deane: (Default)
I've started another series of YouTube videos which once again highlights just how slow my internet upload speeds are. With 1Mbps theoretical max and 0.5Mbps actual max (when the wind is blowing in the right direction) it took seven hours to upload the latest episode. So I decided to upgrade to something faster.

Since I was already at Telus' web-site, I decided to try their online Customer Service chat. The 'Internet 50' service that I was interested in upgrading to advertised upload speeds of "up to 10Mbps". I explained to Donald, the Customer Service rep, that I was concerned about that "up to" and wanted to know whether there was a guaranteed minimum. He quickly copy-pasted the same information that was on the web-site, telling me that I would get download speeds between 20Mbps and 50Mbps. I repeated that it was the upload speed which concerned me, particularly since my existing service with them only ever achieved at best half the advertised maximum. He responded to that by copy-pasting the "up to 10Mbps" information from the web-site. I explained yet again that it was the minimum speed that I was concerned about. Was it possible that I would upgrade my service and still end up with the same shitty 0.5Mbps that I already had? After a long pause he told me that he'd have to transfer me to Technical Support.

After about a five minute wait I got Rina from Technical Support who told me that she'd be happy to help me investigate why my internet connection was slow. I explained to her that I was more interested in finding out what the guaranteed minimum upload speed was for the 'Internet 50' service. Rina was much more efficient than Donald: she copy-pasted all of the speed information from the web-site at once, rather than doling it out a piece at a time. I pointed out to her that nowhere did it say what the minimum upload speed was. She reassured me that it would be "much faster" than my existing speed. When I asked how much faster she went away for a while then finally came back with the information that average upload speeds on the service varied between 5.12Mbps and 10Mbps. Not exactly what I was looking for, but closer. I asked if I could get 5.12Mbps guaranteed in writing as the minimum upload speed I'd get on the service, but of course she said no.

Ah well, what are ya gonna do? I decided to take the dive and get the upgrade anyway but it turned out that the 'Internet 50' service wasn't even available in my area. I had to settle instead for the 'Internet 25' service with upload speeds "up to 2.5Mbps".

I wonder how fast it will really be.
 


It Prints!

Feb. 18th, 2013 11:55 pm
deane: (Default)
I wasn't able to get back to the RepPresent last weekend but I was finally able to get to it today. I leveled the bed, twice because I did it wrong the first time, tested out the heaters, did some hand extrusion to make sure that was all okay, then I let it rip on its maiden print. There's video of it printing here.

When I was testing the print head heater it started to give off a bit of white smoke. The instructions said to turn off the heater if that happened, which I did. But the instructions never said what to do about it. So after a bit I turned the heater back on. This time it smoked less and eventually stopped smoking at all. I'm not sure what was being burnt off, but it appears to be gone now.

Here's the finished part:



It's one of the frame brackets for the printer itself. There are some obvious problems. Notice that lip around the bottom of it? That's not supposed to be there. I had the print head too close to the bed and it dragged a bit, leaving the first layer offset from the rest of the part. I moved it up a smidgen and the next part printed nicely.

You can also see some waviness along the lower right edge. I think that's due to the Y belt rubbing up against the motor sprocket. That will be tougher to fix, but I'm sure I'll manage. But compared to some of the first prints that I've seen out there this is pretty damned good and I'm quite pleased. Despite its flaws that part is actually usable.

While I was aligning the bed I over-tightened the clamp for the Z-axis limit switch and part of it broke off. Fortunately the screw I'd been tightening still had enough of a grip on the broken bit to wedge it in place. That left the limit switch a bit loose but still firmly enough mounted for the test build. The second part that I built was a replacement clamp. :-)

Before doing many more prints I need to come up with some kind of roller to allow the PLA filament to unspool without getting tangled. For these first few prints I've been unrolling the filament by hand and I can see that getting old fast. Once that's taken care of I want to try designing a mount for my Nexus tablet to go on the exercise cycle, so that I can use it to watch videos while I pedal.
deane: (Default)
After melting the heater block in December I started avoiding the RepPresent, fearing that I might break something else. I make six figures a year but the thought of frying a $10 component is enough to neuter me. *sigh*

Click for the long-winded details, plus peectures! )
deane: (Default)
Today I used a blowtorch for the first time. It did not go well.

The RepPresent has a small aluminium block which holds the print nozzle and the resistor which heats the nozzle up enough to melt the plastic being fed into it. Since the nozzle is made of brass it expands less than does the aluminium block when heated. So to make sure that the nozzle doesn't come loose when the block heats up, the build instructions say to heat the block up with a blowtorch and then tighten the nozzle with a wrench while everything is still hot.

I did this and ended up melting the block.


Click to see an image of the devastation... )

In my defense, the instructions were frustratingly short on detail:

Use the blowtorch to heat the block. You need to heat the block enough for it to expand by at least the amount it will expand during printing.

That's all it has to say about this particular step. No mention of the temperatures involved. No warnings about the possibility of destroying the heart of your machine.

It's a pretty weak defense on my part, though. I'd had some misgivings beforehand, but did I bother to follow up on them before ploughing ahead? Nooooo! Given that this was my first time using a blowtorch, did I think to perhaps experiment a bit first with less valuable scraps of material? Nooooo!

*sigh*

I don't have the tools necessary to build the block myself, but P may so I've sent him email. If that doesn't pan out then I'll just have to wait a week or so for a replacement to arrive.

deane: (Default)
I figured I should record some of the problems that I've run into while building the RepPresent and how I've solved them, just in case some other RepRapper finds the information helpful. So if you're not interested in the minutiae of building a RepRap machine then you should bail now.


Read more... )
deane: (Default)
Several years ago I got interested in 3D printers - machines which build physical objects by laying down thin layers of a material, like plastic or metal, and binding them together. In particular I was keen on the RepRap project as their machines were the cheapest to build and I liked their goal of trying to create a machine which was capable of duplicating itself. So I began salvaging stepper motors and other components from old floppy drives and 2D printers, with the idea of maybe, someday, getting around to building my own machine.

About a month ago the paramour caught the 3D printing bug. Having observed my glacial progress zie decided to speed things up by ordering a kit containing all the necessary parts. The kit arrived on the 14th. We're considering this to be our christmas present to each other and have tentatively named it the RepPresent.

The machine is currently a little over half complete, but the pace is picking up now that the holidays are here and I'm able to devote more time to it.

Behind the cut is a picture of the machine in its current state, with all the main bits labelled, and a description of how it will work.
Read more... )


Soaring

Mar. 27th, 2011 09:03 pm
deane: (Default)
If you don't know what a wing-suit is, it's time you found out.

If that's a bit too extreme for you, then maybe you'd prefer some FPV proximity flying.

One of my favourite parts of that second video is at the end when the plane is coming in for a landing and we get a brief glimpse of its goggled operator with his back to the mountain that he just flew out of.
deane: (Default)
This video has to be seen to be believed. It's a light show celebrating the 600 year anniversary of the astrological clock tower in Prague. The term "light show" doesn't do it justice, though. It's projected onto the front of the tower and uses computerized surface mapping to incorporate the tower's real features into the show. For example, when they project the image of rain running down the front of the tower, the droplets curl around the raised bezels surrounding the clock faces, just as they would in real life.

My favourite parts are when the tower walls retract to show the inner workings of the clock and when the tower sways back and forth after being hit by a cannonball.

Outages

Apr. 4th, 2010 03:44 pm
deane: (Default)
Two weeks ago BC Hydro decided that the pole feeding our shack needed to be replaced. They warned us in advance that our power would be out for about 3 hours. It ended up being twice that.

During the process they also managed to knock out our phone and DSL line, meaning that even after the power came back on we were still without an internet connection. Given that phone lines share poles with power lines pretty much everywhere, I would have thought that this would be a sufficiently common occurrence that the Hydro workers would have a streamlined procedure for dealing with it. Instead, they seemed completely unprepared. A worker came to the shack, borrowed a phone book and started thumbing through it for the telephone repair number. He ended up calling the same number I would have, getting put on hold just like I would have, and was unable to get repair booking until the next day, just like I would have.

The phone people asked if we wanted a morning or afternoon booking. "Morning!" the paramour and I both shouted, already suffering from net withdrawal. That got us a promise that a repair truck would show up between Noon and 1400. Made me wonder what we would have gotten had we asked for an afternoon repair.

So we were without power and internet service for two days. This was particularly annoying as this was an unusually busy week for me at work and I had six online meetings scheduled during that period.

This week we've have stormy weather with high winds. That almost always means power outages and, sure enough, just after crawling into bed Thursday night the power went out. I climbed back out of bed and shut down all of our systems before they drained their UPSes. When I got up Friday morning the power had come back on so I started to bring the systems back up. I was in the middle of bringing up the last one when the power went out again. So down they went once more.

A few hours later the power came up again and I was able to get all of the computers up and running without incident. Then on Saturday the power went out again for about an hour. We always get a couple of outages during the windy season (late fall through early spring), but this is the worst that I can remember since moving here over a decade ago.

The bright light throughout all of these service interruptions was my cell phone. Thanks to it I was able to attend all of my meetings, even when our land-line was out. I wasn't able to see any of the visuals, such as slides and demos, but that was really a problem in only one meeting. These days I get the bulk of my home entertainment through the internet and there, too, the cell phone was able to step in, providing me with games to play and web browsing. If the battery got too low, I could always plug the charger into the truck's cigarette lighter.

UPDATE: Shortly after making this post, the power went out again, came back on five minutes later, then went down again a few minutes after that and stayed down for several hours. Apparently a couple of local transformers had caught fire.
deane: (Default)
I don't mind doing laundry. The only part I really dislike is folding everything up after it's dry. Fortunately for me, scientists are hard at work on that problem with a robot which folds towels. Be sure to watch the video.

Chernobyl

Nov. 27th, 2009 11:51 pm
deane: (Default)
It's always been a given with me, and in most popular accounts that I've read about the Chernobyl disaster, that the accident was a result of poor design and lack of maintenance. But apparently those were only contributing factors. The main problem was that they were trying to do a scientific experiment on a reactor which was designed for commercial energy production. In order to perform the experiment they had to disable safety features which would have prevented the explosion.

A better design would have reduced the impact on the surrounding people and environment, but most designs1 become vulnerable if their safety measures are disabled.


1As far as I know, there's is no way for a CANDU reactor to go critical or explode because of its use of water as a moderator. About the worst that can happen is for the operators to scoop up bits of the core and throw it at people.

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