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centrex Guru Joined: 13/11/2011 Location: AustraliaPosts: 320
Posted: 09:42pm 09 Oct 2012
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Hi Mattma
The section where the program dies is headed Sub LOAD_CHART_CONFIG(name$,and then a strange symbol then Moda strange symbol $).
Regards
CentrexCliff
I finally had a chance to use the Maximite controlled process controller that I worked on a few months ago and wanted to share the results as a bit of closure on the project.
The controller uses a monochrome Maximite and a relay board with a number of temperature sensors and vacuum pressure sensor built in to control the forming and curing process for the fibreglass/epoxy kiteboards that I make as a hobby.
In the true spirit of backsheding the other equipment I use is also home made; a rocker table for vacuum forming the compound curves (re-purposed beds), a silicon heat blanket (scrap fibreglass and moulding rubber) for controlling the curing process to make it really strong and a vacuum pump ( a re-purposed fridge compressor). Here it is in all its rustic glory!
The three thermocouple wires are underneath the heat blanket and, although not in place in this picture, the vacuum sensor tube ( pvc tube on top of relay box) was placed under the vacuum film used to bend the board into shape.Out of shot here also is the vacuum pump.
The software on the Maximite displays the temperature and pressure readings and turns the pump and heat blanket on and off to maintain pressure and temperature. To create the temperature profile I just updated the setting on the fly but plan to built a timer function into it to do this work.
The first real finding when it was all fired up was that the long thermocouple wires ( 2m) are great antenna and when the heat blanket was on the noise sent the temperature readings crazy.
The bottom trace is the slow trace of the temp sensors. The issue with this was that the relays were set up to open and close based on instantaneous values and so the relays started chattering away.
So I did a bit of a quick and dirty on the software so the triggers for the relays averaged the reading over 10 seconds and it settle down very nicely. Once it hit temperature (only 60 degrees for this particular resin) and the relays shut off the temperature continued to rise for another couple of degrees so it was able to maintain the temperate band by turning on every 5 minutes or so.
I've just bought a new vacuum pump so next time is should be possible to just set it and walk away for 48 hours while the vacuuming forming and curing process looks after itself via the awesome Maximite!!
And here is the end product.
aargee Senior Member Joined: 21/08/2008 Location: AustraliaPosts: 255
Posted: 02:04pm 20 Jan 2013
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Very (rustic-ly) nice!For crying out loud, all I wanted to do was flash this blasted LED.