I have the fans blowing horizontally, but they are not aimed directly at = the PCB, they are just there move the air around to ensure (I hope) that = the temp is the same in every part of the oven. The size of the ovens = are 40cm x 25 cm x 25 cm, and I use all normal heater elements, don't = think it even has a broiler element, plug it into a 230V 10A socket, and = the power is more then enough, they heat up in 20-25 minutes and then = keep the temp well, unless you open the lid for a long time... And I've = kept the light bulb, I don't manage without it.... I used a hot air gun bought at the paint store for some rework, but the = air spread is way to big .. Guess it would be much better with just = another nozzle.... The price was less than $15. regards Attila - SM4RAN ______________________________________________________ Gratis visitkort - klicka h=E4r !=20 Allt inom e-handel! www.torget.se -----Ursprungligt meddelande----- Fr=E5n: Philip Stortz Till: PICLIST@MITVMA.MIT.EDU Datum: den 15 juli 2004 02:14 =C4mne: Re: [EE:] QFP, BGA Soldering >that's what i've been thinking of doing. i was going to use a teflon >tubing fitting on the shaft end in the oven as a bearing for the fan >shaft and mount the motor externally as well. if you used the right >size shafting you could get a reasonable seal around the shaft without >much friction, i.e. a ..220-.240" shaft through a 1/4 PTFE bulkhead >tubing fitting. i also considered using just one oven if the >temperature could be increased rapidly enough (you'd probably want to >omit the metal plate in that case). I've got a "toaster oven" that's = as >big as you can reasonably have plug into a standard 20A 120V outlet, = big >enough to broil a couple of steaks or even bake in (it's huge for a >counter top appliance). i haven't played with it yet but if i used a >30+ amp outlet and ran the broiler and bake elements i think it could = do >the trick (i'd probably add some fibrous high temp insulation between >the inner and outer cases, i think it's just air space right now and >some insulation board under it). are you having the fans blow >horizontally on or under the board or at one end blowing up or down? > >I'm still interested in a hot air pencil for rework though, i have a >tiny mill and could make nozzles for surface mount parts pretty easily >with a little sheet metal drilled with the right pattern and a little >brazing or even sheet metal screws i suspect. (and if you've looked at >commercial tools like that you know the nozzles are ridiculously >expensive for a perforated and folded piece of sheet metal!, imho) > >Attila Muhi wrote: >> >> I use two standard small household owens with PID regulators and a = fan each to rotate the air. Quite cheap, and works excellent. Use a long = axis between the prop and the fan motor, as the bearings don't like = excessive heat. The first owen is heated to about 160 degrees, the = second to about 235 degrees. Put the PCB's in owen #1 for 3 minutes to = activate the flux, then move them to owen #2, and wait until the = soldering is completed. >> >> It might also be a good idea to put some big blocks of aluminium or = iron, at least in owen #2 as heat accumulators, to improve temp = stability. >---------- > >-- > proof that >the U.S. media is now state controlled! Ask your' local tv station why >the hell they aren't airing the news any more! Our system of = government >requires an informed public, with their eyes open. > >-- >http://www.piclist.com hint: To leave the PICList >mailto:piclist-unsubscribe-request@mitvma.mit.edu > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics