PiWeb won't accept Nominal input from characteristics editor, plus 2d curve?

[[Ow...]]

This may be a redundant question as I use just the basic version of PiWeb, but has anybody else noticed this? 

Currently running 7.8.08.

Another question regarding curve (sorry not right place to post but, time is limited), every time I bring in a 2D curve feature it says " nominal points are not exactly arranged in a plane"? 

[[Ma...]]

I think i've seen this PiWeb message on forum some years back.

About 2d curve - is your nominals in X ( or correct axis ) same for all points? It can be corrected in modifying nominals last tab.

[[Ow...]]

Please sign in to view this quote.

Regarding PiWeb, I'm going to try and restart the computer and Calypso, that fixes a lot of things.

Curve nominals are in the correct axis but, the Y numbers do differ around 0.10mm. 

The curve points were digitized to create the nominals, which never puts them all the same in plane axis, so I guess this makes sense. I've just never seen Calypso reporting that in past versions. I'll correct them and try again when time is available.

I do appreciate your quick reply Martin Jansky.

[[Ma...]]

Yeah restart do many magic things :-)

If you digitized that curve i would go extra mile to make correct curve with help of model because vectors will be bad too.

For start just correct that nominal axis which was used as cut, then you can try to correct nominals by trying setting as perpendicular to plane or axis of alignment - this should straighten them.

[[An...]]

For the PiWeb message, see :

 

 

[[Ow...]]

Please sign in to view this quote.

Restart didn't fix the PiWeb issue but Andy Block's post fixed that. I'm not sure how it got changed to "amount mode" , but selecting number scale fixed it :-).

Modifying the nominals with the constant value in the coordinate axis direction fixed the " nominal points are not exactly arranged in a plane" error.

I don't have a model, that's why I digitized it. I do have drawing showing the cam nominals and vectors and what I digitized is very close. When digitizing a involute type of curve and other small features, using a very very slow scanning speed of 0.3 or less is critical to getting good results.

When I get back to working in my office, I'll create the cad model, I just didn't have the time for this little one-on, one-off R&D project.

I couldn't edit my original post but, the amount the Y axis nominals differed from each other was less than 0.010 (not 0.1) and again, I don't ever remember Calypso giving that pop-up error and I believe this is the first curve I've digitized since loading Calypso version 2024 back in December. 

[[Ma...]]

Please sign in to view this username.

 I have VastXT - i am scanning 1mm/s - are you telling me, that running slower have a benefit for active head? I sometimes need to scan gears or similar things to make a drawing ( to be machined new part at our facility )

I am having hard time when i offset that curve, so i am leaving that at center of probe, reducing points and rest make in SolidWorks. Points are good, but sometimes vectors are doing such bad job.

Any hints ( that gear mention was just for imagination of part, no licence for gear and no need for that 🙂 )? Thanks

[[Ow...]]

Please sign in to view this quote.

Yes, slower will help, 0.3mm/s is where I'd start and I'm using a Vast Gold head. It does take a long time but, quicker than if you have to do it twice because you got bad results. 

Also it depends on the curvature, but using a point density (points recorded) spaced at least 0.075mm will help. The tighter the points spacing is, the slower you will have to scan to keep the head and probe from searching back and forth for a point. If still having vector issues, taking thousands of single points (instead of scanning) will help but even slower.

 

[[Ke...]]

Please sign in to view this quote.

Curious if you have standard speeds/densities that you tend to use?

I have only needed to use Curve sporadically; but more recently I have been needing to digitize curves(probably nothing shorter than 10mm overall); I have been using 2-3mm/s with 0.1mm step width for longer curves, and 1mm/s with 0.05mm/s for shorter ones.

[[Ow...]]

Please sign in to view this quote.

Martin Jánský,

I was in a hurry in my last post (was focused on a 10 day vacation) and didn't exactly address the "offset of the curve for the probe" issue you said you were having. The only problem I recall having back when you had to correct them for probe radius was that sometimes it would flip a few vectors and offset the nominal in the opposite direction. That may have been caused by having too many vectors close together (?), I can't remember.

In newer versions of calypso, after selecting to digitize, a check box appears for stylus correction and it has always worked for me.

 

Edited May 28

[[Ow...]]

Please sign in to view this quote.

Keith Forche,

Unfortunately, I don’t have any standards; although it would be nice if somebody did.

It seems like every type of geometry requires a certain prescription.

I’ve digitized a lot of stuff over the years and most of my knowledge has been developed through trial and error, digitizing geometry with known specifications (prints, models, masters) and having other means (optical, laser 3D scanning, etc) of identifying the feature accurately to compare to the digitized data to.

The probe size, rigidity and the size and the amount of expected short arcs, involutes and changes from common parametric shapes play a role in how slow or dense one might start with. Depending on the accuracy required, I’ll digitize and transfer the points to cad software and for cad to recognize them, the points must be in sequential order. If the curve points do not come out in sequential order (even after choosing actual to nominal), then the probe has searched back and forth to create the curve and is generally not going to be that accurate.

Not always possible but, the key is having other means to double-check the data collected. 

Digitizing a 3D curve is fun, challenging to say the least.

[[Ma...]]

Please sign in to view this username.

 Thanks - i don't recall if i am having this option. I should make a study for me to find best settings. I am experiencing lower demand for my machine so i'll do some tests in free time 🙂