cooker in bits

MG007 · Posted: Thu Sep 27, 2007 1:46 pm Post Subject: cooker in bits

Hi, hope someone can help out here!

Im trying to build a DIY vacuum former which requires a fair bit of heat over a large area so I was planning on ripping some cookers apart and using the elements from them.

Ive managed to get my hands on some old cookers from the dump and taken them apart to get the elements and all parts from them out. and all the internal wiring seems simple enough the bit im not so sure of (and due to the voteges and currents involved I dont want to experiment!) is connecting it up to the mains.

The first thing I want to do is make a small test bed and try each pot and heating element on their own to make sure they are working so could anyone give some advice on how I would go about this?

If theres any details you need to know, power ratings etc, let me know and ill get them asap.

Sorry if this has been asked before or this isnt the place to ask, im new in these here parts!

Diyisfun · Posted: Thu Sep 27, 2007 1:52 pm Post Subject:

We made a vacuum former years ago as I worked in domestic appliance development we had all the bits.
We finished with the elements being mounted in a box on a chain (so it could be swung to give gentle heat) we also had the elements controlled by energy regulators (the cooker control knob).
The plastic sheet was held by metal strips with clamps, & we had a big tank to store the vacuum, when the sheet got soft it was lowered to the former, switch the vacuum & yup protype vac form.
The elements you have will all be 220v this should be stamped on the end & so should the wattage. You want black heat evenly distributed. Hope this is enough info to get you going

MG007 · Posted: Thu Sep 27, 2007 2:01 pm Post Subject:

cheers, im not really anywhere near the former design stage at present but ive got a few ideas in mind.

The bit im needing more help on is the wiring of the elements, energy regulators and the mains power. Any circuit diagrams would be most helpful!

a random aside, whats difference between an energy regulator and a potentiometer?

Diyisfun · Posted: Thu Sep 27, 2007 2:42 pm Post Subject:

Energy Reg cycles, pot is a reduction in volts, depends what wattage elements you have, you can wire them in series or parallel, your problem will be if your on a domestic circuit will be the loading.

How big an area will you be after heating.

You can do a small piece by heating it with an electric fire, the old radiant type.

I think your bigger problem will be drawing the vacuum

MG007 · Posted: Thu Sep 27, 2007 11:27 pm Post Subject:

The vacuum shouldn't be too much hassle, ive managed to get my hands on some 3 phase vacuum pumps and I have access to a 3 phase supply.

am I right in thinking that this is how to wire up the elements?, just in a test bed atm.

bernardgreen · Posted: Fri Sep 28, 2007 6:41 am Post Subject:

Add an earth to the mounting of the energy controller to protect against a fault in the controller making the control knob live.

Diyisfun · Posted: Fri Sep 28, 2007 7:04 am Post Subject:

Yes the wiring is OK but add the earth as suggested

MG007 · Posted: Fri Sep 28, 2007 3:32 pm Post Subject:

Cheers for the help, been testing things out for a few hours now and everything so far seems ok. One problem we have faced is double elements.

The grill elements we are using (and a few of the hobs) have 4 conecters and we have a few energy regulators that have: Load A, Load B, Live, Neut, Pilot terminals.

Am I right in thinking that the pilot line is just a low voltage line for lights and such? and to connect the element up I should connect 2 points to neut and the others to Load A and Load B?

Cheers

Diyisfun · Posted: Sat Sep 29, 2007 9:18 am Post Subject:

load A + B are just the inner & out element, neon will be at 240 when either load A or B is on.

empip · Posted: Sat Sep 29, 2007 10:58 am Post Subject:

Some periphery info in this fieldl...

From little acorns ... Retrac Composites LTD started by Jonathan 'Wingnut' Greaves ex motorsport mechanic ...

Quote:

...Autoclaves were heated pressure vessels used to consolidate the composites but they were very expensive and used mainly in the aerospace industry. After a bit of research I thought there cannot be too much to this, so we built our own at a fraction of the cost. That Autoclave was the first in F1 and is still working today. Autoclaves are commonplace now, I have three at my latest company Retrac Composites and I think McLaren have seven or more...

http://www.jonathangreaves.com/page3.htm