Newbie- Complete hobby build from SCRATCH, 3axis

[lamesh99]

today, i made my first real model cut. the idea was to cut out simple router mounts for my dremel-like router. problem was i haven't had the time to get some 15mm mdf, so i used 25mm. wasn't really a bad idea, but i'm having some issues. first, i addressed the flexing of the Z towards the X, replaced Al with tool grade steel rods, tightened some loose screws, and got actual results. problem is within the software, either meshcam or kcam. first piece i cut out was shortened on each sides by 0.7mm, but the 22mm central hole was within 0.20mm tolerance. now, the 100xcca60mm models of router mounts are shortened by 1,2mm on 100mm side, and 1mm on 60mm side. also, the central hole was shortened by 0.7mm in radius (1.5mm in diameter). has anyone had similar problems wit these combinations before? i altered the meshcam's .nc extension into .gc so that kcam could swallow it more easily, and i have been wondering if this could be the cause.
any help most appreciated

[hub]

Originally Posted by lamesh99 today, i made my first real model cut. the idea was to cut out simple router mounts for my dremel-like router. problem was i haven't had the time to get some 15mm mdf, so i used 25mm. wasn't really a bad idea, but i'm having some issues. first, i addressed the flexing of the Z towards the X, replaced Al with tool grade steel rods, tightened some loose screws, and got actual results. problem is within the software, either meshcam or kcam. first piece i cut out was shortened on each sides by 0.7mm, but the 22mm central hole was within 0.20mm tolerance. now, the 100xcca60mm models of router mounts are shortened by 1,2mm on 100mm side, and 1mm on 60mm side. also, the central hole was shortened by 0.7mm in radius (1.5mm in diameter). has anyone had similar problems wit these combinations before? i altered the meshcam's .nc extension into .gc so that kcam could swallow it more easily, and i have been wondering if this could be the cause. any help most appreciated

I'm pretty sure it's not a CAM problem. Did you check the gcode file, was there anything wrong with it?
Changing the file extension has no effect on how the part will turn out.

Are you sure your steps/unit is correct?

Do you have backlash? If so do you have backlash compensation on?

Flex on the machine? How much?

Or lost steps maybe?

Hub

[lamesh99]

Originally Posted by hub I'm pretty sure it's not a CAM problem. Did you check the gcode file, was there anything wrong with it? Changing the file extension has no effect on how the part will turn out. Are you sure your steps/unit is correct? Do you have backlash? If so do you have backlash compensation on? Flex on the machine? How much? Or lost steps maybe? Hub

i actually solved it yesterday, but hadn't had the time to reply to myself. problem was in steps/mm setting. i forgot that, when i first tested everything, i roughly calculated the ratio, and left it that way. i recalculated it, and got 133,78steps/mm. since i'm using threaded rod (allthread?), that's not so much. i plan of upgrading a bunch of parts later on, as i get more hang of the machine. so far, it has been a straight, but slowly climbing learning curve, but i like it that way. bunch of guys here were very helpful, but you can't fully understand something until you sink your teeth in it.
thanks for replying, hub!

[lamesh99]

Originally Posted by cncmakers001 Good design.

really? thanks a lot! always nice to get a compliment! any suggestions for improvements?

[zhipps]

I finished putting together the tom Mcguire's circuit on my breadboard, and I'm having some problems getting it running right. It doesn't step like it should, and when I try to jog it to the left, it turns on and wont stop! You mentioned in your post that there were some functions in Kcam that you had to shut down. Can you tell me exactly what you did, or point me in the right direction. I appreciate your help!

[lamesh99]

Originally Posted by zhipps I finished putting together the tom Mcguire's circuit on my breadboard, and I'm having some problems getting it running right. It doesn't step like it should, and when I try to jog it to the left, it turns on and wont stop! You mentioned in your post that there were some functions in Kcam that you had to shut down. Can you tell me exactly what you did, or point me in the right direction. I appreciate your help!

i had to turn off some features in kcam because i have (at the moment) a prehistoric (abacus almost) PC. i had some skipping during continuous rotation, but that was because of the PC, it didn't deliver impulse packets in flow, but in separate packets with a slight pause. did you setup the LPT pins correctly? could you post some photos?
in table setup, in axis display features i checked all boxes except the invert z coordinates, and i set the application priority to normal or high, especially if i ran something else in the background. i found this on kellyware's online help section, but i cant find it anymore, unfortunately. hope this helps

[lamesh99]

tested the configuration with 36V supply today. as opposed to 12V PC psu (350mm/min max), i am getting around 600mm/min. a lot more than i hoped for next step, PSU build. 36v, 10A.

[lamesh99]

i made myself a little enclosure for the BoB and the driver boards. nothing complicated, just an old alarm control panel enclosure and a piece of 8mm MDF cut to size. looks a lot more organized and professional

[lamesh99]

i've had some issues from the moment i finished my first driver board for this. the issue was in motor overheating. thing is, the mcguire driver has an optional enable input. it's optional because it draws the high state (~5V) from the 7805 stabilizer, thus making one phase of the motor constantly energized, which, at higher voltages, simply burns the phase (happened to me when i was testing with 36V) after some time. this problem is relatively easy to solve, simply alter the schematic, so that the enable function is normally in low state, so it's only enabled when it gets the signal from LPT.
next issue was with my BoB. the enable outputs towards driver boards are connected in parallel. yes, when one axis (out of five) is enabled, ALL others are too. this works when all three axis' are working, but problem occurs when only one or two are. again, overheating, and possible damage to the motor. again, this can be solved easily. simply take the signals from one axis that is not used, B, for example, by changing the pin setting in the software.
after that, it's all a breeze. almost

[lamesh99]

forgot to post some photos to explain better: