Saturday, July 22, 2017

Visualizing airflow!

This is beyond cool, Schlieren Photography. My first thoughts were, "Hey! Would be awesome to visualize the airflow over diy rc wings."

Upon closer scrutiny, it's setup requires a fair bit of space, and needs a few pieces of equipment that are probably not so easy to obtain.


Still bloody cool though!

Sunday, May 21, 2017

BV141 Inspired Flying Wing

First up, I want to be clear that this little side project has been stopped as it's far too complex for what I'd like to achieve. Without further ado, here're a few snapshots of my BV141 inspired flying wing.


The BV141 is highly unique in that the pilot sits on a separate pod that's not obstructed by the prop, allowing great visibility in its proposed role as a recon aircraft. I thought this would be a fun to tackle, as such a wing design would provide many advantages:
  • Plank-style wing would be very easy to construct from dollar tree foam/readi-board
  • Tractor prop would be quieter than pusher
  • Pod could be used for a camera with no obstruction from prop
This is where I decided not to continue it further:
  • To connect the pod securely to the main fuselage (or wing), would require additional weight a traditional pusher prop wing won't require. Such additional complexity would mean more work in the event of the crash.
  • Spinning blades of doom in the front. Nuff' said.
  • Wetted area of the addition pod, would pose much more drag than a single in-line fuselage on a pusher wing.
  • The flight characteristics of my kfm4 wing were superb, and I thought that it would be better to start from an already good design.
Even so, based on my estimates, it should be possible to get the design completed under 250g, and it'd be legal to fly here in Canada.

250g is truly a challenging limit to build to. Not only do we need to use lightweight components, we have to decide between spending the weight on batteries for longer flight times, or for payloads.

Lightweight aircraft also have difficulty flying in the wind. 

I'll be reverting to a pusher chevron wing design. It's long been my wish to have a wood fuselage alongside foam wings, and with my canard project stalled, this will be my new target.

Wednesday, May 03, 2017

Can't fly my designs anymore.

I've been extremely busy this year. I've been spending lots of time trying to making a life outside of work, and it's not easy. For some reason, I found it easier in Adelaide/Montreal/London, but here I'm finding it difficult to meet people who share similar interests. That, and I'm working loads of overtime, with only Sunday off. Blargh.

Anyways, with summer approaching, I thought it'd be good to complete and maiden my canard design, but I came across some new laws regarding drones that were just announced over a month ago:


First, I'm nonplussed to have my fixed wing designs lumped under the blanket term "drones". I'd like to think that drones are self-guided autonomous vehicles, and none of my aircraft can fly on their own!

But never mind that. First, there are restrictions for aircraft between 250g to 35kg. Aircraft that fall within this limit can't fly close than 75m from buildings, vehicles, vessels, animals(?!) and people/crowds.

Last I checked, dust mites and waterbears are considered animals. So basically, the entirety of Canada is off limits unless you are a commercial operator, or fly sub 250g aircraft?

The distance, 9km from an airport, heliport etc or anywhere that aircraft take-off and land, also basically says, you can't fly anywhere. I mean, where can't a helicopter land? And for places helis can't land, they _have_ got to be animals around. What are we supposed to do? Use a space-based microwave beam to remove all trace of life before we fly our models?

The final one, name/address/phone number on your drone is just asking for malicious people to cause issues. Violate any of these, and there's a 3k fine waiting in the wings.

There's more I can write, but I finished work just an hour ago, and I need to be in bed shortly before I have another long day tomorrow.

I'm not a hardcore rc hobbyist. I am simply someone who is innately passionate about learning about new interesting things, and I also love creating things. I'm very proud when I can create something of my own design that flies and works.

This law limits my ability to design, create and fly larger models. And this means, I won't be buying parts and components from my local hobby shop - or any hobby shop at all. It does not help the hobby businesses here in Canada.

 Hopefully, saner minds will come up with a better set of rules.

In the meantime, I'll be designing smaller sub-250g airframes when inspiration strikes.

Friday, December 02, 2016

Moana

Moana is just too friggin' awesome. I think I shed a few tears during the movie. Only comment I got is the lack of bird shit on those cliff ledges, 'cause I know birds do it there :P

Looks like my mp3 player's gonna get a new OST....

Thursday, September 15, 2016

Nikon D500 first impressions

Looks like I've been rather busy and haven't blogged in a while! The last month or so was rather interesting. There were two anime cons in town barely 2 weeks apart from each other (WHY!?) and a fortnight ago, visited my first renfaire.

Panasonic LX3, booyah!

I've also been dealing with matters of the heart, but this is not the blog to blab on. In any case, my D300 has been having issues - it was saying the battery was too low, but it's definitely not, as I bought a whole new one for it! I sent it to Nikon Canada for repairs, and they said that were no longer any spares for it. I was highly bummed.

On the flip side, they offered me a D500 at a slightly reduced rate, so I decided to go with it. Honestly, if I were more of a thinking person, I would have just declined the offer and bought another D300. But I managed to convince myself to get it after calculating the "amortization" of my D300 after 7 years of faithful service.

Now to be clear, I haven't actually powered up the camera yet. All I've done are read some reviews, and plugged the battery in to charge. I like to write, ok? That's one of my hobbies.

Ok anyways, so let's go. The first impressions of the body are excellent. It feels a smidge lighter than the D300, and maybe because it's brand new, everything feels so tight (my D200/D300 were used...). There also appears to be a mottled pattern (was it on the d300? hmm) that probably help with how the camera looks when it's worn.

Then I noticed the articulated screen. Hmm. Not a fan of that. More places for dust and sand to collect. It is definitely a boon for low/high angle shots, but still... in my opinion more points of failure. I'll see how it goes.

Battery is, unsurprising, a new type of battery. I don't really care so long as it works. The charger is a lovely piece of work though.

The card slot is still the same place, and features dual XQD and SD slots. I've rarely had a need to fill the buffer on my D300, but from what I read, a top of the line XQD basically means you can't fill the buffer, even on raw. Wow. I don't actually have a XQD card yet, so can't say how good it is.


The prices of the XQD are insanely affordable though. I remember back in '07, I bought on of those newfangled Extreme IV CF cards for... oh, 160AUD thereabouts? Somewhere along the great ocean road. A 4gb card gets me about 350 shots, and I usually carry a portable HDD to dump stuff. Yes, I used to shoot lots of crap back in the day. I'm much better now. Trust me.

A 64GB Lexar XQD 2.0 card runs similar - about 160CAD. And assuming 30 megs a RAW, easily over 2000 shots.

Two thousand shots. That's like 55 rolls of bloody film. Gods. I honestly do not think I'd shoot that much these days. I was having concerns about "OH MY GOD I NEED A NEW PORTABLE STORAGE" but no. Assuming I overshoot the 2k limit, I still have a SD card slot to use as fallover storage.

WIN.

What's next. Ah, the flash. That's probably my number one BLEH thing about the D500. The lack of commander mode. My SB600 is now a pure on-shoe flash :( Oh well.

Oh yes the last gripe. How many megapixels is on this camera?! 21?! That's 11 megapixels more than I'd like thanks. I really don't need the pixel count. But this is mainly a first world, pixel peeping problem on my end, so I'll just squelch it here.

And as for lens choice, I only have one lens with me,  my trusty old 16-85VR. When I was looking at the D500s, there was mention about a newer, 16-80VR. That lens shoots from a beautifully wide F2.8, and closes down to F4 at the end of its range. Silence, my fluttering heart. Can you say perfect lens? I checked the price. Nope. Nope. If I were shooting as much as I was in the UK, I'd definitely consider it for the extra stop and supposedly "better" qualities. But not now.


Mounting the lens went without a hitch until... wait, my lens is mounted, why is the viewfinder blacked out?! Glaring at my lens, I was like... why you no let me look. Upon closer inspection.... Oh my good lord. There's actually a built-in viewfinder curtain. I'm assuming it's for those long exposure fans. This camera really is the pinnacle of tech, isn't it?!

(I would like to mention it's a really nice, circular viewfinder. I've only seen those on full frame FX cameras. I feel so papered.)

Without a charged battery, the last thing I can talk about are the buttons. The AF-ON button falls perfectly under my thumb as before, and there's new joystick besides it. I wonder what's it for. If I could use it to select focus points, and the big-old OK button to reset the focus point it'd be the bee's knees.

A convenient switch for photography/video is at the bottom, and there is a very convenient live view button. There is also a nice italized "i" button which I assume is for info. Somehow it doesn't fit the more serious text around it. But wait, there's a button labeled... "info" besides it. In a serious font. Maybe the i button is for uploading to instagram?

The strip of button on the left appears to be very similar to the D300's, though there's an additional Fn2 button on the bottom.

Given I have no battery, I can't comment on the top LCD, which I guarantee is awesome, and backlit. Please be backlit. On the left, the dial is very similar, with single shot/continuous low etc shooting choice on the locked ring. The top of the dial has 4 buttons. The ISO button has moved to the shutter area, and the mode button and what I assume is exposure metering added to it. There now appears to be a dedicated bracketing button... I used to use that for my flash EV compensation. Wondering where that's gone too.

Stay tuned, but there's no guarantee I'll post more. XD

Thursday, July 28, 2016

Ghostbusters!

A very amusing movie! I can't believe all the internet hate from the trailers. I thought the first two trailers were quite meh, but the international trailer was pretty solid. And the film was pretty damned enjoyable and funny, and given by how the crowd with me were laughing!

I especially enjoyed how the show doesn't take itself too seriously, and the 2D ghost near the end just clinches it. Very proud to have worked on the ghost fight sequence, that looked even better after the final grade.

Who you gonna call?

Wednesday, July 27, 2016

Electro Etching - Complete

It's quite difficult to find Copper Sulfate, but somehow I managed to find a small 100g bottle from Lacy West.
As this was a quick test, I just glued up a pile of waste plywood pieces into something able to support the piece being etched. They are kept more or less about 6 centimeters apart.

The first test plate was slightly damaged due to some over-enthusiastic filing to get a clean area for the wire to be soldered on. I also used a small bottle of TSPe to remove all the oil and fingerprints.
A used pasta sauce container is to be used to hold the electrolyte.
For a power supply, I got a pretty nice unit off Banggood, the cps-3205 capable of up to 5A current supply, and variable from 0 to 32 volts.
I went with 1v, for my etching voltage. The current draw during my tests were hardly taxing on the power supply, topping out at 150mAh.
The cathode appears to have worked as described by various websites, the copper plating onto the cathode.
This is the result after one hour in the electrolyte, checked at 15 minute intervals.
This is side-on through the usb microscope. Seems like a fair good bit of etching was done. 

The toner came off easily with a piece of tape. Some of it could not be removed, and I used a fingernail to scratch it off.


Didn't have any proper oxidization agents, so I just used a black sharpie to colour in the etched areas as a test :)
I thought this looked really nice!
This is the inverse of the previously etched image.
The edges are definitely more deeply etched than the center. Several sources have indicated that this would be the case, and a way to help with this is to use a cathode in the shape of a grid, not a solid plate like I have done.
Here's the reverse give the sharpie treatment :)

Sunday, July 17, 2016

Electro Etching - Toner transfer II

Success! I got the toner to transfer cleanly! I tried again with the same temperature in my oven (about 190-200 degrees C), but only leaving it in the oven for five minutes. The first attempt here transferred the center portion very nicely, but the edges totally fell apart.
Two things came to my mind. First, I did not apply as much pressure as the previous attempt. Next, I also forgot to degrease it. I then tried again, this time having a much tighter grip on the clamp in addition to degreasing the brass.
 It came out pretty good this time!
 
The thickness of the lines however did expand. It comes as no surprise given that we are pressing down on them, and that they'd spread.
The transfer's lines are very crisp though, and all of the toner was transferred across.

Two other things need to be done though, and that the resist should actually be printed in reverse... I want the areas in black to be etched in, so I bungled that. And I would also like the maple leaf to be on the right. I'll keep that in mind for the next attempt, this test should be good enough to begin some actual etching!

Edit: Aaaaand I've got a version with the reversed and flipped image. It's all good! The tears at the edge are simply caused by the metal not being flat. I used a pair of shears to cut the metal, and this was what caused the warping. Gotta see how I can cut metal without the warpage - maybe a jewellery saw?

Electro Etching - Toner transfer

 Small piece of brass that would fit into the aluminum heat spreaders was cut out and sanded down with 400, then 600 grit sandpaper.
The test image was printed on Pulsar FX Toner Transfer Paper. I choose this image for the fine lines and small details as well as the larger solid section.
 The brass plate is then degreased with a dab of TSPe, and carefully handled after.
 Here's the sandwich!
 Clamped down.
 Top shelf of the oven!
Water removes the transfer paper from the toner resist. The paper floats away easily, and feels exactly like the paper found on the underside of water slide decals. A quick google search indicates that these papers are probably Dextrin Coated Paper.
Success! The toner transferred well, and seems to be very sturdy. It even resists my attempts of scratching with a fingernail. However...
The fine details are all squished. Was it too much heat? Or was the clamp applying too much pressure? Gotta sand it off then and try again! I'll report back when I get a better result!

Saturday, July 16, 2016

Electro Etching - Figuring out printer settings

After much web browsing and forum lurking, I decided on getting the HP Laserjet P1102W to print the toner resists. To keep things cheap, I bought a refurb printer that, unfortunately, arrived with the output tray, as well as the upper cover broken. Blargh. Thankfully, Amazon has a pretty damned good return policy, so that went back.

The P1102W is a curious machine. It supposedly prints at 600DPI, but it has FastRes 1200 mode that somehow gives the sharpness of a 1200dpi printer. The "true" 1200dpi printers supposedly use the so-called ProRes 1200 print modes - or what I could understand from their PR blurbs.

While browsing the HP website, I came across the HP M201dw that was slightly larger than the 1102, able to print duplex, and... could print in ProRes 1200! And here's the best part - there was a special offer going on at Staples... 99.93 - from a usual price at 229. Got a unit of it :)

My first time setting up a printer using wifi, and that went surprisingly smoothly. Just had to press the wps button on the router a few times, install the driver and that was it!

Now I wanted to find a setting that gave the thickest toner and proceeded to print a sample vector image though Affinity Designer. However, all the changes I made on the printer or the print dialog settings gave me, as best I can tell though the usb microscope, identical prints. The print quality _appeared_ to be pretty good, though solid black areas had some kind of mottled pattern, mildly visible even through the naked eye.

Curiously, printing the test images as a raster image through Pixelmator revealed a rather different story. The edges weren't as crisp when compared side by side with the vector prints through Affinity Designer.


The two images here show a ~2cm crop of the prints. The upper print was a 300dpi raster image through pixelmator, versus the print though Affinity Designer below. The vector print is super crisp in comparison. You can also see the mottling in the solid areas.

I think this is a superb start, will report next when I attempt to do the toner transfer!

Monday, July 11, 2016

Electro Etching - Heat Spreaders

I am trying my hand at electro etching, and the two common ways to heat and transfer the toner resist onto the workpiece (I'm using brass for a start) is either with a regular clothes iron or a modified laminator. Both of these methods appear to work very well for circuit boards, but I want to try my hand at something with fine detail, and I thought I'd try a different method I saw on youtube.

With the iron and laminator, I believe that there would be some level of shearing between the toner and the copper when heat is applied by an iron or laminator. Using two plates to hold together the transfer sheet/copper and then heating it up would remove the shear from the equation, possibly giving a higher quality result? Well that's what I think anyways.

Originally, I bought some 316 stainless steel round bars, similar to the video. THAT was a stupid idea. I only have hand tools, and the stainless steel basically chewed up anything I threw at it. After learning more about metals, I decided on aluminum for two reasons, a) It's got a good heat transfer co-efficient and b) workable with hand tools.

Copper has a much better heat transfer co-efficient, but I don't want to deal with oxidized copper (eww) and as I read, it's a harder metal.

The "heat spreaders" are basically aluminum bars I got cut from metalsupermarkets. 2inx2in an eighth of an inch thick. A small hand file was used to remove burrs and smooth the edges, then a series of wet/dry sandpaper, 400/600/1000 were used to smooth their contact faces. Sandwiched between these two prepared surfaces would be the brass plate as well as the toner-impregnated transfer paper. A c-clamp will be used to hold the pieces together while they are heated and the toner transferred from the paper onto the brass.

With this done, I am waiting for the last big piece of the puzzle - the laser printer to arrive. I've already got a bunch of copper sulphate for the mordant. As for the paper to receive the toner, I've got a bunch of  Pulsar's Toner Transfer Paper.

The container for holding the mordant is still being decided on... some articles I've read float the piece to be etched horizontally with styrofoam, and some have it held vertically. Each of them have their own pros and cons, and I'm deciding on what would be best for quality and usability indoors.

Should be fun :)

----------------------------------------------------------------
Decided to take a peek under the el-cheapo usb microscope to see what's the surface like between the original and polished surfaces:


 Fascinating!

Wednesday, July 06, 2016

DIY Canard Airframe 10

The downthrust has been bugging me, so I took to creating a small wood wedge that would tilt the motor down by about 5 degrees. Unfortunately (I seem to be using this word far to often) the tilt causes the sleeve of the prop adaptor to hit the lower screw >.>

Gah. Now kinda concerned if the airframe can fly or not without downthrust. Hopefully the weather will be more conducive and I can give her a spin soon. Grrr.

Monday, July 04, 2016

DIY Canard Airframe 09

AAAAAND we are back! It's been over half a year since I've worked on the canard, and now that the weather is finally warm (and dry!) I decided it was time to get back to finishing this project.

I've got the servos installed, and did a quick run to the park to make sure it still glides ok. That it didn't disappoint. Now I'm concerned about the thrust angle of the motor. The motor is a few mm below the thrustline, and I'm not sure how much downthrust to give it (or not?).

A quick google indicates some people have flown their models with no downthrust - I'll probably stick with that for now. There's also the incidence of the canard to consider. ARGH! Hopefully will have news in a day or two with the maiden!

Saturday, July 02, 2016

Is Star Wars more popular than Star Trek?

Or at least, it _seems_ that way to me. Exhibit one: Canada Day Parade, Vancouver Downtown.


I was patiently waiting for a Bleach, or Naruto, heck, anything cosplay-related contingent, but nothing showed up. One thing lead to the other and I pondered, why isn't there a Star Trek contingent? And as I turned back time, I remember that at anime cons, I _always_ see SW related costumers. I honestly cannot remember the last time I saw a Trek costumer. I definitely have, somewhere, but I can't say when.

This made me consider the universes of both space operas. From my limited point of view - I'm not a big fan of either, but definitely read alot more trek books - Harry Potter FTW btw - Star Wars is infinitely more relatable. Sith, Imperial Stormtrooper. Jedi, even your alien bartender. They are everyday slices of life, in a different skin. I can relate to them.

Trek on the other hand, is humans in post-scarcity, vs the things they find while out exploring. I can't relate that easily to Picard or Janeway. They hold grand moral values that, while I'd love to be able to hold on to, I don't think it's something a regular wolf can do on a day to day basis.

At around this point, my mind went off on another tangent. Guildwars popped up for some reason, and I was like... isn't Star Trek like PVE? It really is a group of humans banding together to explore the world, face down "evil" and save the day. Just like ST.

Starwars on the other hand reminds me of PVP. It's the clashing of people and ideologies, the grand battles, lightsaber to lightsaber, turbolaser to turbolaser. No matter the scale or weapons, it's still People Vs People.

Also, Star Trek is people in sleek, futuristic uniforms. Starwars in my opinion, has so much more texture and differences.

I think I need to cook dinner. So hungry.