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14-Alexandrite
August 31, 2021
Question

Chain assembly link Pattern, 3D cam roller pattern and timing belt tooth pattern

  • August 31, 2021
  • 5 replies
  • 11574 views

We want to assemble a chain in a curve using a curve pattern. But the pitch distance is not equal in the straight line and in the curved path. It is the same along a straight line and varies along curved paths. This is critical assembly and so we should assemble the chain as exactly as they are in real assembly. How to assemble a chain in a curve using a curve pattern without changing the pitch value?

1) There may be a lot of ways to assemble the chain links in a curve. But chain assembly is used universally and so there will be a simple solution to do this (For instance, pattern). So, we want to assemble the chain links using "pattern" along the curve or else a very simple method to do this. Because for a long chain assembly we could not assemble multiple times or go for a lengthy process.
2) There is a way to do this using "pattern". While we search on the internet in all places this method is used. But the problem is the chain links will not assemble in the exact place as the pitch value varies along the curve. But as the assembly is critical we need to assemble the chain exactly in the same place as they will assemble in real life.
 
Our trial and difficulties:
                   We have tried to pattern this using eight patterns.First and second are for top straight line pattern two times for inner links and outer links. 3rd and 4th are for curve patterns. 5th to 8th are mirror patterns.
1) If we change the no of links, the pattern will fail and we need more time to correct them and reassemble the links.
2) If we change the no of links, sometimes the link position will change (the same link comes nearby at the pattern ends) so that we have to reassemble the links once again.
3) Creo Parametric does pattern using number id. For instance, if we do a pattern first time, the number will be 1 to 10. For the second pattern, the number will be 11 to 20. We have connected the "no 10" link to the "no 11" link. When we change the number of links for the first pattern as 1 to 5 and for the second pattern as 6 to 10. The pattern will fail and creo will not change the assembly reference from 10 - 11 to 5 - 6. This is the major problem in Creo which should be fixed or we need to know the solution if any one is there. Because this not only affects the chain pattern but also all other patterns like sprocket teeth pattern, gear teeth pattern, toothed belt pattern,etc. 
4) If we try to assemble other complex curve shapes (using more idler sprockets) this will be very difficult to assemble.
5) Sometimes if the no of teeth on sprocket changes, the last link on sprocket (curve) will not meet at the straight line end it has to be assembled a little inside from the straight line. This is very difficult to assemble using more steps and more patterns. (My given curve to you is like this). We have achieved this using relations. But if we change the no. of teeth this will also fail. We do not have enough time to program this. 
6) Finally, if there is an option to pattern along the curve using equally spaced displacement (not distance along the curve) between points, all this problem can be fixed easily. Using programs it is possible to develop such an option. So, kindly add this pattern option in the curve pattern tools.
 
We also found an udf chain assembly curve and that also was not properly assembled. They only look like a proper chain assembly.
Also, we need to assemble cam roller on cylindrical groove cam using pattern on curve and also creating tooth on curved belts.
Any solution?

5 replies

21-Topaz I
August 31, 2021

A picture may help, but have you tried a point pattern on a curve? You can control the point spacings with relations or with sketch constraints depending on how you want to set it up. The picture below isn't a chain but it shows that you can pattern on points that are non-equally spaced while following the direction of the curve.

Capture.JPG

 

 

 

Patriot_1776
22-Sapphire II
August 31, 2021

The problem is that the length of the link is linear (straight line), and that distance can't be done simply using points on a curve spaced on the length of the distance between points on the curve itself.  On a small sprocket radius, the length between points will be a good percentage larger than on a large sprocket radius where the curve is almost a straight line, and then there is the fact that in most runs there IS a straight section.  On a drivetrain that has numerous sprockets it becomes extremely complex.  Therein lies the problem.

19-Tanzanite
September 1, 2021

AFAIK, not possible in basic Creo.  Perhaps you can hire someone who can program a custom solution for you.  You should post on the product ideas form and point out that this is something that Solidworks seems to be able to do.

Patriot_1776
22-Sapphire II
September 1, 2021

CAN Solidquirks actually CORRECTLY do this?

19-Tanzanite
September 1, 2021

I don't know if it can do it perfectly, or correctly, whatever that means.  I don't have it and so I don't know the details - however, the help link I attached to my comment showcases the tools and options available to a machine designer if they use Solidworks, and I strongly suspect that one can get pretty good accurate results - easily!  In comparison, you have to be a wizard at Creo patterns to get a decent looking result.

PTC, like any other company, should probably review what competitors offer and copy them whenever feasible.

Patriot_1776
22-Sapphire II
September 1, 2021

Hmmmm, I just had an idea that might solve this...

14-Alexandrite
October 16, 2021

Any solution from PTC?

Patriot_1776
22-Sapphire II
October 18, 2021

LOL  You must be new here...🤣  Don't hold your breath, I've never seen a PTC employee solve any major geometry problem here.

Patriot_1776
22-Sapphire II
November 8, 2021

Hey Dunamis, check this link out:

Chain solution - PTC Community