Scat Cat 500 - Build thread from kit

thenated0g

Drinker of coffee, Maker of things
Mentor
A coworker of mine, that knows im into planes, gave me this old kit his parents got for him when he was a kid and never built. Looked like a nice entry into balsa building as the wing is solid foam so i started working on it. Going to try and get it going as fast as i can with the motors and stuff i have and assuming it survives maiden maybe purchase some thing more powerful to upgrade later.

Thin ca for most of the fuselage build so far, with some titebond here and there. Wings sheeted with gorilla glue.
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Starting this crazy puzzle of parts.
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Trailer edge attached and taping skins together to get ready for vacuum bagging
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Puzzle continues
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Tail feathers joined
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Wings out of the vacuum bags, needs trimming
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Leading edge going on
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Aileron control rods
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Wing tips getting glued together before attaching and sanding
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Vacuum bagging the wings with gorilla glue:
 

L Edge

Master member
I would like to pass some info about this plane. If you are going with landing gear, suggest you move it about 1' forward. My son and I pylon raced the Scat Cat in the 70's and its a beautiful and fast one except it had a bad trait. Landings were a problem due to the gear would hit the grass and it would tip over the airplane and do damage like break the prop or damage the tail feather. We and others moved the landing gear forward by 1" and that stopped the tip overs. Keep it tight next to the pylons and you always came out a winner with the scat cat.
 

thenated0g

Drinker of coffee, Maker of things
Mentor
I would like to pass some info about this plane. If you are going with landing gear, suggest you move it about 1' forward. My son and I pylon raced the Scat Cat in the 70's and its a beautiful and fast one except it had a bad trait. Landings were a problem due to the gear would hit the grass and it would tip over the airplane and do damage like break the prop or damage the tail feather. We and others moved the landing gear forward by 1" and that stopped the tip overs. Keep it tight next to the pylons and you always came out a winner with the scat cat.
Thanks for the info, i appreciate it. I had already decided to not have landing gear as i fly off a nice fluffy grass area and i am hoping the lack of gear will make it go a little faster.

@thenated0g - looks great - I am toying with the idea of a kit build! :D
The spririt 2m was a little too much balsa for my first build so this is just right. I actually have an RAcores gremlin sitting on the shelf that i think i will build after this one. Similar wing build (balsa over foam( but the fuselage is like abs gutter plastic stuff. Kind of a unique build, looks cool
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OliverW

Legendary member
Thanks for the info, i appreciate it. I had already decided to not have landing gear as i fly off a nice fluffy grass area and i am hoping the lack of gear will make it go a little faster.


The spririt 2m was a little too much balsa for my first build so this is just right. I actually have an RAcores gremlin sitting on the shelf that i think i will build after this one. Similar wing build (balsa over foam( but the fuselage is like abs gutter plastic stuff. Kind of a unique build, looks cool
View attachment 149935
I wish they still made the gremlin
 

thenated0g

Drinker of coffee, Maker of things
Mentor
Yeah. I saw an original Gremlin kit for auction a couple years back but it went for something like $150 which was over my limit.
Ha, well i wont tell you how much i paid for mine than. He must have been clearing out stock as i got it shipped to me last year for under $60.
It is a pretty interesting kit. At its core its very simple and i have been thinking about really looking at the parts to see about, not designing, but making some suggestions on how you could do a copy of it simpler. Like im pretty sure you could get some square gutter pipe, make a cut out for the wing, cut a piece of ply for the motor mount and attach whatever wings you want to that and it would be pretty darn close. I have a hot wire cutting setup so i may trace the root and tip cords, sweep, etc and see. Racores follows me on instagram so when i get around to doing that i will just ask him if its ok to share the plans i make with scratch builders in this forum before i do so, but he seems like a pretty nice guy with no interest in building them anymore so hopefully he wont care.
 

rockyboy

Skill Collector
Mentor
Ha, well i wont tell you how much i paid for mine than. He must have been clearing out stock as i got it shipped to me last year for under $60.
It is a pretty interesting kit. At its core its very simple and i have been thinking about really looking at the parts to see about, not designing, but making some suggestions on how you could do a copy of it simpler. Like im pretty sure you could get some square gutter pipe, make a cut out for the wing, cut a piece of ply for the motor mount and attach whatever wings you want to that and it would be pretty darn close. I have a hot wire cutting setup so i may trace the root and tip cords, sweep, etc and see. Racores follows me on instagram so when i get around to doing that i will just ask him if its ok to share the plans i make with scratch builders in this forum before i do so, but he seems like a pretty nice guy with no interest in building them anymore so hopefully he wont care.
My memory could be wrong about the final selling price but I do remember several people were bidding on it and I thought it was a little crazy how much it finally sold at.
 

thenated0g

Drinker of coffee, Maker of things
Mentor
The wingtips are interesting. The gap will be bridged later with covering. Since i had some uneven surfaces and i was mating wood to foam i used gorilla glue.
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Sanding
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My first modification to the build is to remove the gear block and replace it with a thicker (in diameter) but significantly lighter in weight carbon fiber tube. Used my sharpened copper pipe to drill out the path and some GG and water to set in place.
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thenated0g

Drinker of coffee, Maker of things
Mentor
My memory could be wrong about the final selling price but I do remember several people were bidding on it and I thought it was a little crazy how much it finally sold at.

Probably a lot of nostalgia and realizing that you can't get them anymore. I have had more "older" guys comment and send me PM's on this Scat Cat than any other post i have ever made on instagram and youtube and facebook.

Here's a picture one guy sent me this morning on IG, guess his club used to race them(scat cat) all the time:
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thenated0g

Drinker of coffee, Maker of things
Mentor
Lets talk about speed and power. Usually on my builds i go for 1:1 power, this stems from my solo learning experience learning to fly rc on the ft versa and almost quitting the hobby as i used the wrong motor so now i just aim for 1:1. That is a pretty darn simple search. I just look at motors until i find one that puts out the thrust i need. In this case the criteria is "go as fast as i can" which is something new so been doing lots of research. Short version is please suggest away!

Trying to go with what i have on hand for motors i think i have a good start. NTM 3536 1800kv. Previously I had 2x of these motors powering my big 200% ft jet:
https://www.youtube.com/playlist?list=PLMieSP4Ym7qq7fJKcNTFCLj3oHem4saP6

@nerdnic has some nice test he did in this video showing how it does on 4s and 6s:

Motor specs:
Model: NTM Prop Drive 35-36A 1800
Kv: 1800rpm/v
Max current: 65A
Max Power: 700W @ 12v (3S) / 875W @ 15v (4S)
Shaft: 4mm
Weight: 120g
ESC: 70A
ESC:
100a PowerUp​


Battery:
4s 1800mah 70c Nano-Tech​

Props:
I have the 7x7 nic tested in the video below but i also grabbed a 7x8, 7x9, and 7x10. Plus i have 2 motors so if i burn one up i can learn my lesson and go back down to 7x7. I know in the calcs the jump from 7x7 to x10 is about 60mph more but the x7 was already really close to 100a so not sure how much i want to test the esc and motor.​
And because there is a chance of blowing something up in the motor/esc department there will be no positive wire connection between the RX and the power system, i will go old school and use a Nimh pack for a deadstick landing if needed.

For servos im going with a couple 50g regular size servos that have 9kg torque.
Now i know from looking at the thickness of the airfoil and how deep the chord is that it is not going be be warmliner/hotliner fast, but considering i don't have any edfs or "fast" planes at the moment this is really relative, just want to make it go as reasonably fast as it can.
Assuming it survives the 4s runs i will order some 6s packs.
 

thenated0g

Drinker of coffee, Maker of things
Mentor
Left aileron connected with CA hinges. Epoxy was used where the metal arm goes into it. Still surprised by how small the ailerons are, but i guess since it will be going fast it doesn't need much.

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L Edge

Master member
Left aileron connected with CA hinges. Epoxy was used where the metal arm goes into it. Still surprised by how small the ailerons are, but i guess since it will be going fast it doesn't need much.

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Are you going to monocote it?
It will be interesting what kind of speed you will getting out of it with the 4S and 6S system. It should be fast and the interesting point is that it will be a "pussycat" on landing. We were required to land deadstick and it handled real good with crosswinds. In our days, we had only wooden props. So if you had a top prop,(use to go thru 10 wooden props and perhaps get 2 that are good for racing), you wanted to land last so no one hit your airplane and your prop.

Thanks for bringing back those good memories.
 

thenated0g

Drinker of coffee, Maker of things
Mentor
Trying to decide between, Painting and iron on laminate, monokote, or vinyl wrap. Mono would be the easiest. But i am a big van of vinyl wrapped planes since doing my big 8ft zagi wing. Just not sure how i would get it to adhere to balsa. Do i need to super77 it first? Or seal it with minwax or a coat of paint first?
 

L Edge

Master member
Trying to decide between, Painting and iron on laminate, monokote, or vinyl wrap. Mono would be the easiest. But i am a big van of vinyl wrapped planes since doing my big 8ft zagi wing. Just not sure how i would get it to adhere to balsa. Do i need to super77 it first? Or seal it with minwax or a coat of paint first?

Have not worked with vinyl wrap so I can't help you. Monocote was the only way to hit 3.5 lbs exactly so you could compete with the other pilots. There were even challanges by other pilots if they felt you were under the limit. I seen races were they would tear the winner's engine down to see if it was modified. Of course, the rebuild engine never puts it back to orginal rpm's.