Now it starts to get psychological.

There will be differences in the commanded position and the D.R.O. reading.
This is due to the resolution of the steps.
It will go to the nearest available position.

Depends how accurately you want to make a part.

D.R.M. as an old workmate of mine once said.
D.R.M. = Does it Really Matter.
Keep up the good work.
Waiting with baited breath.:)

Your calculations will be close but you should use the built in steps per unit function in Mach to fine tune the steps per mm on your settings menu

This is not the same thing as incorrect steps/unit.
Unless your resolution is extremely course, you should not see results like this. The DRO should read whatever the commanded position is, rounded to the nearest step.
Was this using MDI? Are you sure it wasn't a typo?

Thanks guys...

Al, I would like it to be as close as possible, otherwise what is the point of building a cnc machine? My last machine was spot on or close to it (within .005) in terms of file and DRO, I want this one to be the same as it is classes above the last one.

Pete, will be doing the whole Mach calc when I get further, currently only the Z is semi operational.

Gerry, yup, there was a bit of a memory typo. Just ran a couple of files again and got the following:

File -3.175- DRO -3.184
File -3.20 - DRO -3.3019
File -6.35 - DRO -6.3679
File -18.5 - DRO 18.5142

Its all over the shop so will do more tuning and create a file specifically for the MM when that done. Wiring up the final motors today so hopefully the whole machine will be moving later today....

One more thing guys, I need to get another gas spring so was wondering where your Z top is in relation to the Z plate and the rollers? Does the bottom stay within the bottom set or the middle set?

I have enough rack to take it up to the middle set of rollers, its just my gas spring that is stopping it.

Current one is 585mm charged to 150Nm....

Cheers

The higher your reduction ratio the smaller the increments. I am sure you know this. My reduction is 7.2 with 10 micro step on a 1.8° motor (2000 steps per revolution) with 30 tooth gear and my step movement is 0.0003" (0.0076mm). What is your calculated per step movement? Use a dial indicator and switch your jog mode to single step and check your movement to see if it matches the amount your DRO states. You can also use this for finding if there is backlash occurring from something.

Thanks for that Pete, by chance I am now ready to start doing just that.

This afternoon was a huge milestone for me, all motors are now running and the machine moves by itself now. Lotsa little things to button up but I am smiling ear to ear, and that don't happen very often :)

Going to button up the Z axis and do some tramming and then I am going to give my Sharpie holder a run to test things out. Will post what happens when it happens :D

So I did what Fox did..... the beast draws pictures! Sharpie holder from Kyle work really well.....

Now I move on to finish things up so I can cut stuff.....

Excellent work, your table is too clean...:)

Ah...but you can't see what's out of shot!! :D Thanks Tom, been a long time getting to this point, just a teensy weensy bit to go......

While I am at it I also drew an Aztec/Mayan Calendar. Sharpie wasn't sharp enough for the detail at this size but at least the machine makes circles like it should. More than happy......!

Cool ! Congrats !

Nice machine, perfect draws.

Thanks Ros, appreciate the comment.

While I am here, I am working on getting my proxies working. Just wanted to double check that they can be used as both limit/lift protection AND home switches at the same time. I am currently setting them up for homing, something I never had on my last machine. I am a little confused by having lift or limit trip an estop while all the while acting as homing. Am I right in this assumption or will I need separate home & limit/lift switches to accomplish what I am after.....

If you are using Mach it is smart enough to use them as both. Your configuration defines their use.

Cool, thanks Tom. Should have my little relay board all done later tonight so I can try it all out.

I'm proud to declare that I'm from the "no limit switches required" camp :D

BUT it doesn't mean I can't get involve in conversation on setting up one. :p

I know the same switch does home, limit & lift duties. In Mach3, it comes with the home & limit function very well defined. Once you did your configurations properly, Mach3 will do the trickery. BUT the lift function is not a standard feature. so you might have to do some programming or just leave it as it is. you will know when the screen flashes "limits"

Thanks Ken, am about to try the limit thingo. All the homing is now done and working. Infact, I have homed the machine a number of times as a) I never had a machine do it and b) it's kinda cool to watch it happen :D

Off to try the limits.... with my hand over one of my 4 e-stops ;)

Now I am really happy.... limits now working as well and I even figured out how to get off them :) One step closer to cutting, spindle power and cooling now my target.

The finish line is right around the next corner, floor it!:cool:

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

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.

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 !

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

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

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....

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.

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)

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.

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....

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 :)

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.

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.

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.....

Talk is cheap ;)

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

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

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

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.

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 :)