[Th...] Posted September 17 Share Posted September 17 Hi, anyone has experience using long extension and do you use counterweight? For Vast XT Gold. The extension is almost 22 inches long. The whole setup weights around 250 grams. Should I use counterweight on the opposite end and if so how much?weight cmm.PNG Link to comment Share on other sites More sharing options...
[Ma...] Posted September 17 Share Posted September 17 There should be counterweight to eliminate torque. Link to comment Share on other sites More sharing options...
[Ke...] Posted September 18 Share Posted September 18 I'm sure someone here has a magic formula... This is my "deep bore" probe: 10" and about 270g. The combined weight of my counterbalance is about 170g. I hold the system plate in the middle (red line) and adjust the counterbalance length, until the system is visually balanced. Link to comment Share on other sites More sharing options...
[Cl...] Posted September 18 Share Posted September 18 500g is the max weight. As far as length goes. I know the specs for the XXT TL1/TL2/TL3, but not the XT. I do use some very long styli and extensions. No issues here. Believe it or not. That stylus system and all its stylus is used for one part. Link to comment Share on other sites More sharing options...
[Da...] Posted September 18 Share Posted September 18 Please sign in to view this quote. Very nice set up Keith ! Link to comment Share on other sites More sharing options...
[Th...] Posted September 18 Share Posted September 18 Please sign in to view this quote. According to the spec sheet, the max supported length on an XTG is 500mm. This lateral setup is ~58mm over that, but would be well within the acceptable range for a full VAST sensor. Link to comment Share on other sites More sharing options...
[Je...] Posted September 19 Share Posted September 19 Please sign in to view this quote. Best to test on CMM. If the CMM is able to pick up the stylus, tare and drop off without issue then a counterweight is not absolutely necessary. You may want to test qualification results with vs without counterweight but I don't usually see much impact. If you are well within weight limit then it may be beneficial even if previous criteria is met (torque against the probe pocket is a concern also) As far as length is concerned, you are exceeding supported length spec for VAST XT and may experience difficulty with qualifying. That doesn't mean it won't "work" but failing to qualify at that distance would not be something that ZEISS would support. You may also want to consider this: I also advise using CFX5 20mm when extensions get over 500mm. Also keep the number of joints to a bare minimum (try to use a single long extension instead of multiple shorter). It is more expensive but the performance improvement is significant. Link to comment Share on other sites More sharing options...
[Je...] Posted September 19 Share Posted September 19 Please sign in to view this quote. . Okay, that stylus system is a beast. It's impressive how much weight and length a VAST sensor can facilitate. It's definitely a strength. Maybe the cmm should just pick up the entire stylus rack 😂 Link to comment Share on other sites More sharing options...
[Ro...] Posted September 23 Share Posted September 23 Long ago I was told by a programmer I respected a lot that you should be able to set the (XT/XTR) stylus system down on the granite, and it not tip over. If it does then it needs counterweight. I don't know if that's true or not, it's probably not, but I've always made sure my systems could stand up on the granite. Now that being said, there have only been a couple times where I've had to put together a side probe so long that I needed a counterweight. The last time the counterweight was 2 gage pins taped to an extension, and it was only in use for a month for 1 automotive prototype job. Link to comment Share on other sites More sharing options...
[Je...] Posted September 24 Share Posted September 24 Please sign in to view this quote. This is good guide to base your construction off but in no way is this the rule. Try to balance within weight limit and confines of machine volume (counterweights take up space too). If not possible, let the CMM tell you what it is capable of. Place the system in then sensor and define/qualify it. If it is able to pick up from pocket, tare/balance, qualify and drop in pocket then you are off to the races. I have this 400mm long stylus system out in the wild in 24/7 automation production without any balance counterweight and it runs 100% perfectly on a VAST Gold. No issues passing a GR&R holding a 25 micron Roundness tolerance, 40 micron size tolerance on a 200mm+ bore using FlyScan. Again...Ø20mm CFX5 [img][/img] Link to comment Share on other sites More sharing options...
[To...] Posted September 24 Share Posted September 24 Here's something publish by Zeiss some years back.Tilt Torque.pdf Link to comment Share on other sites More sharing options...
[Ch...] Posted September 24 Share Posted September 24 Please sign in to view this quote. I use this as my rule of thumb. It might not be scientific but it's simple and robust. Pretty sure I first heard it from Owen Long. Link to comment Share on other sites More sharing options...
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