Jump to content

I have a problem with using Insert mate


Mannyroad

Recommended Posts

Hi,

 

I've modelled a part for my motorcycle and, for reasons that aren't important, need to mate it to a 2nd part in an assembly that represents the geometry of the top steering yoke on the forks.

 

Anyhow, the new part, a small arm, has two circular bosses extruded from a face. The bosses are centred 80mm apart and are 12.5mm dia. The rectangular plate to which the arm needs to mate to has two holes, centred 80mm aprt and of 12.5mm dia.

 

My problem is that whilst I can easily use the Insert mate to insert one boss into one hole, when I try to use Insert mate to mate the 2nd boss into the second hole Inventor won't allow it. It says there is a relationship issue.

 

I've trawled the internet and Youtube to try to find a solution to what ought not to be a problem, to no avail. I've added a couple of pics to show what i mean below; one boss is mated fine, retaining rotational freedom, but the other boss simply won't insert/mate with the other hole. The dialogue box doesn't really mean much to me. See snip shots below. Any thoughts?

 

attachment.php?attachmentid=62239&cid=1&stc=1attachment.php?attachmentid=62240&cid=1&stc=1attachment.php?attachmentid=62241&cid=1&stc=1

Capture1.jpg

Capture2.jpg

Capture3.JPG

Link to comment
Share on other sites

Sorry Mannyroad. I don't know where all the Inventor guys are? :unsure: I don't use the program so I can't be of any assistance.

 

Can you post your solution in case someone else comes along with the same issue?

Link to comment
Share on other sites

  • 3 weeks later...

Was your solution to use the insert constraint on one, and a mate constraint on the other axis?

Sometimes if there is a radius, the inserts can pick different planes, and they won't work well.

Link to comment
Share on other sites

This is usually an infinitesimally small discrepancy in distances. Measure the distance from axis to axis of the fork piece. In the measurement window that pops up, set your unit precision to "all decimals". If it isn't exactly 80.000000000 mm, the mate constraint will refuse. I usually work in .000 precision, so my fix for this (common) problem is to set a maximum limit on the constraint to .001.

Link to comment
Share on other sites

Sorry Mannyroad. I don't know where all the Inventor guys are? :unsure: I don't use the program so I can't be of any assistance.

 

Can you post your solution in case someone else comes along with the same issue?

 

This question was asked before here or on another forum. I thought I answered it.

 

The solution is to use a constraint that removes one degree of freedom (DoF) such as an angle constraint and not another Insert constraint.

 

An object in 3D space has 6 DoF. An Insert constraint removes 5 DoF as it specifies that the axes of two cylindrical objects should be collinear AND that the they share a common face. Essentially, Inventor's Insert mimics the behavior of a hinge. When the OP tries to use another Insert constraint Inventor indicates that the object would be over constrained as it cannot be sure it can make the two axes of the second hole and boss collinear not to mention adding another positional constraint (how far up or down should the centerline should the parts be positioned with respect to each other).

 

Drawing a construction line from boss to boss and another line from hole to hole and making the angle between the two lines = zero is a way to add 1 DoF resulting in a rigid assembly.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...