New Typhoon MkII

[Doc J]

Phase one done Friday.

A HUMONGOUS thanks to you Gents who have contributed so much of your experience and practical advice to the new the Typhoon Toccata! There were many changes needed that I knew about already, but actually even more coming from you guys that I had no idea about!

The design sketch is now completed.

Credit where credit is due: With so many of your often small but really significant changes (31 on my list) made around the old lady, it's probably more your plane now than mine, and that is maybe as it should be. But I'm happy to say that the overall shape and curvy looks remain much as they did on that stormy day when I first put pen to paper a decade and a half ago.

I'm not going to publish the sketch here as I have found that not to be the best idea, but I'm quietly confident that you'll like the new Toccata version, and you'll like the performance boost from the new aeros even more.

You gentlemen; and you know who you are, have spoken.

My sincere thanks again.

Doc.

 

[Doc J]

Ha! blast from the past.

The model is older than I thought. Taken in Jinan, China in 2002 - and amazingly I actually look younger now.

Crikey,

Doc.

 

[Hill Hobbit]

Perfect proportions!

Er, the Typhoon that is…

cheers
JT

 

[Doc J]

Perfect proportions!

Er, the Typhoon that is…

cheers
JT

He's got to go...

 

[Doc J]

Yaaaahhhhh!
Someone mentioned that I forgot to say what I'd actually modified.

OK here is the final mods list:

Typhoon “Toccata” MKII a 2 metre all-rounder (to supersede Typhoon MKI)
Modifications to original Glider version and Electric version (fuselages)

General:

• Full carbon wing/fuselage version option (SS)
• Heavily carbon reinforced version option (S)
• Light version option (L)
• Better specification materials and resin

Fuselage.

• Entire fuselage made to round section for better strength.
• Fuselage is enlarged slightly (3~4mm) to make it stronger in high-stress areas
• 2 nose types: G-Type = slip-on nose and E-Type = canopy type
• E-type nose is a blended 'tear drop' for 38 mm spinner, & the nose 'cabin' fits most normally used batteries
• Straight sided fin profile for better rudder hinging
• Heavier Aramid/S-glass nose as standard
• Fuselage ballast is still possible on the G-Type, not on the E-Type.

Wings.

• Slightly updated/optimised wing planform, but shape is similar to the original
• Latest version JH 817 high response airfoil
• Larger chord flaps and ailerons
• Larger wing joiner 35 x12mm (1 3/8” x ½”)
• Wing ballast 25x10x250mm x 2 (1”x3/8”x10”x 2) 976g (34Oz)

Tailplanes.

• Elevator type stabilizer – no AMT
• Slightly optimized shape to take advantageof the elevator.

All in all I have tried to modernize and improve the orginal, but keeping the orginal lines and feeling of the plane.

BTW the CAD is not done yet, so if anybody has any other cool mods please speak up.

Cheers,

Doc

 

[Doc J]

Update CAD is started...

Cheers, Doc.

 

[Doc J]

 

[agarchitect]

Looking good!

A couple of observations:

1) From the top view it looks like the slip on/off nose cone may not slide off as the fuse front kind of curves back towards the leading edge of the wing.

2) Would it fly any different (better or worse) if the wing and stab tips were more curved (similar to the MK 1) at the leading edge rather than squared off?

 

[Hill Hobbit]

Ditto

 

[Doc J]

Looking good!

Hi Adam,

A couple of observations:

1) From the top view it looks like the slip on/off nose cone may not slide off as the fuse front kind of curves back towards the leading edge of the wing.

The top view you see is the universal fuselage with the electric front end. It has a simple canopy, no nose cone.
The side view you see is the universal fuselage with the glider front end which has an inner nosecone and a slip on/off outer nose cone.

2) Would it fly any different (better or worse) if the wing and stab tips were more curved (similar to the MK 1) at the leading edge rather than squared off?

In fact the tails are not exactly squared off, but anyway difference on this model would be very small indeed - unmeasurable in practical terms. But the reason I used this tailplane is because its the same as the Forza, and so has an elevator not an AMT.

Cheers,

Doc.

 

[Doc J]

Ditto

Hi Jonty:

Ditto as above.

Doc.

 

[Hill Hobbit]

Ahh, my bad! I forgot that there are two different nose designs, the bulbous one in the plan view having a canopy hatch. I then twigged the cross sections on the right showed the glider’s nose design.

Sorry about that
JT

 

[Wayne]

I like the design of the servo pocket locations in the wing. Good design. No, that is a great design! Thank you for putting thought to the space limitations, this is an area we see some designers forget to give the proper attention to. This is a nice advantage of the sinewave spar giving critical space for the servo tray. (I might suggest a little bigger pocket, looks a little small in the drawing..? I'm probably wrong.

I don't know how thick the wing is at the aileron, but if it is getting really tight, consider flaring the wing in the servo box area. This is something they did with the Prodij with great results, very skinny wing, but could still fit a fatter servo. That Prodij was probably the best 60" plane ever made. Maybe not pretty or well finished, but it had a very wide performance range for a 60" plane. Here are some pics that sort of show the bumped area for the ailerons. Both top and bottom bump out a couple of mm.

Timing is good, I was just paid for this last Prodij, she ships out today. The last great example of a great performing model.

 

[Doc J]

Ahh, my bad! I forgot that there are two different nose designs, the bulbous one in the plan view having a canopy hatch. I then twigged the cross sections on the right showed the glider’s nose design.

Sorry about that
JT

Its OK Mate, - you didn't draw it.

Doc.

 

[Doc J]

I like the design of the servo pocket locations in the wing. Good design. No, that is a great design! Thank you for putting thought to the space limitations, this is an area we see some designers forget to give the proper attention to. This is a nice advantage of the sinewave spar giving critical space for the servo tray. (I might suggest a little bigger pocket, looks a little small in the drawing..? I'm probably wrong.

I don't know how thick the wing is at the aileron, but if it is getting really tight, consider flaring the wing in the servo box area. This is something they did with the Prodij with great results, very skinny wing, but could still fit a fatter servo. That Prodij was probably the best 60" plane ever made. Maybe not pretty or well finished, but it had a very wide performance range for a 60" plane. Here are some pics that sort of show the bumped area for the ailerons. Both top and bottom bump out a couple of mm.
View attachment 13302
View attachment 13303
Timing is good, I was just paid for this last Prodij, she ships out today. The last great example of a great performing model.

Great plane!

PRODIJ is an example of model that was designed and built to perform, and was made with the latest technology of the time.
I'm sure the design is at least 20 years old.

It was not conceived to look good and sexy - although I find it so; rather it completely disregarded fashion and everything about it was put there to wring the best possible performance out of a 60" wing - which it did/does really well.

I think the Prodij uses Marcel Guwang sections, maybe MG5. I had a lot of conversation with Marcel over this many years ago when I ws beginning to develop my own wing sections. For info this is also a reflex type section and it works very well. Not so aerobatic, but adequate and screaming fast.

OK, Back to the Toccata:

Having given this new model possibly more thought than I have ever invested in a model aircraft design, I have made the servo bays in the new Typhoon Toccata at 45mm x 45mm in an 8% thick wing. At the point I put them, the wing can actually take 10mm thick servos with no problem at all, so no need to "bulge" the wing - though that's one way of doing it.

Reasoning:

• Given the high torque performance of the latest servos available, they no longer need to be placed in the mechanical centre of the control surfaces, and the small size makes them fit into a much smaller servo bay. Basically they are well strong enough to do the job.
• Added to that, stiffness wise, the trailing edges in my models are all carbon reinforced to prevent twisting as far as possible, so the load transmission gets much better.
• Logically its always best to put the servo bays a far inboard as possible for reasons of lowering the MOI, but we also have to keep them out of the way of the cluster of wing joiner and ballast boxes at the wing roots.
• Last: In the inboard area its always easier to compensate for the stress raiser that the servo openings actually generate too.

So, 10mm servos are OK, obviously 8mm are OK and there are now a lot of both, so no problems.

6mm wing servos?

While we are on the subject, right now I have two sets (8) of 6mm thick wing servos from Kingmax which I can tell you all have been thoroughly tested - and they are really great.
Therefore, I am completely sure the MKS and KST and maybe other servo makers also have this kind of servo under develpment.

Plug for Kingmax:

Kingmax servos are rapidly gaining share in the GPS Triangle market as the servo of choice, and I'm sure those GPST guys know what they are doing with their ultra-expensive models.

I know Kingmax has received a bit of a bad rep, probably justifiably so in the beginning, but time passes and knowledge accumulates. Jeeze, I remember the time years ago when if I saw "Made in Japan" I'd hesitate to buy the product. I'm not sure about all the Kingmax products, but right now the 100, 8mm and new 6mm servos are close to, if not on a par with KST.

The future:

With these servo developments - which no doubt will continue - in mind, I hope I have designed for posterity as in the future I think bulging wings and huge servo bays will no longer be needed - or at least I hope so!

Cheers,

Doc.

 

[Wayne]

I think everyone makes a "6" mm servo these days. The KST is not as nice as I would like, and actually measures 7mm. We have a brand new 6mm servo that we are really impressed with and it has a better price too. Hope to get them up on the site tomorrow. They were designed for micro RC trucks, so they are tough too. I think we are the first to find these little gems.

I do like your servo placement. I wanted to make sure you understood correctly. I am a fan.

Can you make the pockets a bit bigger? 45x45 is doable but when you add the lip, probably too small for a 10mm servo in a tray:

 

[Doc J]

I think everyone makes a "6" mm servo these days. The KST is not as nice as I would like, and actually measures 7mm. We have a brand new 6mm servo that we are really impressed with and it has a better price too. Hope to get them up on the site tomorrow. They were designed for micro RC trucks, so they are tough too. I think we are the first to find these little gems.

I do like your servo placement. I wanted to make sure you understood correctly. I am a fan.

Can you make the pockets a bit bigger? 45x45 is doable but when you add the lip, probably too small for a 10mm servo in a tray:
View attachment 13315

How about wider in the "X" east to west direction?

Doc.

 

[SailHigh]

Doc,
Since the AMT is out, what is the decalage angle now? Can't clearly see it from the drawing.

 

[Hill Hobbit]

I am 99.9% sure it’s 0-0.

In fact I’d bet on it!

Let’s see what James says…

 

[Hill Hobbit]

Regarding servo apertures in wings, I haven’t (nor have other folks I know) actually used the crossbar mounts on a Servorahmen mount for years. They really aren’t necessary, as the alloy spindle or IDS horn locates into the bearing, then the two screws do a great job of holding the servo in place. The 3rd screw is basically impossible to access.

I’ve never had to tighten a screw, ever.

I always cut the crossbar blocks off the mouldings.