Hoosier Kitty 2

[High Point]

After weeks and weeks of research and asking a lot of questions on this forum, my Hoosier Kitty 2 is coming together. This has been a learning experience for sure. From shaping the wing to cutting my carbon tail boom to size. Now that I have a good understanding of what all is involved, the next build will be a lot faster.
On completion I'll post some pictures.

If anyone has time, I'd sure appreciate a few close up pics of your installation and modification of the timer. I received 3 (VPS Rotary Damper) from Volare. I removed the plastic gear from one and going to drill a small hole on the shaft for the pin, but want to make sure (the shaft is pretty short as you probably know). 

Curtis     

[ironchefmpls]

I'm going to start building this from the Hummingbird kit pretty soon. It uses it's own timer, so I'll be no help there. I'll be interested in how yours turns out.

[BubbaNel]

Josh Finn has a nice video, here: https://www.youtube.com/watch?v=e4exHmhsDPs

There are some links from this thread:  https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=5216.0

and a good step-by-step article from the Oakland Cloud Dusters, by Manuel Cisneros, titled "Inexpensive Rotary DT Timer", here: http://www.oaklandclouddusters.org/In-the-Workshop

- Bob -

[Tmat]

The Oakland Cloud Dusters how to is very good!
Use the 2nd version, imo it's what I'd use.

Tmat

[Woody22]

I bought the Hummingbird kit.  The timer that came with the kit seemed of poor quality so I built my own.  I used silly putty in the fuselage and aluminum tubing.

[High Point]

Woody, that's a nice installation of your DT. Can you give more information on the fuselage silly putty installation and the modification of your tubing to make it work? Any pics?
Also, how is its running action, does it take a lot of force for rotation?

Thanks,
Curtis

[Woody22]

Sorry I don’t have any better photos.  The aluminum tube goes through the fuselage.  I’ll attach a photo of the right side of the fuselage so you can see.

The fuselage had a predrilled hole for the putty.  There’s a piece of music wire rotating through the putty which slows the rotation speed.

I used several diameters of K&S tubing.  They fit snugly inside each other and can be glued together with ca.

It rotates about the same as any other dt.

[ironchefmpls]

I have seen a lot of posts about making springs to run the DT. Has anyone tried sourcing springs from McMaster Carr or similar? It would seem to be a valuable shortcut if they work.

[High Point]

Here are pics of my Hoosier Kitty 2, finished and balanced today! Learned a lot on this first CLG with pop up wing recommended to me a month ago.
Test glides are next as soon as there is some nice green grass to land on here in South Texas; in a drought right now.
Thanks for all the help and recommendations on this project.

Curtis     

[iflyhlg]

Looks good, now build a few more and each one should hopefully be better than the one before it, I am now on number 15 and still have number 3 that was built in 2011. Two are in England, two in Oregon and one in Muncie. They went out of site before they DT'd due to such strong lift and wind (in England}

[High Point]

Thanks, learned A LOT on building this kind of glider. The pop up wing is neat how it works. Saved all my patterns and little special tools and jigs I made.

Curtis

[FLYACE1946]

Hello Hi Point,  I think you do amazing work. Just want to fly and keep all you build. DT helps a lot. I know taking a picture can help a lot. Especially after one flies away and you might want to see what you lost.

[High Point]

Test glide and catapult launch this morning of my new Hoosier Kitty 2. I was very pleased with everything so far. Glides great!

Curtis

[ironchefmpls]

I finished my Hoosier Kitty 2 a couple days ago. I found the kit pretty high quality. I used a 1/8" piece of mahogany instead of the supplied plywood for extra stiffness. The kit included two DT options, an internal handcrafted one and an external plastic one. The plastic one looked easier to implement so I went that route. Getting the CG right took the very slightest amount of nose weight. After that the weight came in at 25 grams. It could have been lighter with more careful gluing, but I'm satisfied.

It was calm in the Twin Cities last night, so I went to the local field for some test flights. The hand tosses went really well. I am used to the higher sink rates of my 8" gliders, so seeing this one fly level for 100 yards was kind of shocking. I decided to press my luck with a 1/4 power level catapult launch and took the tail off with my trigger finger. Rookie mistake, but it should be an easy fix.

[BG]

Glad you guys are enjoying the Hummingbirdmodelproducts.com Hoosier kitties .... seems the consensus is that I should switch to supplying rotary damper style DT mechanisms.

Any thoughts?

Bernard

[PeeTee]

Well I've always used rotary dampers (Ace Controls) and I would not go for anything else.

Peter

[ironchefmpls]

I vote for only the plastic damper. I am, however, having a little trouble dialing the string lengths on either side of the spring. There was too much tension at first and I couldn't get 2 minutes before the DT deployed. I let a tiny amount of line out and now it is taking a full minute to from 6 o'clock to 4 o'clock. If you supplied just the plastic damper and gave some guidance on how long to make the strings, that would be great. The holy grail would be to supply a plastic spool to replace the gear part. It might be too precise a part for a 3D printer, and maybe too prohibitive for an aluminum tool for injection molding.

I can't wait to get it back in the air. I am new to larger catapult gliders, but this seems like a really good design. Now I just need to do something different on the launch.

[iflyhlg]

Ironchefmpls, the secret to the forward hook is to pinch the fingertab between your fingers and then just roll your fingers forward until the tab releases. If you pinch your fingers together when you make a fist and then extend your fingers forward or away from your fist you will notice that tips of your fingertips start to separate, Hold the tab in the tips of your fingers and when you roll them forward, they will allow the tab to slip out of your fingers. The first few gliders I tore my tails off too so don't feel bad. We tend to open our hands when launching and when we do we tend to stick our fingers up which is right in the way of the stab.

[danberry]

I have seen a lot of posts about making springs to run the DT. Has anyone tried sourcing springs from McMaster Carr or similar? It would seem to be a valuable shortcut if they work.

McMaster-Carr doesn't have one with low enough pull to be useful.

[ironchefmpls]

I think I solved the DT sensitivity. The old 1/4" spool (clear plastic) was too large and the spring tension was too much at the beginning and too little at the end of the run. With a smaller, 1/8" spool (black), the tension was closer to constant throughout the run.

Ironchefmpls, the secret to the forward hook is to pinch the fingertab between your fingers and then just roll your fingers forward until the tab releases. If you pinch your fingers together when you make a fist and then extend your fingers forward or away from your fist you will notice that tips of your fingertips start to separate, Hold the tab in the tips of your fingers and when you roll them forward, they will allow the tab to slip out of your fingers. The first few gliders I tore my tails off too so don't feel bad. We tend to open our hands when launching and when we do we tend to stick our fingers up which is right in the way of the stab.

I'll try the finger roll method. Hopefully I'll get the hang of it before I embarrass myself at next week's contest.

[Tmat]

Regarding launching with a forward grip:

What I have found successful is I keep my thumb and forefinger together and held horizontally with the other three fingers tucked in beneath.
I bring the grip tab into down into the vee (formed between the forefinger and thumb back side) and pull the tab forward into my fingers.
I keep my thumb and forefinger horizontal and roll them apart to release.
The key to avoiding stab strikes is to keep those fingers flat and release with no upward motion of the thumb.

If you do this, you won't hit the stab. I've had hundreds of launches without a stab strike.
The last time I loaned my glider to someone to try, I took for granted that it's obvious how to hold and launch. And "pow"! the stab immediately blew off in pieces on their first launch!
I keep a spare stab and fin in my flight box with some thick CA for just this reason. ;-)

Tony

[Sailaway]

I made the same mistake of having my fingers pull of the stab at launch.

After installing the new stab, the incidence changed. Luckily it made the wing TE go more up  (less incidence). Just need to watch out as I experience fixing it on the field. Luckily the stab tilt was OK, a bit less than original, but to me it appears that a less stab tilt is easier to handle then more tilt.

Any subtle technique I should have known when installing the new stab so that the incidence would not change ? Thanks in advance for sharing.

[Tmat]

Any subtle technique I should have known when installing the new stab so that the incidence would not change ? Thanks in advance for sharing.

Not sure how you managed to change the decalage?
If I'm changing the stab, I first remove the old glue carefully from the boom so there are no bumps.
Then I tack the stab in place with a little bit of glue stick. I can move it around, get it lined up and get the right stab tilt. Then
I hit the bottom with thin CA. Same process with the fin. Glue stick, then thin CA.

Tony

[Sailaway]

"If I'm changing the stab, I first remove the old glue carefully from the boom so there are no bumps."

At the field, in a hurry that was not done diligently by me. It looked almost OK, but not quite.

[BG]

Hi All,
A good practice with small FF cat gliders is to have a small sanding block and modelling knife in a small field box (along with some clay, thin CA, spare parts etc.). this allows for quicks field repairs and for cleaning things as needed. When I go out with my cat gliders I always carry this small field repair kit with me.

BG