Techone

10 December 2018

Test Session 4

Port wheel component superglued.

On arrival, the EPP foam pant parted from the port wheel component.

I used 1 pc of 2s800 followed by 2s500.

Was it me that it exhibits port side heavy now?

The model was more neutral with 500 but the 800 seems to provide better power to the motor.

Out of range seems to be a possibility.

It recovered in time and did not crash.

1. Consider using 'proper' Flysky receiver.
2. Hotglue the port wheel pants.

No rush, I am not too into this hobby now. Currently, interest in golfing.

7 December 2018

Test Session 3

I used 2 nos. of 2s500 and 1 of 2s800.

I discovered 3 units of 2s800, and had only charged 1 last night.

Straight flights seems more positive using the 2s800.

Inverted did not need input after 1-2 clicks elevator on level flight.

The CG must be in the zone.

Changing back to 2s500 is no problem.

Most landings displaced the port wheel component.

I have to snap it back on and/or adjust.

I think I will superglue it on.

I swapped the battery to the port side.

The wings became level and the low starboard wing symptom is past.

Power on, power off is much better now.

Straight ups, rolls etc are better behaved.

I do not know if it is worth it, given the nature of EPP, will it be better if I move the esc to the starboard side where the receiver is?

Tidying up, I could glue the esc and receiver.

Or, should I try a 'proper' full-range Flysky receiver?

There was a glitch this morning.

6 December 2018

Test Session 2

Normal rate is now 30% aileron, rudder. Elevator, I forgot.

The model became docile at Normal rate.

The previous battery that caused a deadstick caused a deadstick again, no power and straight down from 10-20 meters, zero control. Cell checker says it is 7.6v though. Anyway, this battery is marked.

The port wheel component broke off from the landing leg. Next flight was one wheeled, later on, at the end of the flight session, I discovered I could just snap it back on. 

This crash caused the elevator pushrod length to be lengthened. I had to use the adjuster several times, this time at the servo horn's end.

Hovering and knife edge seem doable in the morning air. Snatches of 3-5 seconds of hovering and 10-20meters of knife edge were done. Tail-slide is possible, 4 points roll, hammerheads/stall turns and Cuban eights were also executed. All that was lacking is familiarity and my skill level. Just need more practice.

I think the CG is about alright. I could put a drop of superglue to lock in the pushrod lengths, and maybe I will do them at a later stage. I want more and better batteries to do future trim sessions. That, or simply have more trim sessions with the current batteries, 1 marked and 1 good.

5 December 2018

I glued the servos and adjusted the pushrods in the manner I wrote of previously. I charged up a battery and left the model alone for a few days. I was surprised how fast that battery charged, but discovered this morning that I had charged the un-used battery. I had only one battery to fly this morning.

The elevator looked flush with the stabilizer, but the whole horizontal tail appears to be at a slight positive angle to the wings. That ought to be impossible, but that was how it looked like, maybe it is the EPP foam.

I hover-launched and pulled elevator to maintain attitude. Landed shortly and  shorten the length of the pushrod a bit by a bit. After a few more hover-launches, landings and adjusting. I got to the stage when the model is almost neutral rightside up and upside down, and I would describe the model as "floaty", not glider-floaty but the imprecise wishy-washy type. I just did not get consistent behaviour. Should I move my CG forward just a bit?

The model continued to exhibit a starboard low attitude. I tried a combination of left aileron and rudder. I was just playing around, to see if they would help. The wings did not stay level, and knife-edge appears to pull towards canopy.

The elevator throw is enough for loops and bunts but I think the aileron throw is still too much. Maybe the model will be easier to manage after I tone down the aileron throw. Thinking about it, I think I should reduce the rudder throw as well because currently it is too much for knife edge, just a bit lesser might be good.

Flight ended with a deadstick. 1st cell was about 2.86v, 2nd cell 3.7something v, must have got a bad battery.

For now:

1. Charge the 2 batteries.
2. Reduce at the transmitter, the aileron and rudder throws by 1/3 (at normal rate), sticking to the same exponential setting.
3. More test flights with elevator adjustment and roll/yaw adjustment.

29 November 2018

Last night, I sighted the guides and superglued them. I didn't re-insert the guides with superglue, I relied on applying droplets to the junctures of guides and foam. Maybe I should have removed the guides, coated the guides with superglue and then Insert and align the guides once again. Thinking about it now, the cure time of the superglue is quite long, and it ought to be enough for aligning. I was perhaps a bit obsessed with getting the guides aligned and placed my faith of the ability of superglue to seep to the contact areas. That is what superglue ought to behave, no?

I didn't use kicker to accelerate the curing of the superglue. The idea being that I would like to give the superglue time to seep into the foam. I am thinking that if the medium viscosity superglue cured too fast, it will not seep in properly. So, I dipped the junctures of guides and foam and left it undisturbed until morning. 

This morning I checked on the guides and discovered one loose, a success rate of 5 out of 6 isn't too bad. So I applied a bit of superglue and kicker onto the loose guide, found it cured hard and secured. Does that mean I should not have bothered with my overnight curing idea?

I test flew it when the sky started to lighten, and observed:

1. A roll tendency to the right. Would that be the ailerons or the thrustline?
2. A tail-low attitude. Would that be the CG or the drooping ailerons?

For the apparent right rolling, I tried to shorten the left pushrod. Seems to work, then it seems not to be effective. I tried again, but it was still not conclusive. I also added some left aileron trim.

For the tail-low attitude, when the model was brought vertical, it sort of hovered. Just saying that it was interesting to watch. When the plane was inverted, it needed a lot of elevator. I moved the battery forward slightly, it seems to be better, then it seems to be the same, the cause-effect seemed non-conclusive again. I tried substantial amount of elevator trim, it seemed better, but when the model was inverted, it needed even more elevator. Why was I perspiring before the sun came out? Perhaps it was the humid air, I forecast rain for today.

Strange enough, the amount of trims do not change the positions of the surfaces much. Is this because this is an EPP model and slack is inevitable? Perhaps I should try to shorten both ailerons' pushrods, that ought to relieve the elevator trim totally. I still want my tail to be straight and flat. CG/incidence/thrustline should all start with the tail straight and flat. Taking the analogy of golf, I liken this to a 'neutral' grip. This is what I believe to be the 'neutral' setup which will result in less drag and less correction issues.

And then as I wagged the sticks in the morning light, it dawned that the servo horn moved strangely because I had not glued the servo to the fuselage and it was twisting! I had forgotten that all the 3 servos needed gluing. I did not write them as to-dos to remind myself last week.

That ended this morning's test flight. I shall glue the 3 servos and re-set the transmitter trims. This morning test flight is a waste. I think my procedure for setting the ailerons did not account for the weight of the ailerons which then resulted in a "flap-down" wing and therefore positive incidence and which require substantial elevator trim.

I shall set the ailerons in this manner:

1. rest the model vertically on a wingtip, this is to relieve the effect of the aileron weight;
2. on the upper half, loosen the pushrod's set screw so that the pushrod can slide in and out;
3. clamp that aileron of the upper half to its wing so that that aileron is flush and straight;
4. tighten the pushrod's set screw; and
5. repeat for the other half by flipping over the model so that it rests vertically on the wingtip of the adjusted half of the wing.

My other observations and further thoughts:

• My WLToys F949 flies faster.
• I did not balance the propeller; it was not "purrly smooth" with the motor running, it is definitely imbalanced, but hey...there's already plenty to do.
• I got to quickly progress to hover catch, nose dunking is just not cool.
• The bottom of the rudder is the lowest point at the rear. Should I glue something like an ice cream stick to the side of the fuselage or just release-launch and hover-catch throughout? 
• The roll to the right... could it be because my battery was strapped on the right side? I recall the roll sort-of stabilized once the model is at a certain shallow angle. This is one more to be take into account as probable cause. Really important to have wings level.

21 November 2018

 I started by soldering the 90 degrees header connector to the receiver board. It was a fiddly job, I pushed the header connector all the way into the board. It fitted snugly and will probably work even if I omit the soldering. But of course I have to give it a go, my soldering tip does not reach into the midst of the bottom end of the header connector. The board heats up (I must have placed the tip against the header too long) but the solder doesn't flow. Worse still, I noticed that some bits of solder formed a bridge with adjacent pins. I tried removing it with a needle nose plier, then a cutter and that didn't work. I heated the solder blobs again and tapped the receiver against the table and this worked. The excess solder broke loose and fell away. It doesn't look good, I don't see shiny silver at the base from the underside. The connecting points were blackened and the solder contact probably exists on faith alone.

The receiver, servos, esc & motor were all connected and I was happy that I managed to bind the receiver and have it working the servos and esc. As can be seen, the 4 servo plugs occupied the width of the receiver (15mm) and looks long.The receiver board is 21mm x 15mm.

Binding sequence (I thought YouTube would help, but was disappointed by the first search result,  that video didn't show any binding procedure. In the end, I googled a web page.):

1. Press receiver binding button, plug battery in to esc.
2. Press transmitter binding button, switch on.
3. (ESC start up music sequence)
4. Unplug battery from esc.
5. Switch transmitter off.

Setting up my Flysky transmitter:
Hmm... I used a previous AFHDS slot, and the "model-reset" didn't work, so I have to run through everything manually. :

1. Model name changed to "Extra800"
2. Receiver setup to "AFHDS2A" (obviously done before testing of the receiver)
3. "Reverse" for Channels 2 and 4 for direction correction (Channel 1 was fine)
4. Manual trims of all 4 channels were centered.
5. "Sub-trim" for Channels 2 and 4 for centering of servo horns (Channel 1 was fine)
6. "MIX" all set to off.
7. Didn't bother with the range, I think they look alright, so I left them all at 100%.
8. "Dual Rate" on Channels 1, 2 and 4 on left toggle. "Normal" at 50% range, -50% expo,  "Sport" at 100% range, -76% expo.

The horn connectors were adjusted to give approximate centers. Then I tried to get the pushrods to be in straight lines by sighting the pushrod guides along from the rear. But when the stick is moved, the pushrod ends moved closer to the surface/servo. Should I have the guides and pushrods straight when at neutral, at extreme or somewhere in the middle?

I didn't decide, so I left the guides unglued.

19 November 2018

The EPP Extra 800 looks so easy to assemble and since I have bought the kit including the motor, esc and servos, I believed the manual when it wrote that it takes 30 minutes to assemble. I was very surprised when I took many times longer, quite a few hours.

EPP is sort of porous, the superglue drips, and I messed up the parquet floor. It cured readily on my fingers and thumbs but not on the assembled pieces. The EPP pieces are cut accurately for assembly, but not that accurate for gluing. If on one side you see that the pieces match almost perfectly, then the other side you see gapping joint seams. I had to remind myself constantly that the EPP concept is flexibility and it is pointless to have full seam strength, so just dabs would do. So I spot glued with superglue, flip over, applied stationery tape on both sides of the seam and swiped hot glued over the seam. Basically, when the fit is good, I used superglue, and I use hotglue when I am confident I can bring parts quickly together and hold them in place.

1. The hinges do not seem to be long lasting, but I told myself it is enough and if they tear, I can just do a hotglue hinge later.
2. The EPP pieces for the fuselage didn't match at the nose, the vertical pieces were shorter. I pared the right side of the horizontal fuselage for a bit of right thrust angle and used hot glue to secure the fiberglass motor mount. I figured that hotglue is forgiving in terms of flexibility and gap filling and I don't know which way to go regarding down thrust.
3. For the LG, I inserted the CF rods to the T-cross pieces but did not glue them together because they fit very well. The wheels were inserted with the rims away from the T-cross, to keep the rims away from the wheel pants. The ankle pieces were glued to the CF rods because the fit was a bit loose. The ankle pieces were inserted deeper, exposing ends of the CF rods, then a dab of superglue on the exposed ends and then pushing on the ends until they are flushed with the ankle pieces. The legs were inserted through the slot, their ends inserted at 45 degrees to the 2 FG pieces with elongated holes, then superglued to the horizontal fuselage after making sure that the wheels are parallel to the fuselage. Then the inverted U pieces were superglued at the slot area, snugly against the LG.
4. The aileron servo and the elevator servo were placed with their horns towards the nose, but the rudder servo's was placed towards the tail because it seems the pushrod length is a bit short.
5. I used the short servo horn on the elevator but the long horn on the rudder to bring the pushrods straight.
6. The pushrod supports has to be inserted to varying heights when pushrods are kept straight. I will superglue them, and the servos, after I have my receiver installed and servos and horns centred. 
7. The bullet connectors for the Motor/ESC were too stiff to insert by bare fingers. I had to use a plier when my grip failed. I didn't have this kind of problem before.
8. I superglued the spacer ring that best fit the provided 8040 prop to the motor. The spacer ring doesn't fit the motor properly, I had to eyeball it to ensure some concentricity.

I am using this receiver because it works with my Flysky FSi6 transmitter (which works for WLToys' F949). I need to solder the 90 degrees header connector.

15 November 2018

I thought I wouldn't but I did. I bought a Techone Extra 800 (comes with motor, esc, servos, prop) and then another, a Techone MXS-HCF that was on offer. That meant also I bought 2 pieces of 2s500mah and a bottle of foam safe (for the depron MXS-HCF, but I figure it is ok for the EPP Extra 800 too. Hotglue was in my mind but nah...).

I suppose the Extra 800 will be a good plane to have in the boot. Now where is the charger? I need to find a receiver too.