How do you deal with revision changes?

Blob87 · Oct 27, 2021

We have a customer that is in the prototype phase and as a result we deal with revision changes to their parts frequently. Most of the changes are relatively simple, like adding some holes here or changing a diameter there, but sometimes they are more substantial like changing the overall thickness of the parts.

So how do you deal with revision changes when programming? I am currently in the middle of a part that is on Revision E and they sent a new Revision F while I was running the first operation, so I had to stop and make some programming changes before continuing. These are relatively complex aerospace parts with a good bit of 3D machining which required me to create a bunch of surfaces to drive toolpaths. Reprogramming these parts is no small endeavor.

Basically I've come up with two options when dealing with this:

A) Import the new model into my existing program and only change the toolpaths that need to be changed. This is the fastest and easiest way but now my program is filled with six or seven old models and a number of sketches that do nothing but add clutter and the possibility to accidentally select features from outdated revisions.

B) Reprogram the entire part including recreating all construction features, sketches, and surfaces. By far the most time consuming and tedious but eliminates confusion on which model is current and keeps the program uncluttered. We bill the customer by the hour so we'd not be losing money on the job if we went this route - but there are much better things I could be doing with my time.

mhajicek · Oct 27, 2021

The customer's PO or work order should specify the part number, revision, and quantity. Once they send that, they're on the hook for what they ordered. You may choose to allow them to cancel or alter an order (it's probably a good idea, to keep your client happy), but you don't have to. You could certainly bill for any parts you made at Rev E before they sent Rev F. I prefer to do R&D rapid iteration work on time-and-materials; my clients generally like it that way too. That way you don't waste time quoting every little thing. Then once we get into production we do a fixed price, and I try to improve process efficiency and drop the price a little as we go.

What I do to handle revisions, is save a new copy of my CAM file under the new revision, import the new model, and make any necessary changes. That way I still have the unadulterated previous revision in the original file; it's not unheard of for someone to order an older revision part. I'll usually leave the previous revision model in the new file, but change it to red, and delete any older models.

Booze Daily · Oct 27, 2021

Most of my Rev’s come after the parts are delivered. In that case I stamp the print “Void” and attach the new print with a form to remind me to change for the next order.

I’ve never had a print revision after I started the order, but for T&M I suppose I’d just soldier on and keep track of my time. Maybe mark that additional time up 25-50% just because.

Mtndew · Oct 28, 2021

I keep the original file and create a new one for the revision and label it such.
If it's a minor revision, I will just do a "save as" and alter as needed.
If it's major, then obvious re-quoting is needed.
Also tell the customer that X amount are already machined per the old rev and they pay for those too.

metalmadness · Oct 28, 2021

Blob87 said:
We have a customer that is in the prototype phase and as a result we deal with revision changes to their parts frequently. Most of the changes are relatively simple, like adding some holes here or changing a diameter there, but sometimes they are more substantial like changing the overall thickness of the parts.

So how do you deal with revision changes when programming? I am currently in the middle of a part that is on Revision E and they sent a new Revision F while I was running the first operation, so I had to stop and make some programming changes before continuing. These are relatively complex aerospace parts with a good bit of 3D machining which required me to create a bunch of surfaces to drive toolpaths. Reprogramming these parts is no small endeavor.

Basically I've come up with two options when dealing with this:

A) Import the new model into my existing program and only change the toolpaths that need to be changed. This is the fastest and easiest way but now my program is filled with six or seven old models and a number of sketches that do nothing but add clutter and the possibility to accidentally select features from outdated revisions.

B) Reprogram the entire part including recreating all construction features, sketches, and surfaces. By far the most time consuming and tedious but eliminates confusion on which model is current and keeps the program uncluttered. We bill the customer by the hour so we'd not be losing money on the job if we went this route - but there are much better things I could be doing with my time.

I deal with rev changes all the time midstream and it is super annoying but part of the game of R&D and prototype. Usually what happens is similar to you, simple mods or something. Last time a big change happened I was halfway through programming about 150 toolpaths and they threw a rev change at me explaining that "aw yea we just moved this feature"...which in turn moved the entire model structure all around. At the level my programming is useless and needs to be redone. What I will do then is keep the toolpaths and just File/Merge the updated model into the existing Mastercam file so that I really only need to re select geometry. Rev changes like this become problematic when all of your toolpaths are driven off the model AND the following toolpaths use stock models as geometry to drive rest machining operations. I hate when tht happens.

If it is some small holes added I will sometimes model them myself into the existing program and save a copy as Rev1.5 10-27-2021 as an example. So the old OG file still exists but is no longer a working file. If I feel like it I might even go in and change the previous one to "....OLD" so that I know just by looking at it that it is obsolete.

Good file organization is key. If there is a project I usually have folders and subfolders so that everything is in its right place and I am never having to look through a file list 100 items long of all the same part with different revision changes.

MaxPrairie · Oct 28, 2021

I would rather take the time to post new code rather than editing a long post. Fusion 360 can be nice when updating a rev, but then again you have to deal with the people at Fusion 360...

Edit: Once the print's rev is updated, the old print is shredded and the new print rev will show up on the program title.

mhajicek · Oct 29, 2021

You guys use paper prints as masters? For me a printout of a print is for reference only, the master is the file that sits in the part directory.

Client A

Part 1

CAD

Latest Print
Latest Model
++?? - fixturing etc.
OLD - previous revs

CAM

Part Number Part Rev Program Rev
Old - previous revs

NC

Rev

Op#

NC
Setup PDF

Old - previous revs

implmex · Oct 29, 2021

Hi Blob87:
Were you aware many CAM softwares allow you to migrate the toolpaths form one revision to another pretty easily.
I use HSMWorks in Solidworks 2015 and like you, I sometimes have to change a part on the fly because of a Rev change.

I can't recall the last time I had a problem.
I just do a part swap, do a stock swap (if I have to) and let the software recalculate.
Those sketches and surfaces that I can keep and use will integrate seamlessly.
Those that won't I can dump from the new CAM file because they're now useless anyway.

I've become so accustomed to it that I thought all modern CAM software could do this.
I also archive all the old models and keep my CAM assemblies clean with no extraneous garbage in them.

If you do elect to re-program the "simple way" as you describe in your first post, can't you just hide or suppress the old models and sketches.
In Solidworks I can just create a configuration for the current machining assembly that I keep as the default assembly configuration.
I would expect you could do something similar.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

MaxPrairie · Oct 31, 2021

We make one or two of a part then never make it again. If the customer needs the part again 5 years later they send a new print which almost never happens.

Search

Largest Manufacturing Technology Community on the Web

Search

How do you deal with revision changes?

Blob87

Plastic

mhajicek

Diamond

Booze Daily

Titanium

Mtndew

Diamond

metalmadness

Hot Rolled

MaxPrairie

Hot Rolled

mhajicek

Diamond

implmex

Diamond

MaxPrairie

Hot Rolled

Similar threads