700 Something unique

[Smoggie]

There are loads of really nice 700 size helis on the market today, but I decided I wanted to try something genuinely different, a 700 heli that breaks all the 'rules'.

This is it:

It's a Henseleit TDSF. The 'SF' stands for 'slow flyer'. It's inspired by super lightweight 3D slow flyer planes. Jan Henseleit decided to see just how light a fully 3D capable heli could be made if you threw out the rule book. He knocked it out of the park!. Ready to fly the TDSF weighs in at 2.4Kg (5.3lb) which is well under half the weight of even a light 'normal' 700 3D heli. It's lighter than some 500 size helis but it's a true 700 that will easily accept 720mm blades. He does this trick by removing everything that's not essential (frames glued not screwed together for example) then due to the light weight you can use much smaller motor, ESC, servos and batteries compared to a standard 700. The motor and ESC are the same size as might typically be used on a Goblin 380 or 420. Servos are 'mini' size, battery is a 5S 4400mAh.

So you might think that such a puny motor and ESC would leave the TDSF very under powered... think again! :

Jan is retiring from making new helis but it making one last batch of the TDSF. I managed to get my name down for one. they are all being hand made so I'll have to wait till May to get mine but the way things are going it will be that long before the lockdown ends, so timing should be perfect!

 

[Admiral]

Certainly unique I like the concept, keep the size and reduce the weight. Strength would be my only issue I challenge the ground too often to fly a light weight, although less mass, then lighter impact.

 

[Smoggie]

..... although less mass, then lighter impact.

I think this is the idea. With a weight of only 2.4Kg and RPM of 1000-1500 and a fairly slow flying speed the heli wont hit the ground as hard in the event of a crash. This is quite like the 'slow flyer' indoor 3D planes it's inspired by. These planes look terribly fragile, but in reality they stand up to a crash far better than 'normal' planes.
Having said that, I dont generally worry about how well a heli crashes, I fly quite conservatively (boring many would say!) so I dont crash much.

 

[Geena]

You won`t be disappointed with the TDSF at all. I have a friend down here who has one, and he loves it. He flies on very low head speed, and gets crazy long flight times on it.

 

[Smoggie]

Geena, you were spot on. I wasnt disappointed and I go love it.. and i do get crazy long flights!

Here she is

 

[Smoggie]

It weighs in at 2460g ready to fly including the 5S 4500mAh battery. That's less than half the weight of a typical 700. I find that to fly with the performance that a standard 700 has, I need between 1250 and 1400rpm. Those speeds give me 11 and 9 minute flight times respectively. 18+ minutes are possible at lower headspeed.

It flies fantastic, very agile but also more relaxed to fly that a normal 'heavyweight' 700.

 

[D.O.G.]

Smoggie dude, you have some of the neatest and wildest helicopters in your collection. I do envy your collection

 

[Blade 400]

There are loads of really nice 700 size helis on the market today, but I decided I wanted to try something genuinely different, a 700 heli that breaks all the 'rules'.

This is it:

It's a Henseleit TDSF. The 'SF' stands for 'slow flyer'. It's inspired by super lightweight 3D slow flyer planes. Jan Henseleit decided to see just how light a fully 3D capable heli could be made if you threw out the rule book. He knocked it out of the park!. Ready to fly the TDSF weighs in at 2.4Kg (5.3lb) which is well under half the weight of even a light 'normal' 700 3D heli. It's lighter than some 500 size helis but it's a true 700 that will easily accept 720mm blades. He does this trick by removing everything that's not essential (frames glued not screwed together for example) then due to the light weight you can use much smaller motor, ESC, servos and batteries compared to a standard 700. The motor and ESC are the same size as might typically be used on a Goblin 380 or 420. Servos are 'mini' size, battery is a 5S 4400mAh.

So you might think that such a puny motor and ESC would leave the TDSF very under powered... think again! :

Jan is retiring from making new helis but it making one last batch of the TDSF. I managed to get my name down for one. they are all being hand made so I'll have to wait till May to get mine but the way things are going it will be that long before the lockdown ends, so timing should be perfect!

She looks so cool in this pic Smoggie, and in the video she looks and fly`s like something from Jurassic Park

 

[Sidik Hartono]

It weighs in at 2460g ready to fly including the 5S 4500mAh battery. That's less than half the weight of a typical 700. I find that to fly with the performance that a standard 700 has, I need between 1250 and 1400rpm. Those speeds give me 11 and 9 minute flight times respectively. 18+ minutes are possible at lower headspeed.

It flies fantastic, very agile but also more relaxed to fly that a normal 'heavyweight' 700.

Hi Smoggie, running for low head speed is only for big size helicopter like 600 - 700 series... or 450 also can ?

 

[Smoggie]

Hi Smoggie, running for low head speed is only for big size helicopter like 600 - 700 series... or 450 also can ?

You can run lower headspeed on smaller helis too (but not as low as you can run on bigger types). The same rules apply, by reducing headspeed you get longer flight times. You do of course lose some performance unless you can trim weight from the heli. Increasing your collective pitch range can offset some of the loss of performance, the TDSF for instance used +/-15 degrees of pitch.
Also you have to think about tail holding performance. As you reduce main rotor RPM the tail also runs slower and you lose tail hold. The TDSF has a high gear ratio on the tail so it works well at low headspeed but most 450 size helis have a tail ratio optimised for high headspeed, so the tail can blow out at lower RPM.

 

[Sidik Hartono]

You can run lower headspeed on smaller helis too (but not as low as you can run on bigger types). The same rules apply, by reducing headspeed you get longer flight times. You do of course lose some performance unless you can trim weight from the heli. Increasing your collective pitch range can offset some of the loss of performance, the TDSF for instance used +/-15 degrees of pitch.
Also you have to think about tail holding performance. As you reduce main rotor RPM the tail also runs slower and you lose tail hold. The TDSF has a high gear ratio on the tail so it works well at low headspeed but most 450 size helis have a tail ratio optimised for high headspeed, so the tail can blow out at lower RPM.

you are right, tail can't lock
I just tried hovering with low speed with my trex 450,
pitches: -2 to 10
idle: 60/60/60/60/60

I saw the landing skid vibrates a little, and it's not stable enough for hovering, especially when there's a little wind in the park

low speed is not suitable for new pilots like us

 

[Smoggie]

here is some of my old man boring flying with my TDSF from the weekend:

 

[Blade 400]

here is some of my old man boring flying with my TDSF from the weekend:

She fly`s so smoothly and looks really futuristic. If this is what you call old man boring flying Smoggie, I look forward to it