The Sliver - a TD .020 Project

Tee Bee wrote:I haven't run it yet, Mauricio.  Stay tuned.

ahh, okay ... in the translation I did not understand what you were saying exactly!
I remain attentive then!

Update on the Sliver: It has been flown successfully but is suffering from engine issues that I'm working through. Long story short, the Cox Pee Wee RC exhaust throttle sleeve that I installed is too restrictive and limits the TD power to about 50%. The airplane struggled with handling at this low power output on the initial trimout flight. After a few minor changes, flight tests will resume. I need to find a safe way to open up the sleeve exhaust port enough to allow full power. See the build thread in the RCU 1/2A forums for the complete story.

http://www.rcuniverse.com/forum/1-2-1-8-airplanes-70/11640642-sliver-build-thread-td-020-project.html

Plane looks really GOOD Troy , it's a shame you're having engine throttle issues but i am sure you can get them straightened out ! Man that sucks one screw hole stripped out ,, if ya got to go that far if it were ME i would replace ALL the screws with the Blind nuts !!

"I would replace ALL the screws with blind nuts."

Done did it.

I'm not going to let the throttle issues get me down. I'm off work tomorrow(Mon) morning and hope to do some test flying without the throttle sleeve in place. We'll see how that works out. 1/2A Nut has given me some stuff to look at on the throttle since he uses the same setup. I still can't determine why mine isn't performing well, but I don't want that to prevent me from flying it in the limited spare time that I currently have. I've got a couple more planes ready for some flight testing as well, so I look forward to a trip to the club field. I've been working lots of hours over the holidays and am craving some time off!

Guess what I've been doing.

Great news Troy, hows that engine pulling the plane now?
Ye ole cooler air will be more dense making the engine work harder
to get the plane through the soup.

She's flying pretty good under full power without the sleeve. 6 flights total now with a little tinker-fiddle between each one. Better every time. about 5 minute endurance with the 15ml tank. Airplane proven, now for the throttle issues...

5 mins. with the stock prop is not bad at all compared to the stock tank,
perhaps if you can get the throttle set up for extended flight times.
Hope to see a vid when able.

I run higher rpm with lower disk load / higher pitched props so the NV can be
set more lean for longer runs with 15 ml / 9.06 mins. with some throttle play
example here with this vid:




AmpAbuser
Published on Mar 5, 2016

TD .020 / 3.75 x 3 E-flite Prop / Best Level Pass- 29,554 RPM / 84 MPH / Throttle Sleeve
Static at launch 22,529 / 4.6oz thrust / 64mph / 36w / per prop calc
Best dive down wind out of 3 video's / 31,419 rpm / 89.3 mph
RTF 5.3oz - Actually has unlimited vertical / 35% Nitro / Run time 9.06 mins

Tee Bee wrote:Guess what I've been doing.

Hey Tee Bee, what a beautiful postcard: the model next to you, in what seems to be a beautiful day!
I am happy to know that the model is going very well and that the engine works perfectly ... now comes the throttle adjustment part, I will be attentive to your progress and when you can place a video, I would love to see that wonder in action!

1/2A Nut wrote:5 mins. with the stock prop is not bad at all compared to the stock tank,
perhaps if you can get the throttle set up for extended flight times.
Hope to see a vid when able.

I run higher rpm with lower disk load / higher pitched props so the NV can be
set more lean for longer runs with 15 ml / 9.06 mins. with some throttle play
example here with this vid:




AmpAbuser
Published on Mar 5, 2016

TD .020 / 3.75 x 3 E-flite Prop / Best Level Pass- 29,554 RPM  / 84 MPH / Throttle Sleeve
Static at launch 22,529 / 4.6oz thrust / 64mph / 36w / per prop calc
Best dive down wind out of 3 video's / 31,419 rpm / 89.3 mph
RTF 5.3oz - Actually has unlimited vertical / 35% Nitro / Run time 9.06 mins

I had seen this video, another great result in your hands !! ... I like it when you put it up and you give full gas! Climb as a rocket friend!

Most of the guys I routinely fly with are in their 70s and 80s and do not enjoy using my video camera to film my endeavors. When they do, they end up zooming in on the plane in flight just before it leaves the screen forever. No worries though. When one of my more camera-savvy friends or son is available, we will definitely capture some Sliver footage for the world to see.

Yes video from the right assistant can make all the difference.
I like first person vids it gives me the freedom to always have
an option to film the flight. 4k cameras are under 100 bucks
these days.

I like the one on the left. Maybe it would record straight to BetaMax for convenience.

Thanks Roddie! Same to you. It's been a blast to fly already.

More flight testing today.  Things are looking up.  After the previous issues with the throttle not working correctly, I had made 5-6 flights without the sleeve.  Today, I reinstalled it and spent some time running the engine and dialing it in.  I guess those break-in runs were helpful in my quest, as the throtttle worked fine today allowing a full range of power!  I put up a handful of flights with a stock Cox 4.5x2 prop with decent performance all around.Great fun!  Got a local clubmember to video one of those flights with my iphone.  Not the best quality but better than nothing.  Should earn me a little street cred for all my efforts, anyway. . For the final flights of the day, I switched to a Cox 4x2.5 prop with alum spinner.  That was the ticket!  The engine purred nicely and the percormance better matched the plane's handling.  Unfortunately, no one was there to document that setup in flight.  Another time... Stay tuned for a video link later when. I can upload using my computer.  My iphone isn't allowing me to login or upload to youtube for some reason.  

I'm still at the flying field enjoying this beautiful day as I type this.

Tee Bee
Published on Dec 1, 2017


This is my Sliver.  Designed by Steve Adams of Select Hobbies.  This is a prototype and I started building it 5 years ago.  I finally got serious with it and finished it after many hours of head scratching and building.  I made a few minor tweaks to the design as I went along.  It has full house 4 channel control using a throttle sleeve from a Cox Pee Wee .020 RC engine.  Uses Spektrum 4 channel receiver, 400mah NiMH battery pack, and Dymond servos.  D47s on the flight controls and D37 on the throttle.  Burning Sig Champion 25 fuel with a bit of extra castor oil added.  The model is all balsa and covered with Ultracote Lite Scale White with Monokote graphics.  The Russian graphic translates to "Sliver".  For information about the design, see my build thread in the 1/2A forum on RC Universe or contact Steve of Select Hobbies through the website.  Lackluster video shot on iphone 5S.

Specs from audio tach app: Cox 4.5x2
- Best idle pass 5,248 rpm / many 7,028 rpm
- Static In the hand at launch 16,795 rpm
- Static 4.93oz thrust / 32 mph / .027hp / 20.14w
- Best pass 20,495 rpm / 39 mph
- 3:15 mins run time / tad bit rich




You can get a even more rpm with a modified TD .010 spinner but not with the 4x2.5.
the hub is too big for it.

Try a 3.75x3 E-flite prop with the TD .010 spinner:
Be prepared for increased vertical climbs and speed.

- shorter bolt
- lighter spinner
- possible increased air flow to the blades at the hub
- less osculation at the far end of the crank
- less crank case wear
- improves field and air mojo
- unhinges the competition
- brings in more looky-loo's



For big hub props you can shim a TD .049 spinner the center one has been chucked up
in a drill and speed filed to better match the bolt head can shorted the spinner to improve
rpm and reduce mass.

Sorry for the reduncancy.  I'm copying this post from the original build thread at RCU.  It's just easier that way and I'm feeling tired and lazy.

I went back out for more test flying this morning after working the night shift. After the previous flights, the engine seemed to be running stronger today and more consistent with some break-in. I decided to re-attach the throttle sleeve and experiment a bit. This time, she ran just fine from idle to full power! Once the throttle ring position and servo throws were sorted, I resumed the test flights starting with a Cox 4.5x2 prop. She ran, flew, and throttled great. On the 2nd flight, I conned a clubmember into capturing some video footage on my iphone. I didn't have a camcorder with me. The linked video is not very good quality but it does show the versatility of the engine's performance well and captures what the little plane is like to fly. For some reason, the engine flamed out early on this flight. Murphy's Law, I guess. She ran through the entire 1/2oz tank on all the other flights. After my videographer left the field, I experimented with a Cox 4x2.5 prop combined with an OEM alum spinner. Bingo! That was the ticket and the airplane flew and ran even better. It's unfortunate that I wasn't able to capture it on video in this configuration. Will try again later.

The yawing instability I experienced on the first test flight last weekend is gone for some reason and no longer concerns me. I think it must have been responding to the gusty conditions at the time. On the last flight of the day, I lost control of the model while handlaunching in a gusty wind. It smacked the sidewalk causing some minor but repairable damage. I look forward to getting her repaired and back on the flightline soon. A little glue here and patching there and she'll be good to go.

Nice airplane, skaliwag!!! A bit of a challenging build but a ton of fun to fly. I look forward to seeing how/if this design evolves beyond this prototype stage. Meanwhile, it's pretty cool to have the only model like it in the world.

https://www.youtube.com/watch?v=7lSXffaPdDQ

Tee Bee wrote:

https://

friend, it just looks GREAT !!, congratulations, I wish you enjoy that model a lot !! ... thanks for sharing!

Way to go Troy!! I didn't know it was a Prototype or missed it ? Sounded good and flight looked on too / i see more fun to come with this model !! Good job on getting it ready and the maiden flight , Thanks for sharing . just gets better the more you play with them!