Sunday, 2 September 2018

ODR Rocket deployment groundtests

Got a bit of time this afternoon to do some ground tests of the deployment system of the ODR opensource rocket. Its my first dual deploy rocket so I'm learning lots as I go. One thing I definitely discovered is its quite tight in the upper section where I plan to fly the main chute...I was using some quite thick webbing as the recovery bridle which I might replace with some thinner kevlar to try and reduce the volume of stuff I need to cram in there... failing that I could always reverse the roles of the sections and fly the main chute in the lower section of the airframe. For more details of the ODR opensource rocket check out this post.

Monday, 13 August 2018

Making Drogue and Main parachutes... aka SEWING IS HARD!

I'm trying to get the ODR rocket build finished and am finalising the electronics bay for dual deployment where it will blow a charge and release a tiny drogue parachute at apogee and then deploy another charge to push out the main chute at a predetermined altitude on the way down.

I wanted to use a crossform parachute after all the work I put in working through the maths of them (paper and calculator spreadsheet here) and as ever I wanted to make them myself...although 5 hours in on the sewing machine I began to question why!

For my Panta Rhei flight I used a reasonably heavy ripstop nylon and I cut it with a soldering iron which gave an excellent edge that required no hemming, however this wasn't suitable for the job for the ODR rocket. I needed to consider packed sizes of the chutes as ODR is a slim rocket with not masses of room in either section for the recovery system. As such I wanted to use some very lightweight ripstop nylon I have as it would pack much smaller, however I also needed it to be strong as with dual deployment the main chute is deployed when the broken air-frame is falling at some speed. I designed the drogue to bring the falling air-frame down at about 20 meters per second as I had seen similar fall rates on online that others had used. The main is designed to further drop the descent rate to around 5 meters per second which is quite a large change in velocity so it needs to be pretty strong.

I decided that I would cut the nylon traditionally and then stitch a double hem to add strength to all the edges. I first used baking paper to cut an over size pattern and then cut the rectangle sections and pinned the hems. This was essentially the same process for the tiny drogue and for the main. I made 2 rectangles and then pinned and stitched them together to form the cross. The sewing machine I borrowed of my daughter is an excellent albeit small machine and it didn't have the clout to stitch through the 2mm nylon cord I was using for shroud lines so they are hand stitched onto the drogue. For the main chute I wanted to reinforce the area that the shroud lines attached to on the chute and attached some small squares of ripstop into each corner, this took ages to do as I hemmed the squares first and then attached them but it should hopefully increase the chances of the chute surviving deployment!

If I had access to a more capable machine and also had more room in the air-frame and could overbuild the chutes slightly I would definitely consider making the lines continue all the way through the chute to make a very strong version.

I've not quite finished yet and have to fit the shroud lines to the main but I've finished the shroud lines on the drogue chute and am pleased with the way I have worked out to terminate the attachment end. I first measure out the desired length (1.6 times the length of the rectangle side from the calculations which equalled 56cm) and then stitched the lines together. I then individually stitched a matching length loop into the end of each of the 8 shrouds and then I stitched the 8 shrouds together and finally with the aid of a bit of stitching and a few drops of superglue I wrapped all the shroud ends in some thick polyester thread. Very pleased and I will use the same technique with the shrouds on the main.

Finally .. whilst I had my daughters small sewing machine set up I stitched some small Nomex fireproof blankets to protect the parachutes from the deployment charges. I definitely rushed these through and they are rough but functional!..

So there we go, learnt loads and got to grips with the small sewing machine... I could definitely do with continuing a bit of sewing to increase my skill at it!

Tuesday, 24 July 2018

Screwdrivers, Allen keys and nut spinners.....My current kit

So even for me this is a geeky post! I wanted to share this current collection of tools which I am very pleased with and its covering most of my maker needs for screwdrivers, nuts and bolt driving and more. I have stacked of other larger drivers and kit but this seems at the moment to really hit the spot and cover a lot of bases in my day to day making of electronics and rockets and also maintaining my 3d printers and CNC's. So above from right to left is my Wera Tool Check Plus, my Xiaomi/Wiha 24 in 1 driver kit, my Sealey STM103 torque screwdriver and then a 1/4" to 4mm adaptor and finally a set of 4mm sockets rangeing from 2.5mm to 5.5mm. The Wera Tool Check Plus is a pricey but glorious bit of kit, the mini zyklop wrench included is a joy to use with its tiny degree ratchet and small size making it great for reaching and working inside tight assemblies. There are loads of reviews about the Wera Tool Check online so check em out!

The Xiaomi/Wiha 24 in 1 kit is a little gem... Wiha are a great German tool brand and apparently they loved what xiaomi were doing and partnered with them to make this set. Its definitely aimed at small electronics and phone assembly/dissasembly (makes sense in terms of the Xiaomi connection) but contains a range of mini torx, as well as allen, posidrive and other 4mm tools. Its available on lots of chinese retailers like banggood and fasttech etc and it is definitely worth the (not masses) of money. The driver handle has a spinning head to allow one handed use and is smooth and comfortable and oozes quality. The magnetic tray and the metal box all work flawlessly and make you (well me) want to keep it all in order! (rare for me!)

So the Sealey stm103 is a torque screwdriver that works by sensing the amount of torque you place on it.. it reads out the torque on the display, it has numerous modes and can read peak torque or, as I find more useful, you can define a desired torque and when the sensor detects you have reached it it will both bleep, buzz and also an LED lights. Its amazing that this can be bought for less than £35 and comes with a certificate of inspection and calibration etc. Very handy indeed. Finally the 1/4" to 4mm adaptor has been a great find and expands the repertoire of both the Tool Check and the Xiaomi/Wiha kit. Over the years I've had a few variable cheap multi driver 4mm kits and therefore have accumulated a few spares in that format.. including the small set of quite cheap and cheerful sockets... however at that scale and for low torque they continue to serve well.

So there we go... geeky post, but all this lives together most of the time as a little kit and I find it invaluable!

Friday, 20 July 2018

USB soldering iron hack

Been a big fan of these cheap and cheerful USB soldering irons since discovering them via @biglesp ... There's a couple of things with them, the first one is the well known fact that it's best to run them off a USB battery pack as otherwise they present a bit of current at the tip. This leads to the second thing that bugged me and I fixed! So the iron is designed to only heat the tip when the user has it in their hand..  it achieves this with a touch switch and also a motion detection system. The trouble is is that my USB power bank auto switches the power on and off when it detects a draw at the socket. This meant that I could plug the iron in and use it but if I put the iron on the stand and it timed out it would turn off but also wouldn't wake the USB supply when I retouched/moved the iron meaning I would have to pull the USB cable out and reinsert. So... I have modified it to be permanently on. The instructions are pretty straightforward..  remove the yellow wire to the touch switch that you can see in the top picture and then also remove the silver tube component (a small tube with a soft spring inside which acts as the movement detection switch). Finally you then need to bridge the 2 pads to close where the silver tube switch would have been (see picture below). Now your USB iron is always on!

Sunday, 8 July 2018

Open Boat Tail rocket... Maiden flight!

OBT_maiden_7July18 from concretedog on Vimeo.

Ardent readers of this blog (all 6 of you!!) will recall a while back I designed and built a small rocket with a boat tail and I finally got chance to fly it at a family and friends BBQ last night. It flew really well on a classic Estes B6-4 motor. It was a really still evening but (even though I flew a pretty tiny parachute) it still managed to end up drifting the wrong way and landing in a thicket in a bog! After much rummaging however the rocket was recovered successfully!

I'd designed it with around 5 grams of mass in the payload section and as it was a maiden flight I didn't fancy sticking a pricey altimeter in it so a willing volunteer was found in one of my European Space Agency lego minifigs!

If you fancy building or improving on my design, it's all opensource and available here. 

Thanks to Rob for shooting this video on his phone!

Friday, 6 July 2018

ODR, Open Development Rocket. Now Opensource!

So here it is! Some of you who follow me on twitter may have seen me talking about this rocket build but this is the official release of the project. A while back I released the OBT small rocket design and this is the next opensource rocket ODR. ODR is either pronounced "owther" and is the mystical Norse force or could be O.D.R standing for Open Development Rocket! 

ODR started as a project for my needs, having passed my L1 high power certification I wanted to build an airframe that could fly well on L1 power but could also serve as a learning and testing platform. Therefore ODR has been designed with a large electronics/avionics bay and can be configured for single or for dual deploy recovery systems. Its simulated in OpenRocket and can fly on G-I 38mm reloads and as soon as I actually fly it I will update the project. 

There are numerous sections I need to finish and some parts that need much better documentation but I have done some docs and have supplied all the files on Gitlab. The main tubes are phenolic tubes purchased in the UK from the excellent (I have no link with them other than am a customer) Blackcat Rocketry. All the other components are designed in opensource free software and the files are included. It has used CNC routing and a 3d printer but equally could be done with a printer and a laser cutter. So find your local makerspace/fablab etc. 

So get in touch via Gitlab and or twitter @concreted0g if you have questions and I'll try my best to help. And yeah... that's a librespace foundation sticker... lets claim space.. the libre way. 

Tuesday, 12 June 2018

A Visit to Hack Oldham!

It's ages since I did a "I visited a cool hack/maker space" post so very pleased to say I got to go visit the fantastic Hack Oldham as part of my work with Indycube last week. A great visit where we swapped stories from the trenches of co-working, community development and making! Its a fantastic multifaceted space with lots of room and some stunning kit. Massive thanks to the mighty Andy ( @p0welly ) and Lisa ( @StudioG_Oldham ) and Keiran ( @Keiranwdigital ) for showing me round and taking time to talk! If you are around Oldham and need somewhere to work or make or both... get in there!

So above is the main space on the ground floor, bright and cheerful and really useful and reconfigurable. A great place to co-work and a decent sized event space. 

The geek bar and behind it storage for regular users of the space.

Still on the ground floor here is the permanent full time residents area 

That's a fab prize!

So.. moving into the labyrinth of basement rooms where the fab kit lurks its good to see good old rule zero in effect!

 Into one of the maker spaces, some fine woodwork tools to be seen. They had a great system where they had all tools on mounting boards with a uniform bolt spacing so that the tools could be reconfigured/moved and yet alow people to follow health and safety requirements for a minimum distance between tools. A great solution.

 LOVELY old Myford in good order. They had recently converted it to single phase... Great to see machining tools get some space in maker spaces.

 The electronics lab bench area with a good range of kit available and also a fab honesty box system for commonly used components below.

 Lasers and vinyl cutters.. classic tools for maker/hackspaces!

More bits and bobs... 

 I think they knew about my vice addiction! Great set of record vices here!
So there we go.. a fantastic visit, hopefully I'll get to work with them in the future and get to go back and pester them again.. better not upset them though... they have Daleks!

Monday, 4 June 2018

OBT, Opensource Boat Tail Rocket project


Over the last week I've designed, simulated and then scratch built this little rocket with a boat tail. The boat tail is the small section below the fins which tapers to the minimum diameter of the motor mount. I wanted to learn about boat tails and make one as they are useful for a couple of reasons. There primary function is to smooth out the airflow and they create a lot less turbulence than a typical square ended rocket (there's a great PDF on boat tails here). The second reason being that boat tails are often used when coupling a smaller rocket to a larger booster for example in boosted dart type projects or other multistage designs. This OBT (Open Boat Tail) rocket has a decent payload section and should be a useful addition to my rocket collection as I need to do some flying of the new nanoalt altimeter from the flame trench with other commercial altimeters to see how it compares.

The OBT is made with some 3d printed components and I have CNC routed the fins out of 2mm balsa but that could easily be achieved with a craft knife! It uses classic estes tubing BT50 for the body and BT20 for the motor mount tube. All the supporting software I have used is opensource as indeed this design is so feel free to check out the repository. If you make one I would love to see it!

All measurements can be got by opening the openrocket file (.ork) and you can see the general placement of the parts..its a crude simulation really and could be dialled in a little more. Its worth noting the 3d printed parts are over ridden in the simulation with their actual mass and depending on your approach your components weight may differ. There is a pdf of rough instructions on the repository with some pictures (repeated here) that show the general assembly. All the STL files for the parts (centring ring, boat tail, nosecone etc) are provided, but they are scaled and tweaked for my printer and the shrinkage of my current PLA filament.. so they may need tweaking.  I've generated these models in OpenSCAD and therefore if you download OpenSCAD (again free and opensource) you can tweak the dimensions to suit your printer. (hit me up if you need help on how to do that).

So here it is... all the files are on this repo

Tuesday, 22 May 2018

New DIY Rocket Fin Jig

 So wanted to make a more accurate and adaptable system for ensuring rocket fins go onto builds accurately and I've (after a few iterations) come up with this design. It uses some established ideas floating around the rocketry community that pertain to guillotine style jigs but I've made mine to be a little different in that it is baseless and doesn't need to be placed on a board. Also the lower support for the rocket body tube is adjustable to hold a range of diameters. As such this jig can accommodate a range from the smallest Estes bt5 tube at 13mm diameter to a maximum of 80mm. Hopefully the rest of this post explains a little bit about how I made it, why and how it is used.

The three plywood plates I designed in Inkscape and cut on my CNC router. The reason I went for a threaded bar design instead of a base is that the central plate can be moved within the rails and can therefore be used for very short rocket air frames or can be made to hold the body tube securely whilst avoiding a body tube anomaly such as a camera housing etc. Using threaded bars also gave me maximum adjust-ability and meant that I could assemble the jig with utmost care for parallelism and making everything square.

 Looking underneath the fin holding aluminium rails the CNC'd wooden sections have the inverted V to receive a body tube. The point of the V aligns with 2 smaller V sections (seen at the top of this picture just beneath the aluminium angle rails.) this means a fin inserted into the small V is aligned with the centre of the body tube. You can also see in the above picture that there are some small holes and a shock cord passed through with some salvaged toggles to put a bit of tension on it. This shock cord can also be moved to a higher set of holes to support the range of body tubes.
 So here is a larger body tube (around 56mm OD) being held in the jig
 And above is a picture using the shorter setting and holding a smaller 24mm tube.

Above is a shot showing the adjustable rails that can slide left to right and then be tightened into position. The position is accurately set by inserting a fin into the V section to centre it and also placing a spare fin or a spare piece of fin material at the far end of the jig into a matching central V slot. Then the jig rails can be tightened and after an alignment check the fin glued. Then the tube can be rotated and realigned without resetting the jig to attach the next fin. The fin setup can be seen below with a fin and some fin stock at each end of the adjustable rails.

So there we go... hope it makes sense and feel free to ask any questions in the comments!

Monday, 7 May 2018

Imp... my UK Rocket Altitude record!

 So.. Had a fab weekend. I travelled down to the mighty BigEARS rocketry event (another post on that later) and whilst I was there I finally got to launch my imp scratch built rocket and set a new UK rocketry altitude record in the A impulse class! The previous record was from 2013 and set at 143 metres and I am very happy to report and show that imp achieved 214 metres!

So above is imp just prior to launch, I managed to nearly half the mass of this rocket  compared to the previous record holders airframe. Imp weighed just under 18grams and this was achieved through some saving of weight due to the altimeter but also through my 3d printed transition and nosecone. I printed both these objects as a single filament line wall 0.4mm wide with no infill, I then sanded the outer surfaces smooth further reducing the wall thickness... the nosecone weighed less than half a gram!

As you can see I went for a standard rail deployment with a short standoff rail lug and there are certainly gains to be made if I did another attempt using piston ejection launch methods. I sanded down the estes tubing to reduce weight and also did a small bit of an attempt to aerofoil the thin balsa fins.. I now have some thin 0.8mm g10 fibreglass sheet in stock and would probably go with that as a fin material if I had another attempt!

I fiddled about on the pad for far to long getting it to sit right and at the height on the rod I wanted. Then returned to the control box and got the countdown from the very experienced range safety officer (RSO) Rod Stevenson. It leapt of the pad and shot away... it wasn't actually the most straight or vertical flight so, again, some gains to be had there. It deployed its small silver mylar streamer well and came down ok. Took quite a while to find the tiny airframe but me and my brilliant teammate Seren Hinchliffe searched and recovered it with payload section and airframe intact. We walked back to the RSO area, nervously opened the payload section and retrieved the altimeter... which was happily blinking so I knew it had logged ok! (Incidentally I followed the Perfectflite guidance diligently on the vent hole advice which resulted in 4 holes at 90 degrees at 0.8mm each around the altimeter bay).

I gathered a legendary bunch of witnesses, Rod Stevenson, (EARS  RSO), Charles Simpson (UKRA Chair) and Andy Mell (UKRA council) and a few others and we counted the blinks on the altimeter indicator led numerous times making sure we all agreed and had seen it (and I video'd the LED!). It reported 703 feet which converted to a shade over 214 metres... :) Job done! Massive thanks to the above and particularly Charles for nudging me along that morning to fly and also massive thanks to my team mate.. Seren who took photo's, carried stuff and helped massively in the search part of the flight!

A happy, hot and been camping in a field scruffy record attempt team. x

Wednesday, 2 May 2018

Toolmaking - Stud Clamps

I love making little tools. I've been meaning to do this one for a while but I finally got round to it as I needed to do some work on an M4 threaded assembly. A few years ago I did an engineering operations qualification at night school and I had to make numerous different tools/jobs to finer and finer tolerances, one of the jobs was the larger stud clamp in this picture. Basically you cut and tap some hole for a range of threads (in the case of the larger one M6 to M12) and then cruelly are made to hand cut all the way through your work piece ( a test of nerve and skill on the course as it needed to conform to the specified tolerances!). The resulting object is very useful for a few different tasks... Primarily if you thread a bolt or threaded bar though a hole and then clamp it in a vice the cut section closes tightly around the threaded object and allows you to work on it/cut it etc with it held firmly and without any damage to the object. A secondary use is if you have a threaded stud stuck into something with little to grip onto to remove it (imagine a cylinder head stud for example) you can thread on the stud clamp and then clamp the cut end with a pair of mole grips and it creates a hug wrench to remove the stuck stud with.

So it tends to be that M6 is the larger end of stuff I work on and therefore I decided to make a smaller version for the sizes M2, M3, M4 and M5, I used a little piece of en1a and again did the cut with a hacksaw... which is on the limit of being too wide for the M2 section but just left enough thread to form a precise clamp! I also chucked some drill bit gauge holes into the piece for the drill sizes needed to drill a hole to tap for M2,3,4.

Its not to as high a standard as the larger one in many ways, but is functional and I do get a great sense of satisfaction out of making things like this... with a bit of care this tool should see reasonably regular use in my shop for the rest of my making days!

Friday, 27 April 2018

Linux on Linx1010b

So ages ago I needed a windows 10 box for some open university software for a module I was doing. I picked up this Linx1010b baytrail powered tablet with keyboard dock for not very much coin and it certainly did the job.  I like it as hardware and tbf it worked ok with windows 10 for the tasks I did on it... since the end of the module though I have not really used it and a big part of that is that I'm a linux dude at heart.

So I decided to have a crack at getting a linux distro on it. A quick search revealed that it was possible but a little complex as it requires a 64 bit distribution but uses a 32 bit uefi. However I also discovered a brilliant tool isorespin by Linuxium which respins any 64bit iso and makes it bootable on not just the linx1010 device but many bay trail or apollo based devices. Not going to give many instructions on the isorespin tool as the linuxium site has plenty!

I respan 3 different linux distributions Ubuntu, Lubuntu and Xubuntu, all booted on the linx 1010 and ran but with a few niggles on each. Ubuntu seemed a bit bloated and lubuntu and xubuntu seemed a bit quicker. Lubuntu and Xubuntu each had the issue that the screen on the linx1010b was rotated to portrait view, with lubuntu this was cured by downloading and installing ArandR which allowed screen rotation... but didn't persist on reboot. Another problem with Lubuntu was once the display was rotated the the axis on the touch screen were inverted and reversed, this was true in xubuntu also but again for xubuntu I found a persistant solution for this.

I also had problems with wifi on each of the distributions, I found that the adapted wifi driver included in the linixium respin tool worked.. but only partially.. wifi would connect during the installation and on first boot.. but if I made any change to my wifi connection or indeed tried to swap to a different network it would fail until I rebooted again. I haven't quite solved this but have a workaround in that I am using a usb ralink wifi dongle which works flawlessly and I had disabled the internal wifi on the linx1010b (details below)

So my process for Xubuntu to install and solve the few niggles is ...

  • Use the linuxium isorespin tool to respin xubuntu 16.04.4-desktop-amd64.iso using only the option in isorespin to include common options for baytrail devices 
  • Flash the resulting iso to a pen drive (I used etcher on my ubuntu box but you could use the dd commmand in a terminal)
  • Boot and install the xubuntu image onto the linx 1010b ... keyboard and trackpad work during install but the display is in portrait for the install so bend your neck!
  • After install find the monitor settings application and rotate the display to the right... aaaahhh and relax your neck! (note... when you boot the machine you will have to log in in portrait but it will rotate to landscape after login)
  • Now to fix the axis problems on the touch screen, hit cnt-alt-t to launch a terminal and then move to the following directory
cd /usr/share/X11/xorg.conf.d
Then edit the following file in nano..
sudo nano 10-evdev.conf

  • Then you need to add the following highlighted lines in the screenshot below to the file and save the changes.

sudo reboot 

And your touchscreen should now be working.

  • To disable the internal WiFi i used used ifconfig to work out which of the 2 WiFi devices was which and what they were named... I discovered that wlan0  was my internal misbehaving linx1010b WiFi card so I then disabled this via running the following in a terminal
cd /etc/network

sudo nano interfaces

and then add the following line to the file (replacing "wlan0"with your WiFi device name) and save

iface wlan0 inet manual 

save and exit nano and then restart the network manager services by the command

sudo service network-manager restart

You should then when you click on the WiFi applet only have the external WiFi card enabled by default.

Finally I found that the installed firefox browser wasn't to good and wouldn't run youtube clips very well, for a long time I have been a chromium fan and indeed it didn't dissapoint after install with everything streaming and audio working etc... I always forget that to install chromium it isn't just apt-get install chromium but is in fact

sudo apt-get install chromium browser

So there we go... I love it.. its a really nice super portable and has a great 9hr battery life and now lives up to its super hacky collection of stickers! I know that the mighty @biglesp is working on a similar project getting linux running on an apollo based teclast t7 so keep an eye on his blog for that!

Monday, 23 April 2018

Basic Income, Bereavement and Being Human

A great guy, Mike Scott, who works for Indycube once said “basic income allows us to be adults” meaning we can get the work done but build it around our responsibilities and day to day duties as adults, parents, carers, household runners etc. I’ve been thinking about this a lot due to a recent bereavement. Sadly, my lovely step dad, had a brief but brutal battle with cancer, a hospital journey of 9 weeks which led to him passing away, too young, but with dignity and peacefully.

His last day I took a days basic income allowance and made the journey up to Liverpool to spend some time with him, there was no booking of carers leave, no forms, no conflict, just me calmly moving my diary around and speaking to those I needed to. I spent hours with him and my mum, supporting, hand holding, crying and laughing… the saddest stuff yet a healthy way to be and we all had the opportunity to say the things we needed to say.

Halfway through the day I needed a break, emotionally drained I needed to do something. I knew that the fabulous DoEs Liverpool had just moved premises as I had visited the new place a few days before. I went over for a couple of hours before returning to the hospital later. At DoEs I had some hugs and then did a good stint with a scrubbing brush, removing the paint and dust and decades of grime from a few square metres of flooring. Therapy indeed and a good break, no finer act of solidarity for a great makerspace and co-working space that also (like indycube) recognises the co-working visa.

My stepfather passed away that evening. Thank you Basic Income for allowing me to be human that day.

Sunday, 1 April 2018

Very quick visit to the NEW DoEs Liverpool!

Was up in Liverpool today and some planets aligned and I managed to get a quick visit to the new DoEs liverpool building! Today was the day that all the kit from the old Gostins site was moved across so it was a brief nip round the unopened site to look at the space that was quickly filling with all the trappings of a maker and co-working space.

Here are a few pictures but the takeaway point are.. ITS BIG (much more room for lots of creative stuff and kit and co-working!) Its light.. Gorgeous big windows and lots of internal glass walls give it a really light and airy feel.... and its COOL.... there are lots of features of the original building left and it has some real character! Its a super, functional, accessible place and is going to be amazing.

It was utterly heartwarming to see the DoEs community in there working hard, full of laughter and team spirit... if you want to feel that warm glow also I can heartily
recommend chipping in on their fundraiser... >>>>>>> DONATE HERE!!!! <<<<<<<

Just one of the lovely rooms in the new building.

Loving the old cast iron (disconnected) remnants of the industrial 3 phase wiring. 

Fab old sign above the stairs!

Finally... as I walked off to where I was going next.. I noticed... its on Kempston St... I am hoping for some amazing retro joystick themed makes coming out fo the new place!!