1978 syncrowave 300 pedal

[wendell]

Was looking around the Miller site a fwe days ago and stumbled upon the neatest message board...

I have a Syncrowave 300 s.n. HK320788 that i got about 6 months ago. A buddy gave me a 5 pin amperage control foot pedal for it. I can't quite read the model # but I think it's RFC5-25, wich would make sense. I plugged it in and it seemed to work. Since then the micro switch that starts gas flow and activates the rheostat(sp?) died. Now when I turn on the machine gas flows, the torch is hot w/ starting current and, if enabled, HF is on. My Miller rep says he can't get a switch and that I need a code# in addition to the s.n. to get a replacement. My questions are; how many different 5 pin pedal did Miller make? Wher on my PS is this code#? Which one do I need? And finally, if I'm having such a time getting my foot pedal up and running, how will I ever get a torch mount fingertip control (which I desperately need)? I posed these same questions to the Miller help line and have yet get a response.

I hate to ask a bunch of questions in my first post but I've been blown away by the info on this board and really need to get my tig up and running again. Any help will be great
thanks

[karish]

Wendell,

I have an older Synchrowave 300 too. Although mine is a bit newer (1980s) I had no problem getting a foot controller. I called Miller on the phone gave the nice lady the machine's S/N and she gave me the part number. I called to the few shops we have in the area and got one. The torch should be the easy part. I have a Weldcraft WP-20 on mine, but one can use a number of torches on the machine. Enjoy your big blue lump!

[wendell]

Interesting. I have a torch (water cooled weld craft 20) but would like to get a finger tip amperage control for it.

Your experience was exactly what I was expecting when I talked to my sale rep. I'll have to give miller a call direct. Thanks a lot for the advise. While its a far cry from the Dynasty, I really like my big blue lump. Got to figure that if the board goes on it I can still get good money for the copper

[cruizer]

Pop the foot control open, there you'll see the levered micro switch. Remove it and swing by your local electronics shop. These switches are plentifull and might cost you 5 bucks!

[wendell]

Cruizer,
Thanks for the tip. I've been in the pedal and it is definately the switch. I'd love to buy one w/out having to order it from a dealer. Do you have any tips on what to look for at an electronic shop? Am I in good shape as long as it looks the same?

Thanks a bunch, stay out of the cold up there.

[cruizer]

first make sure that the lever on the switch is actually hitting the button in the switch. If it isn't just bend the lever in such s way that it does. If the button is missing altogether, ie, worn out , pull the switch out. The wire configuaration doesn't matter as there are only 2 wires.
The switch is problably made by Microswitch. So have a look on Ebay, or send me a pic and I'll send you one if you have no electronics firm around where you live.

[cruizer]

OK, the code for the 5 pin is

A makes contact with B to turn the contactor, HF, Water, ect to "ON"
B

If you want to check your remote controller function, merely remove your remote and with a piece of mig wire jumper one end "INTO" Amphenol port "A", and the other into Amphenol port "B". Everything should turn on, if it doesn't you have other problems, probably a relay inside your machine.

C
D
E

This is your Potentiometer, without getting into confusing details.
Looking at the back of your potentiometer, pins facing down, the code is

C (furthest left pin) E (center pin) D (furthest right pin)
It's a 1K ohm 2 watt long shaft pot.

Remember that your remote control works in relation with your machine's control pot, IE, if your machine's control pot is set to 125A, your remote pot will have a max range to 125A

[wendell]

Pulse tig

Thanks alot Cruizer. I had already tested the micro switch and it was bad. Got a new one from Miller ($15) and am up and running. The big Blue Lump is running great. One more question...

I seem to pulse just about every thing I weld (aluminium and steel). I get better penitration w/ a smaller HAZ and it's a lot easier to attain the "stack of dimes" everybody is looking for. For steel I usually set to about pulse /0.5sec, 50% on time w/ a 25-50% difference in amps. My question is, what are the drawbacks? Are there times when I shouldn't pulse?