Kbcc 125 DC controller

If you tell me what value(s) you need, I will try to source them here and send them north.
 
You might check Digikey or Mouser electronics. One post indicated that Digikey shipping was $8 to Canada. Also some of the Chinese/HK vendors ship direct (but take forever to get delivered). You could also get a larger embedded resistor and remotely mount it. Something along the lines of a braking, dummy load or current sense resistor. Also an alternative is you can make your own resistance, use Nichrome wire and cut it to the length for the specific resistance needed. So the one listed below is 0.259 ohms/foot, 1.9" would be 0.01 ohms. I assume this resistor is acting as a current sense resistor in the KB controller.
https://www.digikey.ca/
https://www.ebay.ca/itm/50W-100W-0-...m-Housed-Case-Wirewound-Resistor/182880437622
http://www.ebay.ca/itm/0-01R-Current-Sense-Through-Hole-Resistor-Pack-of-5/301935295362
http://www.ebay.ca/itm/TT-Elect-Ope...Current-Sense-0-005-Ohm-5W-1-NEW/190910684800
https://www.ebay.ca/itm/TEMCo-Nichrome-60-series-wire-16-Gauge-25-Ft-Resistance-AWG-ga/281603704187
 
Shawn: The HP resistor is essentially a resistor with such a low ohm value it's not much different from a piece of wire. It's NOT a choke. I just suggested winding it into a coil to make it into a compact shape so you could install it. Also, it needs a good connection to the pins on the board.
Soldering would be preferable unless you have some molex-style pins or a factory HP resistor you can canniballize. Do you have any thin copper wire on hand? About the thickness of thin string (0.025" diameter or so) about 3-4 inches of that would probably work. You want around 22 ga. enameled wire, although pvc insulated wire would be ok too, as long as the wire itself is about 22 gauge.
Mark
ps be sure the motor or HP resistor does not become disconnected while powered or you could damage the board. That includes output fuses that are underrated. Output fuse should not get hot. Or input fuse neither.
pss you can probably get close to 2 HP out of the unit (at least intermittently) if you can keep the SCRs cool. It all comes down to cooling.
 
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Great information guys. Thank you.
Being a former electrician I have decent knowledge or wiring, but don't know too much about electronics, and don't claim to.
I have some old telephone wire on hand, which is 22 awg.
The resistor I have really is no good to me, so I'll solder the wire to that mounting board. I'll check the resistance when I get it all wrapped up.
Thanks!
 
Well the wrapped up wire didnt help anything. It ran the same as with the resistor.
It will run well with a piece of 14 awg wire in there. But that wire actually gets warm and the other big resistor gets quite hot. And I only ran the lathe for 5 minutes taking light cuts....
This board is supposed to be able to put out 1.5 hp. I don't think it's pushing nearly that much... Me thinks this might be too good to be true...?


What if I put a smaller pulley on the motor and run it faster. Does DC work the same as AC in regard to amps? If I take load off the motor and run it faster will it reduce the running amps and take it a bit easier on the board?

I really want this to work...
 
OK- can you get any adjustment range on the IR pot? This is kind of a guessing game, how long is your 14 ga wire?- it sounds like you just need to experiment some more. We don't know exactly how much current that motor draws. Also, I can measure the HP resistor on mine and tell you what the voltage drop normally is. I think it's normally about 0.7 volts but I'll check. Stick with the 14 ga wire for now.
I'll do it tomorrow- stay tuned. Yes DC and AC are roughly similar in regard to amps. Do you have any means of measuring low ohm values?
Is the motor speed staying constant with varying loads? If it speeds up or slows down under load that's a clue as to the size of the HP resistor and the setting of the IR pot.
Mark
ps you are getting a good range of speed control correct? And you are running off 120 volt AC correct?
 
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14 awg wire is about 6".
I have an old fluke 77 that will measure down to 1 ohm but not lower.
It has DC amperage but the fuse is dead. I'll replace it and see what it tells me.
The AC input amps are about 15-17. Pretty high...

I had set the ir pot lower cause under no load the motor hunts.
With the IR pot lower, the motor does slow slightly under load.

I have a good range I speeds. The min/max pots and speed pot seem to operate fine.

I'll go measure the DC current now.
 
The KB chart tops out at 1.5 HP with a 0.006 ohm HP resistor, but you can probably push that to 1.75 HP, with a resistor of say 0.005 or 0.004 ohm.
Remember you will be pulling in excess of 15 amps so all your wiring needs to be heavy. Here's the KB chart in case you don't have it:
M
ps I can estimate how much 14 ga wire will get you in around 0.005 ohm- let me get back to you in a sec
 

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I have seen that chart.
I also have the full manual on this driver.
 
OK it looks like 14 ga wire has about 0.0025 ohm per foot so that means you would need about 2 feet to get 0.005 ohm
So try maybe 1.5 or 1.75 feet
Mark
ps considering the current draw I wouldn't go to a thinner gauge if the 14 ga is already getting warm
 
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