The Shop > Electronics & IC Programing

KBIC controller probs

<< < (5/6) > >>

Gazz292:
well, i sent amadeal an e-mail describing the board, what functions it does, what lathe i have etc,
the reply said that for £25 plus a tenner postage he'll sell me a 'filter board for a CJ18 lathe'

erm, a filter board is usually just a few capacitors and a choke or 2, i guess is hould ask him if he thinks that brake/interlock and tacho board is a filter board, but to be honnest, i'd rather spend that £35 (if i had it) on a bar of 120mm delrin.

The lathe runs fine without it, i just have to not be silly and try to change direction with the machine running, and look where the speed knob is before turning it on (but so far when i turn the speed up to polish something, after i'm done i turn the speed back down) and i'm unlikely to put anything in the chuck that can't withstand 1100 rpms for a second or 2.

i've been thinking of taking the relay and brake resistor off the board and wiring them up as shown on the instructions for the main board,

i have noticed that resistor i pointed out on the main board that was getting extremely hot, isnt doing it now, it gets warm but only when the lathe is in use,
with the interlock board in the circuit, that resistor would get very hot even if the motor wasnt running (main power on via the NVR switch, but lathe off via the speed pot switch)

the resistor has been hot enough to burn off the colour bands, so something deffo wasnt right.

andyf:
If the resistor is the big green affair between the relay and the transformer on the "filter board", it probably didn't have any colour bands - power resistors usually have their value printed on.

For reasons too vague to explain, I think it might be worth pulling out the blue relay and checking that it's switching on and off properly (to make sure, for example, that its contacts aren't welded together). If I correctly understand what you have done, it isn't doing anything now, so removing it shouldn't cause any further problems . 

Maybe fit a flap over the Fwd/Rev switch to remind you to turn off before changing direction?

Andy

Gazz292:
the resistor that baked is on the main speed control board, shown in pic 2 of my first post, photos of other controllers show it was deffo a banded resistor,

the brake resistor is a big green wire wound jobbie, with the resistance printed on it,

basically i'm only feeding power to the secondary board to run the tacho, so yup removing the relay and big resistor wont stop that working... i hope,

i keep the knob removed from the direction change switch, so i have to think before i change direction, but it's not something i think i would do anyway, might catch it one day i guess, and in doing so turn it to off, which will blow the speed board it seems,

the direction switch has a 'spare' switch stack now, it handled the interlock function before, i guess i could use them for my own interlock, maybe using a relay to cut main power, so the no volt release switch drops out if i move the knob whilst powered up,

andyf:
Oh, THAT resistor (said he, not having a clue what it does). According to the components list for the KBIC series, on a 230V model it should be 15K-5W/70°C-5%.

Ive sent the parts list and schematic to your email addy, in case you want to try and work out what has been turning the resistor into a slow-blow fuse.

Andy

Gazz292:
thankyou to everyone who has helped me with this problem, and thanks to andy for the schematic,

i've had a little look, but can't figure out what was causing the resistor 17a to overheat, but it was deffo caused by that secondary board, so it can stay out of circuit,

So if i blow the main board by changing direction whilst the chuck is spinning, or i start her up at full speed with some fragile material in the chuck and explodes due to the G-forces, then it's my fault, and i'll either learn from the experiance, or it'll be the last thing i do  :zap:

i'm old enough and daft enough to take responsibility for my own actions, and i firmly believe that i am the one to blame when i do something wrong, not the maker of the machine like some people in the world,
(read a story recently of someone who bought a table saw, was offered the version with a safety devise that stopped the blade and dropped it in the machine if it detected you cut into your hand, he declined as it cost more than the machine without it, he promptly chopped a finger off, then sued the shop for letting him buy the machine without the safety brake  :drool:

Anyway... to be honnest i found the need to set the speed knob to zero every time i wanted to start it up a bit of a pain, i much prefer it now, i set the speed to what i think is good for the material, and leave it there, i get the same speed next time i start up after taking a break to get my legs working again,

and i wont leave the lathes main power on overnight again because i stop it via the speed knob and forget the main switch, well actually the darn thing had cut out on me for about the fifth time that day, and i'd walked off fed up that every time i got the hang of the way i was doing something, it'd die and i'd have to start over again (i've only just made my very first object on the lathe, so im learning a lot fast, but it's so much easier to learn new things if you can't complete what you start)

R17a was already toasty before i left it powered up overnight, but scary to think it could have gone up in smoke,
 
i keep saying i will put in a dedicated power circuit for the bench mounted power tools, a new radial circuit from the consumer unit in the garage thru a no volt release switch, then to the sockets, and some mushroom emergancy stop buttons at knee height along the bench infront of each machine,
hitting one of them will interupt the power feed to the NVR, causing it to drop out, so a reset is needed at the main switch, which will be by the door, so i can turn the circuit off as i leave.

i could even make a cover up that goes over the light switch, opening the cover operates a switch that knocks the nvr off,or i could put a switch in the door lock... or i could just look for a better functioning brain on ebay  :bang:

Navigation

[0] Message Index

[#] Next page

[*] Previous page