Wednesday, 21 December 2016

OpenRocket 3d print design tip!

So I'm working up some ideas for a high power rocket and aiming to go for my level 1 UKRA certification at some point next year. I'm planning to scratchbuild as much as possible which means it can be tricky to know the exact weights of items you are designing into the rocket.. such as the nosecone which I plan to 3d print.

 I can get a really accurate estimate of what a component is going to weigh by modelling the piece in CAD (I have some code I use in Openscad that generates nosecone geometries based on parameters I feed in) and exporting a .stl file as if I am going to print it.

I then load the stl into the slicer I would use to generate the gcode for my 3d printer "Cura". Rather wonderfully having selected the infill and the material, Cura will give me a weight value of the finished item. I can then jump back into OpenRocket and overide the mass of the component which is then incorporated into the design and adjusts the centre of gravity accordingly. Neat!

Thursday, 8 December 2016

Maker sustainability (or future risks to us doing cool stuff)

A few years ago I was asked to run a stall at a maker event attached to a model engineering exhibition in London. It was a fascinating experience as it linked 2 communities, the live steam/machining/model engineers and the 3dprinting/laser cutting/satellite amateurs etc. It proved to me how much value there is in bringing together these communities and how much we have to offer each other.

There are lots of themes that regularly get discussed around  how much knowledge transfer there is between different groups and its good to see some intergenerational projects going on. I wanted to focus on 3 different communities I have interacted with or am part of, the rocketry community, model engineering (as mentioned) and also amateur/HAM radio  I am saddened when I hear of older members of these groups passing away or indeed the membership of local societies becoming so low they close down. I do indeed mourn the loss of skills and knowledge but I am becoming increasingly aware that we (the maker community) are at risk of losing other stuff, namely structures and accreditation that enable us to do cool stuff.

So.. to provide an example for each group starting with my current favourite subject.. Rockets.

 I want to up my game in 2017 and get into higher power rocket launches and I have plans to try and get my level one certification and also my RSO (Range Safety Officer) exam. Currently the UKRA (UK rocketry association) administer this certification scheme which involve the candidate flying a high power model at a UKRA affiliated club with someone of a higher UKRA certification in attendance and administering the tests etc. Now if had done my certificate some years ago I could have found UKRA affiliate clubs in the Wirral (around 1hrs drive) or around Manchester (1.5-2.5hours). However these clubs have now stopped and my options are Gwent (4-5hrs) Surrey (5-6) or Birmingham (3 hrs). Now this is fine but it shows how vulnerable the certification scheme may be in a few years time... I guess to the point where ultimately this could disappear and the system for people to develop beyond small hobby rockets may not exist.

In model engineering/Live steam similar systems exist (I'm not massively involved in this scene but am aware) for example boiler testing, so if someone builds a model steam engine and wants to run the engine on a club track or on a public running day they need the boiler (a heated high pressure steam filled box!) to be tested and certified as the potential danger if a boiler failed under pressure is probably not dissimilar to a hand grenade! Again this certification system relies on clubs and members of clubs being certified and becoming accredited assessors. (Here is a list of assessors if of use!)

Finally HAM/amateur radio has similar issues in that the exam and certificate systems (although held centrally by the Radio Society of Great Britain RSGB) the actual people providing instruction and hosting and marking and submitting the examinations are clubs and club members. HAM radio does seem to be gaining a lot of support in the maker scene but still some clubs (particularly outside the larger cities) are struggling with an older and perhaps dwindling membership.

So how do we solve this? Well, I'm not sure I have all (or even any) of the answers but part of it is certainly supporting and getting involved in local clubs and if possible becoming involved to the point of being able to assess and accredit others is vital. But also if you are setting up a makerspace/hackspace/techgroup whatever, make sure you spend a bit of time thinking about how you can be sustainable not just in terms of cash flow and membership and knowledge but also certification and accreditation your members might need.

I also wonder if there are more practical stuff to be done? How about the larger maker events (faires, makefests, big hackathons) build in some accreditation events.. this seems an easy win for perhaps the amateur radio foundation license.. (may be more tricky for rocketry certs!)

As for me... I'm off to fill in my UKRA application form and pay my subs for next year.. :)