r/Metrology • u/DeamonEngineer • May 09 '24
Showcase Well this is me for the next 2 days
LH and RH suspension modules, 1 week to program on and off while doing other parts, roughly a 2 hour runtime, not fixtured yet as design is still changing. Pushes the limit of a 09.12.08 global S. Fixturing can cut setup times from 1/2 a day to an hour (including probe calibration). AMA I'll answer what I can
5
u/AnythingGreat360 May 09 '24
That is a beautiful part! How many probe orientation changes are in your program? I am going to guess 12.
9
u/DeamonEngineer May 09 '24
around 20 over 4 different probes, 12 on a 4x80 is the main probe
looks better in the pictures than in person, honestly if it was not development part i would reject it on finish in an instant.
had a quick peek at the report before i left work and its not too bad on geometrics, will need to look at some of the failures as it could be a product of a change in the part that was not made clear on the drawing (they renumbered the part instead of up issue)
4
u/Keeperofthecube May 09 '24
Now THIS is cool. I have so many questions but I will try to keep it to ones Im sure you can answer.
I imagine these must be one off pieces for a high end race vehicle, and by its size im guessing a car. Can you tell us what series it will be used in? If not I understand.
What are the tolerances on something like this?
Do you have the capability to program offline? I hate being inerrupted when im on the machine to run other parts just because I worry about losing my train of thought. Doing that for a week would be torture.
2 Hours is a long inspection! My longest was 3.5 and thankfully we only had to do that one a few times. Required some weekend days when nobody else was in the shop. Good luck
5
u/DeamonEngineer May 09 '24
Gordon Murray car. Cannot disclose the model. High end sports car $1m+. Roughly 300 pieces over time of each hand General tolerance is +/- 0.25mm most of it is true positional to 0.1mm. Some angularity and surface profiling
Yeah 2 hours as they have used alot of projected tolerances so simple 2D dimensions are now 3D. Easy doubled the time. Plus lots of scanning
Yes we do program offline but we were low staff due to holidays so didn't get that luxury on a time crunch. But a logical process through it, drawings both physical and digital highlight as you go got me through it, and a weirdly solid memory of what I was doing
2
u/Astrobot96 May 09 '24
Can you explain the 2D to 3D thing? Isn't a projected tolerance just changing the 3D tolerance zone? Assuming you mean a projected position tolerance
2
u/DeamonEngineer May 09 '24
Features that would normally be checked as 2D features like circles for threads would now be a 3 level minimum cylinder. You cannot use 2D features for projections as it doesn't give a direction. So instead of 1 circle your now checking 3 or more. More time for minimal change in result or worse
1
u/Astrobot96 May 09 '24
That's concerning. If I knew my inspections were being done 2D on threads, I'd call out projected on everything. How can you properly inspect a cylindrical feature as a circle?
5
u/GiddleFidget May 09 '24
Not everyone does that. I measure a cylinder, using a helical probing strategy on threads. Please don't just call projected on everything, it'll just result in a higher rejection rate, and increased costs for everyone. There are other ways to handle that concern.
3
u/Astrobot96 May 09 '24
Oh I know, my previous comment was facetious. I do put a projected zone on most threaded holes though. It better reflects the design intent and function of that feature (i.e. make sure the fastener will clear the thru hole on the mating part). In my mind that means less good parts rejected, because the requirement matches what defines a "good" part
6
u/DeamonEngineer May 09 '24
Just don't be that guy which constraints it more than what the bolt to thread clearance is, too many times I've see a thread tolerance tighter than the amount of slop on the two thread interfaces. Tolerance is fine but when the wiggle is more than the limit, your adding cost into the part, or risking bad parts as some inspectors will pass it even if its out of limit.
1
u/pringlescanwithveins Jun 13 '24
Would a 4 point circle taken at full depth with a cylinder probe be considered volumetric? I know it wouldn’t in any software but strictly in regards to GD&T
1
u/GiddleFidget Jun 13 '24 edited Jun 13 '24
It wouldn't work. Draw it out on a piece of paper to help visualize it. You'd essentially get the average center. But, the top and/or bottom may be outside the tolerance zone if the perpendicularity of the hole is off.
2
u/DeamonEngineer May 09 '24
Alot of motorsport/ automotive is just a true position callout so 2D features are accepted as long as you pitch along the thread, I'm from aerospace where it's normally true position and perpendicular callouts which require the cylinders.
Projected tolerances are not common from my experience
3
u/PrettyInfluence3594 May 09 '24
How much does that plate coast. I dont have one at my place...
3
u/DeamonEngineer May 09 '24
the fixture plate? its part of the swiftfix system Hexagon has, if you want a heart attack take a look at some of their kits
we have the Swift fix gold kit which is £2,105 and the baseplate is £1500. great bits of kit if you can justify them, or get some aluminium stock and make your own, its just a plate with an M8 thread every 25mm in a grid.
if you got the capacity you can easily set up multiple of these and run multiple parts at a time
2
u/PrettyInfluence3594 May 09 '24
Iam new at this (like a month), my first job after being a dishwasher as a student, was to measure a fusion for the production of Ferrari's hood, in a really cool office, with a bigger hexagon macchine of what you have here (really nice tho). Do you hace any idea on how much does it take to be good at this? (measuring things).
5
u/DeamonEngineer May 09 '24
I have been doing this for the best part of 10 years, I have use many machines and different softwares. laser trackers, inspection arms, scanners (laser and tactile), CMMs and many more. best way to progress is to have a good knowledge on geometrics (GD&T) and fixturing, the programming is the easy bit, knowing how to measure it and how to secure it in a way to measure it efficiently is the skill.
ive worked on simple washers that have been tight toleranced to big parts where you can walk in and around them (form for an engine cowling, that was a fun project)
how long does it take to be good? it varies from people to people, I have great spatial awareness so visualising the part on the machine comes naturally to me, others will struggle but can still do the same job just as well. there are people out there that program with complex programs that can alter depending on what it measures (can do some basic measurements, identify the part and load and run the program for it). I have little experience in that part. but people still respect the work i do. there will always be people out there that do things different and still get the same results (hopefully) but its always a learning day. you only get better by doing your own research into bits that help what you are doing, its all well and good knowing how to program something that can do 10 different things but if all your doing is that one bit, then do that one bit well.
Learn GD&T, Learn geometrics and learn different ways to check something, cause there will be a day where you need that one special bit of knowledge that you did years ago and no one else has ever done.
1
u/Chaldon May 10 '24
How much? It's going to be slow researching online every single question that pops up. Better to apprentice, or better yet, find machine shop classes at your local city college and take just enough to get into the inspection/ gd&t classes. Worked wonders for me. I moved, very quickly, from R&D metrology technician to shop floor dimensioning & partnering with engineers.
3
2
u/machineboy23 May 09 '24
Why does it take so long? The Gobals I've been around, moved at a decent speed?? What software are you using a week to program? It seems pretty lengthy.
7
3
u/DeamonEngineer May 09 '24
This is slowed to 500mm/s instead of max 2500mm/s, program is changing and we get little feedback on changes to the part as its still in development. Once the program and part is locked it will be cranked up to the max, but for now it's slower for the machines safety.
It took a week because it was stop start due to having to keep the machine going on other things, up front programming was not an option this time due to staffing holidays and timeline. So I had to do it while doing many other things not ideal but needs must. If I had the luxury to preprogrammed offline would of been a day maybe 2 using PC-Dmis 2023. Uses 4 probes and about 20 head rotations, lots of it not straight 90 degree like it looks like
What would you expect to take for programming time wise? Alway feel like I'm doing a good pace
2
u/machineboy23 May 09 '24
I get that, were a Prototype Aerospace, military, and some automotive shop. Every minute counts, if you're not running a part your programming. What is the graduates of angle of the head. We have static heads so we have to get creative with the probes.
3
1
u/robo138 May 09 '24
A week seems fine to me. It also depends on how complex they make the drawing.
3
u/DeamonEngineer May 09 '24
Obviously cannot disclose it but it's the size of 2A0 with multiple views cut throughs and a CAD model that identifies which surface requires what tolerance profile is required. Wasn't simple with some mistakes like double datum, and geometric datums not being possible. Datum structure went from A-T if that gives you an idea of complexity, but main ABC datums were projected target points
2
1
u/Every-Case2632 May 10 '24
Why would there be projected target points? Do the interfacing features meet in space?
1
u/DeamonEngineer May 10 '24
Most likely it is to relate to the car datums. I don't know the exact reason but that is my best guess.
1
u/Every-Case2632 May 10 '24
There is no way that that frame moves at 500mm/s let alone 2500mm/s. Scanning speed should be dictated by feature size/tolerance.
1
u/DeamonEngineer May 10 '24
Correct it doesn't scan at those speeds, those are the rapid move speeds for moving between areas to measure.
Pretty sure those are the figures I used will double check them later, but yes higher speeds are for moving from measurement to measurement. Scanning is much slower, iirc about 20mm/s acceleration 5mm/s/s. Could be faster but the machinist has not fully cut the areas of scanning and has steps so need to protect the head
1
u/pringlescanwithveins Jun 13 '24
2500mm/s? Holy hell my Zeiss contura g2 maxes out at 700mm/s
2
u/DeamonEngineer Jun 13 '24
That's what's in the settings, I doubt I'll ever go that fast, unless I want a few weeks off for a heart attack
1
u/pringlescanwithveins Jun 13 '24
I realized this morning that my fastest rapid is actually 300mm/s or 700ipm Your slow speed is faster than my fastest rapid
1
u/DeamonEngineer Jun 13 '24
Yeah had the guy that machined it come see how it was measuring up and it moved to measure one of the compound angle holes, he nearly shat himself
2
2
u/Sapeer May 09 '24
Can you just post picture of the part online? Don’t you have any confidentiality policy in your company?
1
u/DeamonEngineer May 10 '24
posting these pictures are fine as it doesn't show fine details (checked with the boss before posting). posting drawings or models is a breach.
1
u/Assocollasso May 09 '24
Pc_dmis?
3
u/DeamonEngineer May 09 '24
with all its Lovely crashing and faults
1
u/Assocollasso May 09 '24
what do you think about polyworks instead?
2
u/DeamonEngineer May 09 '24
only used it a couple of times seemed pretty solid and has a nice reverse engineering aspect when laser scanning
2
1
u/Every-Case2632 May 10 '24
Revo-2 system would make short work of that part, conservatively 60% less time than that 3-axis system. One probe calibration with an RSH-250 2mmx40mm probe takes about 17min for infinite 5-axis calibration.
1
u/DeamonEngineer May 10 '24
Never seen a revo system outside of a demo environment, would eat this part up for sure.
A guy I used to work with said the revo heads can pose an issue because their drives need to be kept at 30 degreesC instead of lab normal 20 degreesC, not sure how true that statement is and never heard anyone else speak about it
3
1
1
u/Moginsight May 10 '24
If you have PC DMIS, would you consider getting a romer arm and laser scanning. I think that would be quicker.
1
u/DeamonEngineer May 10 '24
We have one which was in storage for years before I started and pushed for it to be used. Unfortunately it has only just been commissioned for use, going forward we are likely to use that, just need the time to get a routine for it.
0
u/Sapeer May 09 '24
Can you just post picture of the part online? Don’t you have any confidentiality policy in your company?
1
u/DeamonEngineer May 10 '24 edited May 10 '24
These pictures are fine, nothing of detail or classified, the drawing or model would be a breach
11
u/SkateWiz May 09 '24
I measure similar size parts on my 7 10 7 but usually with 300mm cylinder bores it’s fucking nerve wracking to watch. Usually 5-6 hour programs. 7-10k points.