MARCEE Minnesota Area R/C Electric Flight Enthusiasts Articles & Reports

Astro 010 Experience (Including Geared)

Irvin Cooper

This is not a comprehensive test.  I got the Astro 010 while traveling during the winter and I also got invited to fly indoors but found out the night before that the plane I was going to fly was too heavy.

So in one evening I built "Floor Sweepings" out of mainly carbon fibre and anything else I already had including 3 kinds of covering etc.  "Floor Sweepings" is the plane pictured with the Astro 010 below.

(A construction section for "Floor Sweepings" will be added later)

All runs were with 8 - 350 mah Cells:   My intent is to use the Astro 010 on fairly high performance mini sport planes so the on / off throttle is just fine.

All the below flights were done outdoors in 5-10 mph wind.

First Scenario / Flight - Astro 010 with supplied 5.5X2.5 Prop.   This is a gutsy little motor.  The performance was very good.  Motor Runtime until noticeable sag was 5 min.  Assuming the batteries were up to capacity that means an average of 4.2 amps.  Which is higher than recommended by Astro Bob or Doug Engraham - Probably should use 7 Cells with the supplied prop.  The plane was quick and responsive, pulled through loops and rolls well.

    -- Side note, the Gunther / zagi prop (nominally 5X4) also works well on 7 cells.

Second Scenario / Flight -Astro 010 with a Cox 5X3 Prop.  Wow, much better, the plane was faster and "hyper active"  Not quite as steep of sustained climb angle, but good.  For a sport plane, I like the Cox 5X3 much better.  Motor Runtime until noticeable sag was 6 min.  Again assuming the batteries were up to capacity that means an average of 3.5 amps.  This is right at the top of the Astro recommendation.

Third Scenario / Flight - Astro 010 2.25:1 Gear (MPI Unit) .  Gunther 7X6 (Titanic drive prop).  Wow Wow Wow.  Great performance significantly better climb than the two straight drive props.   Motor Runtime until noticeable sag was 7 1/2 min.  Again assuming the batteries were up to capacity that means an average of 2.8 amps.  This is well within the motor controller recommendation !!  And the best performance. 

Gear Box Description & Pictures / Specifications

Most speed 400 gear boxes will mate up to the Astro 010/020/050 brushless motors.   So at first I just figured I would drill out the bore on a MPI Maxx pinion and I would be all set. 

Problem, the motor shaft is so short on the 010 that the set screw/hub side must be towards the motor which gave alignment problems with the standard gears for the MPI Maxx.

So I converted mine to standard 48pitch R/C Car pinions a 12Tooth for the motor shaft and a 27tooth for the driven (27/12 = a ration of 2.25:1).  Both come standard with 1/8" bore.  I cut some short lengths of 1/8" ID Brass tubing to fit inside the bearings to reduce them to 1/8" bore.   I used a R/C Airplane 1/8" axle shaft as the output (driven) gear box shaft and the Gunther 7X6 propeller.   These gears were thinner and I had no problem lining them up.  (Note: If you wanted to and had the tools to do it accurately, you could shorten the gearbox assembly by cutting off and rethreading the 3 spacers that hold the two gearbox faces.

Astro010-fs0.jpg (27436 bytes)

Make sure you have the ball bearing MPI Maxx Gearbox.  The bushing model is too inefficient.  Use light oil like 3 in 1 and lube prior to flight.   Set the gear fit so that you can feel some clearance all the way around the pinion.  This gearbox and prop add about 5/8oz over the direct drive prop and adapter.

You will need to reverse the Astro 010 to run this configuration.   That is very easy, just switch any two of the three wires going from the esc to the motor.  I used a 2 pin deans connector so I can just unplug and plug to change directions quickly depending on the application.

Astro010-fs1.jpg (40149 bytes)

 

Here are some pictures (click to enlarge) showing the whole set up on "Floor Sweepings"

Astro010-fs2.jpg (148609 bytes)  Astro010-fs3.jpg (60609 bytes)  Astro010-fs4.jpg (103667 bytes)  Mark 1.5 -->  fs-m1-5.jpg (64809 bytes)

"Floor Sweepings" Specs

Span

34"

Length

25"

Weight

11.3oz Direct  / 12 oz Geared

Area

330sq.in.

Motor

Astro 010

Gearbox

2.25:1 Modified MPI Maxx & 7X6 Gunther

Cells

Sanyo 8-350ma

Servos

FMA 80

Esc

Astro

Mark II "Floor Sweepings" will be about 3oz lighter and better craftsmanship and Plans will be added here as part of the article.  But until I get that done and to try to answer all the questions I have been getting, here is a description on how I built the wing.  Keep in mind that the MARK II wing will have some differences.

So without the benefit of pictures or drawings, I will try to describe the building of the wing

The wing is all Carbon Fiber and a flat bottom airfoil.

The .050 or .060 means I can not remember without doing an autopsy I drill holes along one side of the leading edge and trailing edge tubes at 1/2" & 5/8" in from each end, 1 dead center and 2 just enough off of dead center each way so that my wing servo will just fit between them.

Take the 3 8.625 long and insert them in the 5/8" from each end and the dead center and epoxy. Gives you the basic frame and the bottom of the wing.

Now epoxy in the 4 9.25 long in the 1/2" in from each end and the two slightly off center holes. Being they are longer they will bow up and start the upper shape of the wing.

Then I drill a hole in at about a 45 degree angle on each end and insert the 2 9.75" long rods, they will then bow out and become the tips.

With the whole structure laying flat with the curved airfoil up, epoxy the 3rd 30" long arrow shaft to the top of the curved rods about 3" back from the leading edge. I also wrap dental floss around these joints and CA to strengthen. My after thought here is if your original arrow shafts are long enough, have the top one run all the way out to the tips.

Take dental floss or Iron Wire fishing line from the top of the 3rd arrow shaft and loop around the wing tips several times pulling them up level with the top of the 3rd arrow shaft I then continue the floss down to the horizontal stringers and all the way across and back up around the other tip and to the top of the 3rd carbon shaft.

My preferred covering is with Mylar laminating film which has the heat sensitive adhesive, heat shrinks and is only .0015 thick - easy to work with, and very light.  (One source of the film is mayberry@mb.sympatico.ca )

You end up with a sort of Diamond shape airfoil with a little curving toward the trailing edge where it picks up the top of the curved rods.  It built very quick, is very very sturdy and light by my standards.

Keep in mind I have only built one so far but it seems to work pretty well. It does leave some funny bumps at the leading and trailing edge where it just sort of matches up with the curved tips.

I am planning to pursue this type of construction some more so I should be able to improve on it. Then I plan an article on the MARCEE page on Building a MARK II "Floor Sweepings". But it will never be like the first, as I built it after 8:00pm in a strange town where I did not know where to find hobby supplies so I built entirely out of my field hobby box along with the Carbon Fiber I had picked up at a kite store that was going out of business. And flew it the next morning at 9:00AM.

Also if you pursue this and get some better methods or ideas, please pass them on.

MARK II will probably have a V-Tail so I can mix it with the ailerons to have some rudder effect. And I will probably build up the tail feathers by my Flexing .050 Carbon Rod.