Crickets....
01-22-2023, 09:50 AM
#1126
[QUOTE=speedracerntrixie;12759676]The builder says it weighs 6.5 kg
It would be very cool if it was mostly wood.....but I have no idea.
I would like to see a construction article about that plane.
It would be very cool if it was mostly wood.....but I have no idea.
I would like to see a construction article about that plane.
Last edited by combatpigg; 01-22-2023 at 09:56 AM.
01-22-2023, 11:14 AM
#1127
[QUOTE=combatpigg;12759693]
As would I. The fuselage sides look solid so I’m thinking balsa is improbable but not impossible. It flies much lighter then 6.5 kg though. Many people have a hard time believing my Divergent pattern airplane weighs just 4.5 kg being a fiberglass fuselage and balsa sheeted foam wing and stabs. All paint finish as well. That includes the 5100 mah 10 Lipo call battery. It took a few years to develop the fiberglass layup to be strong enough but not overbuilt.
01-22-2023, 12:48 PM
#1128
[QUOTE=speedracerntrixie;12759701]
As would I. The fuselage sides look solid so I’m thinking balsa is improbable but not impossible. It flies much lighter then 6.5 kg though. Many people have a hard time believing my Divergent pattern airplane weighs just 4.5 kg being a fiberglass fuselage and balsa sheeted foam wing and stabs. All paint finish as well. That includes the 5100 mah 10 Lipo call battery. It took a few years to develop the fiberglass layup to be strong enough but not overbuilt.
I would have guessed the Fokker weighs 6.5 pounds.not kilos.
Your plane turned out very light.and very nice..!
It would take me a quart of primer / filler and a quart of paint [at least] to paint it with Klasskote.
It's very easy for ideas that involve fiberglass and epoxy paint to get heavy.
I worked at a FG sailboat factory in HS and controlling weight was one of the managers biggest responsibilties
.If the boat was in danger of turning out too heavy, the final [3rd?] layer of matte was going to recover more effort for the laminators to roll into the previous layer.
I experimented a little with FG cloth over a 1/16" balsa sheet box fuselage and it turned out plenty strong for a .40 sized project. I can't recall the weight of the cloth...I think 2 oz was used on the outside and also on the inside from the firewall to the wing saddle.
As would I. The fuselage sides look solid so I’m thinking balsa is improbable but not impossible. It flies much lighter then 6.5 kg though. Many people have a hard time believing my Divergent pattern airplane weighs just 4.5 kg being a fiberglass fuselage and balsa sheeted foam wing and stabs. All paint finish as well. That includes the 5100 mah 10 Lipo call battery. It took a few years to develop the fiberglass layup to be strong enough but not overbuilt.
Your plane turned out very light.and very nice..!
It would take me a quart of primer / filler and a quart of paint [at least] to paint it with Klasskote.
It's very easy for ideas that involve fiberglass and epoxy paint to get heavy.
I worked at a FG sailboat factory in HS and controlling weight was one of the managers biggest responsibilties
.If the boat was in danger of turning out too heavy, the final [3rd?] layer of matte was going to recover more effort for the laminators to roll into the previous layer.
I experimented a little with FG cloth over a 1/16" balsa sheet box fuselage and it turned out plenty strong for a .40 sized project. I can't recall the weight of the cloth...I think 2 oz was used on the outside and also on the inside from the firewall to the wing saddle.
01-22-2023, 02:35 PM
#1129
Had a guy show me rolling the wet resin after applying to the cloth with a roll of toilet paper. It sucked up the access resin and reduced the weight significantly, so I do it with all my applications then fill and sand the weave with feather coat. I have had items turn out almost as light as with cloth and paint. Did it with a friends kayak and there is a 3.5 lb difference between the new and old one. Same design same construction.
01-22-2023, 04:10 PM
#1130
The fuselage molds are sprayed with a light coat of Klass Kote epoxy primer, then the layup which consists of glass, 1/32 balsa and more glass. Then vacuum bagged. Once cured, the formers and gear plate is installed and the halves are joined. Fuselage leaves the mold at 31oz and 95% ready to paint. Wings are sheeted via epoxy and vacuum bagging. Sanded out and glassed with thinned epoxy resin. Then wings are primed with Klass Kote. The pictured model was painted with Rustolium matte finish paints. If you guys are interested I can post a link to the build or you can just go to the electric pattern forum and look for Divergent build.
01-22-2023, 04:36 PM
#1131
The fuselage molds are sprayed with a light coat of Klass Kote epoxy primer, then the layup which consists of glass, 1/32 balsa and more glass. Then vacuum bagged. Once cured, the formers and gear plate is installed and the halves are joined. Fuselage leaves the mold at 31oz and 95% ready to paint. Wings are sheeted via epoxy and vacuum bagging. Sanded out and glassed with thinned epoxy resin. Then wings are primed with Klass Kote. The pictured model was painted with Rustolium matte finish paints. If you guys are interested I can post a link to the build or you can just go to the electric pattern forum and look for Divergent build.
My recent attempts to look anything up at RCU have come up empty.
I can google some past threads of mine but all of the photos are gone.
01-22-2023, 06:24 PM
#1132
I used 2 layers of 1.4 oz plain weave, one at 45 degree bias the second at 135 degree bias. Then went in the 1/32” bass core followed by the final layer of 3.6 0z crows foot weave style 120 at zero degrees. Then a layer of peel ply, a layer of 1 mil release film and two layers of paper towel for breather material. It all goes into a vacuum bag and has to be under vacuum no more then 90 minutes from mixing the first batch of epoxy. Thread here.
Divergent kits
Divergent kits
01-23-2023, 10:59 AM
#1133
I used 2 layers of 1.4 oz plain weave, one at 45 degree bias the second at 135 degree bias. Then went in the 1/32” bass core followed by the final layer of 3.6 0z crows foot weave style 120 at zero degrees. Then a layer of peel ply, a layer of 1 mil release film and two layers of paper towel for breather material. It all goes into a vacuum bag and has to be under vacuum no more then 90 minutes from mixing the first batch of epoxy. Thread here.
Divergent kits
Divergent kits
You went to a lot of effort..not just for the plane but also for the documentary.
That's the first time I've ever seen balsa sheet added to the lay up.
It's been many years since I bought any cloth or resins.
There was 1 guy who had a local store for at least 20 years..maybe 30.
There was always a steady trickle of customers but once he closed the doors nobody else has stepped up.
Who knows what sort of bureaucratic obstacles a business like that has nowadays.
Aerospace Composites is the only other source for materials that I am aware of.
01-23-2023, 12:22 PM
#1134
One that might interest you all is that Speed's method of laying up a plane is almost the exact same that Four Winns lays up a full sized boat. From the outside in, it's gelcoat, a layer or two of FG, balsa and more layers of FG. Compared to other boats, the Four Winns hulls are much more rigid due to the inclusion of the balsa layer
01-23-2023, 01:49 PM
#1135
One that might interest you all is that Speed's method of laying up a plane is almost the exact same that Four Winns lays up a full sized boat. From the outside in, it's gelcoat, a layer or two of FG, balsa and more layers of FG. Compared to other boats, the Four Winns hulls are much more rigid due to the inclusion of the balsa layer
I wonder where the hydroplane builders buy their balsa ...?
01-23-2023, 02:37 PM
#1136
I don't build with balsa, other that airplanes. If it gets wet, it swells up like a sponge. I build my boats from aircraft grade birch ply, birch boards and spruce stick stock.
01-23-2023, 04:37 PM
#1137
You guys should check out this place. Fiberglass Supply. They are probably a little bit farther for both of you, being located in Burlington near the Skagit Airport, but they offer a pretty good selection of composites, resins, gel coat, etc. I think they also have some balsa core.
Astro
Astro
01-23-2023, 05:58 PM
#1138
Thanks for posting that great step by step look at the inside of your plane..!!
You went to a lot of effort..not just for the plane but also for the documentary.
That's the first time I've ever seen balsa sheet added to the lay up.
It's been many years since I bought any cloth or resins.
There was 1 guy who had a local store for at least 20 years..maybe 30.
There was always a steady trickle of customers but once he closed the doors nobody else has stepped up.
Who knows what sort of bureaucratic obstacles a business like that has nowadays.
Aerospace Composites is the only other source for materials that I am aware of.
You went to a lot of effort..not just for the plane but also for the documentary.
That's the first time I've ever seen balsa sheet added to the lay up.
It's been many years since I bought any cloth or resins.
There was 1 guy who had a local store for at least 20 years..maybe 30.
There was always a steady trickle of customers but once he closed the doors nobody else has stepped up.
Who knows what sort of bureaucratic obstacles a business like that has nowadays.
Aerospace Composites is the only other source for materials that I am aware of.
01-23-2023, 08:05 PM
#1139
You guys should check out this place. Fiberglass Supply. They are probably a little bit farther for both of you, being located in Burlington near the Skagit Airport, but they offer a pretty good selection of composites, resins, gel coat, etc. I think they also have some balsa core.
Astro
Astro
I would rather go to Burlington than South Everett.
Years ago I swore off doing any more extensive FG work....but there are times when the "pull" is too great to buy $500 bucks worth of supplies so that I can build a plane that is 2% better than if it were made of all wood...
Last edited by combatpigg; 01-23-2023 at 08:09 PM.
01-23-2023, 08:55 PM
#1140
I can't see any better way to build a 1/2A Speedster fuselage...[than FG] .but I don't think solid balsa sheet can be beat for the wing and tail surfaces...!
For an open exhaust model...70 sq inches of airfoiled 1/4" thick balsa wing is as small as I dare go for a RTF weight of 9 ozs
With the extra weight of a tuned pipe...100 sq inch wing of 1/4" thick balsa ... for a RTF weight of 11 ozs.
Figure 150 mph is doable with an open exhaust 1 cc engine and possibly 160 mph with a "high timed" piped engine.
01-24-2023, 06:52 PM
#1141
160 mph is a tough nut to crack. My last exploits in pylon racing was Warbird racing in Sacramento. The rules required that the airplane needed to be a recognizable replica of a WWII heavy metal fighter. I choose the Italian Macchi 202. Made a plug and pulled some molds. The airplane has a 61” span and 520 sq. in. wing using my own airfoils. Power was YS 115 run on 30% and 40% nitro. Top speed was around 180. Our course was two pylons 750’ apart and we flew 10 full laps from an air start. My best time was 1:16.2. 160mph out of a 1/2A would be impressive indeed.
01-24-2023, 09:55 PM
#1142
Nice smooth, flowing lines..!
I've never heard a 4C glow engine run like that..!
Looks like APC was right on top of the situation.
How many planes and engines did it take to get through the season...?
What are those tail feathers made out of...?
For a 160 mph 1/2A to be feasible I think the piped Profi control line speed engine is the ticket.
I just looked this one up [to copy the photo] and the poor orphaned engine just sat there with no bids at $300
Steve Wilk of Eliminator Props specializes in C/L Speed props and is a great guy to work with..with what seems like an infinite selection of "possible" props for many applications.
I've never heard a 4C glow engine run like that..!
Looks like APC was right on top of the situation.
How many planes and engines did it take to get through the season...?
What are those tail feathers made out of...?
For a 160 mph 1/2A to be feasible I think the piped Profi control line speed engine is the ticket.
I just looked this one up [to copy the photo] and the poor orphaned engine just sat there with no bids at $300
Steve Wilk of Eliminator Props specializes in C/L Speed props and is a great guy to work with..with what seems like an infinite selection of "possible" props for many applications.
01-25-2023, 05:05 AM
#1143
Robert Holic ( not sure of the spelling ) who is the current owner of APC used to race with us. Fred Burgdorff the former owner and founder was also a race guy. We had 14x12, 14x13, 14X14 and my favorite 13.5x13.5 props to run. I mostly ran 30% nitro but some ran up to 55%. Unfortunately to keep our AMA sanction we needed to adopt breakout times for each class. For the gold class, that meant flying the course no faster then 1:30. The planes were capable of 1:20 for the most part so a guy could fly a sloppy course and still win. Took the skill out of it and for me the challenge/fun.
The tail section was solid balsa sanded to airfoil shape and bagged with 3.6 glass with a 1.6 oz strip of Kevlar. After bagging the side opposite of the Kevlar was cut through to the Kevlar and a V groove sanded in and the Kevlar became the hinge.
The tail section was solid balsa sanded to airfoil shape and bagged with 3.6 glass with a 1.6 oz strip of Kevlar. After bagging the side opposite of the Kevlar was cut through to the Kevlar and a V groove sanded in and the Kevlar became the hinge.
01-25-2023, 10:33 AM
#1144
Robert Holic ( not sure of the spelling ) who is the current owner of APC used to race with us. Fred Burgdorff the former owner and founder was also a race guy. We had 14x12, 14x13, 14X14 and my favorite 13.5x13.5 props to run. I mostly ran 30% nitro but some ran up to 55%. Unfortunately to keep our AMA sanction we needed to adopt breakout times for each class. For the gold class, that meant flying the course no faster then 1:30. The planes were capable of 1:20 for the most part so a guy could fly a sloppy course and still win. Took the skill out of it and for me the challenge/fun.
The tail section was solid balsa sanded to airfoil shape and bagged with 3.6 glass with a 1.6 oz strip of Kevlar. After bagging the side opposite of the Kevlar was cut through to the Kevlar and a V groove sanded in and the Kevlar became the hinge.
The tail section was solid balsa sanded to airfoil shape and bagged with 3.6 glass with a 1.6 oz strip of Kevlar. After bagging the side opposite of the Kevlar was cut through to the Kevlar and a V groove sanded in and the Kevlar became the hinge.
I imagine there were some racers from SF...since wasn't it TOTALLY ILLEGAL to run a model plane engine in SF for many years now...?
I'm impressed that there were so many participants who were able to get tooled up to race such a one of a kind...High End Event.
There must have been a lot of talk for a number of years to drum up enough interest and support.
01-25-2023, 06:56 PM
#1145
I don’t recall any from SF. I’m unaware of a model airplane ban. The race series had been going at least 10 years prior to me getting involved. The series did attract entrants from the Chico area, Southern California, Nevada and Utah. IMO it makes sense that it is quite popular, of all the classes at Reno not many people talk about any other except for the Unlimiteds. Just something about Mustangs, Spitfires, Bearcats and the like rounding the poles at 170mph. Those YS 115 engines on 40% nitro with open headers really get the excitement going.
01-29-2023, 11:15 AM
#1148
01-29-2023, 11:34 AM
#1149
