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Bridgeport 2J head noise

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Jasincole

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Hello,

New user here. Site was recommended. On to the reason I’m seeking out some experienced help.

I recently bought a used Bridgeport 2J head mill. Upon getting it leveled and wired up I turned it on to hear quite the noise coming from the head. The noise is coming from direct drive only. The motor sounds nice in neutral and the back gears are quite quiet. Not used to gears being so quiet. But then comes the direct drive noise. At 1k rpms and below its fairly quiet, but from 1k to 2k rpms it gets real bad. Then from 2k to 3k it starts to quiet down some and the rattling becomes almost intermittent.

I’ve since had the head apart because the quill skirt was worn and sticking in the bore. I’ve repaired the skirt and reassembled the head. Here some things I took note of during the tear down.

The clutch dogs are worn some. I did manage to fix this a little bit by adjusting the engagement in the hi-lo selector. After doing this I had very little backlash, but there was still a tiny bit. This did not seem to fix the rattle noise at all, I was sure this would have helped some, but to my surprise not as much as I thought.

The backgears and drive belt all looked good. No missing teeth etc. again to my surprise really. But it’s dead quiet in Lo.

So now I’m kind of wondering what the noise is from? I’m starting to think I don’t have the correct alignment since I removed the castle nuts to fix the quill skirt. I will add here, that it certainly looked like someone had these nuts removed before I did and had the quill out. Could this simply be a an alignment problem? Do I need to float the head back into alignment?

I’ve read that I need to use a pony motor and remove the belt to take pressure off the spindle? Then lock these nuts down after letting it quiet down when finding center? Any other ideas on what the rattle is from? I’ve pretty much given up on the bearings being bad. I checked most when it was apart. Nothing is popping out as a significant source for the rattling. It’s not a grinding noise and it’s not constant across the entire rpm zone. Doesn’t make sense if it is a bearing. I’d be surprised

Well anyway, enough for now. Look forward to further discussion. I’ll try and get an audio source so you can hear it.

Jasin
 

Karl_T

H-M Supporter - Sustaining Member
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Welcome. I am clueless here.

My solution. You have checked nothing major is wrong. just use the machine.
 

Technical Ted

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I'm not an expert, but here's a couple things I did to quiet down my 2J head.

I assume you have checked the delrin bushing inside the two pulleys. This is probably the biggest source of noise, but if it's only in Hi this might not be the cause. If they are in rough shape you'll want to replace them before you damage the motor's armature shaft and/or the bore of the pulleys.

The Hi/Low lever stop can be adjusted up/down and also flipped over to change the adjustment of the engagement. There's a allen set screw on the side holding it in the adjusting slot. Since it's only in Hi, I would check this first by testing.

One rough way to float the head in is to loosen the castle nuts some and tap the head in different directions with a dead blow hammer. Be gentle. If you find a position where the noise goes away, tighten things back up and see if the noise is better.

One note, these heads are inherently noisy. In a big machine shop with a lot of other noise they don't stand out so bad, but in a small, quiet home workshop they can make quit a bit of noise.

Good luck,
Ted
 

Janderso

Jeff Anderson
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Welcome, this is a great place to share ideas and to never stop learning.
 

Jasincole

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Aug 6, 2018
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I did adjust the hi-lo lever to increase clutch engagement and when I had the head apart this did seem to make a difference in the backlash of the clutch dogs. Not perfect, but for a used mill I think very acceptable given the wear I saw.

I have not checked the bushing, thinking of doing them for the price regardless and getting a new belt. Sort of preemptively ruling out sources of noise.

I’m also highly considering doing the pony motor float method. Just because it seems to me the most rational approach for alignment.

A short video so you can see what I am hearing. Excuse the rotary phase converter.
 

Janderso

Jeff Anderson
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Glad you got some response. It looks like you have found a remedy.
 

Jasincole

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Aug 6, 2018
Messages
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Thanks. I’m actually pretty confident now that it’s the clutch dogs that rattle. Under load while using the rattle disappears. Still plan on doing bushings and belt before Xmas. But for now I am happy to use it as is.

Slowly I am making my way through all of it and cleaning as I go. Replacing the way wipers adjusting and cleaning the acme nuts etc.

The next thing I want to really check out is the one shot lube. I know it works, but I’m not sure how well.
 
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