mtesa - as long it is DIY :)

Almost a yearly update;)

2011-07-16T10:50:00.002+02:00

Well, I did a lot, since last entry.

Burned some simulator time.

Got new radio, Turnigy 9x.

Modded it, naturally.

Made some new, exciting models.

I'll make separate blog entry for every model, with building notes, and tips and tricks.

And an entry about the radio too.

ZAGI is airborne!!

2010-08-03T15:13:00.002+02:00

I made an 120cm Zagi with TowerPro 2406-12 motor, 18A ESC, 1600mAh 20C LiPo.

It is a blast!!

Pictures soon.

BB's are finished

2010-01-23T21:49:00.004+01:00

I finished both of them.

Here is how tail servos are mounted inside the fuselage.

Complete fuselages with landing gears.

And complete planes.

Due bad weather, more snow, they say, I'm not able to maiden them.

So, I'll start my nex project, Foke Wulf 190D.

2010-01-23T21:46:00.001+01:00

I built an KFm3 wing for my BlueBaby airplane and was astonished by it.

But it is not so good looking wing.

So, to make it a bit nicer and "looking as a proper wing" I thought of this.

On picture 1 is a wing I made. I know it has a extra spar, but I had a feeling it is

too fragile so I added another spar.

On picture 2 a line is drawn which shows what will be sanded down. The red part

will be removed from wing.

Picture 3 shows sanded wing.

Picture 4 (thick line around wing) shows packing tape which will cover the wing.

Fuse is RED, and landing gear is finshed!

2010-01-20T22:40:00.003+01:00

Landing gear is made out of 110mm plastic water pipe.

I used a hacksaw to cut a ring 4cm wide at one side and 2cm wide on the other.

then made a cut at 2cm end to create a strip. Ofcourse, the plastic retained its shape

so I had to heat iti with hot air gun and bend it to get the shape I want.

Used 4mm bolts with nuts to make two "axles" for my HobbyCity wheels.

These are for testing purposes. DIY wheels will be made later.

One of the fuselages received to coats of water based white paint two days before, and one coat

of red today. I'll see how it will look after it dries completely.

Two babys = twins? Not!

2010-01-19T09:07:00.008+01:00

This is the wing which survived a crash of myDIY1 Blue Baby.

For its heroism, it will receive completely new fuselage with brand new electronics.

And new paint, or, to be more correct, tape.

This one will receive a blue-yellow packing tape skin.

I forgot to shoot inside the fuselage. Two servos with control lines made of guitar strings are allready mounted.

New KFm3 wing is made just ike the old one.

DO NOT TRY TO FIX IT OR IMPROVE IT IF IT AIN'T BROKEN!

After your intervention it WILL BE!

Top of the wing with servo and controls mounted.

Bottom side.

Top side. Wing is covered with red and white TESA packing tape.

This is fuselage for red-white wing. All electronis are inside. I'm trying to get smooth coat of

water based colour (white for now, but it will be red at the end).

Still making landing gear for both.

Protech Topic 400 is finaly ready to fly

2010-01-16T12:41:00.003+01:00

Here it is.

Way back, wrapped in foam, is RX, Multiplex Pico 4ch 40Mhz.

In front of it, small pcb, is a LiPo battery monitor, that beeps and flashes red LED when

battery voltage drops.

Next, two HXT900 9gramm servos with my push rod stoppers.

Partialy hidden in plastic is Turnigy brushed 20A ESC connected to 380 size motor.

Below the motor and on the sides are 120gramm lead weights (used to balance alloy car wheels).

Another one - DIY link with tube or "bowden"

2010-01-13T09:54:00.003+01:00

I don't know its true name, but guys over here call it "bowden".

As I said before, due lack of shops with these, I decided to make it on my own and in my own way.

So, first I was thinking about a rod itself, and my first choice was round bamboo skewer with 4mm diameter. But, fellow flyer talked me out of it and suggested use of steel wire 2mm thick.

But I already got a pack of bamboo (some 50 pcs 50cm long) and PERFECT plastic tube for it.

The tube was taken from window blinds (horizontal ones). Again I'll post pictures of those later.

But then I got some 1.2, 1.7 and 2mm steel wire. All I had to find was suitable tube.

And my kids provided a solution.

A very popular juice is sold in plastic bags, and you drink it with provided thin straw.

I took couple of those for a test, but I thought it is too "soft" and flexible.

Younger kid got a sweet licker and it got much stiffer plastic tube for handle.

And I took a couple of those too.

I connected several of them with clear packing tape and got two tubes some 1m long, one is flexible and one is more rigid.

Put a 1.2mm steel wire trough rigid one and 1.7mm wire trough flexible one.

Tubes are glued to fuselage from inside, just for esthetic reasons.

At the one end wire is in Z shape, and on the other link stopper from previous post.

One more DIY task is down.

DIY Link stopper

2010-01-12T22:30:00.004+01:00

Well, why not...

Source of materials was my box of

Do you see brass spacers in lower right part of picture?

Those are computer motherboard spacers.

Placed it in a vice, and hold it with a piece of soft wood.

Then a spacer is put into a drill secured tightly to working surface.

This way I used a drill as a sort of mill.

Part of the spacer with thread is filed down to smooth surface and

a groove is made, like one on the lower picture.

A hole in servo arm is made wider so newly made tip of link stopper can snuggly fit into.

After that, a small bolt is screwed in to make a grip onto steel wire used as control surface link.

Done!

Busy busy busy

2009-12-08T09:37:00.002+01:00

Building another two BB's.

This time I made some alterations and I'll document it as soon as possible.

So, I'll have to DIY some pushrods.

I was tempted of buying at least a pair for reference.

Due heavily filled duty rooster at work, at New Year's Eve comming, holiday season also, please contact me at my email mtesa78240 via gmail service.

BlueBaby is AIRBORNE !!!

2009-11-01T16:53:00.004+01:00

And it flies like a pro :) Runway needed for takeoff : 5 meters or less. :)

First takeoff as made by a Alen, and he landed it after a minute or so for some aditional trimming.

Second takeoff was allmost followed by disaster. MOTOR FELL OFF :))))

I did not secure motor with screws, only with epoxy. When motor got some heat it melted epoxy end fell off. Well, not completely, it stayed hanging by the wires to esc.

Alen landed it, glided it to the ground. Djordje had some spare screws so we screwed it to the firewall, and took off again.

After a minute he handed me the controls. 5 minutes later, on my request, he landed it.

Motor was not too hot, Esc was warm, battery totaly cool.

I need to make some minor adjustements.

Experience with this plane will be used on fuselage no.2 and new wing.

So, my posts will be scarces now. Will post when figure out/make something interesting.

If anybody has any questions feel free to e-mail me.

BlueBaby 42" is finished.

2009-10-30T08:45:00.005+01:00

Made out of 6mm izofloor, flooring thermal insulation foam. More info in previous posts. Wing is an kfm3 airfoil with ailerons driven by HXT900 servo, without dihedral.

I have built another wing, out of Styrofoam, witch is an Clark Y, with dihedral, 10x5mm spruce spar, no ailerons. Covered it with packing tape. So we will try this one too. I’ll upload a photo later.

Tail surfaces are driven by two 5gr servos. Motor is towerpro 2408-21 with 18a esc powered by 1000mah 3s lipo.

control unit is hobbycity 2.4ghz 6ch tx/rx combo

will try with several props 10x4,7, 10x05, 9x06

Landing gear is made out of three bamboo skewers glued and threaded. Wheels are made out of fish food container lids with a piece of izofloor inside.

I tried to make it as much DIY as I could so with 470 gr AUW I think it's not too bad.

Strange thing is that i had to move battery almost behind the motor to get proper cg.

Tried some taxiing and it rolled fine.

I tried to get it airborne, and it rolled on the right.

While getting it straight it flew away from tarmac onto a field where it rolled even more. Yes, I panicked and made a mistake, causing even more roll. Plane dived to the ground and crashed.

Result: - One crooked motor axle, - One broken 1047 prop - Piece of foam fell of at the nose of the plane - Wing tip on the right side fell off

Damage is fixed. I'm waiting for a modeler’s roundup at Sunday

motors without bearings are a "no go"

2009-10-05T13:07:00.002+02:00

Ok, so I got two stators wit 23mm diameter, wound them with 0,4 and 0,5mm copper enameled wire. Used stock bells with 6 2,5mm neodium magnets. shaft 3mm thick.
Fastened the shaft into my dremel an fired it up. It refused to spin.
After increase in power on dremel, motor started up. I'll do some measuring later today and compare it with a towerpro 2418-21t-3d.

burried treasure is found.

2009-10-04T20:47:00.003+02:00

A month ago, we were at coffee shop, and a colleague of mine pops up with a friend. Trough conversation I discovered that he is a model enthusiast too, but has given up some 8-9 years ago. I was invited to his house (his shed is more appropriate, because that is where we went). In there we found a Futaba SkySport 4 TX, a Protech Topic 400 electric sailplane, Ikarus Berliot III model, a RC boat and some other items.
So, for the time beeing I'll slow down a DIY (kinda shoot my self in the foot) and try to repair found planes. Yes, repair is needed. Topic 400 is missing complete electronics and a canopy (a chance for small DIY :) ). Berliot III has busted tail surfaces (3mm depron/izofloor), tail boom and broken landing gear.

On I go.

Update 16.01.2010.

First, I started on the radio. It had an 82nd CH TX crystal installed, and matching RX crystal inside MPX Pico 4ch receiver inside Berliot.

Everything was very VERY dirty .

I disassembled the radio, cleaned it with a lot of alchohol and old toothbrush followed with some distilled water and good and long drying period.

After that I switched it from mode1 to mode2 and assembled it.

Tested it and it works fine.

Berliot had an busted ESC (FET was blown away) so I ordered a spare (5pcs for $5).

Now it works. Canopy struts are busted so I have to make new one. This time from bamboo not balsa.

As for Topic, I decided to leave original motor in. Ordered 20A brushed ESC from HK as well as 1000mAh LiPo. Put it all in with two 9g servos for rudder and elevator. Push rods and tubes are DIY-ed as well as push rod stoppers on servo arms. RX is MPX Pico 4ch. I fitted a battery warn indicator as well. Canopy is made out of plastic bottle.

It came out waaay to tail heavy. I had to put 120gramm of lead in nose to get proper CG, 65mm from leading edge.

Even with this additional weight it is 182gramm for wing and 532gramm for fuselage with everything inside. Total weight si 714gramm. One source says it is 870gramm plane and the other says 860gramm (1.9lb).

The thing is that I had to place 120gramm and still 150gramm below projected weight.

I will maiden it as soon as weather allows it. Today is cold, 0 degrees Celsius, with strong NW wind.

But my garage is warm, so...

On I go

I'm workin' on it

2009-09-25T12:17:00.002+02:00

Yup, still on track.
Completed two motors, but not tested yet.
Got some stuff from hobbycity (esc, one motor, props, servos) and still waiting for radio.
BlueBaby fuses are complete, KFM3 wing is still waiting for me to bend upper part.
Got some plywood and started work on a Styrofoam cesna with "flat bottom Clark Y".
I'll try to make wings interchangeable from bluebaby to cesna and vice versa.
Found detailed info on Davis airfoil, so there is another wing to try.
1.2m depron (izofloor) Fox glider is cutted and partialy glued. It'll wait for its own electronics.
12pole motor out of floppy drive stators is on. Magnets are 6,5x5,5x3 mm. Bell will be scratchbuilt with aluminum shaft and bell top section.

Still working and trying to dodge high costs

2009-09-06T17:40:00.002+02:00

Well, I said once that I'll not brake another CD-ROM for motor but,... :)
I found out that there are TWO VERY STRONG MAGNETS IN EVERY OPTICAL ASSEMBLY!!
I didn't knew that before! Why, oh why!? I tossed at least 30 of them into garbage, and then went online to order some ?!?!
So I tore some more CDROMs and got to another problem (meybe you guessed it?) ... magnets are not the same! Every drive had different magnets. But, I got my hands on some LG 52X CDROMS and some HP/Compaq's so I have a small collection of those.
Anyway, my first DIY motor will be with stock magnet (the gray, strong, one) and stock winding.
And I'll run some tests and benchmarks before I put it into my model.

My order at an online shop is returned to sender. They say I never claimed a package?!
I didn't get any notice on it. But I'll order it again and try to monitor its path.

Kfm3 wings for my BluBaby are done, so are Clark foil one. Pictures will be up very soon.

Yup, got some more stators

2009-08-30T21:47:00.002+02:00

I got 4 of those from 3.5" Samsung floppy drive.
I'll try to get some info can they be used becouse two poles are almost "headless".
Will it hinder performance?
Will see.
I also got some 12pole pure beauty stators as well as 15 pole one ???
Source are floppy drives.

And yes I'll try not to get more. I have almost 40 motors. :)

Red wheels for Blue Baby

2009-08-30T21:37:00.008+02:00

DIY landing gear.

Wheels are made out of 4 plastic bottle caps cut approximately 1/3 from top of cap.

Sanded them to get even thicness.

And glued with some epoxy.

Tomorow, it will be done.

Blue Baby build is going on...

2009-08-30T21:25:00.005+02:00

Blue Baby fuselages are glued. Well, kind of :)
I made two of them, one with 6cm monoblock, named FuseA, and the other with 4.8cm monoblock, named FuseB.
Had to alter top and bottom fuse decks to compensate wider fuse.
So FuseA is glued completely and FuseB got only monoblock and side panel glued together.

This is FuseA.

Kfm3 wings are traced and cuted. I'll buy some 10x5mm spruce spar tomorow for it.

In meantime I made simple flat bottom wing, just for fun. We'll see will it fly and how.

Tail surfaces are also cut and hinged. Clear packing tape is used as a hinge.

Motor magnet placement calculator

2009-08-29T10:05:00.002+02:00

I realy don't wont to reinvent hot water, but I took it as a task to remember all those math lessons from school. So I came up with this Microsoft Excell 2003 XLS or OpenOffice Spreadsheet.
FTP user:diyrc pass:diyrc

It basicaly calculates an airgap and maglen spacer thickness based on your stator and bell diameter, and magnet dimensions, number and thickness.

You can play with it to get optimal values for your motor.

Blu Baby 42" constructio had started...

2009-08-29T09:29:00.009+02:00

Following a plan (and diverting from it in certain things (wings ;)) found at RCGroups.com I started a build of not one but TWO Blue Baby fuselages.
Thinking behind this decision is that this will be my trainer aircraft, and being a such, I think that it will be a good idea to learn and experience how different setups behave in air. Mainly I'm thinking on wing constructions.
So, these fuselages, being identical, can act like a spare fuse if God forbid I crash one beyond repair. I can go in the field and fly "the same" aircraft with different settings and different wings.
Not to mention, the we can fly both of them at the same time.

So, this is how I started it.
The plan is downloaded, printed, put together and cut away.
According the plan, I need a piece of 2" thick foam for fuselage monoblock.
I have one 4.7cm (1 inch=2.54cm) so its a 1.8" foam, and a 6cm (2.3").

And I choose the first one. Why? Closest match.

Then I traced fuselage sides and top and bootom pieces with a sharp tip pen and cut it out.

Monoblock is traced also and cut with my foam cutter.

Yes, monoblock piece has some bruises (it's a construction site find) but nothing serious, just small dents.

This is it, all fuselage parts cut out. I even glued them last night, so I'll add a picture of glued fuse later.

On we go

2009-08-26T08:30:00.004+02:00

I can't wait to fly my own model, so I decided to start building them before I got other issues resolved. Yes, that is right, THEM and ISSUES. Plural.

Them means that I startted a build of two trainers yesterday, and I will start another one today.
Why three trainers? I want to.

Issues?
Issues are:
- I still have no radio :) !
- Not a single servo in shop
- No ESC and no motor either

But hey, I have a lot of foam and spruce (sorry no balsa source yet), some tools and a lot of will.
So in my next post I'll try to upload some progress photos.

And now, .... we wait for magnets

2009-08-22T20:45:00.005+02:00

A lot of work is done.
Cleaned all stators. Removed all stock windings. All bells, with the exception of five of them, had stock magnet rings and glue residue removed. Five stator are wound with 0.35 and 0.4 mm copper enameled wire.
All ready for new magnets.

Surfing the web for DIY ESC project. Got two of them, with board layouts and controller software. Unfortunately, the only shop which makes custom boards refused to build mine, for low number of boards. The minimum is 20. Will try another approach with them.
If it fails, I'll buy a cheap one just to test my motors, and build mine, again in DIY.

While waiting for magnets, I'll try tu build first trainer, a Blue Baby 42.

Making a foam cutter

2009-08-22T20:15:00.007+02:00

Got this wire from a cheap heater.

Wire must be unused. Used wire cracks and snaps. Unwound it and got a really long piece of wire.

To build a cutter I'm using an obsolete TV antenna. I disassembled it, removed small aluminum rods (note the holes) and cut to size. I used some pieces of metal that have a 90 degree angle built-in. In this particular case an shelf mounting bracket (white one).

Small square piece of electronic board with a tiny hole in it is glued at the bottom. heating wire is threaded trough the board and fixed to ceramic line terminal. On the other side of the terminal is a high current rated wire. Note the coaxial connector (we are calling it "chinch"). Easy to use, easy to find, cheap and I like all my potentially hazardous electrical DIY apparatus to be easily disconnected.

On the upper side is my square tube fixed in 90 degree with some zip ties (temporarily at the beginning, but they stayed... ). High current rated wire is fed trough a sqare tube to avoid kinking, touching, yanking, .... you imagine it. A small clamp is mounted on the end of the wire and soldered. I can move a clamp up and down to adjust the length of heated wire. A small X sign near the hole is from firs measurement.
I was close :).

Wire is perpendicular with the board. That is what I want.

To cut airfoil wings a man needs a long foam cutting bow. So you build one. Two strands of 3mm steel wire are twisted together and form one end of the bow. So, build another one and fit it at the other end of the already mentioned square tube. Put some cutting wire in the bow and that is it. The power is delivered trough the same wire and clamps as in previous cutter.

Got even those. Two extender boards,obsolete for its owner, and a small piece of board from a CDROM. These can be used for motor mounts. Even made one in less than two minutes.

more scavenging

2009-08-22T19:37:00.012+02:00

And this is what I got so far:

Several types of brushless motors (different diameters and bell depth). Even have 4 of the same type (upper left corner). Got two of them and stacked startors (upper right). There are two big stators and bells from 3.5" floppy drive (bottom left).

This is a stock Pentium4 (socket 478) CPU cooler. Note the two small ball bearings?
They fit perfectly for 3mm shaft :) But note that not all CPU coolers have bearings.

This is something I pulled out from a CDROM drive.
Various plastic cogs. Maybe to build a gearbox or to use them as a base for landing gear wheels.
Rubber bushing, to dampen vibrations where needed.
And the shafts. 3mm . Long enough.

More cogs and some motors found inside CDROM. Flat one drives a laser trolley, and round one powers a tray.

And this is something I'll definitely try to use. An 12 pole stator. And I got 7, SEVEN, of them. Who said LRK???

The same, but disassembled.

First flyers... or somthing like that

2009-08-18T15:35:00.004+02:00

Made some simple gliders with kids.
Downloaded some templates, printed out, cut those out, and had a lot of fun.
My kids were cutting some slingshot gliders, which you can see on images in previous post, on top of the foam. They fly/glide pretty well. And fast.
I myself tried with this one.

Three wooden spars were a pain in the *ss. Did them with sharp knife out of 1x1.5cm piece of spruce. Wing has no dihedral. Spruce is sanded like in a airfoil, so is rudder and elevator. That was not mentioned in original plans, but I did it just to see how will it come out. Son said he will do final sanding of the wing. But it flies/glides pretty well as it is. As a weight in the nose we used a pretty large nut washer.

Foam is in the house !!!

2009-08-18T15:19:00.009+02:00

There is a large construction site near my job. So, one day, going home from work, I saw some floor and roof insulation material laying around. This material is over here known as IZO-FLOOR. Its harder than regular white styrofoam and somewhat heavier but not much. So, I talked to a guy on site and he agreed that I can take those pieces with me. And I did.

Pieces are 8cm, 5cm, and 1 cm thick. I think they will be great for fuselages and more.
They didn't have nothing thinner, so I went to a hardware store and bought a pack of 3mm and 6mm thick foam, 5 and 10 euro each.

I think I'm on the right path here.
I still have to figure out a source of wood. Balsa is not existent, so I'll be using poplar, birch and lime tree.
Naturally, I dont have a band saw ir circular saw to cut wood, so I'll have to make one :).
A small lathe will be required also, but.... Later.

DIY goes on...

2009-08-18T15:00:00.004+02:00

OK, I built a hot wire foam cutter.
Plastic box found. Power connector from busted PC power supply, bought light dimmer for 9 euro. Connector is standard audio connector which is widely available, but good enough to transfer power and current required for the job. Transformer is taken from my DIY soldering iron (200V to 24V). I wired it in following order: power socket -> dimmer -> transformer -> connector. This power supply is powering my soldering iron too. Turn dimmer to max power for soldering, turn down for foam cutting.

The cutter itself later on.

Money needed ;)

2009-08-17T21:57:00.000+02:00

If you are on this page already, click on some of the ads, if you want...
All money earned, if any, will go into RC items or to build a new and bigger aquarium ;)

Acquireing motors from CD drives

2009-08-17T21:09:00.001+02:00

Being a member of IT support staff in a 500+ employees firm, and in this line of business for last 15 years, with several good friends with similar jobs, it was a breeze to acquire 20+ malfunctioning CDROM drives. Today, it's hard not to think about those drives that i tossed in garbage bin :(
But hey, let's start busting those.
I tore them apart and found some interesting things.
Yes, I made a mistake at start. I haven't write down model and supplier for those drives but I'll be more careful later.
This is what I dug out:
1. Brushless motors, which spin the CD or DVD, we'll use those for our DIY airplanes.
2. Plastic cogs, which load and unload CD tray. Maybe they can be used for speed reduction? Will try later on.
3. Brushed motors for lens navigation and tray movement. Several people on RC forums claim that its not "time and material effective" to work with them. But I'll keep them in a separate bin.
4. Rubber bushings for vibration absorbing. Into separate bin.
5. And at the end, an 3mm steel shaft, on which laser is driven. This can be a perfect long prop shaft.
And this is only a half of my loot.
Several of them are identical so there is a possibility to stack them and get bigger, fatter stator.
I already did it with two of them (upper right corner).
Hardest part was to remove factory supplied magnet material inside the bell. Removed those using brute force.
I left gray ones in those little buggers in first row. Removed stock wire and wound 16turns of 0,35mm on one, 12turns of 0,40mm on second. They are identical.
Two in the middle are 32turns of 0,35mm and 22 turns of 0,40mm. Also identical motors.
And the one on the left is 19turns 0,40mm.
Others will be built when my shipment of strong magnets form Switzerland. I ordered 40 pcs of 5x5x1mm and 40 pcs of 5x5x1.2mm from www.supermagnete.ch. Total is 26 SFR with postal expences inside country, VAT included.
I found an excellent source of cheap RC goods at www.hobbycity.com and will order an inexpencive dremmel like power tool.
Nexte major update will be when those items arrive. Until then I'll try to acquire some more motors, dissassemble them and create a list at this page.

Introduction iliti uvod

2009-08-17T21:03:00.001+02:00

This is firs and last post in Serbian. The reason is that I want to make information's on this blog widely available, and I think this is the right way. Anyway, most of us who are interested in these topics have more than enough English knowledge.
On to the second but firs post.

Ovo je prvi i poslednji clanak na Srpskom. Razlog za koristenje engleskog jezika na blogu je taj da zelim da sto vise ljudi ima pristup objavljenim informacijama za koje se nadam da ce im biti od pomoci. Ionako, vecina nas koji govorimo Srpski a interesuju nas teme sa ovog bloga, vladamo u dovoljnoj mjeri stranim jezikom.
Dakle, idemo na drugi a ipak prvi clanak