# My latest R/C RBG

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#### Serenity

##### Active Member
I was browsing around one of my local hobby shops a few months ago, and I noticed in the replacement parts department that they had all of the major parts for a Parkzone F27 Stryker. The wing/fuselage/nose cone was $18.99. The elevons, complete with control horns were$3.99. The vertical fins were $7.99. The complete hatch set was$7.99. With taxes, all the parts were around $41.00. I gathered the parts up and bought them. Over the course of the last couple of months, I have gradually assembled the parts. I have an old Parkzone F27B that I bought in 2004, and I still fly it from time to time. I've thought of buying the newer F27C model, but at$250 it's a bit pricey.

At any rate, the parts were easy to assemble, and all I had to do was add a motor mount and launch lugs to make it an RBG. Ready to fly weight is about 13.9 ozs. That's not bad for a glider with a 37" wingspan.

I test flew it on Saturday evening, and it did great. I flew it 4 times on Estes D11-P and one flight on an Aerotech F12 reload. Unfortunately, I don't have any launch pics, as the only people who went were my son and I, so I was short one person to be able to get pics. If I was flying, my son was handling the launch control, which left no one to take pics. If my son was flying I was handling launch control, so again no one for pics. Hopefully we'll have enough people next time to get some launch pics.

Incidentally, I have named this version the F27R. I'm sure you can guess why it has the "R" designation.

Here's two pics, one of the top and one of the bottom.

#### AKPilot

##### Well-Known Member
Now this is cool! Especially as I'm familiar with it, having an r/c one. And you're right, the parts are very easy to access.

I'd like to see close-up pics on how you added the Motor Mount tube, if you don't mind,

#### eugenefl

##### Well-Known Member
I would have never thought to piece together an R/C rocket glider in such a way. You could probably repackage this kit into a fashionable rocketry kit and mark up the price. LOL. This is a really great idea.

#### Serenity

##### Active Member
AKPilot wanted detail on the motor mount tube. I have included 4 pics for clarification.

The 1st pic is the main motor mount tube. This is simply a piece of Estes BT55 tube covered with a piece of black monokote trim and epoxied to the wing where the motor mount for the electric motor would have been attached. I also cut away some of the foam in this area to reduce the angle of the motor mount tube. If I make another one, I would cut away even more of the foam to make the mount point flatter, as there is still a little angle and as the F27R leaves the launch pad, it has a tendency to take a dip down which is easily corrected by bumping up elevator. I used the BT55 tube as it will hold an Aerotech RMS/RC 32mm reloadable motor. This is the RMS that was designed for the Aerotech Phoenix, and I wanted the option of being able to use that. I have a 1/8" ply bulkhead epoxied into the front of the motor mount. It has a hole in the center to make it easy to insert the adapter tubes. This MMT tube is 6 1/4" long.

The 2nd pic shows the motor mount tube with 3 adapters that I made for it. The adapter on the left is a 29mm motor mount adapter tube. I can insert this in the main MMT and use the Aerotech RMS 29/40-120 if I so desire. If I use this, I would use a mild motor like the F22 BlackJack reload. Just be sure to leave out the ejection charge. This tube is 6 1/8" long.

The adapter in the center is another piece of 29mm tube, and I put that into the main MMT tube to act as a spacer for the 32mm RMS/RC motor to thrust against. This tube is 2 1/4" long.

The adapter on the right is a piece of Estes body tube (sorry, I don't remember the BT number) that adapts the main MMT to hold a 24mm motor, like the Estes D or E motors (although I think they've quit making the E9-P) or the Aerotech 24mm RMS/RC motor. You can use the regular Aerotech 24mm RMS motor, but again you need to leave out the ejection charge. This adpater is 6" long. It has an internal thrust ring glued into it 2 1/2" from one end. You can put the 2 3/4" Estes D11-P into this end. If you put the adapter in the other way, the thrust ring is 3 1/4" in, which works pretty well for the 3 3/4" long Estes E9-P.

Picture 3 shows the MMT with the 29mm MMT adapter tube inserted, and Pic 4 shows the 24mm MMT adapter tube inserted.

Hope I didn't overload you with all these details on the motor mount and adapter tubes.

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#### AKPilot

##### Well-Known Member
Hey thanks for the pics and the suggestions. I know of yet another good project to take on now.

#### Clipper

##### Well-Known Member
Serenity,
Did you do anything to lighten the foam?

#### Serenity

##### Active Member
Nope. The foam was left untouched. 13.9 ounces just as it came from the hobby shop.

#### bcanino

##### Well-Known Member
What battery, receiver and servo's did you use?

#### rokitflite

##### Well-Known Member
Have you flown it yet?

#### dlazarus6660

##### Well-Known Member
I wish you had done this a few months ago before I went to the trouble of building an Estes Astro Blaster. I have not flown it yet.(not quite finished)
But I like your idea better.

#### Serenity

##### Active Member
bcanino - I am using an Expert Electronics, Pro 720, Sanyo NiMh, 4.8v, 720 mAh, 4 cell battery. Receiver is a HiTec FM Super Slim RCD9200 FUT J Dual Conversion Ultra Narrow Band 8 channel. That's way overkill for this model since I am only using two channels but it's what I happened to have on hand and available. The servos are HiTec HS-65HB.

rokitflite - Yes, I have flown it. On an Estes D11-P I get about 30-35 seconds of flight time. On an Aerotech E7-RCT I get about a minute and a half of flight time. An Aerotech E6-RCT yields about 2 minutes of flight time. An Aerotech F-12 will give about 2 and a half minutes of flight time. You have to be careful with the E7 and E6 loads. Launch at something like a 45 degree angle, and let it gain some speed before pulling into a more vertical climb. It's very easy to fly, and glides really well. You can do aerobatics with it, but that just cuts way down on the flight time. I haven't flown it yet around any thermals, and I am anxious to try that, as I think it is light enough to thermal.

dlazarus6660 - ummmm.... you wished this had been done a few months ago.... if you look at the date on the original post you'll see that it was August 2009.

#### bcanino

##### Well-Known Member
bcanino - I am using an Expert Electronics, Pro 720, Sanyo NiMh, 4.8v, 720 mAh, 4 cell battery. Receiver is a HiTec FM Super Slim RCD9200 FUT J Dual Conversion Ultra Narrow Band 8 channel. That's way overkill for this model since I am only using two channels but it's what I happened to have on hand and available. The servos are HiTec HS-65HB.
Thanks for the info. Did you use that battery because it was what you had on hand or use it balance. Did you have to play with the balance point any?

#### Clipper

##### Well-Known Member
What is your all-up-launch weight with the Aerotech F-12? Was that a reload or single use?
Did you notice the C.G. shift from the start of the brun to the end of the burn, in the way it handles?

Thanks, Eric

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#### Serenity

##### Active Member
bcanino - I had several different batteries on hand from which to choose. When I was working on installing the receiver and the battery, I tested a number of different configurations. With the 8 channel receiver as far forward as I could get it, and the 720 mAh battery right behind it, the CG balance point was right on without having to add any dead weight anywhere. I like configs where I don't have to add any extra weight for balance.

As far as "playing" with the balance point - I have the RC electric airplane version of the F27 Striker. Mine is the older one, not the new F27C. So I took the RC electric airplane, installed the flight battery, and checked where the CG was. I played with receiver/battery combinations and locations with the rocket glider version until I got something that matched the CG point of the RC electric version.

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#### Serenity

##### Active Member
Clipper - I didn't get an all-up launch weight with the F12 installed. The F12 is the Aerotech 24mm reload version that goes in the 24/40 casing. You install the delay charge, but you do NOT install the ejection charge. So you get a motor with thrust but no ejection.

With the loaded F-12 24/40 motor, the CG is moved back a little bit but not very much. Are the controls more sensitive during the lift-off and thrust phase? Most definitely, but nothing that can't be handled with a delicate touch on the controls. Some people like to set up dual rates and use the low rates on lift-off, but I've been flying RC for 30+ years, so I usually don't bother with low rates. When I started flying RC, there was no such thing as dual rates, exponential rates, etc - people today are very fortunate to have all the advanced features of modern RC equipment.

#### Sac

##### Well-Known Member
Yip I miss the old kraft radios. I been flying turbine and ducted fan for almost 30 years. The first "Turbines" caught on fire a lot. Thats what happens when you use propane. But I still like to go back to a nice sailplane. You just cant beat motorless flight. Most of my rocket sailplanes are called RAG as in Rocket Assisted Glider using air start. Bungee the 2.5 meter bird up then fire 2 D11-p's for extra altitude.