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Old Mar 03, 2002, 04:35 PM
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Jim Walker's Avatar
United States, TX, McKinney
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Herr Mini Sport from Start to Finish

This kit caught my attention as a great platform for some things I've been wanting to try. The things I refer to are:

Using the same or similar drive system that I've used so successfully in my NES Virus in a much lighter aileron/elevator plane. Also I wanted to try the new GWS retracts.
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Old Mar 03, 2002, 04:37 PM
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Here's what is included in the kit......
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Old Mar 03, 2002, 04:39 PM
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Nice CAD drawn plans.....
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Old Mar 03, 2002, 04:43 PM
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United States, TX, McKinney
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As usual, Herr kits are very nice. I will probably change some of the wood to accomodate the modifications I'm going to make. Some strengthening will be needed to withstand the jump from direct drive speed 280 to geared speed 300. I plan on using the new Dubro micro push rod system pictured here for the ailerons and elevator linkage.
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Last edited by Jim Walker; Mar 03, 2002 at 04:45 PM.
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Old Mar 03, 2002, 04:47 PM
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I won't need the supplied Gunther prop or the hard plastic wheels. They should come in handy for some other project though.
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Old Mar 03, 2002, 04:53 PM
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Here's the intended flight system.

Simprop speed 300, in my opinion the hottest motor in it's class. It makes my 16oz NES Virus tear up the sky at half throttle. The new GWS retracts with a JR servo that has plenty of torque according to the instructions. 600AE's make the Speed 300 scream even more than the 720 Nimhs in my Virus.
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Old Mar 03, 2002, 04:59 PM
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Here's a picture of my work bench and my main support equipment. The static thrust stand holds the motor on a moving pivot. This is tied to the right angle arm which transforms the horizontal pull into a downward push for the digital scale.

The Simprop speed 300 with the MPJet 5:1 gearbox swinging an APC 9-6 on 7 600AE's generated an amazing 14+ ounces of thrust!!!
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Old Mar 03, 2002, 05:03 PM
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The flight pack weighs in at 250 grams plus 16 grams for the HS-55's on back order totals out to 266 grams or 9.4 ounces.
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Old Mar 03, 2002, 05:08 PM
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I played with the motor constants of a Graupner speed 300 until I got the static thrust and the battery amps the same as my not-so-accurate measurements of the Simprop system. I guessed at the empty airframe weight (realistically I hope) and plugged it into motocalc. The predictions are very impressive!!!
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Old Mar 03, 2002, 05:12 PM
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As I complete each sub-assembly with it's modifications, I'll post pictures and weights. I plan to take this all the way to the end whether it be successful flights and a big smile or augering in and back to the building board.

Bon Apetite!
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Old Mar 03, 2002, 05:18 PM
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Wow! Thanks for the excellent write-up -- looking forward to seeing your updates!
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Old Mar 03, 2002, 06:57 PM
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oakdale, ny, usa
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May the force be with you

Jim Walker:

Great write up of your progress & love your neat bench...If you saw mine you would freak!

I was in love with the MS until a friend had some problems with his.

Did you do a search for this model?

I don't think there has been much luck with the stock power plant.

I agree that nicads are the way to go if you can afford the extra weight.

Don't get too caught up in the static thrust figures. This plane may need the airspeed more than anything.

Please keep us posted & good luck
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Old Mar 10, 2002, 05:11 PM
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Jim - how's the progress on the mini going? I'm currently building a Herr GeeBee R2 and found the laser-cut parts really needed to be sanded down to remove the "burned" wood, and I broke a few pieces along the way because they were so delicate, and I am not. Same experience with the MS kit?
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Old Mar 11, 2002, 09:00 PM
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Van,

this makes my third Herr kit and I just use the parts as is. I haven't tried sanding away the laser burn, but I'm sure it would be time consuming not to mention breaking parts. The laser burn hasn't affected the looks or the performance as far as I can tell.

Sorry for the delay on the update, I got laid off right after I started this project and guess what gets my time.......

I decided to start on the wing first since it will get the most modifications and be the hardest to construct. I started by cutting out the two half wing plans and taping them together. Then I went to the LHS and hand picked some spruce for the spars and a nice hard piece of balsa for the leading edge. Since I'm building the wing flat with ailerons instead of with dihedral, I will just leave the spars and the leading edge as one continuous piece for added strength.
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Old Mar 11, 2002, 09:08 PM
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Here is the wing laid out with the ribs and approximate position of the retract assemblies. Instead of beefing up the one rib for the static gear as shown in the plans, I strengthened the ribs on both sides of the "pocket" where I intend to mount the retract mechanism. I'm not sure if I will be able to use the Dave Brown light wheels as they are almost thicker than the ribs verical height. I'm going to just build the basic wing frame and then start modifying when I have the 3D object in my hands.
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