@madpilot rants

Converting a Makibox – Designing the Y-Axis

I’ve been iterating the Y-axis in Fusion 360. A common design I have seen on other moving-bed designs is four linear bearings – one bearing at each corner of the bed. The problem with this design is you lose the distance between the bearings in travel. Since I have only have a maximum of 165mm on this axis, I didn’t want to lose too much to dead play.

Example of a moving bed with 4 bearings

Round 1 – Two Bearings

My first thought was use a single bearing on each side, introducing a minimum lost travel of 12mm (the width of the bearing). This looked like it would cause rotation problems, though – especially when dive cutting in the outer edges of the build area.​​​

Drilling on one side of the axis, causes excessive rotational forces at the bearing

Round 2 – Four Bearings

I went back and looked the parts I could salvage from the Makibox, and it turns out I have four 170mm linear rods at my disposal. This means I can create a passenger carriage – one that isn’t driven by the lead screw, but instead is pushed along it’s rails by the bed itself. This design gives four points of contact, eliminating the radial moment of the two bearing design (Note: this doesn’t deal with linear rod or bed flex, just the rotation issue). The disadvantage is the base is now double the size, but as the bed would have moved outside of the frame envelope during operations, it’s not that big of a deal.

Here is a render of the Y-axis. If you imagine a bed on top of it, attached to the two carriages – the left (driver) carriage is driven by the lead screw, while the right (passenger carriage is pushed by the bed. (I tried making a video, but the Fusion 360 animation workspace doesn’t support animating joints!)

Dual Y Axis Render

The Y-axis will have a 131mm travel – the loss is 7mm from the ball bearing, 7mm from the coupler and 20mm from the anti-backlash nut.

Issues

There are still a couple of side issues I still need to work out:

  1. ​The mount holes for the anti backlash nut are too close to the shaft, so I can’t heat fit brass inserts to screw in to – I may have to thread the plastic. I may be able to find some small nuts to secure it. Ideally once the mill is working I’ll be able to machine a bracket from a small plate of aluminium
  2. I have brass inserts in the carriages because I initially thought I would screw the bed down from the top – making replacement of the spoil board easier. This may not be an actual problem though – I’m not sure how often the spoil board needs changing. I may just make them screw holes, and be done with it. I have to think about it a bit more.

Next up: the X-axis

Tell your non-tech friends and family: Don’t use LinkedIn Intro

If you have friends or family that are using LinkedIn (And there are a lot of them – I’ve got family members that don’t use Facebook, that do have LinkedIn accounts), please take the time to inform them about the importance of password security.

Knowing that many of their users aren’t particularly technical, they have added a number of dubious (I’d say dangerous) techniques to bolster users connections (and by effect their userbase). Of these techniques, there are two which ask users to enter their email username and password so they can access the user’s email inbox directly. This is a bad idea. Please send this post (or wholesale copy it and email it to them – I’m putting this post under Creative Commons, so copy away) to your less technical friends and family, and offer to help them fix up the mess if they have already given up their username and password.

Giving third party applications like LinkedIn your password is a bad idea.

Dear friends and family,

When you signed up for LinkedIn, they may have asked you for your email login and password, allowing them to search your contacts to create connections. By giving LinkedIn your email login and password, you have given them complete access to your email. This means they can read ALL of your email, and theoretically send email on your behalf.

You might have seen a screen like the one below:

Screen Shot 2013-10-24 at 10.55.47 AM

This is one of the services you should avoid. Even though it says that they don’t store the password, or send email on your behalf, you shouldn’t trust external services with your login and password. Ever.

LinkedIn has also announced LinkedIn Intro. This service DOES store your username and password – and it has to it in such a way that it can easily be read. This service PRETENDS to be your email server, so your email program downloads your mail from LinkedIn rather than your real server. It does this by PRETENDING to be you and logging in to your email server, downloads and changes your email to display their header. This is why they will need your username and password.

So, if you get an invite to use LinkedIn Intro, please ignore it.

What can you do if you have already signed up for these services? The easiest thing to do is to changer your email password. If you don’t know how to do it, get in contact with a trusted friend or family member that can help you out.

Please remember: Anyone that has your email username and password, can read and send email on your behalf, so don’t give it to anyone that asks for it.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 Unported License.

So… It’s been a while.

Yeah, so I’ve decided to start blogging again.

While twitter is good for short bursts of vitriol, I’m missing the longer form of the game, and I think it is time to get back to it.

So what have I been up to for the past year-and-a-half? Besides my consulting and freelancing work, Adrianne and I started (and have almost wrapped up) Horse & Cart; Me and some other guys built a landing page for a product over a weekend (and got a shit-ton of sign ups); I started working on 88 Miles again, with the intention of doing 2 hours a day on it, which I was doing really well until I bought and subsequently had to move into a house. That stuff is a serious time sink. Who knew. (It’s ok, though – I’m back on 88 Miles again. New version due on 15 September!)

Any way, I managed to find a couple of hours to throw some paint around here, upgrade WordPress (which I’m glad to see still looks like it was coded by moneys throwing faeces at a keyboard – I don’t know why I do this to myself) and get this site uploaded to a new server. Oh – don’t bother reporting problems with this site on IE < 9 – I don’t care.

My intention is to continue blogging about tech, code and business stuff, just like before. And of course, you can still find my pithy rants on my twitter account.

Speak soon,

Myles.

…and we still don’t have day-light saving

Abusing JavaScript for fun and profit: Redux

The fine lads at Sitepoint have just just notified me that part I of my article outlining my JavaScript Mario Brothers game is up on the front page. This part goes through the JavaScript and CSS techniques I used – it’s a bit theoretical, but if you are a frontend developer and want to get a better understanding of how to use JavaScript classes, go and check it out.

The next part will get into some game

theory (not that I’m really an authority on that) but it really was a fun experiment.

One lost laptop: Returned

Yesterday, whilst being distracted by a phone call as I got in to me car, I did what we all dread doing – I left my EeePC on the top of my car as I drove away. I noticed that something was a miss a few streets away from me house, and promptly (after having that sinking feeling) re-traced my tracks to see if I could see it. But I couldn’t. After all of the stages of grief: Denial (Surely, I couldn’t be so stupid), Anger (Godammit!), Bargining (Maybe if I drive around again…), Depression (Why me!!!) and Acceptance (Well, maybe I can justify that 9″ version now) I got a phone call from Justin Gill at Perth college. One of the students there had founded on the side of the road and handed it in.

I for one am glad that there is still some honesty in this world. So to Justin, and the still anonymous student – thank you so much! You have made this geek very happy.

Wordle Meme – Crazy text clouds

To draw you all away from the fact that I’ve been lax in posting this month, here is some graphical distractions. The Wordle meme is simple: Cut and paste the copy from you blog or website, go to Wordle and it generates a crazy text cloud. Don’t let the Java Applet get you down to much. Mine is here:

MadPilot’s new(ish) phone number

Now that I’ve relocated back into my home office, I’ve decided to revert back to my old VoIP number: +61-8-6424-8234.

Although Skype was doing a perfectly good job at taking and making phone calls, the NetGear SPH101 Skype phone wasn’t really up to the task (the battery life isn’t that great and the call quality can leave a little to be desired) and I’ve got a perfectly good VoIP phone sitting here, which has much better voice clarity. (Oh, it it means my business cards will be correct now too!)

I’ll redirect my Skype number to the “new” number in the interim to give you all a bit of time to update your records. I’ll still leave the Skype phone around to Skype-to-Skype (handle: madpilotproductions if your interested) calls too I think.

See me speak at Web Directions South ‘08!

I got asked to talk at Web Directions South 08 a couple of months ago, but it was one of those “I won’t believe it until I see it in HTML” kind of moments. Well, John and Maxine just announced the speaker list for this year, and guess what – I’m on it!

I’ll be speaking about web service APIs, OpenID and OAuth in a presentation imaginately entitled “Web APIs, Oauth and OpenID: A developer’s guide”.

Online web applications are big business, with many people relying on the cloud for data storage and workflow. These days, an API is an essential part of any online system, but this presents authentication and authorisation issues for the humble web developer. Learn how to create Web APIs, how OpenID and Oauth works and what you need to do to implement them.

I am REALLY excited by this. The line up this year is huge and it is a great privilege to be speaking on the same bill with people like Derek Featherstone and Jeffery Veen as well as some of the fantastic local talent, including fellow sandgroper – Kay Smoljak.

This years conference adds another stream (total 3: Design, development and business), has 10 international speakers and some a good number of local up-and-comers,who get their first chance to speak at an international conference (Yours truly included).

Web directions is always heaps of fun – this will be my third one. Not only do you get to hear really smart people talk about really cool stuff, you then get the chance to hang out with said really cool people and chat with them.

So, if you are thinking of going, let me sweeten the deal a little. If you use the discount code: WDS08-ME when you sign up, you’ll get $50 off the price of your ticket! It should be three types of awesome, so hurry up and ticket yourself up.

When: 23-26 September 2008

Where: Sydney Convention and Exhibition Centre, Darling Harbour, Sydney

Bash history – a geek meme

I was browsing through some ruby blogs and came across this crazy memeshell command history distributions.

By running the following command in bash (zsh needs a -n 1000 after history apparently)

history|awk '{a[$2]++} END{for(i in a){printf "%5d\t%s \n",a[i],i}}'|sort -rn|head

and you’ll get the top ten most used shell commands. Mine are:

259 ENV=test
45 cd
36 vi
36 ls
34 svn
18 script/spec
12 rake
9 fg
8 cap
7 script/generate

I’ve obviously been doing a lot of testing on a project I’m working on (Alas, it’s PHP). Most of the other calls are pretty rails centric though :)

I wouldn’t mind seeing what the rest of the Perth Ruby developer’s histories look like :)

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