So I need a foam cutter. I managed to tune my aluminium foundry so that it works like a charm, and now I want to lost foam cast!
The thing is that I need to scavenge a transformer from somewhere. People on different forums on the internets say that you can "find the transformers in various appliances" but don't specify!
I am stuck home tomorrow with the kids so I might get wifey talked into getrting a dimmer for me, but the transformer might be too much, there is no shops that sell electronics like that on her route tomorrow.
I have lots of shit that might contain a small transformer, if someone here would point out what to disassemble! I'd love to cast stuff with my friends on new year, just need to stay off the booze until the milten metal has solidified...
Tips appriciated!
>>921866
A microwave should have one, but you should learn what you are doing before you go kill yourself. Please don't kill your self, OP.
>>921866
anything new won't have a useful transformer, more likely switch mode psu.
what do you need one for anyway?
smash up a 110v hairdryer and use 2/10 to 3/10 of the nichrome wire inside, connect to 12v car battery. adjust length of nichrome to suit.
>>921967
Allrighty. I do have a few MOTs lying around. And my stick welder never worked anyway. I believe I got them rewound down to 6-7V? The microwave transformer seems a bit overkill but if there is no other options.
>>921972
I don't have a spare hairdryer. I might have some nichrome wire though from dismantling a few toasters last year? And yea, sometimes 110 sounds good, for example when rewinding some transformers.
>>921866
You're making a hot-wire?
To choose a transformer you basically look at your voltage and current needs. I think Crash Hancock's video uses a 25v 2 amp. A lot of junked stereos will have 25-35 volt transformers. There are a ton of dirt cheap transformers on popular online auction sites.
>>922065
Yea. But can't buy any as I don't have the time and the one that goes shopping can't be bothered with too weird tasks, after all she has her own schedule and so forth.
So for a future project I might buy something, now I need to take something apart that has a transformer.
Anyway, I just remembered I have a pic related, it states as the input just 230V so I presume its a transformer and besides it's heavy as shit. I presume I can just dim it down, or is there any reason why it might break? This indeed would be the easiest solution to use as I'd have the foam cutter done in a few hours.
After all I'm going to have some DIY-inclined friends here for a new years party and lost foam casting is so much easier with a cutter than by hand....
>>922018
>And my stick welder never worked anyway.
As in well, or at all? Because if it produces a current, you can just short it through some nichrome.
>and lost foam casting is so much easier with a cutter than by hand....
Do you have a drill and a rotary rasp?
Where you sroung from ? LOL
First questionvdo you have internet yes you do use e-bay next day delivery. Problem solved
Another questionis do yon know any kirhofs lavs or any electrical lavs ?
What curent you need to drive your wire how many ohms it has. If your wire is low power you can put your dimer away.
To cut foam I will sugest awg 28 wire streched betwin springs ( hot wire will extend it's lenght )
60 cm awg 28 chrome-nickle wire should be driven by regulated power supply 20v at 1.4 amp depends on density of polistylene foam wire should have 300C - 400C deg celtius but 160C will melt it but slow.
Thicker wire consumes higher current shorter wire lover volts longer wire higher volts in big simplification.
Have fun dont get yourself electricuted!!!
>>922231
Scandinavia. No next day deliveries. Anyway I'm getting my dimmer here soon so I'll try the transformer I have. And I do know my PUIMURI, meaning combine in finnish. P=UI U=RI. But instead of calculating it I will make one that can produce excess heat so that there is the option if cutting balsa for example. Got this addition from the king of random video.
I have a ton of wall warts so if this fails then it seems like I have to search for one from those, swallow my pride and measure and calculate the current and voltage appropriate for a given resistance...
I'd like to slightly overkill, preferably not MOT overkill but that isn't out of the question, just need this bugger to be ready quickly.
>>922194
1. It's not such a weird task.
2. Fucking hell you sound whipped
>>922018
>Allrighty. I do have a few MOTs lying around. And my stick welder never worked anyway. I believe I got them rewound down to 6-7V? The microwave transformer seems a bit overkill but if there is no other options.
A MOT is way overkill. Also, for stick welding you need at least around 30 volts, but it depends on what you are welding and what size stick you are using. The low volts like 1.5-3 volts is for spot welding, not stick welding. Most people use 2 MOTs together for a stick welder. A MOT for a wire cutter will more likely go "POP" and melt through.
For a small wire foam cutter you only need like 5 volts and 30 amps max. A repurposed PC PSU will work for that. Wall adapters are normally unregulated and burn out when trying this stuff. You'd need to open them up and redo them to be more robust. For longer wires like something to cut big blocks of foam you'll need something more probably.
>>921866
Just get 12v Downlight Transformer, they only cost a few quid and are designed to be Dimmable (unlike normal formers which whine like bitches).
This is what I used - along with a dimmer switch and a length of Nichromium wire.
>>922295
I used actually three MOTs. And got only the voltage up to something like 24 if I remember correctly. It was hard work to wind them tight enough and it was couple of years ago so can't really remember. I rewound one beefy MOT secondary with 8mm copper bar, that have one turn and a voltage of 1,5 if I remember correctly. The amperage is sufficient I can tell you. Someday I'll measure it. As I have a 400V MIG/MAG welder with spot welding functionality so both of these projects are obsolete. They were fun though.
Anyway I used my 12V transformer and actually have a dimmer now. Found a toaster I dug from the trash a year back from my treasurepile. I presume it is nichrome wire in those, at least it heats up quite easily. I had to do the math anyway to figure out how long piece I could use as the dimmer hadn't arrived at that point. Now it's done. I'll build a table for it tomorrow, now it's late. It ain't pretty but it works.
I just realized just that I did one design flaw. I made the wire tensioning so that the wire is fixed. It needs to be so that I can take it loose so I can cut holes also!
>>922296
This might be an upgrade someday. I'll see if the dimmer will kill my transformer. Now I designed it so that it can run without a dimmer, just the resistance of the wire limiting the current...
>MOT step up
>nichrome is expensive
Step down to 12 volts 27 amps with a dimmer worked awesome with MIG wire. Even got it csa approved.
Pic related.
>>922775
Very nice.
