Tag Archive: modelling


Spring is here, the long winter sleep is over. I haven’t been flying for real for the entire winter, only did some simulator practice. So when time was ready to actually fly I was rather nervous.

To cure the lack of fingertip feel I launched the simulator to get some reflexes. Please find some hovering exercise with an Ultimate biplane.

I observed great interest in this plane, ArcticRC and his mate fly this model in the North of Norway. Great plane, great recording.

Nevertheless, I am still flying my modified Multiplex Easystar. I plan to learn flying more before I build a new model. Need to get more confidence in hand starting (although that it might not be needed with planned models), also handling wind gusts and of course flying more stable. I think the more practice I gather with current plane the more I can avoid some stupid mistake with future planes. Although that pilot error is never excluded, how much I might practice.

We had some promising weather during the week, so on Thuesday after working hours we drove to the field and started flying. Clouds around us were rather threatening, wind gusts came from nowhere, but overall conditions were okay.

I had some problem with one of my mini cameras, so I just have the hat cam and the Hobbyking Wing Camera recording. Anyhow it is more than enough material.

I managed to start and land without incidents, however once I did a full roll without willing to do it. I was subject to a stronger wind gust, the plane was tilted almost 90 degrees along longitudinal axis. I wanted to correct, but did not react fast enough and this let the plane do a full roll without me doing really much about it. I think I started to correct but was more amazed by the fact that my Easystar can fly “so advanced” than I was ready to act. Fortunately I was at altitude, so the plane did not lose height that it became dangerous. After this happening I was more alert and could correct wind gusts.

I did some low passes, also some gliding.

My conclusion is that this 3-blade propeller is not really god. It makes transportation much more difficult. The wings cannot be stucked close to the fuselage as you have a blade every 120 degree. With a conventional 2-blade this is no issue. The efficiency is lower, this results is loss of power. And for some reason even though that I have reasonable pitch on it the motor revs crazy high. So I did not dare to use it on full throttle for long.

I ordered APC 6x4E pusher props, will mount one when I get them. That configuration worked much better, but I cracked that prop earlier. Hence the try with 3-blade.

Here is my 11th flight, please check it out.

With best regards,

Sir Crash a Lot



I purchased a shiny new Hobbyking HD Wing Camera recently. Did test it but haven’t wrote a post yet. Now it is high time then.

This camera is slightly bigger than the simple keyfob camera. To summarize the parameters I can write a small comparison for you. HD camera first, SD keyfob second.

Resolution: 5 megapixel vs 0.3

Video resolution: 1280×720 vs 640×480

Memory card needed: Class 10 MicroSDHC (on both)

Price: 35 USD vs 15

Weight: 30 gram vs 15

Wide-angle lens: YES vs NO

Battery life: 2 hours vs 3/4

If you compare the two it is a no-brainer actually. To have decent wide-angle you have to get a converter for the keyfob camera. That jacks up the price to same level as the HD Wing Camera. And then image quality just decides on favor of the HD camera.

Using this camera is very easy. You can find the manual on Hobbycity homepage or just Google on RD32 camera. It is some sort of action camera, that is waterproof and you can mount it on your bike or cross buggy. Or whatever extreme sport you might do.

Appearently this is the same board, but no waterproof shell. Only the circuit board and some shrink wrap around. Hence the price. It is no GoPro, but does not cost 220 USD either.

I made some very simple comparison test. Had the old SD camera and the new HD camera in my hand and tried to pan them around.

I will need to try it out in flight as well. With some tweaks it can be used as FPV camera. Can record and broadcast same time. So quite a versatile unit.

Best regards,

Sir Crash a Lot



I would like to write a post about how to assemble Hobbyking Magnetic Prop Balancer device. It might look easy on the picture, but when you get to it you might find this helpful. Since no instruction manual is shipped, like in case of an IKEA furniture you need good assembly skills.

You will need to align the two sheets that have trapezoid shape and connect them with the U-shaped ones. Something like this.

For assembly you will need to slide the metal inserts and bolt them on with the small diameter screws. Please observe that only one side of the inserts is threaded, so you need to insert the screw from the mating side. This way you will have clamping force.

Then you will need to do so on the other side as well. You might need to peel off the protective paper layer. Depends on how tight the metal inserts are.

After this you can insert the big metal cup on one side. Secure it with the larger diameter screws.

One side is open, the other side is like a sunken cup. Into the open one you can insert the matching big cup. It is threaded, allows adjustment.

With the threaded cup:

Then comes assembly of panels.

Now comes the difficult part. You have to tear apart the 2 magnets. They are really strong. Do it carefully. When they are apart you can insert them into the cup features on both sides.

Between the two magnets should the axle float. The axle is pointy at the ends, so friction will be minimal.

Onto the axle you can slide the 2 conical rubber features. This will support the prop.

If I am right the rubber O-ring can sit on the adjustable side of the balancer.

When ready it looks like this.

A short video of how it does work.

Best regards,

Sir Crash a Lot


My 6th flight was a special one. My wife joined me this time. She is not really interested in RC, but wanted to give me company so she did. While being there she recorded some of my flying even. This gave me some funny footage of me launching the model and landing.

On the other hand she became very bored after a while so this flight was shorter than I anticipated. I could only fly 4 batteries instead of 6. Anyhow it was a good flight, I could do what I wanted during this shorter session.

What I aimed for:

– to fly higher and further away than before,

– to do some basic acrobatic flight

– to not crash on a treetop 🙂

I am proud to tell that I managed all these above-mentioned aims. Despite the strong wind gusts I could fly really high this time. I had difficulties to see the model, I was so far up. Could record some remarkable footage from the area of Arendal. This is the industrial port of Göteborg (Gothenburg) city. On the footage you can see Volvo Bus Corporation head office building, Volvo Museum, and numerous industry buildings along with the container buffer outside of the port. Very exciting location with all the wind mills.

I am getting very good results with my 180-degree fisheye converter. The field of view is good, it really opens up the horizon. When soaring with the plane there are no vibrations that mess up the image. I am getting more and more into gliding actually. The sensation of using the wind and gliding without vibrations from the motor is attracting. I will need to experiment more with gliding.

Best regards,

Sir Crash a Lot


Summer should be normally the time when I can fly my plane. Weather is nice, I should have free time. But practice is showing other picture. In summer I have to comply to company holidays. Due to industry standard 4 week long holiday there is a “shutdown” period during which I practically have to take out my holiday. Due to family reasons some of this time is reserved by family visits. So the available flying time is much less than the original holiday.

Add some weather contraints and you can see that time rushes away and I hardly fly. Anyhow, waiting is over, I made my 5th flight yesterday.

I wanted to try a new location, that is much closer to my home. Until I haven’t got a car I need to consider public transport, this location is only 50 minutes away. It is called Arendal, the industrial/port area of Gothenburg. There is a grass field there, where I could meet with my colleague. I think it is no longer a big secret, he was visible on many videos already, HaBoRC is my flight company. I learn a lot from him, get good advice and practical help when I am stuck with some problem.

Last time he recommended to learn hand starting. It can happen that the grass is taller or you just want to spare some battery power and would like to start the plane from your hand instead of from the ground.

First you have to think it over. To do a good hand start you have to do following:

– do all pre-flight checks. Safety first!

– turn into the wind

– have the transmitter in your hand, hand on the yoke

– get a good grip on the plane, so that you are safe from the propeller. Even when throwing the plane, keep in mind the whole sequence!

– pull good amount of throttle on the stick (max power could be needed)

– align the plane with the ground, throw it forward. If you have great power reserve you can throw it slightly upwards even (maybe 10 degrees, try your ideal values)

– immediately after throwing compensate on the stick (you have your hand on it during throwing)

– recover from the slight dip while the model gains speed

– decrease throttle to a gentle level and start you ascent

If you do everything right you will not get any injury on yourself, nor on the model. Keep in mind safety, the propeller is no toy!

My first start was almost a crash but I could recover. Since I am right-handed launching the plane with left hand felt very awkward. I was never good at throwing stuff, so it felt like a giant leap forward to learn hand starting.

I experienced with flying at bigger distances now. Made “huge” circles around, tried to orient myself when the plane is tiny little in the distance. Later I experienced to fly into the wind at 2/3 throttle and flying up into great height even. Then I pulled down throttle to zero and did glide around. Easystar is a great glider for a motor plane.

Since I had 6 batteries now I could fly double the time. Great way to learn more.

At the 5th battery I felt myself talented and brave and did 2 loops. It went well, I compensated with the throttle during ascent and descent, so they were almost circular loops, no ovals.

At the 6th battery the “devil horns” started to grow unfortunately. I felt brave enough to do a loop directly after takeoff. Into the wind. That resulted in some adrenaline rush. The wind picked the plane up and threw it backwards, so it went over my head. Over the head orientation is very difficult. So I made only a half loop and tried to roll it back to normal flight while wind pushed the plane away and towards the ground. I could recover, but just. Easystar is not really keen on inverted flight, it wants to fly normal. Doing such a stunt so close to myself and so low altitude was just plainly idiotic. I almost crashed, a good lection. When you start to lose respect it is better to land and think it over.

Anyhow I flew around and wanted to improve my low speed gliding skills. Unfortunately the “devil horns” were still there. So I was gliding close to the bushes/trees and lost speed over them. The inevitable happened, I stalled it onto the treetop. As Captain Slow would say in Top Gear, “permission to say cock”… 🙂

I am no good climber, but tried. The bushes were not strong enough to take my weight, but were strong enough to hold the plane. I never thought about it, but tree branches are ideal to support a falling airframe. You have the wings and fuselage, plus the control surfaces on the plane. They match perfectly with the V-shaped branch structure. It gets stuck perfectly. Even if one branch should release the plane the next one will hold it again.

I climbed up, held myself between two bigger branches with both legs and arms. I used my third/fourth arm to pick a branch and try to push the plane from the V-spaked deadlock. Sometimes it felt so that even an optopus would need more arms there…

HaBoRC came with the solution, he found a longer stick that I could use from the ground to push the plane from the branches. It suffered almost no damage. A bit of dent on the leading edge, a bit of scratch from my recovery action. No more. It is a sturdy little plane this.

I have got my lection now. Fewer loops, fewer idiotic proximity flight with trees involved in the future. More respect.

I think I need to optimize my camera use. The hat cam v2 works perfect, the only problem is that I had the hat oriented too much to the ground. So almost no action is visible there. And since I have more battery time on the plane the small cameras cannot work so long. I need to extend their life somehow.

Please find my recording here. I have a spectacular Google Earth intro, zooming from Space to Arendal. Funny 🙂

Towards the end you may find some decent flying from HaBoRC even.

Best regards,

Sir Crash a Lot

Hat cam v2


I am having some amazing progress with my hat cam. I am so far ahead that I actually dare to call it Hat Cam v2 🙂

The idea is that instead of my wife’s compact camera I will use my new company mobile. The compact camera is a Fuji F480, that can record video in 320×240 resolution. That would be fair enough for documenting, but some serious limitations made it less than adequate.

– it could not zoom during recording

– it could not meter light during recording (and adjust light levels)

– it crashed if the light level exceeded a limit during recording (and the recording was lost as well)

– it had limited dynamic range indoors, almost none at dusk/dawn

The mobile phone is a modern smartphone from Samsung that can record in FullHD (1920×1080) if needed. From my side it is not needed, I set it up for 720×480 resolution. Plenty enough for me. What it can do besides:

– it has amazing dynamic range, great recording during any time of day

– it has a reasonable wide-angle lens, good for hat cam

– it can adjust metering during recording

– it can tolerate light level change without crashing

– it can zoom during recording (although no optical zoom, just digital zoom)

– it is very light, some 116 grams (I have to add weight of my bracket)

The big miss is that the mobile phone does not have a tripod mount threaded socket. This is something that mobile phone makers could consider maybe 🙂

Anyhow, I thought that I just make a tripod mount bracket for this phone. A world premiere maybe. Or maybe not.

Please see my build pictures. I used 2 mm plywood, some epoxy for gluing. And for stiffening up the bracket some BBQ matches. Like a frame structure almost. Since I drilled a hole in the center I had to add an extra stiffening beam, that is the remaining plywood from the Easystar build (when I cut out the enhanced rudder). A true piece of engineering this is, very basic in deed, but functional.

This is how you should NOT have the nut. It has to be on the other side, so that the screw is pulling it onto the plywood and not ripping it off instead.

For having some soft interface between the phone and the bracket I added adhesive window insulation tape. This provides nice flexible support, the phone can just sit in the bracket without getting scratched.

I will need to test if epoxy can fix the 1/4″ nut stiff enough, maybe I will need to apply CA glue instead.

I will test this setup next time I fly. Please feel free to copy my design if you like it. However please do make precautions to not drop your phone if you do so. Specially if you have some heavier phone that puts more stress on the glue.

I almost dropped my phone, made some trial recording and the glue snapped. Now I have the nut on the inside, so that the clamping force of the threaded connection is pulling it onto the hat. This way I have better chances to not drop it. And the friction between the bracket and the hat will help to secure bearing of the camera.

The finished product:

Best regards,

Sir Crash a Lot


I just received my parallel charging board from Hobbycity. They were super fast, I expected the package for the end of this week, it arrived on Monday. Great service!

According to reviews it can happen that polarity is wrong on the connectors. This causes risk of permanent failure on the batteries that you connect to it. So it is a good idea to check connections and polarities prior to using this board.

Mine looks like following after removing the isolation from the back.

From behind

And from above:

From above

I think that this looks okay. The red wire is connected to the plus side of the main XT60 connector. And all the charging XT60 connectors are on the same side, the side to which the red wire is soldered.

I checked if the balancing port ground wire is connected to the matching side of the balancing connectors. It looks like so.

I just double check this one more time and then will do a big charging of 6 batteries at once. Since I received my 3 new Zippy 3S 2200 mAh 20C batteries I can use 6 packs. I just made sure that they are all okay, checked the voltages.

One came with 2.2V on one cell, this I corrected to 3.8V with the storage charge option on the iCharger unit.

Later I will try to make a short resume of how you can do such a parallel charge and what do you need to look at to be on the safe side. I will update this very post to give you more details. Stay tuned.

Best regards,

Sir Crash a Lot



My charger arrived


I was in a dilemma about chargers and PSU’s for some time, could not really decide. Now I made decision and ordered them.

I went for the iCharger 106B+ charger and a Lindinger 20A power supply unit.

I went for the iCharger since it is the best and this small model has just right performance for my needs. I plan to charge my batteries to storage charge on the long run and have a full charge prior to flying. This enables long life for them.

The 20A PSU seems to be too large for the 10A charger but the more power you have in the PSU the more stable voltage it can deliver during load condition. And the less it will use the fan for cooling itself. This seemed to be a good compromise in cost and performance.

I had my first charge recorded to show some interesting details.

The charger is quite heavy, you can feel that there is material in it. Good quality feel on the house, the connectors and the buttons. I have some plastic screen protection on the display, haven’t removed it yet. Like on mobile phones, you remove this on first use. This is no quality issue, I thought I might have it on for a while.

The PSU is cooled by a fan, the fan runs very smooth and quiet. I charged one battery so far at a time, we will see how it will run on more load. I plan to parallel charge several batteries at once.

The charger enables all sort of protection features. You can have time based protection, capacity based boundary condition. You can have temperature sensor readings and stop charging on some defined value. And you have the intelligent control of charge that checks all cells during the process.

When I charged the interior temperature of the charger went up to 41 degrees centigrade, this is not much I think. The fan ran quite seldom, noise level was not disturbing in a quiet living room. My wife was reading on the couch, no comments on her side.

What is annoying is the beeping, that you can disable. On default it beeps on every press of a button. That was commented on the side of my wife, she welcomes that muted beeps 🙂

I even did a storage charge, please see noise levels at that operation in following clip.

What next?

I will read the manual, that never hurts. And I will use parallel charge soon. Ordered a charging board from Hobbycity along with 3 extra batteries.

What I read is that you should check polarity on this board. Some of them are wrong polarity, you can damage your battery if you have a wrong polarity connection. I will check mine when it arrives.

I have 10A limit on the charger, this means that I can charge all 6 batteries together with 1.66A each. This is 0,75C charging, so it will take approximately 1.3 hours to charge all of them at once. Since I don’t discharge them fully I assume that maybe less time will be enough even.

With a 20A charger this would be even less time. But I am not in a hurry. Compared to the charger I used so far this is magic speed. The other charger took 6.5 hours per battery. That is slow.

I even have a battery monitor being shipped.

This small unit can display the voltage in all cells, you can check the status on the field. Can have it in the shirt pocket, a must-have almost. Costs 1.86 USD, that is almost like a box of milk that I drink every day. 3% and 1.5 liters costs approximately 12 SEK.

I can recommend:

– the charger,

– the PSU

– the milk even 🙂

Excellent news. My cell checker arrived even.



Best regards,

Sir Crash a Lot


As you could read I fixed the electrical problem that arose on 3rd flight. Since weather was promising I took my plane to the office and we went flying after office hours on Thursday.

I had my 2 keychain cameras along with 2 wide angle converters. No hat cam this time, I am working on my updated design.

We had a guest pilot from the office, he is flying a nice DG1000 glider. Something like this:

And we had a moderately tuned (according to the owner, he plans to tune it further) Funjet on 4S battery and some insane motor and prop. Like a missile it flew.

I had some incident again. One of the wide angle converters unscrewed itself, and the bigger half with the lens in front fell off. During flight. Into the propeller and away it flew. I have mathematical chance to find it, I will look next time though.

I made a slow-motion replay of it happening, you can see that it falls off and then blurry image. Since the other half with the macro lens stayed on (has magnetic lock) the image lost focus totally.

I decided to use thread-lock on the remaining converter, CA might create some white fog on the lens itself.

Then I started my plane twice (yes, 2x) into the vegetation. Very embarassing. And once I tried to hand start and failed badly. So my self confidence was quite low in the first part of flying. Anyhow with some careful flying this came to a reasonable level, I had some great fun in the sky.

Our colleague Fredrik was kind enough to record some of my flying with his mobile phone, you can see me from his point-of-view during the second half of the clip. Great recording he made. I just had to align my onboard camera footage and then you can benefit of 3 cameras at once picture-in-picture. I wish I had more cameras, 3 is just enough 🙂

This time I could fly much farther away, as I gain experience I manage more and more. This gives much nicer footage from the air, the area in which we are flying is really beautiful this time. A lot of green and vegetation everywhere, great variation in height as well.

When I flew out the juice from my batteries I started to record others flying. Fredrik made some nice flying with the DG1000, very fine landing and turns.

We had great time again, a nice day it was indeed.

Best regards,

Sir Crash a Lot


My 3rd flight was not without problem. I enjoyed some nice flying during the first 2 batteries, then all of a sudden on the 3rd battery the power just cut out. Had to do emergency landing even.

The problem and its solution is described here, please see my other post.

It feels so that with every flight I learn something new, gather a lot of experience. I would not consider myself experienced yet, just my level is increasing from something very low to something less low maybe 🙂

Flying is great fun. If you just read this and don’t fly yet, do not hesitate. Just start flying, it is certainly something wonderful.

Best regards,

Sir Crash a Lot