tomclark

I've been a scratch builder since the 70s. Out of 87 builds only 10 have been kits. Have never yet had an ARF. For many years now I have been flying overpowered rockets and pattern planes. Recently decided I needed some gentler flying birds - some that would lower the blood pressure instead of raising it. Recently been in a building craze as I noticed many of my planes are 10-12 years old and due for retirement.

Anyway, last month I built a slightly oversize Sig Kadet. Since we are scratch builders we can build anything any size, right? My Kadet has a 90" span. Now I am following it up with a Goldberg Tiger. This one has a 78" span and a 70" fuse length. (photos of the Kadet and many other of my scratch builds are on my blog.) I have been taking photos of the Tiger build, so here is the first weeks progress/

My plans? Just an ad I clipped out of an unknown mag that I added to my notebook years ago. I draw my own plans, and they are really just the outline of the model. Construction is my favorite simple building methods - lots of sticks. No fancy plan needed…

tomclark

Tigers tend to be tail heavy, so I extended the nose about 1.5". There was a new Magnum 90FS purchased on sale years ago, and never used, so this plane is being built for it.

Ribs are laid out, then a stack of balsa is cut on the bandsaw. Construction changed to dual ailerons - just love flaps and air brakes.

tomclark

Construction of the wing is standard "D" tube, except that I use less sheeting than I used to. No sheeting on the wings sucks, and too much is a waste of money.

I used 1.75 inches under one tip for dihedral. Also using training wheels because almost all of my planes in many years have been tail draggers, so the nose gear is a novelty.

Plane is nearly ready to cover. Just finishing details like radio and hardware installation.

Folded 3 wings in my early days, so now fiberglass all center sections. Have not folded a wing in 35 years.

Will post more photos when covered and flying.

tomclark

Covering is coming along slowly. Have some out of town guests this week, so not much shop time. Hope to finish next week.

blvdbuzzard

I see you have an electric hammer too. Mine works so well I bought a second one.

I have had 3 Jr Tigers over the years and have threatened to scratch build one. Have not made it that far yet.

Yours is looking very nice.


Buzz.

tomclark

Hey Buzz,

Glad you noticed the electric hammer. It was presented to me at a woodworking club meeting many moons ago. Guys were giving me crap because I did everything with power tools instead of hand tools. How did you get yours?

By the way, finished covering on the 4th. Can you tell?

Now to finish hardware and go test fly. What super lines the Tiger has…

Tom

Boomerang1

Absolutely! Any model, any size, any modification you want.

Along with their strange methods in some areas, some to make kit production easier.
No problems, we can fix that to.

I've had a few, usually bought second hand at bargain prices to get an interesting engine
or some radio gear for next to nothing. One was a gift complete with radio gear AND engine!
If they are airworthy I fly them until they end up fuel soaked or fall apart (doesn't take long) but
they sure lack the love & pride factor!

One thing they do feature occasionally are innovative construction methods that can be adopted
for my scratch builds, they changed my method of doing fuselage stringers as an example.

Lovely Tiger.

John.

blvdbuzzard

I picked mine up at a wood working convention.

Been a long time since I have built any planes. I lost a lot of room in the shop, plus lost a lot of time to build. Been trying to get some of those back.

I love the way my Jr Tiger flew. Was just a really nice plane to fly.


Buzz.

tomclark

Well Buzz,

Can't hope too hard that you get back into building. I just visited another thread, and the guys were whining that the ARF they were discussing was too weak, firewall too thin, too prone to flutter, etc, etc. Builders can fix all of those problems even if they are building a kit - just by modifying anything that doesn't suit them. Scratch builders can design their planes to be light but still strong with a good long lifespan. I seldom retire favorite planes before flying them 10 years or more… I really can't believe the guys in my club show up with ARFs with no fuel proofing around the engine. The things fall apart in no time… Sorry to get off on the rant!

Anyway, Tiger is looking good and getting closer to first flight. Have a brand new 91 Magnum 4c I purchased on sale years ago but never used. Just wondering what prop would be best? Any suggestions? I have a 14-8 I am considering…

blvdbuzzard

It makes me laugh every time I hear some one say "I built this ARF" How do you build something that is already built? I find it so funny when people are lost on how to route a push rod, change hinges, make parts for a repair. I grew up having to do that just to get the plane built. The art of building is going the way of the carrier pigeon.


Buzz.

tomclark

All finished and ready to break in the new engine. The Tiger came out at 6.5 pounds. Rest of specs, 76" span, 13.5" cord, and 73" spinner to rudder. Wing loading is 16.5 oz/sq. ft. Lengthening the fuse 1.5 inches was just a bit much, as the battery had to be placed in the rear of the cabin to get the balance to 5.5" back. The Magnum 91FS should be plenty of power.

Really looking forward to first flight once the engine is broken in and reliable. Will post flight photos later.

thailazer

Looks great! Make sure you do a flight report.

Mjet

Good looking , I also near to complete my Tiger. Pl share the build of canopy ( your looks as Balsa build ).


Thanks

tomclark

I already did in the photos above in this thread. It was easier for me to scratch build the whole plane than to try to mold a single canopy. It should be quite easy to build a balsa canopy for any Tiger. Mine is just covered in Monocoat.

tomclark

This morning I finally was able to experience what flying a Tiger for the first time was like. What a nice airplane with gentle flying characteristics. Now I know why so many of you are fond of your Tigers.

The Tiger used a brand new Magnum 91FS that I bought new 15-20 years ago but had never used. Tower had a big sale so it got added to the list of a few other engines purchased at that time. I had good luck with another Magnum 91 2C that I purchased at the same time. As a matter of fact, that 91 is nearly worn out from years of use. But now with the price and availability of fuel, it finally seemed like a good time to use the more thrifty 4C engine.

After a couple of tanks of fuel on the test stand, a bit of fussing with the radio settings, the wind was picking up, so it was test flown before the engine was really broken in. The engine idle was not reliable yet, but it did keep going through the first flight.

Takeoff was uneventful. I kept it on the ground past the point where it was ready to fly because of the slightly gusty weather, and then let it fly, keeping it in close in case the engine decided to stop playing. But the engine kept on running despite the rich setting and the plane showed its good character right away. Should have built one years ago.

My plane is a bit light for its 76" span, and actually would probably not mind an extra pound or two. That would help smooth out the bumps in gusty conditions. Anyway, love the plane. Can't wait for the engine to break in and achieve a good idle. At that point the first of thousands of touch and goes will be enjoyed.

By the way, increasing the fuselage length in front of the wing 1.5" was a bit more than needed - but my fuse is made from balsa, not plywood, so it is a bit lighter than the normal kits.

Loops and rolls were just natural, and inverted showed that the balance point could be moved back a bit more. I already had to put the flight battery at the rear of the fuselage, so that may take just a bit of tail weight.

SigSenior

Tom, what an excellent build! Thanks for sharing your excellent work. I can see the "trueness" of the flight characteristics....which is always reflective of the trueness of the build!

WILDCRASHWILLY

I agree with Sig Senior Tom great job! And you build so fast. I like to build also but I travel heavily for work so I'm very slow. I keep something, sometimes two things on the building boards at all times though. The shop is my destressor when home. We need more people with your skills to post build threads. That's how a lot of us learn, myself included.

golf4two

My scratch-bash of a Tiger. Turtledeck rounded and plastic canopy added (2 pieces of thin plastic sheet on balsa frame. Home made fiberglass cowl. Reversible gear allows tail dragger or trike gear (altho it's a pain to drop the nose gear). Landing lights activated via microservo and switch. 3W LEDs can be seen over 200 yards. Best flying airplane I own.

tomclark

Wildcrashwilly,

Thanks for the comments. Yeah, I do build fast sometimes, then take time off now and then. Just finished another 102" scratch build since the Tiger, so haven't been back here lately.

I wrote a small book years ago about scratch building for my club mates back in FL, and it did help many of them to learn building better. It's full of what I learned after 35 years of scratch building. (That was back in the days before I joined the RC forums on the internet. I'm kinda old fashioned in many ways.)

tomclark

golf4two,

Cool build. Always glad to see anyone use their imagination and build anything anyway they want. Really like the lights idea. Must be very handy near dusk…

Sure agree with what a great flyer the Tiger is. It's almost as smooth as the old pattern planes were back in the 70s. Mine has a dozen flights on it now, and love it…

golf4two

Thanks Tom. You did an absolutely great job.....I didn't mean to hijack your thread. Canopy comment above got me to thinking about my build so I thought I'd share. Lots of ways to "customize" just about any build. Mine is so old some of the covering needs replacement. Enjoy!

Oh BTW: For those who might be wondering about the trike vs taildragger concept: I drop the nose gear (have to take the cowl off) then swap the two mains so they rake forward. Works just fine.

thailazer

Tom.... I like the old techniques as well. I am working on a more refined gasser right now and last week I was planning on taking my CAD airfoil file to the local laser cutter. Got some ambition and made a ply rib template and in less than two and half hours, had my stack of ribs cut out using just a hand coping saw. The travel to and from the laser cutter would have taken that long! At any rate, nice thread here.