Machining Aluminum #122 - Sydney, Australia

[racedirector]

Weird stuff going on. I adjust my z plate today and got it all square and good. Put the Z motor back on and it is doing strange things. After a few stroked it will suddenly grind it way back to the top, just like it suddenly lost power.

Changed the controllers over, tested with another motor and no change. Been driving me nuts all afternoon.

Getting really peeved with my ESS as well. It will lose comms for now reason, lock up for no reason or suddenly the jog keys will disappear as well. I changed computers thinking it was that again with no change. Seriously considering taking it out and running the 126 in extended mode via PP cable to get my extra inputs.

One step forward, 10 steps back... grrrrrrr

[Tom Ayres]

Process of elimination. Start with connections, then check for programs running in the background (including screen savers), do driver tests, test run a different toolpath file, etc. Give us feedback, good luck.

[Fox]

No ground loops etc ? I am happy with eding, none of the mach3/pp 'quirky' noise issues, playing tricks with my mind.

Maybe take a breather, sometimes ir saves huge amounts of time when you get back on things with a fresh mind !

[Tom Ayres]

Fox, it's just not your turn yet...

[racedirector]

Thanks guys..

Fox, no ground loops. All earths come back to a big grounding bar in the control box.

Tom, about to install my third computer, this one with Win XP on it, the last 2 have been Win 7, one 32 bit, one 64 bit. I did get the Z to go up and down nicely but that was with the gas spring off, I had to make sure there was a soft landing for the Z when I turned the power off though as it drops like a rock.

I'll run a file today that does alot of Z action to see what happens. I also loosened all the Z rollers again thinking I may have had them too tight. Will report todays escapades as they happen..

Cheers

[racedirector]

Just found and re-read Ross' (SurfCNC) post back on page 2 and realised I DID buy the wrong strut. He indicated the strut body should be 350mm long and mine is 295. It is an 18mm dia and is charged to 15Kg but the incorrect length is playing havoc with the slides action. Will order the correct one on Monday so hopefully things will start to come right in that department next week....

[racedirector]

Definitely the gas spring acting against the bipolar parallel setting on the motor. As the spring goes down the spring will back drive the motor, not good for either rack/pinion or the controller.

I was reading in the Leadshine manual that wiring Bipolar Parallel offers good stability but less torque at low speeds. This seems to ring true with the Z because my steps per (as per the gear calc spreadsheet) say that my motor should be doing 269.5 rpm. (800 Microsteps, 30T pinion).

Now my motors seem to be a bit strange in as much as when they are powered off they just freewheel instead of having a bit of resistance such as you would have when connecting the coils together, this is due to the wiring config. Pic Attached, BP is the right side wiring.

[danilom]

When powered off motor axis should move freely if the wires are not connected together, as they are not shorted inside the drive.

The more the motor freeweels it means it has less detent torque and its better, he can achieve greater speeds as on the big rpm torque falls to detent torque plus friction it stalls.

If you have a problem that a gas spring pulls you motor up, disable only on Z axis drive idle current reduction to 50%, the gas spring pulls it out when the current gets to 50% and he looses torque. Either that or get the spring with less power (my recommendation)

[racedirector]

Thanks Danilo

The spring isn't dragging it up at all under power, only when I power down. What I ultimately want is a spring the just holds the Z in position at power off so I don't have to re-zero everytime I start up. I didn't have enough proxies to do the Z as well so it is all manual. Maybe I should get my Z stops in place as the total travel exceeds where I have my dust shoe just below the spider.

The trouble I am having with my current gas spring is that it suddenly seems to overpower the motor as it heads down. It only started doing this after I reassembled my Z after tuning it a bit. Even after checking that the V wheels weren't set to tight etc etc it still does it. I am ordering a new spring tomorrow with less charge. I weighed my Z assembly with spindle and dust show attached at it comes in around 13kg. The current spring is 15Kg (150Nm) but I think it is slightly too short.

[racedirector]

Spoke to the gas strut people this morning and a new one is on its way. This time I was armed with min length, max length and weight and have ordered one that will (should) hold the Z axis static on power off. If I got the charge wrong again I can get the replacement recharged at minimal cost. To me $38.00 well spent....

[racedirector]

Got my new gas strut today, much much better. No overdriving the Z and just holds the Z in place with a tiny bit of movement upwards. This one is charged to 12Kg (120Nm) and is currently holding around 11.5kg of Z. Will check again when I have absolutely everything attached to the Z, the 11.5Kg is with the spindle but without the dust shoe. My shoe will be made from 12mm acrylic and will be two piece so that should bring it up to around 12Kg.

I am also happier with the travel I have on the Z. With the spindle collet sitting on the table (1 thickness of 18mm MDF) The strut is compressed to 345mm. Max up with the dust shoe on is 545mm and with it off its 630. Plenty of travel for all sorts of things

[racedirector]

Well, today I enquired about a stall at a local market day on Nov 1. Feeling reassured by my progress I will be committing to that as today was another good day. MY newly aquired Xbox 360 controller works a treat and the VFD received power today. Tomorrow the spindle will get the same and my new water pump will be plumbed into the system. My old one, that worked fine on my previous machine, just couldn't cope with the extra distance and height on the Mechmate. The new one has a 4 meter head and tons of flow so it should push the liquid all the way and back again. Bloody well should, after all it set me back $189.00. Oh well, par for the course these days

Aiming for making some sort of dust by the end of the weekend..... finally.

[Fox]

Wow, that's an expensive pump !
My replacement also cost me 70 euro though, but it has 5 years of warranty, so I decided not to cut the plug to wire it directly to my control box. If i don't tell them i pumped G12 coolant with it and it fails they might send me a new one in a few years ;-) Ps. Had the same problem with the old one not coping with the restrictions in the new system.

[racedirector]

Definitely dust by the end of the weekend, if not sooner! VFD wired up today and the spindle runs!! From tomorrow, hook up the cooling, clean the table of all the workings so far, clean the garage of construction material, whack a chunk of MDF on the table and have at it.

Exciting stuff.....

[pblackburn]

Talk is cheap

[racedirector]

Hahaha, that is true Pete, it is. Proof will have to be in the pudding... or the dust

[pblackburn]

It is most definitely exciting when nearing the end of the build. Wishing you the best.

[Fox]

Great ! Same-same-but-different here !
(I've send you a PM)

[racedirector]

So..... it now cuts.... but not after some dramas. In the process of trying things out I broke one of my CMT bits and the cause was driving me nuts for a while. I could not understand what was going on and why the Z wouldn't plunge cut.

Long story made short but my spindle was going in the wrong direction, CCW. Took me a while to understand what was going on but once fixed the bits seem to cut a whole lot better and not break No pics, will take some of making that elusive dust stuff next time I fire it up.

Before I do that I have to work on dust collection. My tests were in pine so it was more chips than dust but I don't want to do any MDF without some sort of collection. Off to buy some acrylic tomorrow to make my dust shoe then I will route the dust collection hose.

Oh, and also found out I need more/bigger fans in the control box. We have had high heat here in Sydney's west (35c+) and with the door closed one of my controllers shutdown from overheating. My safety circuit protected the machine from any damage though, when the controller turned off the machine went into e-stop. At the moment in this weather I am running with the controller door open but will over compensate in the fan department so I can close the door.

[clarson66]

Your not alone, we couldn't work out why the cuts looked like S**T and why it made some much noise. Changed the wires and got it turning the right way, works so much better

[racedirector]

Yup, thats exactly what I was experiencing. I got lots of smoke at one point and panicked all while totally forgetting about the 4 e-stops I have all over the machine

[Tokamak]

Same here on my first cut, got so mesmerized by the sound of the spinning bit that I didn't even consider the rotation. Never had to consider rotation on any of the routers I've ever used.

[Fox]

I even had my reverse wired up ( my software allows for that cause of lathes etc ) untill I realized that was plain stupid with my colletholder

[danilom]

I use left-hand compression spiral 1/2" all the time for melamine cutting (bought dozen on sale cheap).
The collet and nut never came loose on the Chinese water cooled spindle. So its safe to use it in any direction M3 or M4

[pblackburn]

How about pictures to get it a number. Video is even better.

[racedirector]

Phew, good to hear I am not alone. Should have known better as I had already used the spindle on my other machine

Video/picture evidence coming Pete, its just every time I do something I forget to take pics/video!

[pblackburn]

I know that feeling. There is a lot of stuff I would have liked to had on video to post on here.

[racedirector]

Okie Dokie.... remembered to take video.... or at least I remembered to get my son to do it while I manned the dust collection.

Cutting out a dinosaur as its first cut per se, did an OK job. Table needs levelling (not happening until dust shoe done) and I have chatter on some circular parts but kind of accept that this will happen with direct drive, meaning I should get my reduction boxes happening soon. All in all happy with the way it ran.

https://www.youtube.com/watch?v=dO-QblvJMPk

Cheers

[MetalHead]

Congrats on getting her built !!!

[pblackburn]

Congratulations.