If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #55241
Joined: Thu Jun 11 2015, 08:33PM
Location:
Posts: 2
Hi all, I do a number of small scale castings of keys for musical instruments (flutes/clarinets). These are made out of brass, bronze, nickel silver (a.k.a. german silver) and sterling silver. The critical thing here is that these are non-ferrous. Currently I use a homemade gas furnace to metal the metal in a silicon carbide crucible which has a hole in the bottom which is plugged by a carbon rod. When the metal is molten, the rod is lifted slightly and the metal flows into the casting flask. This system works well but is noisy and has to be done outside which makes it weather dependent. As I’m based in the rainy north of England this is not ideal. Having done a bit of reading up, I’m considering building an induction heater to perform the same process using a similar design to IamSmooth’s or Uzzors (thanks to both for the great info). There are a few things I’d like to know before spending lots of time and effort on it though.
Number 1 - Is it feasible, given the following limitations? - Desire to fully melt small amounts (300-400g) of different non-ferrous metals. The metal would initially be in the form of lots of small, individual, irregularly shaped pieces placed inside the crucible. - Access only to UK single phase supplies of 240Vac, 50Hz, protected by 16A fuse or breaker. i.e. no 3-phase supply. I could use a 32A fuse in the distribution board if really required but I would prefer to be able to plug it in to a standard wall socket.
Number 2 – Would it require lots of tuning for each different metal or even for each individual load of the same metal? (eg. If I want to do 3 crucibles of brass in a day, will I have to tune for each load?). Having read about IamSmooth’s and Uzzors PLL controllers, I note that some tuning is still required. Is this just tweaking a pot for a few seconds or is it minutes of fine adjustment of different things?
Metal Melting Point (oC) (oF) Brass/Bronze 930 1710 Nickel Silver 1110 2030 Sterling Silver 893 1640
Registered Member #54599
Joined: Sat Mar 07 2015, 06:09AM
Location:
Posts: 8
If you haven't already found the answers, #1: yes, #2: no.
To be very brief, induction heating basically works by generating large currents in whatever conductive material happens to be in the sweet spot of the magnetic field. It's basically what happens when you stick a wire in an outlet (or would, in the US, UK plugs are far less prone to such stupidity). The amount of material will definitely affect heating times and a 300-400g melt will take a while with the amount of power you can supply. You will definitely need to make your machine more sturdy, like running the water supply from the tap which will take away pretty much all the waste heat no matter what you build.
Registered Member #55241
Joined: Thu Jun 11 2015, 08:33PM
Location:
Posts: 2
Thanks for the reply. I'd like a bit more info on the tuning from anyone who has practical experience of it. How easy is this - would i have to set up the scope for every melt and adjust pots or just stick the loaded crucicble inside the work coil and let the PLL do the rest? Also, would you recommend series or parallel tank for this application?
Registered Member #54599
Joined: Sat Mar 07 2015, 06:09AM
Location:
Posts: 8
I haven't built one yet so my knowledge is limited to some of the theory. It seems to me that the use of a scope in many builds is to monitor how well the PLL is tracking in the prototyping stage since commercial units don't provide that kind of info.
As for the tank design, it's specific to the caps you buy. You'll have to optimize, but (ideal) capacitor math is comparatively simple.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Induction Heater Questions
