Site Logo
Site Logo
 
It is currently Sun Apr 02, 2017 6:58 pm

All times are UTC [ DST ]




Forum locked This topic is locked, you cannot edit posts or make further replies.  [ 9 posts ] 
Author Message
 Post subject: clearances on shcs etc
PostPosted: Fri Jan 06, 2012 2:32 pm 
Offline
Community Moderator
Community Moderator
User avatar

Joined: Tue Jul 27, 2004 2:22 pm
Posts: 355
Location: Manchester
Hi Folks,
When you place a screw in an assembly you can either accept the clearances that PowerSHAPE wants you to have (which means you'd be putting the same clearacnes in on an M4 screw as an M24 screw. So, in other words, you can't accept the defaults, or you can type in your own sizes. We you ISO standard clearances which means, of course, that the clearances get bigger as the screws get bigger. I don't want to have to tell PowerSHAPE every time I place a screw, what sizes to use. Is there a way to get PowerSHAPE to remember what clearances to use? (so that as the screws get bigger, so do the clearances).

Cheers,

Mick.


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Mon Jan 09, 2012 11:37 am 
Offline
DELCAM Staff
DELCAM Staff
User avatar

Joined: Fri Mar 03, 2006 1:51 pm
Posts: 42
Location: UK
Hi Mick,

Toolmaker's default clearances are based on diameter, so an M24 screw will use larger clearances than a M4 (2mm instead of 0.4mm shank cleance).

You can override the default clearance in Component Wizard when you create a new component, or set a new default on the options page
(Manufacturing > Toolmaker > Power Feature Clearances). This is a single default value, you can't currently set a user defined clearance based on diameter.

Would you like me to open a wish to set a user defined clearance based on component size?

Thanks,
Ian


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Mon Jan 09, 2012 7:45 pm 
Offline
Community Moderator
Community Moderator
User avatar

Joined: Tue Jul 27, 2004 2:22 pm
Posts: 355
Location: Manchester
hi Ian,
I can't get PowerSHAPE to do what you're saying i.e. increase the clearances as the screw size gets bigger, maybe i'm picking a different screw than you. I've included a screendump of what I get when I select a 24mm Z31 from the Hasco catalogue. These are the clearances PowerSHAPE wants me to use. As far as I can see, the clearances stay the same all the way through the size range. We pick most of our parts out of Hasco and, in an ideal world, I'd have the clearances follow the Hasco design guide. However, if PowerSHAPE remembered the sizes you supplied most recently that would be a useful feature.

Cheers,

Mick.


Attachments:
M24 SCREW CLEARANCES.pdf [196.01 KiB]
Downloaded 15 times
Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Tue Jan 10, 2012 10:12 am 
Offline
DELCAM Staff
DELCAM Staff
User avatar

Joined: Fri Mar 03, 2006 1:51 pm
Posts: 42
Location: UK
Hi Mick - nice and easy, just enable the "Automatic clearances" checkbox in Component Wizard 8)


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Tue Jan 10, 2012 12:40 pm 
Offline
Community Moderator
Community Moderator
User avatar

Joined: Tue Jul 27, 2004 2:22 pm
Posts: 355
Location: Manchester
Hi Ian,
It just goes to show how you can see something and completely ignore it!! Some of the clearances are a bit wacky though. For instance, a 10mm shcs gets 2mm clearance on diameter (which sounds a lot to me). A while back, I created a PDF with the various clearances on it (from the Hasco design guide)and stuck it to the side of my PC (for easy reference). I've included it with this post and it'd be appreciated if you could ask development to give us some method of setting our own clearances (maybe some kind of config file).
Another problem with the auto clearances is the pre-drill distance. We're trying to get our machine shop guys to use rigid tapping. So what we do is pre-drill the hole much deeper than the amount of thread we want. I usually go 1 X D, so for, say, an M10 I'd have the tapping drill go 10mm deeper than the amount of thread I want. This means that the guys don't have to go anywhere near the bottom of the hole with the tap. That way they've got less chance of jamming up on swarf. Is there a way to use the auto clearances but also say that you want the pre-drill distance to be 1XD?

Cheers,

Mick.


Attachments:
HASCO STANDARD CBORES AND CLEARANCES.pdf [24.98 KiB]
Downloaded 12 times
Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Wed Jan 11, 2012 5:09 pm 
Offline
DELCAM Staff
DELCAM Staff
User avatar

Joined: Fri Mar 03, 2006 1:51 pm
Posts: 42
Location: UK
Hi Mick,

When we set the Toolmaker defaults we had to take into account a variety of standards and catalogues to come up with a sensible single default. It uses -

2mm shank clearance for any screw larger than M8. 10% of diameter is used for smaller screws.
The pre-drill clearance depth is 1/4 dia + (1/2 dia * tan 30) for screws larger than smaller screws.

The clearances are set using parameter expressions in the library models shipped with Toolmaker.

So, at the moment you can either -
1. Use the defaults (which scale with screw size)
2. Set the clearance manually when you create the screw (and have Toolmaker remember this value)
3. Create a custom catalogue with different parameter expressions

If you are interested in (3), take a look at the expressions used in the library as a starting point (Modify > Geometry on a HASCO Z31 screw and edit the clearance holes in it's Power Feature solid to see them). We want to make it easier for users to modify these expressions in a future release.

Hope this helps! :D

Cheers,
Ian


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Wed Jan 11, 2012 6:56 pm 
Offline
Community Moderator
Community Moderator
User avatar

Joined: Tue Jul 27, 2004 2:22 pm
Posts: 355
Location: Manchester
Hi Ian,
Thanks for the detailed reply, much appreciated. On your option 2, if I place a 10mm screw and set my own clearances, then apply the form, then go back in and select the screw again from the catalogue, PowerSHAPE doesn't remember the settings I typed in just a few seconds earlier. Am I doing this wrong or when you say "(and have Toolmaker remember this value)" do you mean if I copy that screw to a new loocation, the copy will have the same clearances as the original. I can't get PowerSHAPE to remember the clearances I previously typed in.

Cheers,

Mick.


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Thu Jan 12, 2012 10:32 am 
Offline
DELCAM Staff
DELCAM Staff
User avatar

Joined: Fri Mar 03, 2006 1:51 pm
Posts: 42
Location: UK
Hi Mick,

Sorry, here is a bit more detail on (2). You can set clearances on a "one off" basis in Component Wizard using the Clearances tab when you create a component, or you can set a user defined default clearance on the options page (Tools > Options > Manufacturing > Toolmaker > Power Feature Clearances). It's the clearances set on the options page that are remembered.

I think the clearances set in Component Wizard should be remembered too, eg; if you create a screw, exit Component Wizard, do some modelling, then re-enter Component Wizard, it should display the last used values first so you can simply create another screw with exactly the same values as the last one. It works this way for standard dimensions but not custom dimensions.

If you agree, I will open a wish! :idea:

Thanks,
Ian


Top
 Profile  
 
 Post subject: Re: clearances on shcs etc
PostPosted: Thu Jan 12, 2012 1:15 pm 
Offline
Community Moderator
Community Moderator
User avatar

Joined: Tue Jul 27, 2004 2:22 pm
Posts: 355
Location: Manchester
Hi Ian,
Like you say, the component wizard will take you back to the same component you used last. However, it won't remember the clearances you've used on that component. It'd be logical if the software remembered not only the component but also the clearances. It'd be appreciated if you could raise that with development. I'm not sure whether it would be a wish or a bug though. So,as I guess that bugs get more attention than wishes, lets call it a wish eh :) . Like you say, you can create your own clearance set in tool/options but you'd end up back with the same clearances for every component of a particular type, so that's a non-starter.

Cheers,

Mick.


Top
 Profile  
 
Display posts from previous:  Sort by  
Forum locked This topic is locked, you cannot edit posts or make further replies.  [ 9 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB