I cannot find a supplier for nichrome-wire here in austria.
can I use constantan instead of the nichrome, to save the shipping-costs?


andreas

Andreas,

The reprap foundation sells nichrome wire at $0.60/ft. You only need a foot or so of it to make the heater coil for your extruder. I suspect that Zach could put a coil of it in an ordinary envelope and send it to you airmail if that was all that you were looking to buy.

Here is the link for the nichrome.

[store.rrrf.org]


Forrest

you could try to find an unused toaster that uses nichrome wire as it's heating element

reprap foundation is probably the best bet though.

Alternate source:
[www.sisweb.com]

Edited 1 time(s). Last edit at 09/28/2007 01:05PM by d0ubled.

... some soldering-tools have a tube-heater with a hole of 6 to 8 millimetres throug them.

There are lowcost 12-volt-solders in use too, maybe it's worth to look, if the heating-heads are hollow, and then try them as extruder-heating?

Viktor

OT, but I was thinking along the same lines. In the US, RadioShack has a $11 desoldering iron that looks ripe for modification:

[www.radioshack.com]

[edit]as rmadams points out below, this may be the wrong link, the description is kind of confusing. At any rate, they carry it in most stores. I have one and it works well for desoldering through-hole stuff, I'm pretty sure it was under $15.

Edited 1 time(s). Last edit at 09/28/2007 02:57PM by emf.

Note that the link only is for the desoldering attachment:

>You'll also need
>
> 45-Watt Desoldering Iron (640-2060)

Just in case someone gets too enthusiastic and clicks on the link!

Having bought a reel of nichrome that was too thin and another that was too thick I ended up using part of a heating element from an old hairdryer.

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[www.hydraraptor.blogspot.com]

If you want to order just nichrome from the RRRF, you can either order it on the website, and I'll refund the difference, or email me directly and I'll give you the real price. The website isn't setup to handle small shipping costs like that yet.

hi,

thanks for the hints, I thought of constantan, because I already have one at home. but I have measured it now and it would be to long, I would need 2,5m to get 7 ohm.

Zach it would be cool if you can send me the nichrome by airmail (I will send you an email directly), you know the shipping-costs to austria for a parcel are 34$, thats a bit to much for some small parts.

In the meantime I will search my old hairdryer

Hello All,

I am building a Mendel and the last two days I have been working on the extruder. I was unable to get the insulated nichrome wire from Makerbot along with my order hence I pulled it out of a toaster. I tested it before putting it to use and noticed that it could reach temperatures around 180C-190C. Knowing that the target temperature was around the corner I decided to proceed with the extruder assembly as outlined here.
Considering the fact that the nichrome wire is not insulated, I wrapped a layer of kapton tape on the brass screw first and then wound the nichrome wire over it and continued with the instructions.
Having done all this I mounted the extruder in its position and turned the heater on. As soon as I did that I heard a tripping sound and I noticed the temperature rise up for upto 3 seconds (& about 5C) and dropped back to room temperature. I knew something went wrong so I looked at the wiring and noticed that one end of the wire had come off.
I assumed that it was due to poor crimping so I redid the whole thing and made sure that the connections were firm this time around. I put it to test again and encountered the same result.
I was wondering if I am doing something wrong over and over again.

Since someone has used nichrome out of a hair-dryer before I wanted to what measures were taken to insulate the naked wire. Probably thats where I am goin wrong?

Also, I saw someone suggest that the nichorme from reprap foundation is the best bet. If that is the case, then can I get some of that via Airmail to avoid shipping costs like the other person from Austria? (P.S. I am from Toronto, Canada)

Any response/suggestions would be greatly appreciated.

Also, I saw someone suggest that the nichorme from reprap foundation is the best bet.

Zach turned the RepRap Foundation store into the Makerbot store.

Try these guys?
[www.makergear.com]

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

I got mine from a toaster, folded 8mm kapton tape around it, cut a couple of the metal couplings from terminal blocks out for the ends, and stuck spaghetti tubing over them. Only problem I've had so far is that the adhesive on the kapton tape I got doesn't seem to like the high temps much

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Wooden Mendel
Teacup Firmware

First class shipping to Toronto is about two dollars.

Rick Pollack
MakerGear