how can i reduce pauses between programme lines

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-=PAB=-
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how can i reduce pauses between programme lines

Post by -=PAB=- » Fri 21 Nov , 2008 19:13 pm

is it possible to reduce the slight dwell between programm lines while machining? i am using vr milling 2.3 on a triac pc (2000)

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Post by Martin » Sat 22 Nov , 2008 18:09 pm

On the control panel you need to enable(click) on the Turbo button. The software will then look for moves that can cached together. This will not effect programs when the direction of travel is change because the drives have to have a slight dwell before they can be pulsed.

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problem with turbo mode

Post by -=PAB=- » Mon 01 Dec , 2008 20:21 pm

when i run an engraving program with turbo mode activated posistion of the letters are not in line. running the same program with turbo mode deactivated its fine??? why?? what can i do to make it run under turbo mode and still get the accuracy??


any help would be much appreciated. thanks.

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Post by Martin » Mon 01 Dec , 2008 23:30 pm

Update to the latest version 2 software. VRMillining Ver 2.31


You can download it from the Denford website.

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Post by -=PAB=- » Tue 02 Dec , 2008 0:17 am

already using that version - no difference.

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Post by Martin » Tue 02 Dec , 2008 14:02 pm

1. What is the feedrate overide set to? Try running at 100% or less.

2. It may be that the slides are slack. Try adjusting the gib strips.

3. What version of Eprom is fitted to the euro card? Should be ver 2.1.

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Post by Denford Admin » Wed 03 Dec , 2008 16:14 pm

Not sure why turbo would effect the letters so much - it shouldn't blend the moves that much - can you post a pic ?

A long shot:
Have you got anything in the parameter: Shortest Contour (normally 0)
This can be set to reduce the number of tiny moves that get output to the machine - it drops them where it can (eg if a straight line move was made up of lots of 0.1mm moves, it would smooth it out into 1 and reduce the RS232 traffic). If this is set to something it may be dropping too many contourable moves and you see it in the engraving.

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contour

Post by -=PAB=- » Wed 03 Dec , 2008 21:14 pm

the Shortest Contour is set at 0. eprom is mint 2.1. cant understand why its fine when not using turbo. even in simple bigger moves it loses posistion. the battery in my eurostep card has been removed due to corrosion could this be the answer- no damage was done to the card though. will post pic asap.

thanks.

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Post by Denford Admin » Thu 04 Dec , 2008 10:52 am

I'm starting to think that the axes are stalling when in Turbo then - try a simple program of wavy lines of about and inch length and 10-20 degrees change in direction, then increase to say 40-50 degrees. run them with Turbo on and off and see if there is a difference, I'm guessing the blended moves are causing speed changes which are too much for the heavy slides to handle and ares stalling the motors. When out of turbo, every move accelerates and decelerates to a stop, so there isn't so much stress on the motors.

I remember trying to get Triacs to run 3D contouring programs in the old days, and it was nearly impossible to do at anything like a decent feedrate.
Newer stepper motors / drives with better torque curves would be one solution - the other would be to get the USB V5 upgrade which has far better move blending control. Also have a look at the slides and strips - there's a fair bit of stiction there to overcome, which is why the new VMC1300 has linear bearings and can do 3D work at pretty impressive speeds.

HTH

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the pic

Post by -=PAB=- » Fri 05 Dec , 2008 19:24 pm

picture shows the engraving done with turbo and without - machining the same program notice the difference! i dont think its the gibs or motor sticking- checked the gibs and belt tension. its so closely machined and it still happens. think it must be software???? the euro card and axis drive were taken from a vmc triac would this have any effect??i have a 2000 triac pc the vmc was same year of manufacture.

cheers
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Post by Martin » Fri 05 Dec , 2008 21:13 pm

It looks as if the axis is stalling. If it`s mounted in the same orientation as youre photo then it must be the Y axis. You will need to check for backlash & movement with a DTI. The normal way to cure it stalling is to tighten up the Gib strip slightly to allow for wear. It may be easier to drop the back cover off & turn the drive power off. You can then turn the Y axis motor pulley while adjusting the strip. You need to adjust the strip until the pulley resistance builds slightly.

The cards in the rack will be compatible but check that the Z drive is the higher current drive.

What have you set the feedrate overide to??????

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Post by -=PAB=- » Sat 06 Dec , 2008 1:02 am

its the x axis. backlash is fine. would not tightening the gib strip increase the chance of stalling?? extra stress on motor?? how do i know which is the z drive. my electrical is skill is minimal. how do i check the current?

feedrate max is 1000 but this program is cutting at 150- rapid 1000.

cheers for you help so far. :D

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Post by Martin » Sat 06 Dec , 2008 7:55 am

I meant the feedrate overide pot. Try running at less that 100%. The X axis drive card is the on the left towards the Euro card & the Z is on the right.

The slides & stepper motors interact quite strangely. If the slide is too loose or tight then the stepper motor can stall or miss moves. I find that a good way to adjust the strip is to remove the x axis motor assembly & then tighten the strip while turning the lead screw until you feel a small amount of resistance.

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Post by Denford Admin » Mon 08 Dec , 2008 9:53 am

I agree that it certainly looks like stalling - Martin knows best about the gib strips - I've no idea on that score.

Engraving text is probably the best thing to make the m/c stall - because the move blending was quite primitive, it could not look far enough ahead to slow the axes down around sharp corners. If you did some large spirals made up of small moves, then that would probably work great in Turbo. I think its the small sharp changes in direction that are making it stall when in Turbo mode - Out of Turbo every move is allowed to accel and decel, and dosn't stall.
You may be able to improve it by setting up the slides, but am sure the newer USB control will improve its contouring ability a great deal.

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