Archive for March, 2013


The Return to West Baden

In Uncategorized on March 20, 2013 by nicholasandrewray

The Return to West Baden

After almost a decade we are going to have the opportunity to fly at the West Baden Springs Resort Hotel again.

April 6-7 2013


The event will be an AMA sanctioned Cat III contest and run from 9am to 6pm both days.

The entry fee is $170.00 and it includes helium.

Contact Bill Gowen For more information at: Change the “at” to @.

The hotel has offered us a group rate, ask for details when you talk to Bill if you are interested in staying onsite.


Dezso Orsovai’s M89 F1D

In Uncategorized on March 18, 2013 by nicholasandrewray

Dezso Orsovai’s M89 F1D
M89_2013_slanic copy Click here to download a PDF of Dezso Orsovai’s Plan


The Un-Winder

In Uncategorized on March 13, 2013 by propblocks

The Un-Winder


After a decent flying session, I e-mailed Kang Lee. He e-mails me back, tells me I am doing great, but wants some more data. How many turns remaining at the end of each flight?

Me: I don’t know.

Kang: Not sure it is all printable here, but the gist of it was that I was a lazy guy and that I needed to start recording that info as it will be important later.

I understood what he was saying. I could see the merit. There is just one problem. Me. There is no way I could see myself consistently unloading an F1D motor, hooking up my winder and counting backwards. Kang called it right: I’m too lazy.

This is what I confessed to Art Holtzman when I asked him to make me a doo-hickey, as I called it then.

Tell me what you want, he says.

I want half a winder. No handle. No chain. Just a counter and hook, something I can hook my rubber up to and have it give me the number of turns left.

Art: Can’t you just take the motor off and hook it up to the winder and turn the crank backwards like all the rest of the guys do it?

Mike: I think I just explained this. I’m too lazy to do that. I know myself.

Art: Give me a bit.

Understand that this is a Friday afternoon. An hour or two later, pictures of this device start to appear in my inbox. A bit later a fully built unit is being packaged up, some money is exchanged, and on Monday evening, it is sitting at my door.

The one of a kind Un-Winder!

The one of a kind Un-Winder!

The last couple of weeks I have had a lot of practice with this, what I dubbed ‘the Un-winder’, at the EAA contest and later at Racine Memorial Hall.

Now I can walk my model to my table, unhook the motor, attach it to the Un-Winder and get a count of how many turns remain. Easy as pie. Just apply some finger pressure to the motor if a lot of turns remain to slow the unwinding down – No brake or anything special is needed.

Note: I also own one of Art’s winders and love it – Art urged me to swap the larger counter from my early winder to the Un-Winder. The newer counter picture is shown on my winder picture below.

Art's Chaingain winder with the new smaller counter.

Art’s Chaingain winder with the new smaller counter.

Please contact Art for more information. Art Holtzman []

Mike Kirda

Statuses – A source for custom-cut prop blocks

In Uncategorized on March 13, 2013 by propblocks


When I first got back into indoor, I started carving a new prop block. Several hours later, half finished and discouraged, I stopped and did a web search and found an article describing a fixture for a bandsaw that seemed quite promising.

It took a lot of calling around to find someone with some old 1/8″ blade 6 teeth per inch stock. It must still be made, but it hasn’t been in the pipeline for years. I had them weld one up and send it to me. The fixture itself was pretty simple, using old on-hand 3/4″ nominal plywood, some screws, aluminum channel and a thick hardwood dowel. A lever arm rides up an angle and the angle defines the helical pitch.

After cutting a few for myself, I brought some to an indoor flying session. Requests for more follow.

This past year I decided to make them available more widely, so I opened a website:

I have since rebuilt the fixture a couple of times to increase the accuracy on it.

I offer blocks in both Poplar and Balsa. Normally blocks are 2.5″ wide and 2.25″ tall – wide enough for most outlines for indoor. I can make them wider within the limits of the fixture. Blocks are normally cut to 10″, but I can offer 8″ or 12″ blocks, maybe slightly longer.

Please check out the website.  I hope it will be interesting to you.


Mike Kirda


An Alternative Design of Kang Lee’s Carbon VP

In Uncategorized on March 10, 2013 by nicholasandrewray

Kang's Alternative VP

Kang Alt1Kang Alt 2If you would like to download a PDF of Kang’s CAD drawing click here.

~Kang Lee

Editorial Note: Kang sent this design in as an alternative to his first hub. Both hubs are still in the design stage and he welcomes your feedback.


Kang Lee’s All Carbon VP

In Uncategorized on March 6, 2013 by nicholasandrewray

Kang Lee’s All Carbon VP

Back view of VP hub.

All joints are glued using thin CA.  Kevlar is used to secure the hub to shaft sleeve joint, as well as the screw holders to hub joint.

Spring is 9.5 turns of .008” music wire formed over a .025” mandrel.  Here, prop shaft is .013” music wire.

See diagrams for the dimensions of hub components.   All carbon components are off-the-shelf, affordable, and fairly easy to work with.

The VP hub as shown weighs 70 mg.  The hub is both stiff and light and can probably survive exploding motors.

There is some binding between the rod and the tube.   I can hear the VP pop into low pitch.   One solution may be the use of graphite lubricant.

Your feedback is welcome.


Front side of the hub.  Here, a spring wound using a .031” mandrel is shown.  The spring doesn’t seat well over the .028” OD carbon tube “shaft sleeve”.


Carbon tube “hub” before prop shaft sleeve hole is drilled.  The lever arm is glued to the spar “rod” using thin CA.  Only tack gluing is needed.  The lever arm is later securely glued to the end of the prop spar.




Please click here if you would like do download a PDF of Kang Lee’s CAD drawings