal stringers?

Hollowing out the formers probably works, but weakens them. A laminated stringer would be much tougher.

[Wildpig]

Mitch, here on the forum, and a few others I sure, laminate the tail surfaces (sometimes).

[WIDDOG]

I went with the 5/8 inch dihedral which is what the instructions said to use. On my other two kit 507's I used a full inch dihedral. I once again made the wing with a rubber band hold down. Also I am using the Noseblock with a lip set up I used on my last build. It seemed to work out ok last time.

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[Mitch]

Although I have a few 500 kits I have not built them in a while. I am starting to laminate curved tails like on the 400 Spitfire, or 200 Dr1. For those I use 1/32 sheet stock. Cut strips to the thickness I want (just over 3/32) laminate them on a form I cut from a Styrofoam plate. When the tail is finished, sand it down to 3/32. So the finished tail is 3/32 square, 3 ply!

For a 500 series kit I would try 2 strips of 1/32. Cut just over 1/16. Sand a bit when done, so your finished tail would be 1/16 square, with 2 ply!

Mitch

[twospruces]

Not just the tail feathers,

What id you replaced the fuselage formers at the back with a laminated frame to support the stringers?

[kittyfritters]

Not just the tail feathers,

What id you replaced the fuselage formers at the back with a laminated frame to support the stringers?

As you can see from Scigs30's builds, all you need is a warp free build with decent wood. All that effort laminating is overkill. I know, I've taken that approach and it works, but it is an awful lot of effort when the same results can be achieved by simply using 6 to 8 pound wood and thinning some appropriate pieces. Laminated tip and tail bows are worth it simply because of the strength, but laminated formers, and ribs are just an exercise in fine woodworking, wonderful when you see it done well, but not really necessary to get a good flying model. (My humble opinion!)

[WIDDOG]

Very interesting posts. IMHO after experimenting with flying the first two kit 507's; I noticed that the tail did not get smashed up very much if at all. Also IMHO if the tail did get busted up it would probably be kind of easy to repair. Most of my crashes the nose of the plane was affected the most. Also I read Sig 30's posts very closely. They where very interesting and where very informative. I have to say I benefited greatly by reading them.

[WIDDOG]

I have heard that some modelers change the CG on the kit 504 Spitfire. I believe they move the wing back 1/2 inch from what the plans call for. I recall I had to add a lot of clay to my last two Zero's. It has been a while since I read the post talking about this practice. I recall someone saying that the CG was designed more for a Cox motor than a rubber motor set up on 500 Series kits. I will try to find this post again and at least post the address to it. It was a very interesting Thread.

[kittyfritters]

I have heard that some modelers change the CG on the kit 504 Spitfire. I believe they move the wing back 1/2 inch from what the plans call for. I recall I had to add a lot of clay to my last two Zero's. It has been a while since I read the post talking about this practice. I recall someone saying that the CG was designed more for a Cox motor than a rubber motor set up on 500 Series kits. I will try to find this post again and at least post the address to it. It was a very interesting Thread.

The early Merlins were relatively heavy, compared to the airframe weight, so the early Hurricanes and Spitfires were actually rather short coupled in the nose making models of them rather tail heavy. Compare the outlines of the 400 series Spitfire to the 500 series Spitfire, or any accurate early Spitfire drawing, and you will find that the wings of the 500 series are too pointy. This makes the model rather hard to trim since there is a tendency to tip stall at the transition from powered to gliding flight. Rubber motors usually unwind from the front to the back making the model progressively more tail heavy as the flight progresses aggravating the problem. (If you think you are good at trimming build a Comet Ryan SC, with extremely pointy wing tips, and have fun.) Usually, you have to get quite a bit of clay or BBs in the nose to get the balance right. Making all the structure aft of the C.G. as light as possible is a big help.

I built a "500 series Spitfire" over the Guillow's plans with my own structure. It has laminated outlines for the tail surfaces and wings, sliced ribs, a Comet dimer style box fuselage with top and bottom formers. and a nose made of 1/32" sheet instead of plastic. It is considerably lighter than the stock version, but it still took quite a bit (actually several flying sessions) of trimming before I got good performance out of it. I probably could have achieved the same result with a "stock" build with 6 to 8 pound wood, only thinning a few parts, with a lot less effort.

[WIDDOG]

Wow what a great post Kittyfritters. I really find posts like the above to be very interesting and informative. I was reading another post about the 400 series kits. The Modeler decided to use tissue decals instead of the water slide ones. For some reason, I assumed that tissue decals where used only if water slide decals where not available. I have to admit I was wrong about that one. I just wanted to mention the other Modeler's tissue decals looked great. I decided, after reading his post to at least try it out. I am glad I read his post because I now think tissue decals are the way to go. They seem to "Stick" to the plane better IMHO.
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[WIDDOG]

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Got my kit 507 Zero put together and weighted it. Came in with a AUW (All Up Weight) of 33.1 grams. From what I understand that's about an average weight to bring this kit in at. Most of the weight is from the Balancing Clay in the front. I decided that I will build a fourth Zero and really try to cut some weight on it. In the mean time I will experiment with this one on the flying field. I did some preliminary trim flights in the backyard and have it somewhat tuned. Looks like this one is definitely the best Zero I built so far.