Philip Pemberton wrote:
> Lucky you. I tried to track down a fuser - got a quote of £97 + VAT (total of
> about £120, or roughly $200) for a Laserjet III fuser. Second-hand from a
> scrapped printer, too...
Well as a replacement part to fix someone's printer they're worth far more
than the whole printer as scrap. You want to get one out of a scrap printer
that is uneconomical to replace the cartridge, not order it as a seperate unit.
Any type of spare will cost a fortune compared to getting a printer carcass
that is being tossed.
>
>
> The biggest problem I found was finding data on the thermistors. You need to
> keep track of the temperature of the fuser and switch the power based on
> that, otherwise you end up frying the thermal fuse or blowing the heater.
A couple of wires brought out so you can watch it on a working printer helps
here. If you can't do that then just apply heat for a short time to get it
started up, and then switch to a very low duty cycle. Use a seperate
temperature probe of some type so you can see what is going on independently of
the thermistor. Shouldn't take long to figure it out, you just have to start
with very low duty cycle since they usually have much more power for quick heat
than what is needed once they're at temperature.
Or just bake it and read, that will give you a good idea of the right value
for the thermistor.
>
> The other problem is the motor drive, but that's not too difficult - steal
> the motor and drive gears from the printer and use them :)
I've got a ton of 18:1 gearhead steppers, but the motor would work fine too.
Problem is dealing with the gear train but it's not too bad.
>
> I've got the LaserJet service manual here - if someone wants to sell me a
> cheap LJ/LJ2/LJ3 fuser (or point me to somewhere in the UK that sells them
> cheaply), I'd be happy to design something to drive it. Obviously I can't do
> that without a fuser :-/
>
> Later.
Early model LJ's are very heavy to ship. Find something a little more modern
that's lighter but still has a roller fuser to get. Win one or two off Ebay etc
that starts at $5 or something and you'll be much better off. Sub $100 new
printers on sale here in the states, with duties and taxes etc throwing away may
make less sense there so it may not be as common.
About as well off to just get a laminator if that's all you really want,
after the materials and time are considered. I have some other things to do
with both fusers and a seperate controller, so there are other outside reasons I
want to do it this way. While I only bought the cheap one to see where the low
point was, I'd certainly buy a mid-grade one and modify it if that were all I
wanted.
Alan