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Author Topic: Yashinskiy F1N  (Read 2610 times)
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-John-
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« Reply #25 on: January 15, 2019, 02:12:24 PM »

Maxout, if you could find a light-weight high quality carbon fuselage to go with your kit, you'd likely corner the market here in the US; as I don't know if Stan is producing any kits like these(although I wish he were). Also, beyond the introductory model, it would be great to have you kit a full out competition model like the Yashinskiy.
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piecost
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« Reply #26 on: January 15, 2019, 03:33:49 PM »

Yes. You specify the diameter of the wide end.
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Maxout
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« Reply #27 on: February 05, 2019, 11:10:04 AM »

Thanks guys. I'm working with Ross Clements now, so hopefully we'll be able to produce a competitive kit here in the near future. Ross will be campaigning a Cat's Meow soon, and I'll be campaigning something with his flaps soon.
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piecost
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« Reply #28 on: February 18, 2019, 01:15:42 PM »

I am intrigued by the balsa/foam Yashinskiy wing construction which is mass produced as a kit. I
understand from looking at Youtube that Mr Yashinskiy uses a drum sander to shape his wings. The foam seems to be pre- sliced prior to final sanding after being
Attached to the balsa.

I wanted to make a hand sanding jig, without the complexity of a drum. I ottained a 125mm wide by 375mm long steel channel and lengths of flat bar. The two lengths of bar are clamped to the channel to form sanding fences. The height of the forward fence reduces with span to
allow the wing to taper in thickness; the aft fence is set
to give a unifom TE thickness.

I took the three wing thicknesses shown on the ModelbouwForum.nl  plan and reverse engineered the heights required for fore and aft fences. I also calculated contour lines to show how the thickness varies. I was pleased that the quoted thicknesses matched in my calculation.

The jig will be used with a sanding block. The LH and RH wings will be sanded identically on the Jig (without adjustment) and will only differ when the leading edge chamfer is added.

When it is light enough to work outside in the evenings I will make a wing or two. I intend to benchmark my foam wings against this construction but suspect that I will lose interest in the composite wings as a dead-end.
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piecost
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« Reply #29 on: February 18, 2019, 01:16:48 PM »

Plot of wing thickness contours and fence heights attached
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Maxout
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« Reply #30 on: February 20, 2019, 01:40:04 PM »

That's definitely a way to get it done. The J&H solution will be hotwired flaps so as to avoid sanding the foam. The drum sanding method definitely gives a nice finish.

I should note that Hope's newest Cat's Meow gave Bill and I a serious run for our money this weekend. Bill was flying a pair of Yashinskiys and I was flying a hybrid of the two using the Chinese fuselages and Ross's nontapered flaps. Bill got a best of 34 seconds, I got a couple 31s, and Hope did 28. She did an unofficial 30 or so, still well below the ceiling, and I had a 32 second hand launched flight that still didn't transition at full height. 26' peaked ceiling.
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piecost
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« Reply #31 on: February 20, 2019, 09:02:46 PM »

It is good to prove that the Cat's Meow is competative. I have a couple of questions;

What diameter Chinese tube did you use and do you have anu observations on its stiffness?

Also, I am intreged by the Yashinskiy tip. What do you consiser the advantage to be of employing the balsa tip with the chordwise slit at the flap end? I notice in one of your videos that you can bend the tip for trim. Are there any other advantages?
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Olbill
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« Reply #32 on: February 21, 2019, 08:52:07 AM »

Some of the European fliers are using wings with the tips cut off. I asked about this when I first saw 50+ second flights being done. I was told the cut off tip gave higher launches but worse glide. On the latest video you can see Grzegorz Truchan flying a glider with the split tips doing 52.9, 54.0 and 54.4 for a 3 flight total of 161.3 so I guess that removing the tips is not required to get high times.

https://www.youtube.com/watch?v=TTGu_sCyl8w&feature=youtu.be&fbclid=IwAR30P5XaCWEx1uY4AzW98iyTFJ9K5gUgrFcq_tEQDQ3BdypCK0ZofZXixWA
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Maxout
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« Reply #33 on: February 21, 2019, 09:30:26 AM »

It is good to prove that the Cat's Meow is competative. I have a couple of questions;

What diameter Chinese tube did you use and do you have anu observations on its stiffness?

Also, I am intreged by the Yashinskiy tip. What do you consiser the advantage to be of employing the balsa tip with the chordwise slit at the flap end? I notice in one of your videos that you can bend the tip for trim. Are there any other advantages?

I got the 4 mm. They're stiff enough to get the job done, even after sanding. Not sure what size is optimal. Time will tell I guess.

The chief advantage I've found to split tips is that it separates the flap camber from the trim of the tips. I bend a lot of washout into the tips to avoid bunting because I've never been able to build a glider which would both bunt and pull out of even a shallow dive following a less than absolutely perfect launch.

We definitely have not seen the maximum performance potential of domestically produced gliders like the Cat's Meow. That said, I suspect Bill hasn't unleashed maximum performance either. I've seen what he can do with smaller gliders and it's truly incredible.

Some of the European fliers are using wings with the tips cut off. I asked about this when I first saw 50+ second flights being done. I was told the cut off tip gave higher launches but worse glide. On the latest video you can see Grzegorz Truchan flying a glider with the split tips doing 52.9, 54.0 and 54.4 for a 3 flight total of 161.3 so I guess that removing the tips is not required to get high times.

https://www.youtube.com/watch?v=TTGu_sCyl8w&feature=youtu.be&fbclid=IwAR30P5XaCWEx1uY4AzW98iyTFJ9K5gUgrFcq_tEQDQ3BdypCK0ZofZXixWA

I saw that as well. Absolutely incredible performance from those models, and that guy has a throwing arm like nothing I've ever seen. His consistency with a model pushed to its absolute limit is just amazing.

What's even more amazing to me, though, is the realization that 54.4 sec is still fully 5 seconds off the FAI record. Just incredible.
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cglynn
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« Reply #34 on: February 21, 2019, 05:33:41 PM »

That is amazing performance.  Is that a Cat 1 or Cat 2 ceiling they are flying under?
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Olbill
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« Reply #35 on: February 21, 2019, 08:26:58 PM »

Low Cat 2. They said the low point was 9 1/2m. It doesn't appear that there is a lot of slope but that's difficult to see in the video.

I was told the model weighed in the low 8 gram range which is also remarkable.
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Skymon
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« Reply #36 on: February 22, 2019, 03:15:55 AM »

the sequence of two flights from 11:50 and 12:34 show just how much the flight times can vary!
Same plane, same flier; one flight over 30 seconds, one under 3 Smiley

Having a consistent launch and flight is a tough job in F1N.  Grin Grin

I know we are a little off topic now but...
Just seeing that many people flying gliders indoor is really inspiring.


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Skymon
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« Reply #37 on: February 22, 2019, 04:33:42 AM »

So many interesting things to see in that video it deserves it's own thread...

Interesting glossy TE reinforcement at 18:25 and what looks like a dropped counterweight/skid with bracing wire hanging under the fuse....


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piecost
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« Reply #38 on: February 22, 2019, 08:32:51 AM »

I wonder if the kingpost and bracing is a design feature or a fix? The wing looked all foam with carbon tissue leading edge. I could not see a spar. Very interesting
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Maxout
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« Reply #39 on: February 26, 2019, 10:10:15 AM »

So many interesting things to see in that video it deserves it's own thread...

Interesting glossy TE reinforcement at 18:25 and what looks like a dropped counterweight/skid with bracing wire hanging under the fuse....




No idea about the skid/wire stuff, but the wing is clearly vacuum backed foamcore with fiberglass skin (carbon Dbox up front).
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Skymon
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« Reply #40 on: February 26, 2019, 10:29:50 AM »

is that the 'carbon paper' that I see advertised?
it sort of looks like carbon tissue...
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piecost
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« Reply #41 on: February 26, 2019, 04:48:52 PM »

I found carbon tissue to soak up twice as much epoxy per weight of tissue. Perhaps there is some better material being used.
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Maxout
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« Reply #42 on: February 28, 2019, 12:47:23 PM »

I found carbon tissue to soak up twice as much epoxy per weight of tissue. Perhaps there is some better material being used.

Those willing to do the work can get the epoxy weight down where it belongs. Several extremely competitive F1N models have been produced using that material, as well as many other types of high performance models. Not easy, mind you. None of this is easy.

If you can get Carboweave 16, however, that stuff is much better.
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Tmat
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« Reply #43 on: February 28, 2019, 01:06:43 PM »

If you can get Carboweave 16, however, that stuff is much better.
Old hat now Josh. This what you need: https://shop.cn-models.com/index.php?route=product%2Fproduct&path=33&product_id=66
11 grams/sqr meter!

Tmat
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F1B guy...
But don't hold that against me!
Maxout
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« Reply #44 on: March 05, 2019, 08:28:40 AM »

If you can get Carboweave 16, however, that stuff is much better.
Old hat now Josh. This what you need: https://shop.cn-models.com/index.php?route=product%2Fproduct&path=33&product_id=66
11 grams/sqr meter!

Tmat

Good to know that there's a source willing to sell it in small quantities. Last I looked up CW (about a year ago), the US supplier had just shut down his operations.
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Maxout
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« Reply #45 on: March 08, 2019, 09:36:59 AM »

Here's some footage of Bill's Yashinskiy. Great flying!

https://www.youtube.com/watch?v=lhz2-31dm0k
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