Custom ceramic heating element - Page 1
Forum section: electronics / projects

author: aisotton
author_rank: Newbie
timestamp: February 17, 2016, 10:46:23 pm
content: I'm working on a project that requires a custom ceramic heating element, similar to what you'd find in a soldering iron. The dimensions of the element are given, and the voltage and power that it needs to run at is also strongly constrained. I'm at the research/prototype phase, so I only need a few (less than 10).One thing I'm thinking about is taking heating elements out of soldering irons that happen to fit, and see whether I can modify them to fit my needs, but I'm not sure how well that'll work out.Do you have any idea where I could buy that / have it custom-made / how to make it myself?

author: Vgkid
author_rank: Super Contributor
timestamp: February 17, 2016, 11:05:22 pm
content: http://www.omega.com/techref/electric.htmlThey also sell heating elements, wire, etc. Look there first, before you start improvising.

author: uncle_bob
author_rank: Unknown
timestamp: February 17, 2016, 11:28:17 pm
content: HiThe "old style" way to make one of these is to grab a spool of resistance wire (Nicrome is one, there are *many* others). Wire gauge / space available / power / voltage available pretty much dictate how it will perform. You will need to insulate it with something. You will also need to support it with something. The answer to that part is very dependent on your temperature range.That's about all that can be said based on the details you have provided so far.Bob

author: Seekonk
author_rank: Super Contributor
timestamp: February 18, 2016, 05:46:27 am
content: I just ordered a clone Hakko 936 wand and was looking into the various elements made for these and Atten which are 24V 50W. They are only a few bucks each on ebay. Seems like anything you could want is already made. There are some threads here with tear downs of elements.

author: uncle_bob
author_rank: Unknown
timestamp: February 18, 2016, 12:17:54 pm
content: HiIf the constraints turn out to be:We have 1.2V of DC power, it needs to run 1KW, the external electronics can be no bigger than a dime ... errr ... that's a fairly big deal. If you add on a 100 ms response time ... yikes ....Bob

author: Pjotr
author_rank: Frequent Contributor
timestamp: February 18, 2016, 12:55:20 pm
content: OP talks about "Similar to what you'd find in a soldering iron" so it's likely around 50W @ 24V. There is a myriad of those ceramic elements at Ebay, Ali xxx etc. But I agree, OP can be more specific what he wants to archive.

author: daqq
author_rank: Super Contributor
timestamp: February 18, 2016, 01:17:45 pm
content: Is ceramic the only way to go? I've read about some polymer that you could effectively mold into any shape you desired. The polymer was resistive and had a PTC.More info on the constraints would help though. For such small quantities you're possibly better off taking the next closest standard thing.

author: Pjotr
author_rank: Frequent Contributor
timestamp: February 18, 2016, 02:13:51 pm
content: Yes, for small quantities I would also go for standard cylindrical cartridges, i.e. of Türk-Hillinger:http://www.turk-hillinger.us/en-US/startpage/Way more reliable than Chinese ceramic stuff.

author: uncle_bob
author_rank: Unknown
timestamp: February 18, 2016, 05:59:24 pm
content: HiWith "tight constraints on dimensions and power", at least as I read it, an off the shelf element is not going to work. The request may be for "how do I make one from scratch".Bob

author: aisotton
author_rank: Newbie
timestamp: February 18, 2016, 08:58:52 pm
content: Thanks everyone for your replies! Some good insights there.I know I'm scant on details, but I'm thinking of making this as a commercial product and don't want to spill the beans yet :-)The main difference between readily available heating elements and what I need is the voltage. Most soldering-type heating elements are in the 20+ V range (for soldering stations), 120/230 V (for irons without stations) and some 12 V elements to run off car batteries etc. My stuff needs to run at about 6 V. Having an integrated temperature probe is a big plus as well. I know that there are some 6 V irons, but they are underpowered for what I'm looking for (30-50 W).My conclusion so far is to take elements for soldering irons, and then break out the dremel/nichrome wire to adapt them for what I need. As I said, I'm prototyping so it doesn't need to be pretty.If I come up with something interesting I'll post it here for posterity.

author: daqq
author_rank: Super Contributor
timestamp: February 19, 2016, 08:01:17 am
content: QuoteYou can actually but resistive wire off the shelf by the spools.In terms of size you seem to be pretty close to certain ceramic resistor sizes:http://uk.farnell.com/te-connectivity-cgs/sbche1122rj/resistor-11w-5-22r/dp/1174421...Maybe try abusing them? The advantage is there that you can buy any resistance you wish and as such get the required power at whatever voltage you need.

author: uncle_bob
author_rank: Unknown
timestamp: February 20, 2016, 01:09:22 am
content: Quote from: aisotton on February 18, 2016, 08:58:52 pmHiOk, so it's off to the Nicrome wire store to get some spools of wire. There are some wonderful old time formulas on "watts per foot". They tend to fall apart with things like forced air involved. Best to order a few sizes that look like they will work 50W at 10W/ft would be 5'. That's not a terrible place to start. Temperature and longevity also come in. Heat sinking (obviously) is going to help things. As you go up and down in wire gauge you will change length. For a first pass there is nothing wrong with doubling up wire.Next up start shopping for ceramic coil bobbins. They aren't a Walmart item, but they also are not super rare. Industrial ceramics outfits do that sort of stuff.Lots of fun!Bob

author: alanambrose
author_rank: Frequent Contributor
timestamp: February 20, 2016, 06:04:19 pm
content: For custom ceramics btw you can design and have printed 3d printed ceramics by Shapeways, Materialise etc. It's also fairly easy to 3d print a positive in any smooth material / cast a plaster negative from that / 'slip cast' a positive from that in (say, porcelain) clay / bake in a kiln and you're done. Sounds complex, but it's fairly easy - especially if you know any potters/ceramicists. That will give you a custom support / insulator for your resistance wire.

author: uncle_bob
author_rank: Unknown
timestamp: February 21, 2016, 12:34:10 am
content: Quote from: alanambrose on February 20, 2016, 06:04:19 pmHiA lot of schools are set up for this sort of thing if they have an art program. That (in some areas) might be a way to get a handful of parts done.Bob

author: dannyf
author_rank: Super Contributor
timestamp: February 21, 2016, 01:59:25 am
content: QuoteThen just buy those soldering iron heating elements. They are easy to find and cheap to buy. Problem solved.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 21, 2016, 07:12:59 am
content: I have used MACOR brand machinable ceramics on a poor hobby level lathe with normal HSS tools. (I made a microarc tig spot welding tip.) It is a miraculous material, so easy to turn parts from it without any special equipment or experience. You could use that if you need to DIY a custom heating element structure. A lathe with autofeed could make you a nice groove for a heating wire.

author: uncle_bob
author_rank: Unknown
timestamp: February 21, 2016, 01:01:07 pm
content: Quote from: dannyf on February 21, 2016, 01:59:25 amHiExcept he needs a completely different size / shape / voltage and power. Otherwise similarBob

author: Seekonk
author_rank: Super Contributor
timestamp: February 21, 2016, 01:14:53 pm
content: With ZVS modules so cheap, just do induction heating at 6V.

author: uncle_bob
author_rank: Unknown
timestamp: February 21, 2016, 01:18:56 pm
content: Quote from: Seekonk on February 21, 2016, 01:14:53 pmHiFirst one Mr Google turned up was $10.99 .... might be a bit tough if the product / experiment involves low level RF signals.Bob