- Kent, UK
Okay,16amp commando plug fitted, DC clamp meter on, adjust potentiometer RP1 - turned anti-clockwise approx 3 turns, 37amps DC delivered. Cuts much cleaner on 8mm mild steel. For reference also attached AC on feed in shows 27.5amp draw.
Dial set to 15amp - shows 15.2 amp DC, draws 11.2amp AC
Dial set to 30amp - before tweak shows 27amp DC actual, draws 18amp AC
Progressive tweaks to RP1:
approx 2 turns anti-clock shows 33amp DC, draws 21.5amp AC.
approx 3 turns anti-clock ( in total) shows 37.2amp DC, draws 27.5amp AC.
Cuts deeper easier, though noticed higher pitched humm from unit when in higher setting.
I dunno how I forgot/missed this first time round but thanks for it now anyway.
I've been a bit disappointed with the performance of my unit especially when I see mtt.tr's 10mm cuts which mine could never mimic.I've been out in my workshop this evening tweaking my power upwards quarter/half a turn at the time. I stopped at 2 turns anti-clockwise. I don't have a clamp meter so I just relied on my infra-red thermometer and the fact that I am still using the 3-pin plug to warn me of impending doom.
So, initially my machine would cut 6mm cleanly, cut 10mm just about going slow and burn through 15mm (didn't have any 12mm) eventually but very very slowly - so much so that i was now concerned about cooking the machine on duty cycle.
I bumped the power up by turning RP1 a bit at a time and now at 2 turns out it's performing MUCH better. 10mm clean cuts at a lot faster travel speed than I was having to use initially.
Here is some 10mm flat bar before adjustment:
And now some 10mm plate after 2 turns AC adjustment (33amps according to Dog House's observations). As you can see, a much-improved cut and still with the 13a fuse in the 3 pin plug. Slag knocked off easily.
I even turned it back down to the original setting just in case my 'improvement' was wishful thinking but no, it was back to struggling along slowly on a 10mm cut.
So, next up this week is 1 more turn of adjustment and if it doesn't go pop or start to cook I'll leave it at that. It's well-known that 13a fuses can carry a lot more than 13a so I'll leave the plug on it for now, but I have a supply coming from the MDU I can use with a blue plug if it's too much for the one fitted now.
Just want to point out that I was fitting the cover every time to keep the air flow running across the heat sinks inside and removing it for adjustments/temperature measurement. I think it would be easy to overheat the electronics by running with the cover removed. Just in case you're considering doing this yourself.