Forum

Welcome Guest 

Show/Hide Header

Welcome Guest, posting in this forum requires registration.





Pages: [1]
Author Topic: Resize Vector Issues
wdm
Newbie
Posts: 6
Permalink
Post Resize Vector Issues
on: June 3, 2019, 07:46
Quote

I have a new PolargraphSD v3.1 basic unit and the latest version of the controller on my Mac.
I am trying to do EVERYTHING over SD card
I have checked and double checked all my measurements
I use the "resize vector" in the controller to achieve the size I want.
I create a queue with "upload machine spec", then "set home" then "draw vectors"
I then export that to SD and load onto machine
The drawing is much smaller (< 20% of the size) and also may be distorted in height. IE Taller than it should be

Q: does resize vector work or should I create vectors at the correct size ?

wdm
Newbie
Posts: 6
Permalink
Post Re: Resize Vector Issues
on: June 3, 2019, 08:03
Quote

Also - I have a new machine but the motors from this era

this morning I had the mm/rev etc based on my old set up - https://www.instructables.com/id/Polargraph-Drawing-Machine/ this lead to tiny drawings.
I have now set the mm/rev etc based on here http://www.polargraph.co.uk/setup/polargraphsd-controller-application/ and drawings are slightly bigger but still a lot smaller than they appear in the controller software.

sandy
Administrator
Posts: 1384
Permalink
sandy
Post Re: Resize Vector Issues
on: June 3, 2019, 13:46
Quote

Hi! Those old motors are 400 step ones, so I think you'll set
stepsPerRev: 400
stepMultiplier: 8
mmPerRev: 95 (I think those old sprockets were the same size as the newer ones)

give that a shot,

sn

wdm
Newbie
Posts: 6
Permalink
Post Re: Resize Vector Issues
on: June 5, 2019, 08:18
Quote

I had to do stepsPerRev: 400 stepMultiplier: 16 to get it to draw on A2

These values allow me to draw on an A2 sheet but when I added a new page size for A4 (with the correct setup of the machine sent to the SD card) it still drew everything at A2 size even though the controller clearly showed the artwork inside the bounds of the A4.

Clearly, there is something wrong but I can't understand what

also from time to time (mostly when the machine is left idle I think) the motors power off - the gondola falls etc and the motors aren't locked. The Machine still has power and the Motor on/off needs to be toggled to re-engage them. this seems very odd

Adjsutung

wdm
Newbie
Posts: 6
Permalink
Post Re: Resize Vector Issues
on: June 8, 2019, 03:33
Quote

size issues sorted

stepMultiplier is set to 1 for these motors

sandy
Administrator
Posts: 1384
Permalink
sandy
Post Re: Resize Vector Issues
on: June 8, 2019, 17:20
Quote

So the combination of step multiplier and stepsPerRev is designed to make sure that the motors only ever stop on full steps - never on microsteps. Microsteps can be used to get from one full step to the next, but if you stop on one and try to hold the position, then the motor will eventually "collapse" into one of the full steps either side. Doing this once or twice won't make much difference, but on a really long sequence, it might all add up and create some subtle distortions - effectively dropping or adding steps. Might make a difference, might not, but something to keep an eye on.

sn

Pages: [1]
Mingle Forum by cartpauj
Version: 1.0.34 ; Page loaded in: 0.046 seconds.