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Posted by VicT | Yesterday @ 09:57 PM | 711 Views
The reverse thrust after touchdown works great with wheeled floats. However I wanted to try the reverse thrust with conventional taildragger gear. To avoid reverse in the air and possible loss of control its recommended the reverse arming switch (I’m using the E switch on my iX12/DX9) only be activated after touchdown. The ESC directions recommend using reverse only when the prop stops turning. So I activated the prop brake following the ESC programming directions. After closing the throttle the prop does not windmill but stops turning in about 1-2 seconds. The stopping distance is greatly reduced without the use of wheel brakes and without the risk of nose overs and prop strike damage.

Maule with Turnigy AeroStar 60 amp RVS ESC (0 min 13 sec)

Posted by VicT | Jun 14, 2018 @ 07:42 AM | 926 Views
My flying buddy is rough on his Maule and surprisingly she is more rugged than compared to his Timber. Of course the Timber does not have struts because Timber has a full length spar. The Maule has a partial spar that is 46 CM long.

I installed a full length plywood spar in my Maule to reduce downward deflection upon touchdown and I have no stress cracks even without struts. I can add struts for maximum strength for dropped in full impact landings but my floats and wheels are not designed for that.

When my buddy had a seperated strut mount I used Kicker on the foam and Locktite Prof. CA on the plastic. I used Monocote backing to keep my fingers from getting glued and to feel the exothermic heat. I the used a drill the same diameter of 4 round toothpicks and drilled 4 holes in the plastic. I used CA on the toothpicks and pushed them in about 1.5 inches. Small aluminum white nails would be better because of the nail head. See pics:
Posted by VicT | Jun 08, 2018 @ 12:05 AM | 1,058 Views
I use switch C to determine which rate I like best. If one rate and expo can be used for all phases of flight I change my he switch from C to “always on”. This frees up switch C for 3 different throttle curves. They are all pretty much the same except where the lowest throttle position starts.
Posted by VicT | Jun 07, 2018 @ 11:52 PM | 1,051 Views
The SIG T Clips 60” wing span model has a very fast glide and because she has no flaps or spoilers other techniques must be used. I did not want to have a long slow dragged in approach but a normal 3-5 (or steeper) degree glide slope.

I figured out a way to use 3 throttle curves using the 3 position C switch just above the throttle stick on the Spektrum DX and iX transmitters.

The lowest position (2) is a normal throttle curve where the lowest throttle position stops the prop using the ESC PROP BRAKE. The middle switch position (1) is the windmilling prop throttle curve. The lowest throttle position of 15% was determined on the ground by gradually increasing throttle until the prop just started to turn. The highest switch position (0) is a throttle curve where the lowest throttle position is 20%. This was determined by flying an approach with power on that would look like a 3-5 degree normal approach and then noting the 20% throttle setting on the transmitters display. After landing the curves were programmed and audio alerts created.

Throttle cut is still used as additional safety against accidental selection and a warning upon transmitter turn on can be created. A pre-flight Checklist can also be created in the DX TX as a reminder for the specific model. Here is a link to the You Tube video.

Throttle curves for approach and landing (0 min 15 sec)

Posted by VicT | Jun 04, 2018 @ 07:03 AM | 993 Views
Some RC planes are tail heavy and moving the 3 or more lipos forward does not balance the plane at the 25-33% point. Rather than adding lead to nose or prop spinner I plan on using the cylinder shape of the LiIon type cells. I purchased a spare 5 cell pack from Harbor Freight and carefully removed the plastic. A better way would be to cut the metal connectors to each cell before removing them from the plastic holder. This would avoid shorting and allow the cells to be mounted in a radial pattern. Soldering either at Batteries plus or at home would be required. A permanently mounted battery pack could be designed as these cells can be quick charged.
More to come.......
Posted by VicT | May 29, 2018 @ 10:40 PM | 1,071 Views
I recently purchased 10 balance plug extensions. They are used with battery meters and alarms to extend the location. At least 2 of the red metal pins have pulled out from the white plastic housing. Re inserting them does not fix the problem unless the metal barb is bent down to a 45 degree angle. Then the barb will catch into the plastic slot and the pin will remain in the housing. A gentle tug test should be done to each of the pins. So for a 3 cell battery with 8 pins a tug test for each of the 8 pins should be done. Any pin that easily comes out should have its barb bent down to a 45 degree angle then pushed in with a small flat screwdriver connected to motor the metal crimp pin.
Posted by VicT | May 20, 2018 @ 10:29 PM | 900 Views
If an Electronic Speed Control (ESC) fails in flight there may not be power to the receiver to operate your servos. The result will be a loss of control and possible crash damage to a person, place or thing. If the ESC fails on the ground before or after takeoff the risk of crash damage is still present but is minimized. The use of seperate receiver and servo battery power can be used or a back up pack but you will still be faced with a power off landing that might be cause damage. This is how I usually verify and validate new or suspect speed controls.

1. Measure the amp load (using a Wattmeter/ Current meter) and confirm it is below the rated amp load for the ESC. The amp load can be reduced by changing to a lower pitch prop or a smaller diameter. Reducing the cell count for example from 6 to 5 lipos will reduce the amp load.

2. Run the motor for at least 10 seconds with a prop and measure the heat of the ESC. Use an ingrared thermometer and ensure temps are less than 140 F. If you do not have one you should be able to keep your finger on the ESC for 3 seconds or more. If it hurts at 3 seconds the ESC is too hot and the resultant heat can affect or damage the internal electronic components. Increase ram air cooling and have more exhaust area than intake area. Keep the ESC from being insulated. Don’t glue the ESC to the wood or foam fuselage. Keep the heat sink out in the cooling air flow.

3. For new speed controls or used...Continue Reading
Posted by VicT | May 15, 2018 @ 11:15 PM | 1,516 Views
Last week Sean from Horrizon Tecnical walked me through the programming of my Maule 636 receiver so I could use a switch or servo plugged into the ch 5 port. We got the servo working but later that day the ch 5 switch B operated both the servo and SAFE Self Level On/Off. I called Tech today and Joe walked me through the transmitter programming. After 3 or 4 binding attempts and programming changes we finally got it working but had to create a new model. The SAFE switch initially was the A switch and the servo was put on the E switch. I later put the SAFE switch on B where I am used to it. See screen shots of the final set up. Video shows a 12x4 Timber prop backing up.

Maule with Turnigy AeroStar RVS 40A ESC (0 min 16 sec)

Posted by VicT | May 10, 2018 @ 11:18 PM | 1,522 Views
I’ve flown the Timber with stock floats from water and grass. Steering on the grass can be done but takes lots of power and is not accurate. To improve steering and reduce float drag on grass I installed two main wheels just aft of the CG and a left nosewheel that is controlled by the stock rudder servo. I use the stock steering servo arm and a wire pushrod. The right nosewheel is a castor design that follows the left nosewheel. I picked the tires that were soft and light with scale like hubs. Music wire axles and brass tubes are used for axle bushings and steering tubes. I am pleased with the tight turning radius on asphalt and look forward to grass operations. Once I activate channel 5 on the stock 636 receiver a two position DX9 H switch will operate a Turnigy reversible electronic speed control. This will allow reverse taxi and reverse thrust for braking after landing. See following video.

Maule M7 with amphibious float mod. (0 min 38 sec)
...Continue Reading
Posted by VicT | May 04, 2018 @ 10:51 PM | 1,156 Views
Thanks Lonny for weighing all the parts on your postal scale (ounces):

Landing gear and wheels 5.6
Nose cone and prop nut. .8
11x7 prop. .9
Fin and rudder. 1.1
Elevator and stab. 1.4
Right wing and strut. 8.9
Left wing and strut. 8.8
Fuselage. 27.7
Pushrods. 1.0
Misc. parts. 1.1
Wing tube. 1.4

Total. 58.7

An Thrust 22003S 40C lipo. 6.8

Total with lipo. 66.5 oz. .5 oz over compared to 66 oz. spec on pg 3 of the Maule manual
Posted by VicT | May 02, 2018 @ 09:48 PM | 2,051 Views
I put a broom handle on my driveway and placed my Maule on it to find the fulcrum point on the float bottoms. I put my 3200 3S 40 C pack in the battery bay. The fulcrum point turned out to be right where the step is located. So I found a pair of wheels that looked about right and cut out Lite Ply parts. I used 13 min epoxy and a clamp overnight. Measuring the width and length of the “wheel box” I used a box cutter to slice into the hollow floats as close to the step as possible. The nose gear will be a little more complicated as a pushrod will have to be installed to the left nose gear for steering. I would like to make the nose gear swivel forward and up (by hand) for water operations. The mains will stay fixed in place with the additional water drag a compromise. The rudder will be a swivel up and down ( by hand) as well. See pics
Posted by VicT | May 01, 2018 @ 10:36 PM | 2,343 Views
I removed the the water rudder and put on 2 layers of clear 20X tape to protect bottoms. Video shows takeoff and landing. Landing rollout is very short!

Horizon Hobby Maule M7 On floats (0 min 37 sec)

Posted by VicT | Apr 30, 2018 @ 05:52 PM | 1,553 Views
My packs are warmer than I’d like so I added some exhaust stacks for better cooling. I cut the foam stacks away then took an old chrome antenna tube, notched the end and hand drilled out the holes. After cutting the antenna into two 1 inch pieces I damped (water mist) the foam and used white Gorrilla Glue on the chrome.

While in the area I cut out the belly for access to the ESC and battery compartment. I took the motor and wires out to prevent damage and used a large box cutter. Beveled cuts keep the foam from pushing through. Tape or CA will secure the belly “pan”. Now I can angle a larger 3 or 4 S pack. Replaced the stock velcro with my favorite strap and added some compression foam to the wood floor. I have a ISDT cell checker and alarm velcroed inside to the dashboard. That way I can view the capacity remaining (20%) while on the ground. On low flybys I can see the red LED’s flash also. With the belly pan removed I was able to route the balance plug from the dash to the forward battery bay.
Posted by VicT | Apr 28, 2018 @ 07:04 AM | 1,946 Views
I got this idea from Martin on the Maule forum. It frees up the 2 position H toggle switch which is easier to reach and can operate gear, motor reverse, bomb drop, tow release, etc. The knob is harder to accidentally put into the motor on position and the big label sticks out right in front. Use the Custom Voice Setup, Custom Voice Events, and for the right knob (RKnb) in the Gereral sound category scroll and set
0 Throttle Cut
1 Silence
2 Motor On

I used a small bottle of enamel paint from Testors to paint the red and white side of the rotary knob. This stands out and means more than the red heat shrink that I have on the 2 postion H toggle switch.
Posted by VicT | Apr 18, 2018 @ 10:07 PM | 1,642 Views
This is a lightweight version of my first skylight. It does not have the balsa frame with pins holding the clear plastic and does not have the plywood fuselage opening lining. So it is lighter and quicker to make. I use a Starbucks protein box for the plastic. Cut out the biggest rectangle within the top cover boundaries. The front plastic hinge has no overlap with the fuselage roof but the sides and aft clear plastic has a 1/8-1/4 inch overlap. Rather than using a frame to maintain the top airfoil shape the aft window is screwed down so the window is flush with an airfoil curve.
Posted by VicT | Apr 17, 2018 @ 10:52 PM | 1,165 Views
I will be using the struts because on the rigorous test flights without them I have found compression wrinkles on the top wing just beyond where the spar ends and the flap area begins. This is a stress riser due to the servo cutout area. The wrinkle is invisible until the wing tip is picked up. If a longer spar were used out to within 8 inches or so of the wingtip then there would no buckling. Horizon has no Maule spars for spares. So a substitute will be researched. Until then the struts will be used.

Plywood wing spar mod:

I cut out plywood wing spars with dimensions of 1/16” thick by 24 mm deep by 470 mm long. Each spar weighs 12 gms compared to each V strut that weighs 19 gms (w/o screws). The wing maximum depth is 30 mm so there is 6 mm between the spar and top of the wing.
Posted by VicT | Apr 13, 2018 @ 01:13 AM | 1,761 Views
The struts do offer extra strength but the spar tube ends where it contacts the the flap servo. This is where the stress riser is located and if loaded to failure this is where it will crack and cause wing folding. A full power vertical dive with SAFE/Self Level Off and a positive G pullout would cause a max load on the wing and possible cause a stress crack in the stress riser area.

I removed one strut and compared wing flex by resting one wingtip on the grass and “bouncing” the other wing tip up and down. I saw no difference in the two wing panels. There was no stress cracking or stretch marks. I the did inflight tests with full power 3S pack loops and max up elevator. I could not see any difference in wing flex between the panel with the strut and the panel with out the strut. I performed consecutive aileron rolls without seeing wing flex. I did not do spins, outside loops, or snap manuevers. I landed and inspected the wings for stretch marks and found none so removed the remaining strut for continued testing. I purposely made a hard landing and did not see any over stressing.

I’m not advocating the removal of struts but it can be done if you are carefull and limit manuevers to non violent ones.
If a strut fails inflight the stock spar and wing appear strong enough for a normal descent and landing without fear of wing failure or folding. Of course owners and operators take full responsibility for their aircraft and safe operation.
Posted by VicT | Apr 13, 2018 @ 12:33 AM | 1,659 Views
The strap that comes with the Maule can be cumbersome to use when securing the battery. The velcro can be used to keep the pack from sliding and the strap keeps the pack from lifting away from the battery floor. There is an easier way and here is how:

Use EPP type scrap foam on the aft end (or forward end of pack) to keep the pack from sliding forward or backward. Use a piece of scrap foam on top so that the battery hatch just comes into contact when hatch is closed and latched. Tape the foam pieces in place with clear packing tape. With different size packs you will use different size end and top foam pieces.

Pics show an Admiral 2200 3S pack. The stock battery strap is folded on the floor and the pack sits on top of the straps.
Posted by VicT | Apr 10, 2018 @ 09:38 AM | 1,856 Views
I’ve been installing an EMax servo for the other elevator half on Models I value. The cost is under $10 and I don’t worry about the stock servo failing and causing a crash. Here are the servo specs:

If using the 636 RX and reversing is needed I position the servo or use an inline reverser.

The Maule was easy. Measure the length of the rudder servo forward and cut a small hole. You will find that it is hollow and no servo wires are close to being cut. The elevator horn was from spare parts and a Dubro 2-56 rod and black Quick Link clevis was used. After the new servo is glued secure and the new elevator pushrod and clevis are adjusted to length....... THEN cut the plastic joiner. I used an Exacto saw but a metal hack saw blade will do fine. Adjust the clevis so the left elevator is the same angle as right elevator. Move the Z bend at the elevator horn or the clevis at the servo arm in different holes to get equal angles with full up elevator. A 12” long Y cable was taped to a piece of music wire and pushed from the new hole to the receiver and plugged into the elevator port. The stock elevator servo gets plugged into the other Y end. The same signal and power goes to both servos so any fine tuning is done using different holes in the servo arm and elevator horn. A little dab of White Gorilla Glue on the 4 sides secures the servo.
Posted by VicT | Mar 22, 2018 @ 07:59 AM | 1,478 Views
After approximately 36 hrs of Valiant flying I have had to replace two tailwheel wires that seperated and fell away on the grass while touching down. I was able to find and recover both pieces and they broke in the same place. They were replaced with factory duplicates and each seperated in the same area. They broke just forward of the loop and from normal taxi, takeoff and landing operations. Each operator has a different type of mission flying and ground operation time will be different for accumulated time and stress. This Valiant has been used primarily as an inflight trainer with about 10 full stop landings for each 15 minute flight. Taxi out and in times can be estimated at 1 minute each or 2 minutes total for each 15 minute “sortie”. The runway has always been club mowed grass with minor bumps that have had no impact on damaging the tailwire.

The way I figured time is as follows:
In the Function List scroll down 11 lines and press Timer. Scroll to highlight Timer 1 then scroll past Timer 2 and stop on Timers Integrated. On the first line Model will show the total time that the named model program has been in operation. This includes non flying such as programming and adjusting. One could estimate that it takes an average of 1 hour initially to program all functions such as rates, mixes, modes, and audio events. If you have a log book you could create a more sophisticated method of tracking times and notes.

For this particular Valiant...Continue Reading