Wednesday, September 12, 2012

Controller Working!!!

After months of this project being a work in progress, the pressure and temperature controller finally got completed today and....... wait for it... it damn well worked!!!!

I'll be able control the vac pump without the need for a manual regulator and heat blankets including creating safe ramp-up profiles and log all the data for future reference.

Check out some more photos on the forum under 'Equipment Projects'

Monday, September 10, 2012

Heat blanket stage 1

Yesterday I had a chance to pour the main area of the heat blanket. I cured it with out any pressure on it and so unfortunately it picks up a few wrinkles from the protective plastic I laid down on the work surface. However, it only has 660gm of rubber in it so I have some left over to try to remedy it.

Check out all the details on the Equipment Forum here. Construction details

Saturday, September 8, 2012

Heat blanket under way

 I've gathered all the bits I need for the heat blanket and will start making it in a couple of days. I've uploaded photos and discussions on the forum. Check it out here >>Heat blanket kick off

Thursday, September 6, 2012

First project to find a home here - Thanks Mikelli

We have our first project to hit the forum - a board close to my heart - a light wind machine!! Thanks for jumping on board Mikelli and we're looking forward to watching your progress.

Check out Mikelli's 'Door' and see what you think!

Tuesday, September 4, 2012

New forum on site - BETA

With approaching 100,000 visits there are clearly loads of other kiteboard projects out there that are not getting the publicity they deserve so I thought it would good to add a forum to the site so that people can use the site to more easily share their projects and knowledge and generally show off their pride and joys.

You'll see in the pages listed over on the right hand side the new Forum page.

  Forum Page

Because the forum is hosted elsewhere (Nabble) you'll need to register for the forum even if you all ready subscribe to the blog.

So please jump and register on the forum and start a new topic in which ever forum makes sense and lets start building an more interactive community. Please pass the word around to anyone looking for a project home-away-from-home for the board building projects.

Monday, September 3, 2012

Silicone heat blanket

After running the numbers I realised that I wasn't going to be able to run the 200C blanket from domestics mains supply so a change of plan. I'm going to make 1 kW blankets that should be enough to reach 100C which should cover of all the epoxy curing needs. The dye sub heater will have to go on the back burner for a while.

So here the revised numbers for the blanket

150 x 50 cm usable area. 6 separate circuits in parallel each with 6 lengths of wire in it. I bought some 32 gauge wire (0.2mm dia) on ebay from the US which has 34.68 ohms/m resistance for about $4 for 10m.  I've ordered 2 kg of Mold Max 40 from in South Australia for around $50/kg. This is a condensation curing ( tin catalyst as opposed to platinum) 2 part silicone rubber that has a max temp rating of 205C which is more than enough for the spec'd down blankets.

I had originally order Mold Max 60 which is rated to 293C but changed that after running the numbers on the hotter blanket. BTW the 40 and 60 refer to the hardness of the cured rubber on the Shore A hardness scale. 40A hardness is about the hardness of a pencil eraser, 80 is the hardness of a car tyre so 60 is in the middle.

On is seem that the blankets are coming in under 3mm or so. There are typically 2 layers of fibreglass with the resistance wire in between. This gives electrical insulation and makes for a strong finished product.

At the lower temperature of 100C it should be ok to solder the resistance wire to a mains input wires. I believe that solder typically melts at around 170C or so. The best idea on seems to be crimping the resistance wire into aluminium tubes and soldering the tubes onto a bus bar of some sort. Still seeing if there is an easier way to do this and make sure the wires remain well insulated from each other.