SFR2 Speed Fuselage for TDR

[JRAY]

After being delayed by the USPS, my SFR2 should be here tomorrow! Can't wait to get started on it.

[JRAY]

Look what came in Saturday! This fuse is very nice!

[Puttputt maru]

Fun time and lots of elbow grease ahead

[JRAY]

Originally Posted by Puttputt maru

Fun time and lots of elbow grease ahead

Just mount making, after that, is the easy/fun part.

[skipscratch]

very nice.

I have a few questions, I'm very new and learning about speed helicopters so please bare with me

a) would i be correct in assuming that the TDR metal boom mounts inside of the boom of the SFR2 fuselage?

b) about how much does the SFR2 weigh?

c) What is the approximate speed increase that is achieved by this wonderfull fuselage?

thanks for any reply
and sorry again if these questions are rather amateur
./cheers

[Vinger]

Originally Posted by skipscratch

very nice.

I have a few questions, I'm very new and learning about speed helicopters so please bare with me

a) would i be correct in assuming that the TDR metal boom mounts inside of the boom of the SFR2 fuselage? Correct, discussed a few posts up

b) about how much does the SFR2 weigh? Go to the link above

c) What is the approximate speed increase that is achieved by this wonderfull fuselage? See above, about 20kmh

thanks for any reply
and sorry again if these questions are rather amateur
./cheers

https://www.helifreak.com/showthread.php?t=571760

[RJ]

Originally Posted by skipscratch

very nice.

I have a few questions, I'm very new and learning about speed helicopters so please bare with me

b) about how much does the SFR2 weigh?

thanks for any reply
and sorry again if these questions are rather amateur
./cheers

Thanks Vinger for answering most of the questions already. The SFR2 with 16S 4400mAh TP packs, YGE 320 HV ESC, PowerCroco 4540 motor, and pitot airspeed/GPS telemetry is under 6kg. Obviously would be lighter depending on equipment and batteries used.

Regards,
Rick

[Sonixs]

Originally Posted by RJ

Thanks Vinger for answering most of the questions already. The SFR2 with 16S 4400mAh TP packs, YGE 320 HV ESC, PowerCroco 4540 motor, and pitot airspeed/GPS telemetry is under 6kg. Obviously would be lighter depending on equipment and batteries used.

Regards,
Rick

Wow! I would've expected a speed machine to be a lot lighter. I'm no speed demon but I do aim to have the lightest airframe possible for the best power to weight ratio.


Sent from my iPhone using Tapatalk

[itbvolks]

There is a minimum listed....

[RJ]

Originally Posted by Sonixs

Wow! I would've expected a speed machine to be a lot lighter. I'm no speed demon but I do aim to have the lightest airframe possible for the best power to weight ratio.

Yes, of course this is always the goal, but power to weight is not everything for speed, as drag increases as the square of the velocity, so aerodynamics becomes more important the faster you go. And the power requirement to spin the blades at the higher rpm at maximum pitch requires a very powerful motor, which in turn requires batteries and ESC which can support the current needs. All these things add to the weight. So the challenge is to balance all of these things. Looking forward to see what you come up with.

[RJ]

Both SFR1 and the SFR2 prototype used clear plastic tape to secure the joint between the front canopy and the rear fuselage along with a 3mm screw into the front mount on either side. The front canopy forms a lap joint with the rear fuselage. To eliminate using tape at the lap joint, I developed two alternative solutions:

Quick Pins:
Quick Pins are pins that mate with a tube in the rear fuselage. This results in a butt joint between the front canopy and the rear fuselage which is convenient for painting as there is no overlap. It requires a bit of a flange as a former to maintain the shape of the fuselage at the joint. Quick Pins are faster to get the canopy on and off. The canopy is still secured by screws into the front mount.





Speed Clip:
The Speed Clip is not faster to take on and off, but may be better for ultimate speed in that there is a composite channel in the front canopy that receives the extension of the rear fuselage, tying the front canopy with the rear fuselage along the entire perimeter of the joint. The front canopy still overlaps the rear fuselage, so there may be wear on the paint at the overlap. The composite channel also helps stiffen the joint so it has a thinner profile than Quick Pins. The canopy is still secured by screws into the front mount.







Regards,
Rick

[dswitkin]

Nice Rick! What's involved in installing the TDR into the fuselage? Do you ship them with mounting points installed, or do they require some fabrication?

[RJ]

Thanks! Currently, there is still some fabrication needed, by me or the end user, to make mounts to be able to install the fuselage. I have thought about making a fixture to add mounting points to the fuselage itself, but have not yet done it.

Regards,
Rick

[HankAz]

Is the body all one piece and you slide the tail in? Very nice!!! I want one.

[RJ]

I liked JRAY's windscreen so much that I have revised the templates for the windscreen and comet. Nice work JRAY! Also had a request for the HENSELEIT-HELICOPTERS.DE in bold, so including that as well.

[JRAY]

Originally Posted by RJ

I liked JRAY's windscreen so much that I have revised the templates for the windscreen and comet. Nice work JRAY! Also had a request for the HENSELEIT-HELICOPTERS.DE in bold, so including that as well.

Thanks! Glad you liked it.

[RJ]

I was asked if a Kontronik Kosmik fits in the SFR2. I only know for sure that a YGE 320 and a Jive 120 HV fits. I think a Kosmik would fit, but have not done it in person. Attached photo is a see-through of the mounted fuselage with a Jive ESC. The front screw mount is elevated 13mm from the stock position, but about the same position antero-posteriorly.

Regards,
Rick

[TommyBear]

Hi Rick,

Judging by your photo, it should fit fine as a Kosmik with the Kosmik mount will only goes as far as the front battery frame limit.

[JRAY]

A Jeti Mezon 130 fits also.

[RJ]

Thanks so much for the input!

I was wondering about the Kosmik fuse if it sticks out too far and hits the canopy, could it be mounted at 90 degrees with a short tab and a standoff to clear the other terminal screw, and possibly even bent down in front at an angle to help with clearance? (Please forgive my amateur Photoshop skills, maybe the fuse would be below the other terminal).

Regards,
Rick