We occasionally are having parts making it to production with holes that are not aligned. We have concluded that most of the time it was 1 hole was moved using Synchronous and moved another set of hole that were aligned. This created the need to either remake a part or assembly spend time drilling out holes.
Has anybody found a good method of checking hole alignment of a model. Or what do other people/companies due to help alleviate this problem. My only method which is very time consuming is to mate all holes and when a hole moves I see the red lightning bolt showing a broken mate.
Solved! Go to Solution.
I would use interpart links to place one of the sets of holes, that way if the holes in one part moves, so do the holes in the other parts.
Perhaps judicious use of rigid set(s) would prevent holes from moving relative to each other or to a selected face.
This might work, but my only concern would when parts are used in two locations and we use synchronous mostly and that doesn't seem to hold/allow interpart links. I do like this Idea though
Do the holes have fasteners running through them in the assembly?
Does an interference check catch the clash between hole and fastener?
Most of our holes are either threaded or use taptites so when we run interference check there are a few thousand interferences by the fasteners in. We tried to look for large interferences but they can be covered up as larger fastener in hole when it is a smaller fastener. There might be advantage to looking at what the size of incorrect hole locations are but it looks that it will be the whole range of size if it is slightly off to completly off.
I'm with @swertel use interference checks. As for taptight interference..do you honestly need the true shape or can you go with a minimal/max. cylindrical size shaft.
In my previous life, we had to include all hardware for interferences checks and we are talking 10,000+ pieces of hardware with bolt+washer+washer+nut type configurations not to mention the connection plates/components. We used nothing but simplified versions of the hardware. In some cases it was a simple line representation for faster loading of assemblies and for interference checks we used to two sizes: 1) for hole alignments where the body was the max. material size shaft and head and 2) max size plus clearance for tooling to check actual assembly problems.
You have to have a strategy in place if you plan to utilize clearance analysis practices!
If you are doing ST changes to holes then you should be doing these changes at the top assy level. That way you can grab all the holes in all your parts at once. Then make you hole movement changes.
If you are doing the changes at the part level and having problems then you may need to look at your change management process- maybe include approval of changes and a design checker (a different set of eyes) to check the changes.
LOL another set of eye's
I'm lucky if anyobdy checks anything and I hope they use the right drawing. Typically my drawings go right to the shop with only meself creating and checking them.
If I make a mistake, we find out at assembly after the part has been coated. I.E. I do everything I can to have CAD check things for me.