combatpigg

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Much of this time of year I spend scheming about interesting projects. A bonus is when the project doesn't represent much work, but it serves to satisfy my curiosity.
Maybe I was caught napping, but I do not recall seeing any speed results posted for The Blink. After spending some time looking at Blink threads, there isn't a whole lot posted about this great looking little plane that was designed to go fast.
I've got the drawing, but the drawing doesn't have any dimensions. IIRC, it had 15 inches of span.
I'd like to build a "regulation" Blink and try to be faithful to the original Ulmer design as I can.
I built one many moons ago but never equipped it with much power before it crashed. Back then I used GWS park flyer equipment a lot...and I also crashed a lot. I found GWS equipment is great if you like to keep your herd of 1/2 A planes thinned out.
So, back on topic....I need to at least find out what the span was / is, before getting started.

skaliwag

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I have one drawing with a TD .020 says 12' and uses 3/32 materials and another with no engine shows 18'' hat shows 1/8th materials
. Wish I could help you more.

combatpigg

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Thanks Skaliwag....
I'm relieved to hear that it was 18" [and not 15"]...!
Actually, it was a pretty tame flyer if the proper balance and amount of control throw was dialed in.
The biggest issue is maintaining orientation with such a tiny UFO.

Pond Skipper

You can blow the plans up till it matches a .049 or till the square stock matches 1/8th and 1/4th.
The design shape looks good but has one flaw if for max speed the swept forward ailerons cause excessive drag when deflecting.
If you want to fly fast without penalty perhaps the following mod. The larger surfaces require less deflection during flat out speed runs yet when slowed down or in acro play they will provide you that extra thrill most desire. Of course now the leading line is straight reducing drag.

Pond Skipper

https://www.youtube.com/watch?v=lzNWXHCk6I0 Uploaded on Jun 26, 2008
Blink, a small delta.
Building plan downloaded at www.ulmer-rc.com


Notice how the foward swept ailerons effect roll

combatpigg

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PS...now that you mention it, I can see how that would be so.

Making that big of a change to the original changes the purpose of this project slightly.

The best way to go..is to build one of each to see what the difference in performance looks like in the sky.

Pond Skipper

Yea its just a thought another is to split the controls to reduce more surface deflection drag for faster rolls.





In the end one will tend to do small barrel / dutch rolls when inputting any amount of up with the ailevons as shown in the video the other will be a high speed drill maintaining better energy during surface deflections.

combatpigg

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I fly single stick, so I can screw up the rolls equally well with either control layout.

The "mod" that interests me most would be laying the engine flat and doing another coke bottle cowl that blends it into the wing.

To fly a normal "Speed Pattern" with this thing, the elevons just barely need to move at all.
Too bad the old Blink build threads are still in hiding because I'd like to review some of the control linkage methods that were used.
I'd like to use Spiderline pull / pull with 1/16" ply control horns. If I went this route, I'd be reluctant to fly the model too aggressively [until I got thoroughly bored with it].

Pond Skipper

How did your last Blink go with the elevons swept forward?
Yea Im sure low rates are plenty till you want to wring it out or to do some throttle play.

Looks like the Blink design has been around for some years confirmed 18" 155 Sq/In

http://www.rcuniverse.com/forum/1-2-...ont-blink.html

MJD

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I have one kit still for the firewall mount version, and plans that could be scanned if needed.

combatpigg

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My Blink never graduated past a mild reed valve engine / 5 x 3 combo that I can recall. So, it had a speed range of mild to zippy depending on how well the reedie was running.
With jittery park flyer equipment, a plane like a Slow Stick might just wiggle a wing, but with The Blink, it would roll inverted and then fly OK for a while until the next spastic radio disturbance. Eventually, I discovered a nearby indoor RC car operation that seemed to be the culprit. At first, I thought this plane had a design flaw or two, but the jittery radio gear must have been responsible for most of it.
At any rate, I want to revisit this design and do a better job of testing it and seeing what it can do with a healthy TD .049 / 4.2 x 4 prop combo.

Pond Skipper

Yes thank the goodness for 2.4 ghz radios today!!

Are you going with a fully symmetrical airfoil this time? The last posted pic seems to show a semi symmetrical airfoil.. should help from any ballooning effects as there will be plenty of good TD pow pow to create a wampum lines in der skies.

combatpigg

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MJD, I've got an overhead view drawn, but need to know how tall that rear bulkhead is. That looks like the fattest part of the plane.

Last night I took a guess and made the inboard ribs 7/8" tall and the tip ribs 3/8". I'm just cutting diamond foils, then will sand them to shape after framing the wing.

combatpigg

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PS..yes, the airfoils I've drawn are symetric...(so I was already being unfaithful to the original).

With this design, I think Patrick was influenced by all the Mumbo-Jumbo about how flying wings need special airfoils to fly level with the least drag.

If delta models are kept light enough and sleek enough I've never noticed more than the slightest amount of "up trim" dialed into the ones I've flown .
Of course, finding the correct CG for the best dead stick glide needs to be established first before analyzing how much "reflex trim" is needed.

Pond Skipper

Yea reflex airfoil ultimately has the trailing edge as elevons anyways too small of a wing to take advantage of a smooth ramp up.
Good old gapless hinge should be plenty on this wee one.
The large single vertical stab it is being blanketed whenever the wing is in alpha mode. 2 smaller ones out on the tips would improve things.

MJD

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And the pointy tip is nothing more than a drag body once you get below about 3/4" chord or whatever - I would think with that fin you mightn't even need elevon reflex at speed. I trimmed mine down to a clipped delta.

I will get #2 together sometime. A parkie flat 2.4 receiver slides "closely" into the section behind the radio bay, an uncased Rx even better. I was going to drop my Profi .049 into Blink #1 but it ended up going straight to the Toucan instead. It was pretty peppy on the VA .049 MKII / 5x3 combo.

CP need any measurements I can get them tonight. I just got a new 11x17 printer/scanner, so might be able to scan the top view whole. Certainly can scan ribs. I thought mine was symmetric? Gotta look now.

Andrew

These may help ---

MJD

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Thanks! Now I don't have to do it..

The airfoils looks symmetrical.

combatpigg

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Patrick must have switched airfoils because I'm sure I've seen a semi-symmetric Blinkfoil also.
Thanks for posting those links Andrew..!
Instead of hacking out "diamond" foils, It's not much more work to make them properly curved.
Light and simple will still be the over riding theme with this plane.
One "trick I might do is assemble the frame on a pair of circular dowels that pass through the ribs, but cut in the 1/8" x 1/8" spruce spars after all the parts are "jigged" into place. Once the wood spars are installed, then slide the "jig dowels" out of there and admire the perfectly installed spruce spars.

Andrew

--deleted--

Andrew

Patrick also designed another delta called the Li'l Streak that had a 28" span --- this delta did have a semi-symmetric foil. I don't think the Blink ever had a semi foil -- I have the plan sets that Patrick published and some that he had mailed directly to me, all with a full symmetric foil.

rcguy59

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Here's a Blink I started a year or so ago. Finished the airframe, but never covered it, as it was hopelessly nose-heavy with the .074. Anyone know how much to scale it up for an .074?

Hey Pigg, what kinda single-stick radio you got? I had a Royal S/S and a couple of Ace Silver Seven single-sticks way back when and loved the concept, but it seems to have died. Wish I could have gotten my 18MZ in single-stick.

MJD

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Hmmm... 15% - 20% scale-up seems about right.

rcguy59

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Thanks, Mike. Any word on when the SD kits might be ready?

combatpigg

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RC Guy....I used to use the hitec 2 channel radio and also the 2 ch radio that included a sliding switch for throttle. Nowadays, I fly radios with 2 sticks but only use the stick on the right for pitch and roll.
I think they call that "mode II".
Some guys [especially pylon racers] think that having pitch and roll on separate sticks allows more precise flying. I'll bet that's true...I've just never forced myself to relearn how to fly.
Andrew....I assumed the Blink was symmetric before I went on my little search for old build threads and was surprised to see a photo of what I thought were Blink ribs...that were semi-sym.
I do not recall where I saw that [could have dreamt it?]...but once gain I'm relieved to see that The Blink was fully symmetric.