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hoggy
24-09-2014, 08:47 AM
I have set up my cnc 3040t with mach3, when I open jog screen every axis moves ok . when I use p.c keyboard everything moves ok . when I open roadrunner g code in mach3 and send it to my cnc machine very slight movement in a very small area can any one help please advise will be very much appreciated indeed ...john..

EddyCurrent
24-09-2014, 11:11 AM
It sounds like everything is okay but the roadrunner is very small so looks like the machine is just twitching. Have you set up your Mach3 'steps per' ?

Read this; http://www.mycncuk.com/threads/7871-On-going-6040-problems?p=61514#post61514

then watch this; http://www.youtube.com/watch?v=EVrqObwaAF4

JAZZCNC
24-09-2014, 11:45 AM
Eddy The road runner is not small it's quite large it's just using imperial units and you have tried to cut it with Metric units so appears small.

This will most likely be the problem here.
If you want to use Imperial units then Go to Config menu and Native units and see if it's set to Metric units.?
If so then you'll need to change and restart Mach3.
Then go into Motor tuning and change the steps per. What ever is entered in steps per just multiple by 25.4.

If you just want to see the road runner cut larger but don't want to change the units then just use the Scale Axis feature and type 25.4 in each axis Scale Dro.
You'll find this at the side of the Green DRO box with coordinates in it. Click in it and type 25.4 and push enter, you must push enter or doesn't happen.

WARNING Doing this remember to reset the Scale factor to 1 before cutting other parts or every thing will be sacled 25.4 times.!! . . .Thats why it will flash yellow to warn you.!

To be honest I don't think you have enough room to cut the road runner full size on 3040 so just set the sacle factor to say 5x and that will make it big enough to see cut.

hoggy
24-09-2014, 11:58 AM
thanks for the info got it moving ok but it makes a hell of a squealing noise any thing else I should alter ...thanks for all the info very much appreciated indeed..john

JAZZCNC
24-09-2014, 12:08 PM
thanks for the info got it moving ok but it makes a hell of a squealing noise any thing else I should alter ...thanks for all the info very much appreciated indeed..john

Not enough info to help John.? Where does the squealing seem to be coming from.? Problems like this are quite hard to diagnose thru words would it be possible to take a video.

Will need to know at least how the machine is setup in software. So native units and Steps per, velocity, acceleration.
Also details on the electronics. Does it have the 3 axis all in one board or the individual drives.? Pics would help.

EddyCurrent
24-09-2014, 12:15 PM
Eddy The road runner is not small it's quite large it's just using imperial units and you have tried to cut it with Metric units so appears small.

I meant it looked small to the OP

It just shows how naff g-code files are when the units are not specified in a file header, it's a fundamental principle that when 'values' are used they must be given a 'unit' or else they are just meaningless numbers.

e.g. http://articles.latimes.com/1999/oct/01/news/mn-17288

hoggy
24-09-2014, 12:19 PM
native units inches....steps per 12800...velocity 1999.8....acceleration 200....steps pulse10...dr pulse 3....3 axis all in one board hope this helps..john..

hoggy
24-09-2014, 12:21 PM
squealing seems to come from all the axis,s

JAZZCNC
24-09-2014, 12:31 PM
squealing seems to come from all the axis,s

Yes but is it the motors or linear bearings or screws.?

hoggy
24-09-2014, 12:43 PM
its not the motors or screws I think it is the linear bearings..john..

JAZZCNC
24-09-2014, 01:07 PM
native units inches....steps per 12800...velocity 1999.8....acceleration 200....steps pulse10...dr pulse 3....3 axis all in one board hope this helps..john..

That's step per indicates far too high micro stepping. It would appears to set as if your drives are set at 3200 micros steps and using a 4mm pitch screw.
I very much doubt these drives will be set at that figure and if they are it needs changing to half that and either 1600 or 2000 definatley not more.
Suspect that the steps per is wrong for the drives and if that was the case then the machine will move the wrong amount.

Try this.! Type G0 x0 into MDI window and see how far it moves. This will tell you if set wrong or not. It should move 1inch but I suspect it will only move 1/2".?

if wrong then easy way to save you messing around is to use the built in Set Steps per option on the settings tab and measure the distance moved. Mach will then enter the correct amount for you.

If it's correct then I would change the drives to a lower micro stepping because that will be too high for these drives and put more strain on the PC parallel port.

JAZZCNC
24-09-2014, 01:11 PM
its not the motors or screws I think it is the linear bearings..john..

Oh in that case then either send it back if new or get it stripped down and find the issue. Grease is marvelous stuff but it seems in short supply in china so chances are it's drier than desert.?

JAZZCNC
24-09-2014, 01:19 PM
It just shows how naff g-code files are when the units are not specified in a file header,

They are if you know how to read g-code the G20 says it all. It's always at the top of G-code or in the intial string and Mach displays this on the top bar so there's no excuse really.! . . . . Every one should try and learn a little G-code and Units to be cut in is one of the must's along with offsets and mode codes.

hoggy
24-09-2014, 01:23 PM
going to try greasing it and see what happens

EddyCurrent
24-09-2014, 01:34 PM
They are if you know how to read g-code the G20 says it all. It's always at the top of G-code or in the intial string and Mach displays this on the top bar so there's no excuse really.! . . . . Every one should try and learn a little G-code and Units to be cut in is one of the must's along with offsets and mode codes.

Yes but I meant in a proper file header, not the code itself, so that Mach3 for example could scale it automatically.

JAZZCNC
24-09-2014, 01:45 PM
Yes but I meant in a proper file header, not the code itself, so that Mach3 for example would scale it automatically.

Ok last word from me on this as it's not the OP's problem.!!

Mach won't scale it automaticly because it's native units are set to metric so 1 in G-code equals 1 unit and if thats metric it's 1mm or 1" if imperial.
The G20/21 doesn't change any of mach's settings so the native units are the same. It's mostly to identify the units not set or change them.

EddyCurrent
24-09-2014, 01:49 PM
native units inches....steps per 12800...velocity 1999.8....acceleration 200....steps pulse10...dr pulse 3....3 axis all in one board hope this helps..john..

From a similar machine manual they have it set to 400 steps per (that's for a metric machine)
It had 1404 trapezoidal screws, microstepping likely set to 8, motors were 1.8deg.

step per = "The number of steps Mach3 must send for one unit of movement"

So for a metric machine one unit of movement = 1 mm;

a 1.8 deg motor has 360 / 1.8 = 200 steps per rev.
with microstepping set to 8, 200 x 8 = 1600 steps per rev
with a screw pitch of 4mm, 1mm movement = 1/4 turn
1600 x 0.25 = 400 steps per

So for an imperial machine one unit of movement = 1 inch;

a 1.8 deg motor has 360 / 1.8 = 200 steps per rev.
with microstepping set to 8, 200 x 8 = 1600 steps per rev
with a screw pitch of 4mm, one inch movement = 25.4/4 = 6.35 turns
1600 x 6.35 = 10160 steps per

All of that assumes a 1:1 ratio between motor and leadscrew

EddyCurrent
24-09-2014, 01:51 PM
Ok last word from me on this as it's not the OP's problem.!!

Mach won't scale it automaticly because it's native units are set to metric so 1 in G-code equals 1 unit and if thats metric it's 1mm or 1" if imperial.
The G20/21 doesn't change any of mach's settings so the native units are the same. It's mostly to identify the units not set or change them.

You are correct but what I'm saying is, this leads to issues where the machine cuts to the wrong size.

ukracer
11-10-2014, 11:58 PM
From a similar machine manual

Where would I find an online manual for this type of machine. It seems they are awash with them on ebay but no parts or after sales are in existence lol