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DGentile

WIP: Large Electric Kiln

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Julia

 

Yes - you can buy ready made coils - most companies who make furnaces / electric kilns (pottery stuff) will happily make coils to your specs.

BUT - it's usually really pricey.

 

That was the sole reason I chose to start making my own, quite a time ago...

 

Now about the HOW:

 

first you need to know the specs you'd like with your furnace - Amps, voltage, ...

Then you can calculate the required resistance of the coils... and along with the specs for the wire (I only use Kanthal A1 wire - which everybody else seems to be doing to) you can calculate the length in meters and thus also take into account what kind of diameter the coils should have.

 

I have laid out the math a few posts above... so that should be covered... but if you have any specific question regarding this - let me know...

 

 

What you need is some sort of a setup to turn a wooden core at a slow speed.

if you have a lathe - you're all set. (as long as it's capable of SLOW speeds - I had mine at 52 RPM - slow enough to fall asleep, but easy to control)

in case you do not have a lathe - well then you need to improvise.

The simplest idea I can come up with is a hand held variable speed drill, mounted in a vise ... and you need to rig some sort of "tail-stock" to hold the wooden stick at the other end in position... nothing fancy.. .at slow speeds - even if the counterpart has 10mm play in each direction it does not matter.

 

fix one end of the wire to the wooden core (if you do this on a lathe you can just clamp it along with the wood in the 3-jaw chuck... you could also drill a tiny hole through the wooden core ... whatever works.

 

make sure the wire uncoils easily and is not tangled up before you start... wearing leather gloves will make feeding the wire a tad more comfy - but I usually just do it without the gloves...

 

start the lathe or drill and keep a nice but not too firm tension on the wire - make sure it moves along easily without overlapping (in case it overlaps - just reverse the lathe or drill for a few turns and start over.

 

When you're done or want to check - use a multi-meter (ohm-meter) to check the resistance of the coil by holding one probe to each end of the coil...

if you're too high or low - adjust the coil (unwind or add more wire).

 

that's it.

 

it's really pretty basic.

 

I strongly suggest using a lathe - it's a lot easier...

and before rigging something with a drill - see if anyone in your area has got a lathe and is willing to help you out.

 

hope that helps.

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You can buy ready-wound elements. Many pottery equipment suppliers will wind them to your spec, albeit at a price.

 

I got the coils for my ovens from ebay seller jrider12 in Portland, Oregon. He seems to have dropped off the radar lately, but ebay seller pmtoolco, also in Portland, seems to offer similar coils.

 

Prices, shipped USPS flat-rate to the UK, were less than I could buy the Kanthal wire for from anywhere else. The coils I have are wound from 16ga (AWG?) wire.

 

There are a number of far-East ebay sellers offering kiln elements very cheaply now, but these appear to be of very thin wire. The detail is sparse on the ebay listings, but they look like they are cut from a long length of continuous coil. If so, the working life will be shorter due to the smaller diameter and they'll probably need the ends uncoiling to make "tails" for connection.

 

I asked to have my elements wound for 13A (to suit 13A UK fused mains plugs) at 110V and used 2, wired in series, for each of my 18" ovens; one on each side.

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Hi all, I'm new to the forum, came across it while searching for wiring up contactors.

 

I am building an electric kiln, and wanted to get the safety sorted, but I needed a wiring diagram to understand it more thoroughly.

 

I have modified the diagram in post #19, and with the kind permission of DGentile I'm posting the version suitable for single phase power supplies, in case anyone may find it useful.

 

OvenWiringContactordfoggforummod.jpg

 

Another forum full of interesting information, and people I know. Hello Tim:)

 

Thanks again Daniel.

 

Cheers,

Vince.

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hello Daniel

I wanted to ask if you have already used your electric furnace, and the temperature is distributed evenly throughout the chamber?

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I apologize for the bump. Daniel I am very interested in learning about your process, but it's a little difficult to follow without pictures. It says they are protected. Would it be possible to get the pictures back up?

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i was wondering if one could use an old junkyard kitchen oven and modify the body to hold the necessary heat and such for ht. And i definitely would use proper heating coils and such but could this be done? also if this could be done would this be a cheaper alternative , would koawool and a reflective coat of satenite or itc 100 be saficant to retain heat.

Edited by ShawnShaffer

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The photos appear to have gone south with the geese.

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Guys, I've finally did manage to update the broken picture links... all should show up again.

sorry.

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