Author Topic: Scientific Models Half A kit collectors? (Read 25279 times)

Dave Nyce · « **Reply #50 on:** November 05, 2007, 08:19:07 PM »

I've been helping the kids at an orphanage (in North Carolina) to build and fly 1/2A C/L planes for about two years. Larry has recently supplied us a set of stuntmaster kits to build (and some engines, thanks again Larry!). I usually build the first one for the kids to see how it will look when completed, and then one of the youngest kids receives that one when we're done building the rest.

The kids like to have the wheels attached, but the planes fly better (lighter) without wheels. So, I set some aluminum tubes into the front bottom of the fuse, and made up a set of gear to fit. I expect that it should be able to take off with the wheels, and then the gear will drop off in flight. Please see the attached photos.

On this one, I used some forstner bits and exacto knife to open up the fuselage from the bottom, to lighten it. And I took off some balsa from the front of the fuselage to move the engine back a little.

We use dope in spray cans to finish the planes, because the building time is limited. Does anyone still make clear dope in spray cans?

Please contact me if anyone can make donations of 1/2A building and flying materials. Thanks.

Dave

John Crocker · « **Reply #51 on:** November 06, 2007, 05:58:37 AM »

Thats a good idea. Have you tried it out yet?

Dave Nyce · « **Reply #52 on:** November 06, 2007, 07:12:57 AM »

The model hasn't flown yet, but the gear easily falls off when I pick up the plane. The gear wire is a loose fit into the aluminum tubing. Wind resistance may increase friction, and tend to retain the gear somewhat, but I think the engine vibration will cancel out that effect. I'll try it the next time I can get up to the orphanage.

Dave

Dave Nyce · « **Reply #53 on:** November 06, 2007, 12:47:56 PM »

In order to further minimize the overall weight, I used less outboard weight (a penny on the outside edge of the horizontal stab) and used a reverse pitch prop. I only have one of those props. Does anyone know of a source where I can buy additional reverse-pitch 5.0D 3.5P 3-blade props? (also called a pusher prop or a right hand prop)

Dave

nobler · « **Reply #54 on:** November 06, 2007, 03:16:47 PM »

I am pretty much with Z man: I like the Bullet and the Cyclone for Stunt (have built two Bullets, one Cyclone). All models are from scratch, in order to keep them light. This season, the Cyclone seemed to perform a bit better.

Of the standard 18" models, I would have to put the Stuntmaster ahead of the Zig Zag, due to the wider chord of the former.

Currell

Dave Nyce · « **Reply #55 on:** November 07, 2007, 01:19:27 PM »

Does anyone know where 1/2A-sized reverse-pitch 2 or 3-blade props can be found?

john e. holliday · « **Reply #56 on:** November 08, 2007, 12:26:40 PM »

Go to Tower Hobbies site and type in pusher propellors in the search box. Have fun, DOC Holliday

Dave Nyce · « **Reply #57 on:** November 08, 2007, 12:41:03 PM »

Thanks John, but all I could find on the Tower Hobbbies site was a 3-blade 6-4 prop and some props for electric. I think the 3-blade 6-4 prop is a little big for a Babe Bee, and the props for electric seem to have a different hub.

john e. holliday · « **Reply #58 on:** November 08, 2007, 06:34:30 PM »

It just hit me while browsing the APC site. You said Babe Bee which is a reed valve. It will run either direction as well as any Cox reed valve engine. All you need to do is turn the standard prop around and crank the engine clockwise. If you need a starting spring I will have to get the parts box from my son to get a spring. I was racing a Black Widow with left hand prop. Hope this helps. Have fun, DOC Holliday

Dave Nyce · « **Reply #59 on:** November 08, 2007, 06:56:02 PM »

Actually John, I'll be using the Babe Bee on the front of the plane, and I want to run the prop clockwise with a pusher prop so that the torque will turn the plane away from the circle. This, I'm hoping, will allow a smaller outboard weight to be used.

minnesotamodeler · « **Reply #60 on:** November 08, 2007, 07:49:45 PM »

Quote from: john e. holliday on November 08, 2007, 06:34:30 PM

It just hit me while browsing the APC site. You said Babe Bee which is a reed valve. It will run either direction as well as any Cox reed valve engine. All you need to do is turn the standard prop around and crank the engine clockwise.

Nope, turning the prop around won't reverse the pitch, just reduce the pull because the blade airfoil is now backward.
David's right, he needs a pusher prop if he wants to run the engine backward on a tractor arrangement.

Wayne Collier · « **Reply #61 on:** November 09, 2007, 08:37:47 AM »

Dave,
On my Golden Hawk I just used the tip weight supplied in the Blackhawk kit. I also am using the kit supplied landing gear firmly attached. I did hollow out the log a little to save weight. I only put one coat of paint on because paint can be heavy. I'm using a mix and match Cox reedy which is probably similar in power to a Black Widow. I'm using a Windsor/Master Airscrew 6x3 prop turning in the normal direction. I did put in a little rudder offset to help with line tension. I'm flying the thing on 42' Spiderwire braided lines (20lb strength/8lb diameter). I've had no line tension problems even up high, and the lap times are really fast. I've flown it inverted and done loops. My point is that the planes will probably be ok with the kit supplied tip weight and a normal tractor prop even with Babe Bee power- especially if you use 30' to 35' lines and your drop off gear works out.

Best wishes,
wayne

Dave Nyce · « **Reply #62 on:** November 09, 2007, 08:43:19 AM »

Thanks for the info, Wayne.

LARRY RICE · « **Reply #63 on:** November 09, 2007, 09:30:10 AM »

OK! I tried to stay out of this but I am old and have to put my two cents into everything. If line tension is in question simply place a washer under the two screws on the inboard side of the engine. The engine will pull the lines tighter than the torque of the prop will. The wing weight does not help with line tension, it's purpose in life is to counter the weight of the controls on the inboard wing to keep the plane flying level. This is a big help because if the out board wing is up and the inboard wing down the plane will turn, bank and stall into ground.
Larry

Dave Nyce · « **Reply #64 on:** November 09, 2007, 09:51:41 AM »

Thanks again for all of the very helpful info. I built a lot of kits, as a kid, but didn't receive any external input except for the instructions that came with the kits. At 12 years old, I started a flying club with about 10 members. They looked to me for help, but I only knew what I had learned first hand from my own experience. All in all, we had loads of fun. We flew our own interpretation of "stunt" with 1/2A to .40-sized planes, and flew a lot of combat with slab planes and Golden Bee engines.

Now that I'm back into flying C/L, working with the kids, and learning some new things, it's still a lot of fun.

George · « **Reply #65 on:** November 09, 2007, 01:48:56 PM »

BTW David, once you take the plane inverted, the reverse pitch will work against you. That's why most folks don't bother.

George

Dave Nyce · « **Reply #66 on:** November 09, 2007, 02:27:39 PM »

That's a good point, George. Hadn't thought about that.

nobler · « **Reply #67 on:** November 12, 2007, 08:33:23 AM »

I have about two dozen Logs hanging in the basement now, most of which were scratch built. I have found that two pennies, mounted near the longitudinal CG, is adequate for counterbalancing things (the pennies usually are buried in the wing, unless I am in a rush). Also, you do not need a lot of engine offset. One thin washer on the IB mounting bolts is sufficent. For my Speed models, I don't use any.

I can't overemphasize the effect of weight on these little models. Once again, contest balsa will get a well hollowed "typical" Scientific Log (Enterprise, for that matter) fuse and wing combo well below 20 grams. They stunt so much better in this model.

For a real thrill, try an F-82!

Currell

George · « **Reply #68 on:** November 12, 2007, 12:44:23 PM »

David,

Some things to consider:

The older kids should be more skill-capable so you should shoot for very light models as Currell pointed out above.

Younger kids will have less (and fewer) skills so don't expect as much out of them. They also become impatient and want to see results.

When I built my first "Logs" in the fifties, the wings were thicker (~1/4"). I build several planes that had NO additional hollowing and sanding only enough to hide the mill marks on the balsa. A couple coats of clear, a couple coats of color, add decals...off to fly. They were powered by an OK Cub or a Cox Space Bug Jr. They flew as well as I could, but nothing to write home about.

I guess what I'm saying is match the effort and details to their age and abilities. Since you are there to help, you can raise the bar a bit, but don't expect a young person to wait and wait for a finish when they are going to crash it.

Remember KISMIF...Keep It Simple, Make It Fun.

Also, having drop-off gear is neat and fun at your site but may not be allowed at any AMA meets.

I have not built one of Larry's kits yet but the old Scientific kits had the landing gear positioned in a groove in the firewall. It was held in place by the engine. I found that the frequent crashes plus the "prying" stresses imposed by landing in the grass (which usually consisted of one bounce plus one or more loops) would loosen the wood screws I used to mount the engine. For that reason I started using cement and gauze to hold the LG in place.

Of course these are only opinions.

George

nobler · « **Reply #69 on:** November 12, 2007, 03:35:38 PM »

Hi George: Another way to attach the LG is simply to mount it between the firewall and the Log itself. Make the grooves in the balsa.

I talked to Mr Frisoli. the son of the original owner of Scientific, at one of the NVCL Musciano Meets. You certainly are correct that, as the years went on, the airfoil sections went from virtually 1/4" to 1/8", as newer models were introduced (as a general rule). Profit margins were so tight, that they had to do it. Note that the Little Bipe steadily went down in span, over what I recall is at least three different spans.

The Blackhawk Golden Hawk, as supplied, would be one tough bird, and great for kids to knock around. However, it can be scratch built at 1/3rd the weight, and this is what you want for contests, or if you want good stunting capability.

Currell

Dave Nyce · « **Reply #70 on:** November 12, 2007, 03:36:54 PM »

Thanks a lot for all of the helpful input.

Dave

George · « **Reply #71 on:** November 13, 2007, 08:35:46 AM »

Thanks Currell, never thought of putting it behind the firewall.

Here are my two little Bipes, from plans. Scaled up the wings from the little 1/4 size top views:

nobler · « **Reply #72 on:** November 13, 2007, 09:27:20 AM »

Nice looking little Bipes, George.

I'm a self styled Scientific historian, and tracing the ads in MAN and FM and other mags in the early 50s, you find at least three versions, in this chronological order:

Span 16" area 78 sq in
15 80
12 70

And there may have been one I missed.

The Little Bipes you see at Musciano Meets are always the 12" version. They stunt surprisingly well. But the earlier ones are legal and should go even better. I asked Walt about the different spans, but he didn't really follow the ad copy back then. He was too busy designing and flying.

Currell

Robert McHam · « **Reply #73 on:** April 07, 2009, 11:13:12 AM »

Quote from: nobler on November 13, 2007, 09:27:20 AM

Nice looking little Bipes, George.

I'm a self styled Scientific historian, and tracing the ads in MAN and FM and other mags in the early 50s, you find at least three versions, in this chronological order:

Span 16" area 78 sq in
15 80
12 70

And there may have been one I missed.

The Little Bipes you see at Musciano Meets are always the 12" version. They stunt surprisingly well. But the earlier ones are legal and should go even better. I asked Walt about the different spans, but he didn't really follow the ad copy back then. He was too busy designing and flying.

Currell

I have the later instruction for this "Little Bipe" and it seems to be dated 1972. One sure thing about ity being later is that it shows a Cox Baby Bee mounted on the plan. I measured the quarter scale and indeed it was 3 inches in span making it 12" span full scale.

My question is, did the Little bipes of yore share the same fuse and simply had the longer spans or were they actually a bit longer in length as well?

Robert

George · « **Reply #74 on:** April 08, 2009, 05:59:24 AM »

Quote from: Robert McHam on April 07, 2009, 11:13:12 AM

I have the later instruction for this "Little Bipe" and it seems to be dated 1972. One sure thing about ity being later is that it shows a Cox Baby Bee mounted on the plan. I measured the quarter scale and indeed it was 3 inches in span making it 12" span full scale.

My question is, did the Little bipes of yore share the same fuse and simply had the longer spans or were they actually a bit longer in length as well?

Robert

Robert,
The first Little bipe I had was in the 1953 time frame. It was built by a friend, and I traded my "Daisy Defender" BB gun for it. Power was an OK Cub (which I still have). There was no Babe Bee at the time...it came later. The plans you mention are probably the same version that I used for the two Little Bipes above.

I too would like to find the older plans and build one of those...and power it with that old Cub. I am guessing that the original plans look more like the picture in the ads.

I THINK when Scientific made a comeback in the early seventies is when many (if not all) were redesigned with the 1/8" wings. Most were originally designed with a thicker airfoiled wing. Perhaps Currell can set us straight on that.

At least that's how I remember it.

George

Robert McHam · « **Reply #75 on:** January 29, 2010, 08:16:29 AM »

Just days ago one of the P-40 kits that I mentioned in my first post of this thread went for $102.50!! The kit number of this one is S-92 and the example shown in this picture is of the box art that I had.
The one that sold was of an earlier art work on the box but the model is pretty much the same I think.
Profile fuselage and 21 span built up wing. I guess it means I had good taste in models way back then as the ones that I really like seem to sell for the most. Other Scientific kits in condition as good as the S-92 kit sold for about half as much including some of the larger engine models with greater spans.

It is hard for me to understand sometimes what goes on in their minds. surely these are not all being built!

The P-40 was one I really enjoyed and has a great story to go along with it but not not one of the kits I feel like I just have to build. Perhaps one day I may change my mind. It was a really cool plane.

Robert

Jimmy L Dodson · « **Reply #76 on:** March 08, 2016, 01:30:10 PM »

Does anyone know how I can get a subscription to this magazine? Is it still in existence? I used to get this, but lost contact.
Thanks,

Jimmy L Dodson
Beaufort, SC

david beazley · « **Reply #77 on:** March 08, 2016, 05:36:51 PM »

Jimmy, I believe that KAPA is no more.