[Mantas]

Hi there, I have noticed a problem with chatter when machine moves only in X direction doing climb milling. And that I can't rid off changing feed or RPM. At first I thought that this is only bad RPM or feed, but then toolpath went on Y direction and the chatter was gone and that kept doing all the time as tool was cutting in X axis... I am using iMachining for this part, but I can tell you that in the straight line feed is about 50ipm and spindle tested range from 3500 to 5000 no effect on chatter. WOC varying but max set to 0,051" and DOC constant to 0.32". I am using carbide 3 flute 10mm end mill for this. Can this chatter be from loose gibs or this is related to something else? Waiting for some thoughts as I am now away from machine and thinking what can I check to fix this.
Best regards.

[twocik]

Post a few pictures

[Hirudin]

I had (have) that issue as well. Only while traveling in the X+ direction though (also climb milling via iMachining paths). Does your chatter happen going in both directions?
Note: I was having this with my Novakon Torus Pro, not a Tormach.

You can see (hear) in the video (audio) below that X-, Y+, and Y- work fine while X+ chatters. I figure it's gotta be something to do with the X gib. I just ignored it because I'm lazy I guess.

The link is suppose to jump to 2:35 (that's where the roughing starts), but it doesn't seem to be working with the embedded video. You can also hear the chatter starting at 4:12 in the pocket.
https://www.youtube.com/watch?v=VdgHzL84vVA&t=2m35s

[SCzEngrgGroup]

I had (have) that issue as well. Only while traveling in the X+ direction though (also climb milling via iMachining paths). Does your chatter happen going in both directions?
Note: I was having this with my Novakon Torus Pro, not a Tormach.

You can see (hear) in the video (audio) below that X-, Y+, and Y- work fine while X+ chatters. I figure it's gotta be something to do with the X gib. I just ignored it because I'm lazy I guess.

The link is suppose to jump to 2:35 (that's where the roughing starts), but it doesn't seem to be working with the embedded video. You can also hear the chatter starting at 4:12 in the pocket.
https://www.youtube.com/watch?v=VdgHzL84vVA&t=2m35s

Sounds to me like the parallel vibrating....

Regards,
Ray L.

[Hirudin]

Interesting, I didn't know that was even "a thing". I think it is indeed chatter though as sometimes when it makes that noise for an extended period my FogBuster nozzles will swing loose because of the vibrating. If it's too severe the tool holder will pull out of the R8 collet.

... oh, on second thought, I don't have any parallels here. :/ Just a notch cut out of the jaws.

Let's wait for the OP to say whether what is happening in my video is similar to what's happening to them before we discuss it too much.

[MichaelHenry]

Sounds to me like the parallel vibrating....

Regards,
Ray L.

Maybe I'm missing something, but it looks like he is using step jaws there, not parallels.

Mike

[SCzEngrgGroup]

Maybe I'm missing something, but it looks like he is using step jaws there, not parallels.

Mike

Could be - I watched the video on my phone, and it looked like parallels.

Regards,
Ray L.

[BAMCNC.COM]

My Thoughts...

Worn out X ball nut (not likely) (Test using.. yes... Conventional milling... lol (brings back memories))
or
Loose Y Gibs (likely)
or.. Just do routine maintenance on the machine (checks everything)- Collet Maintenance, Gib Maintenance, pump 3x oil through everything while moving the axis...ssssss

Agreed - Video or Pictures

Ray - I need your email - tacticalkeychains at the g...ma..i..l... - HSMPost question (on the forum)

[carlowens]

Hi there, I have noticed a problem with chatter when machine moves only in X direction doing climb milling. And that I can't rid off changing feed or RPM. At first I thought that this is only bad RPM or feed, but then toolpath went on Y direction and the chatter was gone and that kept doing all the time as tool was cutting in X axis... I am using iMachining for this part, but I can tell you that in the straight line feed is about 50ipm and spindle tested range from 3500 to 5000 no effect on chatter. WOC varying but max set to 0,051" and DOC constant to 0.32". I am using carbide 3 flute 10mm end mill for this. Can this chatter be from loose gibs or this is related to something else? Waiting for some thoughts as I am now away from machine and thinking what can I check to fix this.
Best regards.

you ARE asking about chatter on a tormach correct? different machines can have their own peculiarities.

[BAMCNC.COM]

Good point! - Even still the "idea" (not the right word...) is is still there.

[carlowens]

best to ask some questions first to make sure, could be slop in the x axis from a turcite failure that would be specific to tormach for example. would imagine it's for a tormach since he posted here and not on novakon or mikini.

[Mantas]

Hi there all, for those who asked, yes it is tormach PCNC1100. One thing to mention I am trying to write all dimensions in Imperial units as I understand that most of the community are in US, so my part is quite large in X dimension going about 13.8" and in all that X travel there is equal chatter that I think eliminates the possibility for turcite failure. I tightened the gibs, and noticed that X axis gib is not equally tight in +X and -X extremes. Near home position X gib is loose and in far X+ it is tight, so I did compromise to tighten them like in X home they are a little to loose and in +X a little to tight. Then went on Y gib and it was loose I have done at least 2 turns on tightening screw to make it tight as per manual. So I was quite happy and expecting to get rid of the chatter. I took the video but unfortunately I didn't take the first try after tightening the gibs as that was the most interesting test. I started with the +X and did the climb milling to the -X and when I started to cut it was "BINGO" in my mind no chatter, but after 2/3 of the travel suddenly the chatter started again... The first thing that came to my mind was that as I tightened the X gib it was loose in that end where the chatter started so I thought that this is where is the problem. But when I repeated that one chatter started right from the start of the cut. Then I tried to do the climb milling from -X to +X and there was no chatter... Final test I made was going from -X to +X doing conventional milling and also no chatter just ugly finish. I uploaded video of my tests . I am just not sure but it seams that something was OK at the beginning and got loose again??? Or I am missing something.

[BAMCNC.COM]

That is just your endmill by the *sounds* of it, try another endmill, or different speeds/feeds.

That could also be poor quality Aluminum

[carlowens]

how about getting an indicator and physically checking the axis' for slop and backlash to narrow down or eliminate a possible cause, inspecting the machine wouldn't take very long and would be better than making stabs in the dark.
carl

[twocik]

So many different things that could be wrong here, you gotta take them one step at a time. From my phone... It's sound like your EM to me, I'd also check your machine for BL. I know it's a real pain in the ass to stop machining what you need done, but this will only help you in the long run. I test & clean every other week or for a new job.

[MichaelHenry]

Could be - I watched the video on my phone, and it looked like parallels.

Regards,
Ray L.

You need a better phone

[Mantas]

I think that this is not the end mill problem as in the -X to +X there is no chatter and only gets ugly in +X going to -X. As I mentioned that I didn't take on video the first attempt when at first chatter was gone after tightening gibs, up until endmill reached -X of the vise corner and then like someone had turned on "switch" that controls CHATER. And the second attempt was captured on the video I was expecting the same behavior as before but it started right from the beginning (as you can see in the video I even stopped for couple of seconds because I was expecting that there will be no chatter like the attempt before and chatter will start only latter). For backlash I did this using recommended procedure in manual with TDI. OK now for the slop please explane more on this, because I don't know how to check it.

[Hirudin]

It might not be strictly an end mill issue, but it could be solved with a different end mill. I hate to post too many of my videos, but if you haven't see it yet, an opportunity to compare end mills sorta fell into my lap - and I happen to get it on video...
https://www.youtube.com/watch?v=CyNkCqthtog

[Steve Seebold]

It might not be strictly an end mill issue, but it could be solved with a different end mill. I hate to post too many of my videos, but if you haven't see it yet, an opportunity to compare end mills sorta fell into my lap - and I happen to get it on video...
https://www.youtube.com/watch?v=CyNkCqthtog

I think I see some of your chatter problem. You have an awful lot of holder sticking out of the spindle. I would have used a 1/2 inch set screw holder. That would have shortened your holder up by an inch or more. And that is not a Tormach spindle. Your long spindle nose could also be contributing to your problem, although that ZRN coated cutter seemed to work pretty well.

[SWATH]

It sound like the endmill to me too. I think I would start bumping down the rpm during the cut until it goes away, or try a new endmill.