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New to me Hartford Mill

Susquatch

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Got a notice from UPS that my timing belt from MSC has shipped! Not nearly as exciting as @John Conroy waiting for his new baby to arrive, but hey - she is mine!
 

Susquatch

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This morning has been productive. I found that the motor drive belt tension affects the spindle noise. I was able to find a cam position and motor tension combination that was relatively silent at most motor speeds. The more the belt pulls on the spindle pulley, the louder the noise becomes.

I also had as good a look at the castlated gears (spindle clutch) as a fully assembled housing and timing belt affords me. I think I have it figured out. It isn't the clutch teeth making the noise. It's the timing belt teeth in the spindle top that engage the timing belt that are touching the bull gear top cover as the top spindle spins. In the up position (low gear) the teeth are above the housing and don't touch it. In the down position, there is a tight fit between the top spindle and the clutch hole in the bull gear cover. I can see witness marks in the teeth at their very bottom where they are touching something. I believe they are touching the ID of the cover opening.

You might recall earlier in this thread where I found the cover loose and installed a few more pins to hold it. I'm guessing I didn't get it centered on the spindle quite right and it's offset a bit too much. I ought to be able to remove the cover, see where it is touching from the witness marks in the cover, and relieve that edge a bit.

According to UPS, the belt should be here this coming Wednesday. I plan to take the motor off and remove the top housing then. We will see.

Here is a video of the setup in high gear and adjusted as described.

https://www.dropbox.com/s/mfzgvgb0fqd0kjd/20210925_113418_1.mp4?dl=0
 

Susquatch

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Belts arrived today! Took the top housing off. It fits!!! Yeeee Haaaa!!

As previously discussed, I took a real good look at the source of the noise. I'm virtually certain it's the top hub touching the bull gear cover at the front. There are marks on the cover there. As discussed earlier, I bet I did that installing new alignment pins. Crap...... I don't want to remove the cover so I'm planning to put a piece of a latex glove over the bottom clutch, stuff some Kleenex in there, relieve the cover a 16th or so at the front, and then vaccum it all out. Hopefully that will provide the clearance I need.
 

Susquatch

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It's raining here again today so I took the time to install the new timing belt that arrived last week.

It seems to fit quite well albeit a wee tad on the loose side - looser in fact than the old belt. But not so loose to be anything to worry about!

Three Cheers for Nancy at MSC!

While I was in there, I gave everything in the clutch area a real good critical look to see if I could nail down that brrrrr sound in high speed mode. There are a few wear burrs on the outside corners of the bottom castellations. I ground those off with a fine stone cleaned everything, and then put die blue on all the teeth.

There were also witness marks on the outside of the gaurd ring around the top castellations where it had been touching something. I assume that was the opening in the bull gear cover. So I marked that up with die blue too but I didn't feel right about relieving it. Instead, I took the bull gear cover off and relieved the opening about a 16th on the tight side which was the side closest to the front of the mill. Again, I covered everything with die blue afterward.

Then I reassembled everything and fired it up. What an amazing difference! Here is a video from 10Hz to 120Hz.

https://www.dropbox.com/s/80zcjlqapc71ay9/20211004_172136_1.mp4?dl=0

I tried it with various belt positions and tensions. All were plenty quiet enough for me. Ya, I can still hear a bit of a rattle now and then, but nothing I am worried about. It also rattles a bit at startup but I think it's just the fit of the quill spindle spline to the rest of the spindle as it only seems to happen at startup and its easy to duplicate the sound by twisting the spindle back and forth by hand.

I'm very pleased.

I plan to do a little milling with it this coming week (assuming that farming doesn't get in the way) and then it is decision time! Do I keep the Hartford or the Bridgeport?

I'll create a new thread for the decision process when I get my head around it so I can have the benefit of the members thinking too.
 

Susquatch

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Cut my first part with the Hartford just now......

OMG is it ever smooth and quiet! I have made very similar parts on the Bridgeport. There is no comparison. The Bridgeport shakes a fair bit and the bit also wanders around. The Hartford is smooth, quiet, and rock solid - its almost like my lathe! I never knew a mill could be so quiet.

Here is a short clip of a 20 thou cut with a 12mm 4 flute carbide endmill. It's not a very deep cut but it's the same cuts I made with the Bridgeport squaring up the stock. I'm making two pin clamps for my machinist vice. My phone picks up noise I can't hear. It's WAY better than that in person. But even so, wow.....

https://www.dropbox.com/s/dtq8839b69ijmr7/20211005_143231_1_1.mp4?dl=0
 
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Susquatch

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I took 20 thou off all in one pass side milling 1" of steel. I know that's pushing it but I wanted to see what it would do. Might as well have been slicing butter. The horizontal line is where I stopped just leave a mark to show that it was all one pass.

20211005_173705.jpg
 

Dabbler

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I knew you'd like that Hartford. I wasn't kidding when I said it was in better shape than mine. Methinks I know which mill yer keepin'
 

Susquatch

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With the cost info that @Brent H just gave me to finish up the Bridgeport, it's basically a slam dunk.

But you are both right. That first steel was simply amazing! I've seen lots of machinists using mills in my life. I've never seen anything cut so smooth, so quiet, and so effortlessly. My mind damn near snapped shut right then and there.

Nobody yet has said anything significant enough to change my mind.

Hey, I really have to thank you guys for being such a great help on this adventure of mine. I couldn't have done it without you. I am truly blessed.

Thankfully, the journey has just begun. ;)
 
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