ISDX - a near miss

[DeanLong]

Why isn't there an offset surfacefunction whilewithin the superfeature?

Why can't we link superfeatures to influence each other at boundary conditions? To that point, why can't we link superfeatures at all?

Why can't we see surface deviation tolerance, G2 boundary departureandcurvaturevalues in both U andV inreal time?

If this basicClass Afunctionality was "in there", we would be so close to having a stellar Class A tool!

PTC...why is ISDX still relegated to second string?

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[ptc-169947]

Hi all,

Any suggestions or links on how I can model the screw thread in fig 1? I have limited experience with helical sweeps yet was able to get the thread, just not the blend into the minor dia (lower right, fig 2). My current thread comes to a halt.

Thanks,
Stefan

(Wildfire 2, regrettably)


Fig 1 Fig 2

[cid:image003.jpg@01CC6732.8A708F40] [cid:image006.jpg@01CC6732.8A708F40]

[NEALROSENBLUM]

Dear Stefan,



You can create screw threads for standard screws. Or you can go to
www.mcmaster.com and download any number of formats of standard screws.





Sincerely,

Neal Rosenblum

Geometrix Engineering, Inc.

201 N. 13th Avenue

Hollywood, FL 33019

[colin]

Stefan,

Grabbing a step file from McMaster could get you want need if you do not
any parametric dimension. To create a helical sweep that blends down
the way you want you need to have a sweep profile that blends into the
root diameter like this quick and dirty example



Dimension your section off of the sweep end point

[BrentDrysdale]

Hi Stefan,
Somebody may have already said but you can change the profile of the sweep
trajectory to give the run out at the start of the thread. Instead of a
straight line you add a slope at the end or even an arc.

Sometimes it helps to do the thread sweep as a surface then construct the
end details in surfaces and merge them before solidifying the thread. As
others have said you can get standard screws with thread if you look and
mostly it is not necessary or even desirable. That said sometimes it is
required in which case i have used the methods outlined above with good
success.

Hope this helps.


Regards, Brent Drysdale
Senior Mechanical Designer
Tait Radio Communications
New Zealand
DDI +64 3 358 1093
www.taitradio.com

[BrentDrysdale]

Hi Stefan,
Have just re-read my answer and realise I should have said

As others have said you can get standard screws with thread if you look and
mostly it is not necessary or even desirable to model threads in detail.

I missed out those last five words and that made the sentence ambiguous.
Hope that did not cause any problem


Regards, Brent Drysdale
Senior Mechanical Designer
Tait Radio Communications
New Zealand
DDI +64 3 358 1093
www.taitradio.com

[DeanLong]

Hey..how did you guys hijack my thread with talk of screws?

In Reply to Dean Long:

Why isn't there an offset surfacefunction whilewithin the superfeature?

Why can't we link superfeatures to influence each other at boundary conditions? To that point, why can't we link superfeatures at all?

Why can't we see surface deviation tolerance, G2 boundary departureandcurvaturevalues in both U andV inreal time?

If this basicClass Afunctionality was "in there", we would be so close to having a stellar Class A tool!

PTC...why is ISDX still relegated to second string?

[rrich]

There are many ways to look at a screw thread. I like to try and model mine
in the same fashion that they would be manufactured. So I would model the
screw to the major dia. Then cut in the screw thread. Then if needed revolve
a cut at the end for lead in or this could be done before the thread.



Your example in figure 2 looks like you added the thread on. This works
too, but you could have ran the thread longer and then cut on the lead in
(revolved cut) this would give you a lead in look.



Ron



Before revolved cut
After revolved cut

[dgschaefer]

Dean,



This is a function of the schizophrenic forum / email system that has
been adopted. While many (most?) of us use this as an email list, it's
really a forum like MCAD Central under the skin. Emails get published
at PTCuser.org as forum posts and replies get sent out to the
participants as email messages



I think the originator of the screw thread took your incoming email,
clicked reply all and then deleted everything to create a new email.
Unfortunately, the it still has some kind of internal tags to your ISDX
thread and so the forum software sees it as a reply to it.



The net effect is that the forum is essentially useless as it's full of
mismatched posts and a lot of extra garbage that comes through in the
emails, like signatures and the reply text. [1] For this reason, it
works a lot better as an email list since you don't have to sort through
all the chaff.



Increasingly, however, more new members are finding the forum online and
posting there, and that means that email users don't seem to get some
posts and don't get any context on others.



Frankly, it's been broken since they implemented it and it's getting
more broken as time goes on.



[1] - Just take a look at this thread online:

[DamianCastillo]

I think Forums are much easier to deal with than emails. I always enter my questions as a Forum post and make my replies on the forum. I don't mind the emails that tell me someone responded to my question, but I always do everything in the Forum.

The email system was something adopted way back in the day before a Forum was ever built. Many people don't like change, so they left the connection to this old way of doing things in place. Some people claimed that they can't get Internet access at work which I find hard to believe in today's world.

Any company that has an Engineering Department with no Internet access should get with the program.

Just my thoughts. 🙂

"Too many people walk around like Clark Kent, because they don't realize they can Fly like Superman"

[davehaigh]

I was reading Doug Schaefer's post and yours. I'll admit that sometimes, not most of the time, I do reply to an email, delete everything and change the subject line. Since I never go to the web site I've never seen the problem. Of course now the thread has been hi-jacked with a new subject. Reading the forum vs email.

I just don't see how using the website to read and post is easier/better than email.
As I see it here are the problems:

* You have to go to the web site to look at stuff. It requires action on my part, It doesn't come to me.

* Response to questions has to be slower for people looking at the website because they don't get immediate notification of posts. If I see a question I know the answer to, I respond as soon as I have the time to. Quick response is the whole reason the mail exploder works so well.
The only time I use the web site is to look up previous topics.

The problem with email, is you don't typically want all that traffic in your inbox. That's easily solved by setting up some filters in outlook so certain emails get directed to sub-folders of the inbox.

Here's what one of my filters looks like:
[cid:image003.jpg@01CC6881.09599F00]

David Haigh

[TerryMcFall]

I need a "Like" button for David's message...

An additional benefit to email is the ability to add "Message" to Outlook columns which gives an instant preview of many postings. Between that and the Subject column I can quickly scan many messages to determine which ones follow.

[4400snap_511.jpg]

-Ter

[dgschaefer]

In Reply to Dean Long:

Why isn't there an offset surfacefunction whilewithin the superfeature?

Why can't we link superfeatures to influence each other at boundary conditions? To that point, why can't we link superfeatures at all?

Why can't we see surface deviation tolerance, G2 boundary departureandcurvaturevalues in both U andV inreal time?

If this basicClass Afunctionality was "in there", we would be so close to having a stellar Class A tool!

PTC...why is ISDX still relegated to second string?

Dean,

Great questions, I can't answer them (only PTC can). I've long been frustrated by ISDX. As an ID firm, it would seem to be exactly what we need, but it seems half baked and hampered with an inscrutible user interface. Frankly, I try it every now and then and usually give up in frustration.

Doug Schaefer