VR chip suction issue

[tragwag]

I've been having this weird issue where the chip just wildly balls up at the stylus only on one lathe (lets call it Lathe B), no matter the condition of the stylus.
The chip wraps UP the heater wire and usually I'll break the wire when I try to untangle it or use stylus cleaner on it.
On my other lathe (lathe A) I've NEVER had this happen, but when the chip drops there, it trails off winds around the center spindle cleanly, without ruining the cut.
For lathe B it balls up immediately and travels up the heater wire, no matter if the stylus heat is on or off, is suction is on or off, despite all attempts at changing variables.
I've had great runs of a few weeks where I can cut all day on lathe B but there's always this issue after some time.

any ideas?

[DJ2000]

am guessing you have checked the tube has no blockages? a bit of stuck swarf in the tube could cause issues, increasing the vacuum could be worth trying as if its not sucking enough it will soon bunch up, I would try get that suction tube a little closer as well they say around 2mm from the cutter and 2mm above the blank i tend to run at about 4mm on this as you get a bit of flutter and the tube draging on the blank is never good.

the other thing you could try is adjust the head angle a little bit as this can affect how the swarf can come off I have found, am fairly new to cutting myself but these would be what I would try

[SueDenim]

Sorry for repeating this from another thread, but I'd check the entire suction system for leaks.
The bottom of the swarf jar, where the large (and heavy) pipe connects is prime candidate for needing resealing from time to time.

[Dubcutz]

Hi Tyler

Are you using the same vacuum system for both VR's or an individual vac for both lathes?
For the swarf to bunch up like that, from the video looks like a poor suction issue
if your using individual vacs can you swap vacs and see if the issue remains?

Regards
Theo

[tragwag]

appreciate it everyone, thanks.
Yeah I am using a single vacuum for both lathes, that go into two chip jars connected through a Y adapter.
I recently got a gasket for the 2nd chip jar and duct taped all the junctions, which like I said worked great for a week or so and then one day this issue again.
I homemade my second chip tube so I can't swap the chip jars out one for one, or else I would try that.
I'll give another try to cleaning the chip tube even though I do that pretty regularly, and I'll try to get the tube a little closer.
It's about the same distance as my A lathe now, but it could need adjusting due to the loss of suction through the longer hose path to the 2nd lathe.

[DJ2000]

Hi there,

that could be the main issue then, have you tried blocking up the tube on the other lathe and see if it still backs up? I would say either run two sep vac pumps or a bigger one by splitting it the vac has got to be down by 50% id say and if any leaks, blocks or longer tubing than on the other lathe would reduce it more as well

[tragwag]

appreciate the help everyone, I figured it out: there was some chip stuck in the hose.
I bought new rubber hose but obviously it's not clear so I couldn't see.
note to self: check the rubber hose way more often!

[SueDenim]

Excellent! So glad you've sorted the issue mate - these things can be totally infuriating and baffling

[tragwag]

bumping this thread as I've refined the fix some more:
because of the rigid chip pickup hose I was using, and the distance from the chip jar to the lathe, my chip tube was slightly inching up during the cut.
the tube would start to push up on the cutting head but only on the inner diameter.
Sometimes not enough to lift out of the groove, just enough to drop chip and cause issues.

moral of the story: make sure your chip tube and hose are not imparting undue pressure on the cutting head or carriage in any way!

[boryo]

i had the same issue when my head was too light and the stylus wasn't able to cut proper groove but just touch the blank

[tragwag]

i had the same issue when my head was too light and the stylus wasn't able to cut proper groove but just touch the blank

exactly, great clarification. there are a lot of factors that can cause the head to have less than perfect contact, and even if the head weight seems right at the measuring point, it may not remain the same over the entire side. which was my problem with the chip tube exerting too much force and lifting the head up ever so slightly

[HannesFTL]

Bit off topic, but hey

tragwag do you cut on 2 lathes at the same time? Same audio?

[tragwag]

Bit off topic, but hey

tragwag do you cut on 2 lathes at the same time? Same audio?

yeah!

[PMST]

i had the same issue when my head was too light and the stylus wasn't able to cut proper groove but just touch the blank

exactly, great clarification. there are a lot of factors that can cause the head to have less than perfect contact, and even if the head weight seems right at the measuring point, it may not remain the same over the entire side. which was my problem with the chip tube exerting too much force and lifting the head up ever so slightly

Both my VRs have this issue, to tweak, i use 1mm brass sheeting, cut and flattered to use as a shim to lift my right hand side. The feedscrew is never 100% true from what i have seen on VR's, mine both rise as the head travels, so then the the vacuum tube rises, meaning it can lift the head out of the groove if using shorter Shank diamonds.

Since raising the right side 1mm i now get consistent groove depth from start to finish, and way less issues.

[tragwag]

i had the same issue when my head was too light and the stylus wasn't able to cut proper groove but just touch the blank

exactly, great clarification. there are a lot of factors that can cause the head to have less than perfect contact, and even if the head weight seems right at the measuring point, it may not remain the same over the entire side. which was my problem with the chip tube exerting too much force and lifting the head up ever so slightly

Both my VRs have this issue, to tweak, i use 1mm brass sheeting, cut and flattered to use as a shim to lift my right hand side. The feedscrew is never 100% true from what i have seen on VR's, mine both rise as the head travels, so then the the vacuum tube rises, meaning it can lift the head out of the groove if using shorter Shank diamonds.

Since raising the right side 1mm i now get consistent groove depth from start to finish, and way less issues.

Oh, good note! to be clear - what are you raising?
the feedscrew? the torque tube? the turntable?

[PMST]

I raise the whole overhead, in theory this then makes the feedscrew straight as previously it was a few mm off. I tried raising the turntable at one point but I did not like that as it was not level, so I have raised one side of the overhead from the base of the legs. Now my vacuum tube travels level all the way to the spindle.

I assume most VRs are like this, 5 I have seen in person all do the same. Maybe with the clutch section in the overhead it is hard to line it up exactly central.

[Tom The Phonocat]

My VR is also lifted from right side a bit to level the feedscrew . First, I levelled the whole VR , than Deck, then set suction tube as close to the blank and observing the travel shown clearly that head is rising gradually by not even a 1mm. I have placed 1mm blank under feet on the right side and then adjusted the left side of 1200 .. Nice constant groove all the way .

[tragwag]

whoa, ok! I can't believe I've never thought of that before. It's been such a sticking point for my second VR!
I'll check asap and report back

thank you both PMST and Tom for the tips