Clausing 8520 head/quill question

[alreed44]

Hello!

I'm restoring a new to me 8520 and looking for some help. The quill requires quite a bit of force in the last 1/3 of its travel downwards (when using the fine feed, it seems smooth and doesn't need more force) - I'm trying to resolve this issue...

I'm considering starting in on breaking down the head and cleaning it out, replacing bearings, etc.

But is there a simpler/less involved thing I should try first? Does the quill itself get pinched anywhere, in which case I can adjust the tightness of this? Is this hex bolt, highlighted below, the "quill pinch" adjustment?



Thank you!
Alex

 

[frankly2]

Check quill head bore for taper, also the quill itself could have wear taper.

 

[Richard King 2]

Try tightening the screws above and below the hex cap screw and they may stretch open the casting. Micrometer (Mike the quill and see if it is egg shaped. If you need more advice I know a rebuilder that specializes in Clausings. He is not a member here, so message me and I'll tell you.

 

[G-ManBart]

Hello!

I'm restoring a new to me 8520 and looking for some help. The quill requires quite a bit of force in the last 1/3 of its travel downwards (when using the fine feed, it seems smooth and doesn't need more force) - I'm trying to resolve this issue...

Hi Alex,

Just to confirm, if you use the fine feed wheel and move the quill the entire length of travel it's smooth and doesn't require additional force as it nears the end of the travel, but using the rapid feed lever it does require more force during the last third of its travel?

If that's correct, it shouldn't be an issue with the quill itself, or the bore it rides in. If the quill or bore were worn you would feel it using either the wheel or the lever.

I would first look to the gear set that works with both the rapid feed lever and the fine feed wheel. I say that because the way the mechanism works, when you turn the fine feed wheel it turns a couple of gears which engage a gear on the rapid feed lever and that has a shaft which engages the teeth on the quill. The only real difference is that when using the fine feed wheel the rapid feed lever is pulled outboard, changing it's position. When the rapid feed lever is inboards there is a gear riding in a pocket that isn't engaging anything...there could be dried grease or something there dragging on that gear.

There's a good reference page worth checking out if you haven't already...it covers the gear setup I described:

Clausing 8520 Mill | Dales Shop

 

[alreed44]

Hi Alex,

Just to confirm, if you use the fine feed wheel and move the quill the entire length of travel it's smooth and doesn't require additional force as it nears the end of the travel, but using the rapid feed lever it does require more force during the last third of its travel?

If that's correct, it shouldn't be an issue with the quill itself, or the bore it rides in. If the quill or bore were worn you would feel it using either the wheel or the lever.

I would first look to the gear set that works with both the rapid feed lever and the fine feed wheel. I say that because the way the mechanism works, when you turn the fine feed wheel it turns a couple of gears which engage a gear on the rapid feed lever and that has a shaft which engages the teeth on the quill. The only real difference is that when using the fine feed wheel the rapid feed lever is pulled outboard, changing it's position. When the rapid feed lever is inboards there is a gear riding in a pocket that isn't engaging anything...there could be dried grease or something there dragging on that gear.

There's a good reference page worth checking out if you haven't already...it covers the gear setup I described:

Clausing 8520 Mill | Dales Shop

Thanks for the reply G-Man;

Yes, you are correct. Fine feed feels smooth and continuous, while the rapid feed requires significantly more force in its final 1/3 of downward travel.

Is it possible that the gearing is such that I just don’t feel the additional force required on the fine feed as it travels downwards?

Here is cleaned out gear assembly. Hasn’t seemed to affect the rapid feed situation as described above

 

[G-ManBart]

Thanks for the reply G-Man;

Yes, you are correct. Fine feed feels smooth and continuous, while the rapid feed requires significantly more force in its final 1/3 of downward travel.

Is it possible that the gearing is such that I just don’t feel the additional force required on the fine feed as it travels downwards?

Here is cleaned out gear assembly. Hasn’t seemed to affect the rapid feed situation as described above

You might be onto something there with the gearing. It's a reduction gear setup....so your fairly large hand wheel is turning a small gear, which turns a much bigger gear, so the hand effort is low. I think of that like a bicycle with the small gear up front and the big gear in the back....legs are spinning with little effort, but you're not going fast.

I just recently brought home an 8520 as a refurbish then sell project so I'm far from an expert on them. I would certainly see what happens loosening the quill clamp and I'd also try to inspect the gear rack on the quill while the gears are out....maybe it's gunked up with dried grease that ran down towards the bottom, or something like that.

It certainly makes sense that the last third of the travel is going to be used less than the first two, at least for most users, so even a slight bit of wear difference could be what you're seeing.

I'm waiting on a replacement gear for the fine feed setup on my 8520, but when I get it installed I'm going to really pay attention and see if I can feel a difference like you are. Hmmm...very interesting.

 

[palada]

...I'm waiting on a replacement gear for the fine feed setup on my 8520...

Can you share a link to where you're getting the gear(s) from? My 8520 came with a hornet's nest where the gears should have been. There's nest gunk all the way into the head, so I have to pull the quill, etc. and clean it out. I'm just glad they were dead

 

[jcp]

Can you share a link to where you're getting the gear(s) from? My 8520 came with a hornet's nest where the gears should have been. There's nest gunk all the way into the head, so I have to pull the quill, etc. and clean it out. I'm just glad they were dead

This might help....I think I got my pinion for one of the compound gears at McMaster-Carr.

 

[G-ManBart]

Can you share a link to where you're getting the gear(s) from? My 8520 came with a hornet's nest where the gears should have been. There's nest gunk all the way into the head, so I have to pull the quill, etc. and clean it out. I'm just glad they were dead

I used the post jcp mentioned, and then did some online searches and came up with a slightly different solution. I only needed the 12T/48T combo. I went about it slightly differently which saved me some money.

I bought the correct 12T gear that has a 3/8" hub (.25" bore) that fits into the 48T gear, then found a 48T gear that had a hub, which won't work in this situation. It had the correct pitch and PA, so it was just a problem having the hub in the way. I machined off the hub from the 48T gear, put the 12T gear in place and TIG brazed the two together so I didn't need a pinion....then I just made a new .250" hollow shaft and everything fits/works perfectly. I bought the gears from a site I'll link below, which has a lot in stock, but also drop ships gears from a warehouse...both of my gears were Boston Gear parts, in factory boxes, and I think were shipped from a Boston Gear location going off the packaging. They were coming from NC and got to Michigan in three days, which was a bonus.

Power Motion & Industrial Supplies, inc.

Your one-stop shop for industrial automation products. We offer a wide selection of Pneumatic, Hydraulic, Power Transmission, Material Handling and Metalworking products at very competitive prices!

pmisupplies.com

 

[jcp]

Not really a beginner but this is a novice question.
I've got a muffle oven and I've done some heat treating. First thing you find out is that unprotected pretty much everything oxidizes to some degree and it can be a pain to clean or or just plain bad.

I've tried the "wire cage with boric acid as a barrier" - it kind of works but can be tough to get right.

I've read that the same can be accomplished with SS foil. So I splurged and bought 25' of .002" foil labeled good for 2100F (I think).

As I understand, I just wrap the part up tightly and proceed. The foil eliminates the oxygen environment (very little air between part in foil) so oxidation is also minimal. So that's it, just works like magic?

How anal do I need to be about sealing the foil?
How tightly does it need to fit the part?
What about quenching? does the foil stay on and not make a difference or do I need to be able to peal it off quickly?
Annealing wouldn't matter as you don't quench just let it cool somewhat gradually.

So in short - I'm looking for practical advise on how to use foil this way. Tricks, tips, what to expect for results.

Thanks.

I used the post jcp mentioned, and then did some online searches and came up with a slightly different solution. I only needed the 12T/48T combo. I went about it slightly differently which saved me some money.

I bought the correct 12T gear that has a 3/8" hub (.25" bore) that fits into the 48T gear, then found a 48T gear that had a hub, which won't work in this situation. It had the correct pitch and PA, so it was just a problem having the hub in the way. I machined off the hub from the 48T gear, put the 12T gear in place and TIG brazed the two together so I didn't need a pinion....then I just made a new .250" hollow shaft and everything fits/works perfectly. I bought the gears from a site I'll link below, which has a lot in stock, but also drop ships gears from a warehouse...both of my gears were Boston Gear parts, in factory boxes, and I think were shipped from a Boston Gear location going off the packaging. They were coming from NC and got to Michigan in three days, which was a bonus.

Power Motion & Industrial Supplies, inc.

Your one-stop shop for industrial automation products. We offer a wide selection of Pneumatic, Hydraulic, Power Transmission, Material Handling and Metalworking products at very competitive prices!

pmisupplies.com

This is essentially what I did. Where you tig’d I just pinned. Easy deal really. I only had to repair one of the compound gears.
Not having any gears at all is going to be more involved but still doable.