Thursday, 14 July 2016

Super Cheap Digital Read Out (DRO)

So, a DRO for machine tools (lathes, milling machines etc) is a digital read out that tells you the position of or how far a given axis has travelled. Obviously this useful if you want to make a part or a cut into a component to an accurate size, the trouble is... they can be very expensive! Even a hobby level DRO setup for say a milling machine can run to hundreds of pounds.  One common workaround (apart from using the engraved hand wheels) is to use a Dial Indicator set up to indicate how far a given axis has moved and indeed I've used that technique a lot. (it's a nice technique as it automatically cancels any error due to backlash as it isn't linked to the lead screw and always tells you the exact position of the axis). Still dial indicators and requisite holders/clamps can cost a few quid and can be awkward to get into a good position etc... so when I saw this hack to convert a tyre tread gauge into a micro DRO... I knew it was for me..

So these digital tyre tread indicators are super cheap... I paid £3.99 for one and could have spent less if I was prepared to wait for one to be delivered from the far east. They are essentially a short travel version of the cheap digital callipers that are widely available ( and indeed have the output slot that people have exploited to create data logging calliper )..  So the modification consists of a couple of different things... firstly you need to reduce the drag on the calliper slider which is created by a small steel slip inside the device.. this is for when you measure a tyre tread you can position the indicator then remove it from the tyre to read the result and the slight friction on the slider keeps it in position. For the DRO hack we need it to be as free to move as possible. Once this is removed I turned a small collar for the end of the probe from some Delrin which was drilled to fit the probe end snugly and the other end drilled to house a cheap but powerful 3mm diameter neodymium magnet

For the next part I whipped up a quick drawing to be able to CNC rout a plate for the base that would house the larger magnets. I made the toolpaths tight to the 8mm diameter of the magnet so that they were an interference fit and required pressing in on my small arbour press (also for added security I put a blob of superglue under each magnet). I then glued the magnet base to the base of the unit and hey presto... a portable quick fit DRO!

It works great, I am really pleased with it and will probably for the price make a couple more.. Its also great that the 8mm magnets are enough to hold the device firmly even if only 2 magnets are attached to whatever it's clipped too. The zero function of the device means that even though it only has a small throw (27mm) it is easy to sequentially move the DRO and zero and keep a running count of position over a longer length. 

Saturday, 9 July 2016

Another quick make, Ball and socket joints!

In amongst a busy week I managed to fit a little make in! I was inspired to make these by my twitter buddy Rob Ives ... for the uninitiated Rob is a master maker and what he can't engineer out of paper doesn't leave much! Check out his website for some great stuff and projects to download.. 

So anyway.. these ball and socket joints are made from some cheap 12mm nylon beads I got on ebay which I drilled and tapped (awkwardly... the nylon tends to melt when drilling making it tricky) to take some M4 bar.. The wooden sockets are cut on my CNC with the holes for the beads being 9mm diameter. A bit of tension on the bolts and the result is a grippy yet positionable joint. I then turned up a small 8mm lug and tapped it to M4 as well and attached a crocodile clip (with a blob of epoxy) to the other end. Hey presto... another accessory for my ever growing accessory station! 

Tuesday, 5 July 2016

Quick make... baseplate for accessory stand

Stalwart readers of this blog (a very elite club!) may know that I have an ongoing project that started off as some Dial Gauge accessories which then expanded to include a tapping stand and indeed on my last post about making the PocketQube chassis I posted a photo of me using it to tap some small holes. It worked great but made me wish that instead of just a big lump of (recycled in my foundry) aluminium as a base I had something that I could put my precision vice on. So to the scrap pile! Within my hoard I had a base off an old black and decker drill press stand (the type you insert a hand power drill into a collar). Despite being a pretty poor casting that has a few marks from some abusive drilling with a few file strokes the base sat level on a level surface and cleaned up well. A lick of grey enamel paint smartened it up a bit as well.

To attach my DTI/tapping stuff I turned a bit of mild steel to the diameter of the old drill column and then drilled and tapped an M6 hole into it. Into this I inserted a short piece of M6 threaded rod with a bit of thread locker to keep it in. It's worked really well. Next on the list is I need to mill some flats onto the piece that screws onto this base and has the clamp slits that hold the uprights and make a spanner so I can nip it up a bit more. 
The obligatory before pic!

Sunday, 26 June 2016

Liverpool Makefest 2016

So just a quick small picture dump after a great day volunteer Crewing at Liverpool MakeFest.. a great event in a great venue,  Liverpool Central Library,  with a good vibe and lots and lots of people! Perfect...

This pic is about 15mins after opening.. filling up nicely.. got lots more packed than this!

Nice crew badges (gagAAARGGH blogger still doesn't rotate images!)

Ragworm posse showing their wares..

Nice little activity showing where people were from... (a few more N Waleian tags appeared by the end of the day)

I bought some of these! AR pictures with a free AR game app.. the kids loved em! By the wonderful Midnight Polygon

Can't escape Darth...

 These guys are GREAT, they call themselves "we like to make stuff" and I've met them a few times now first time at Makers at MEX they have enthusiasm and humour and make anyone approaching their stall welcome .... proper makers. Spot on.

Friday, 10 June 2016

EMPQ Pocketqube engineering model

I've been working hard on an engineering model for Paul Kocyla for our EMdrive pocketqube project. It's been a good learning curve with lots of realisations for the next iteration! It has no skeletonising as we want it to be as rad hard and as RF dampened as possible. 

Underside showing the cutaways, currently the bolts are oversize and stacked with washers as I didn't quite have the correct size and the PQ baseplate will be mounted using the same holes.

Just a few in production photos.. marking out above and the blanks for the internal brackets

Lots of tapping of the M2 holes on the 6mm internal brackets, my home made tapping stand has earn't its keep! Likewise the little precision vice which is an excellent purchase.

Milling the 2mm wall square tube to size on my trusty Sieg sx2 plus. 

So.. off it goes in the post tomorrow to Germany. :)

Tuesday, 17 May 2016

Palm Sounds is 10

So for as long as I have been writing this blog and longer I have ALWAYS (everyday) 100% had something on my person that allows me to play with creating music... and I put most of this down to the mightiest blog Palmsounds who celebrate being 10 this month. Above is my phone with the AMAZING Sunvox application on it (a complete studio tracker application built by Alex Zolotov which he maintains across the most diverse range of hardware and os's.. maemo/amiga/palmos/wince/ios/android/rpi etc)

I have always been fascinated with mobile tech and my first real love was PDA's particularly the palm range (although I didn't come in at palm III I came in more around zire/t3 era) and this was fueled by the discovery of Bhajis Loops and Microbe... which.. yep you've guessed it all stems from Palmsounds... As does my gameboy collection, my collection of portable hardware multitrackers, my chiptune carts..currently rocking "chord" by Humbletune (a developer I know though Palmsounds!), my field recording kit.. my PDA collection.. which is large.. but pales in comparison to the Palmsounds PDA stockpile! :)

Palmsounds has constantly and consistently been both at the cutting edge of mobile audio, promoting new apps and developers and systems but also has kept an eye on all the wonderful fringes of the scene, if someone has hacked an old calculator to play music you can bet Palmsounds will cover it!

So many developers and apps and hardware have had a push (or indeed have originated from Palmsounds idea's/community) and Palmsounds continues to support and push the boundaries of the industry and the market. I know of many companies whose success would be much lower if they didn't have Palmsounds to push their ideas/products out and guide them with a bit of sage wisdom from time to time.

Finally.. am privileged to have the owner of Palmsounds as a great friend (and colleague) in real life now and also have a list of brilliant people I have met in real life through palms sounds...

Here is to the next 10 years...keep being brilliant Palmsounds ( I imagine Bhajis will run in emulation in my retinal implant by then... cool)

Wednesday, 27 April 2016

Covent Garden Raspberry Pi Jam

So on my recent trip to London it was my privilege to drop in on the Covent Garden rpi jam at Dragon Hall. I was so impressed by the setup here with loads of really great motivated mentors and some cool workshop activities on tap. The proof of any tech community or group is in its outputs.. I met some amazing young people here (really young) who were already running workshops in many areas such as robotics and Python and sonic Pi etc... Stunning... Mind you I knew it was going to be cool when I walked in and spotted this DIY astro pi before I even got into the main room!

cool robots being built!

 Sneaky coder dojo sticker :)

 Lovely accessible soldering workshop took place
Raspberry pi zero cluster supercomputer anyone? :)