# My first knee mill



## jwmay (Aug 28, 2021)

After a long day of travel, I have arrived home with something I hope will brings many years of good service. It came from a high school  auction where it was one of just two milling machines. They had 13 SB 9A's, which I expect I will regret not trying to buy at least one for years to come. Anyways, here's my day in pictures.
	

		
			
		

		
	



	

		
			
		

		
	
Somehow I messed up the picture size, for which I apologize. I'll get it right next time. I am going to try to document my progress while getting this little mill clean and functional. I'm pretty happy about it. Although this means when this thread is finished, I'll have to sell my other mill. SWMBO has spoken. Ha! Plus there's not really enough room for two in my shop...mills that is.


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## FOMOGO (Aug 28, 2021)

Congrats on the new family member. Cheers, Mike


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## Weldingrod1 (Aug 29, 2021)

When you.have the table off, you will find there is a huge hole in the back of the knee casting. Glue a sheet of something over that to keep swarf out of the knee gears!

I found some weird automotive boot thing that fit over my knee screw and caught on the inside of the knee casting; does a good job of keeping crud out and still allows full knee travel.

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## jwmay (Aug 29, 2021)

Well with any luck, there won't be cause to remove the table. But I did find that hole this morning while cleaning the chips out of the knee. As I worked on it though, I came to the conclusion that barring some broken thing, this mill probably won't get anything but cleaned, oiled, and put in service. It would be nice to have shiny surfaces, and fresh paint. But I don't think I have it in me this year. I've got to build a mobile base for it, clean the head, and do something about a missing power feed unit. After that, I hope to be using it.


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## jwmay (Aug 30, 2021)

Just some pics. I spent a couple hours yesterday morning scraping gunk of with a razor blade. The mill had a Rockwell pana-vise mounted to it, which sold separately. But as you can see, the vise left its mark. I'm pretty torn about not making the table grey again, but I'm dying to get the head trammed and fire it up.


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## jwmay (Aug 30, 2021)

Playing with the camera a little. But it's looking better everyday.


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## jwmay (Sep 1, 2021)

Well no pictures today. Just some information in hopes of some suggestions.

First, the quill won't fully extend. It stops a bit short. I feel like I could force it, but am hesitant to inadvertently scratch, scar, of break something. Any ideas?
Secondly, the missing power feed is fine. I know I'll never find a working original. But the PO stuck a handwheel on that side which I believe belongs on a little lathe. I'm torn between ignoring it, buying a servo power feed, and making some kind of cap, or painstakingly trying to make realistic replacements of dial and handwheel by copying the left side unit. What would you do?
Lastly for now, the motor leads are toast, and I believe the windings are open. It's a dual voltage single phase motor. Again, what would you do? Three phase and VFD? The motor shaft is over 4" long. Looks expensive. Lol


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## jwmay (Sep 2, 2021)

Nothin eh? New job is keeping me out of the shop anyways. 
I'm going to print the manual from downloads. Seems like I read somewhere the quill bearings are supposed to have grease. I want to be sure about that. 
I'll move it out of the way for now. I have other projects that have to be finished before I move ahead with this anyhow.


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## 38super (Sep 2, 2021)

I'm running 120VAC, no probs.  Power feeds are well covered in this forum, bought mine for $250 ea.  Same 150in/lb item is now $150.


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## Just for fun (Sep 2, 2021)

Congrats on your new mill.


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## Aaron_W (Sep 3, 2021)

jwmay said:


> Well no pictures today. Just some information in hopes of some suggestions.
> 
> First, the quill won't fully extend. It stops a bit short. I feel like I could force it, but am hesitant to inadvertently scratch, scar, of break something. Any ideas?
> Secondly, the missing power feed is fine. I know I'll never find a working original. But the PO stuck a handwheel on that side which I believe belongs on a little lathe. I'm torn between ignoring it, buying a servo power feed, and making some kind of cap, or painstakingly trying to make realistic replacements of dial and handwheel by copying the left side unit. What would you do?
> Lastly for now, the motor leads are toast, and I believe the windings are open. It's a dual voltage single phase motor. Again, what would you do? Three phase and VFD? The motor shaft is over 4" long. Looks expensive. Lol



Good to find out why the quill won't extend but not that big of a deal in the short term as long as it isn't damaged. The only time I use the quill is drilling, the knee is much more accurate and solid when milling.


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## Bob Korves (Sep 3, 2021)

What brand and model is that mill?


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## jwmay (Sep 3, 2021)

Rockwell Delta 21-100


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## john.oliver35 (Sep 3, 2021)

If you are open to a 3Ph motor and a VFD, then I would recommend that.  I have a 21-100 on single phase.  The minimum spindle speed is 370RPM.  I have had several instances where I would have liked to have had a slower speed.


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## jwmay (Sep 3, 2021)

My only dilemma is the shaft length. I saw a guy had made an extension for his and I just can't believe it'd hold up. I imagine there's plenty of bending force being applied to the motor output shaft. Having a "splice" outboard of both bearings doesn't seem sturdy at all. But only that guy could say I guess.


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## jwmay (Sep 4, 2021)

Dual voltage single phase motor troubleshooting
					

I've got a dual voltage single phase motor I'm really trying to will back to life here. I thought the motor leads were damaged but they aren't. It all looks fine.  I'm used to three phase motors, but don't know what I'm doing with this. The internet didn't yield anything I didn't know.  The...




					www.hobby-machinist.com
				




There's my topic on the motor. Cliffs Notes version is that the motor is fine, and the only thing wrong with it was a lazy repairman..me. So honestly, the lazy repairman is also pretty cheap, and probably won't be switching to three phase with VFD unless some ridiculous bargain slaps me in the face.  But if anyone with this mill and the 3 phase motor wants to trade motors, do let me know.  
This problem was the only one of any significance that I had with the mill. I guess I'll get my Servo power feed ordered while I keep scrubbing!


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## jwmay (Sep 4, 2021)

More good news: The quill is also fine. After looking over a few pictures on the internet, I decided to measure the downfeed travel. Sure enough, someone at some point moved one of the quill locking nuts to the top of the depth indicator. I guess they got a little more travel out of it that way. I've got it taken apart. I'm going to clean the pieces, get as much junk out of the quill as I can, and put it back together as it was originally built.


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## jwmay (Sep 5, 2021)

Chased the threads on the screw, cleaned, and deburred. All is as it should be now I think. 
I'm starting to think this whole job would have been easier if I had disassembled it. There's so much crud. Everywhere I look, and places I thought I already looked. Kerosene though seems to be the answer. Kerosene and a brass brush. 
First photo shows where the power feed was removed, and what was done so they could use it.


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## jwmay (Sep 5, 2021)

jwmay said:


> Well with any luck, there won't be cause to remove the table


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## jwmay (Sep 5, 2021)

The power feed side was machined into what it is. Now it's deburred too. It's a cast aluminum part, and there's the bearing number for the handwheel just so it's saved for all time. Also found somebodies oops in the bearing housing.


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## jwmay (Sep 5, 2021)

This cleaned up nice.


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## Just for fun (Sep 5, 2021)

Looking good!


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## Mike23 (Sep 5, 2021)

Congratulations I just finished going through my SB that was in storage for 20+ years. I almost forgot how nice life is with a knee mill.  Mike


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## Weldingrod1 (Sep 5, 2021)

here's the core holes in the back of the knee. If you ever are in a position to see them on -your- mill, plug them! They let chips get on your bevel gears!

I'm knee deep adding/improving my Rockwell right now. Any interest I'm my posting the progress? You can see the new lube grooves and ports...
	

	
	
		
		

		
			





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## jwmay (Sep 5, 2021)

Weldingrod1 said:


> Any interest I'm my posting the progress?



Yeah of course! You're doing the hard stuff! I'd love to read all about it. Thanks for showing the core holes. I didn't realize there were two.
 I'm just scrubbing mine clean as best I can so I can use it. I wish I had the skill and patience to do what you're doing. Probably not in the cards for me though. I need to get alot better at machining first. At this rate, I'll be out of time before I get that skill mastered. Lol


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## jwmay (Sep 5, 2021)

Well I'm close to closing the book on cleaning I hope.  Here's a day one and today picture.


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## jwmay (Sep 6, 2021)

There was about 8 Solo cups worth of chips up inside the knee. I don't want to remove it, so I fashioned a fancy bent hook, sat on my knees with a flashlight and dug "most" of it out. Here's a picture looking up in the knee casting, a picture of where the bevel gears are, and a couple pics of a contraption to separate the knee dial and crank from the carrier. All three pieces were seized together. It really seems like maybe this had cosmoline on it, and it was never cleaned off. It's obviously been used plenty. 
As for the bevel gears, I stuck my flexi spout oiler up in there and gave it a half dozen pumps. Hopefully that'll wash out any big chips left over.  I've got half a mind to drag a small coolant pump over and run a nozzle up in the casting and wash down all that stuff properly. But I doubt the other half of my mind will ever be that motivated. The mill lasted this long with no lube, maintenance or cleaning. It'll probably outlast me so long as I'm the one at the helm.
Credit where it's due, my digital images of the manual came from vintagemachinery.org.  It's also in the downloads section of this forum.


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## Weldingrod1 (Sep 7, 2021)

I found out why my sliding swarf guard got bent!!! I screwed up :-(
If you put them on backwards, they can -just- slide far enough so that the top guard gets hooked on the bottom of the saddle casting!
The photo is the correct direction!
	

	
	
		
		

		
		
	


	







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## jwmay (Sep 7, 2021)

Since you brought that up, the manual states that you can expose the bevel gears for lubrication by sliding those covers. I've slid them every way I could think, and there's never an opening. Since yours is completely apart, do you see any way that can happen?


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## Weldingrod1 (Sep 7, 2021)

That means you have them on backwards :-(
I'll take a picture tomorrow. 

Here's where you want to put the hand wheel to tighten the mounting bolts.
	

	
	
		
		

		
		
	


	




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## jwmay (Sep 8, 2021)

You're gonna end up making me take this whole thing apart I think. Haha.


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## Janderso (Sep 8, 2021)

Weldingrod1 said:


> Any interest in my posting the progress?


Keep em coming


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## Weldingrod1 (Sep 8, 2021)

Here you go!
	

	
	
		
		

		
			





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## jwmay (Sep 8, 2021)

Thanks for that picture of the slides! 


Weldingrod1 said:


> Here's where you want to put the hand wheel to tighten the mounting bolts.


 I don't have a dial or original handwheel for that side. Mine had a  factory power feed which must have been thrown away in pieces before I got it. The handwheel I do have seems to have come from a Rockwell tablesaw of the time. Anyways it'll get a power feed eventually. Thanks again!


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## jwmay (Sep 9, 2021)

Who could have guessed? More crud! Thanks to welingrod1's picture, I was able to figure this slide problem out. I shined a light in there and it seems my bent metal rod did a decent job of clearing chips. But I hadn't gotten any oil on the bevel gears. From this access though, I can hit it ok.


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## jwmay (Sep 11, 2021)

Bevel gears get grease.  Got another solo cup out of the knee. Took off, cleaned and polished the dials and handwheels. Removed the Y gib, cleaned, stoned and reinstalled after "flossing" the gib area with a long strip of cloth. Bevel gears are greased. Knee cavity is comparatively clean. Gibs are adjusted. Screws are lubed. It's about time to mill something I think. Head needs trammed, and I still need to figure out where to put it...and how to put it there.


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## jwmay (Sep 15, 2021)

Oh boy oh boy we're getting somewhere now.


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## Weldingrod1 (Sep 15, 2021)

Great progress!!!

Two tips: I put my vice one more slot outward, and you should saw off the coolant channel on the column side. A couple of wads of epoxy putty will close the gaps.

You also want to make a couple of covers for the right and left sides. Trust me and do ot now, rather than later when you discover "why" the hard way. ;-)
	

	
	
		
		

		
		
	


	




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## jwmay (Sep 18, 2021)

Will do!
I didn't make alot of progress today, but I got this about half done.


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## Weldingrod1 (Sep 18, 2021)

Ah, I need to make one of those too :-(

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## jwmay (Sep 19, 2021)

Came out ok I think.


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## jwmay (Sep 19, 2021)

It'll probably be a while until I figure out the parts to make so that I can use this power feed. But I've got the power feed!


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## 38super (Sep 23, 2021)

Mind a rapid traverse, end mills at risk


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## jwmay (Sep 25, 2021)

I sat in front of the mill today, trying to suss out how to mount the dro and power feed. Didn't get very far, but an aluminum handwheel casting arrived in the mail today. It'll have to be machined and then I'm down to the dial, which theoretically I can make.  I'm so happy to have this handwheel. What a stroke of luck that someone had thought to make up a batch of these, and just have them sitting around waiting for me to find the thread where he mentioned it years ago. Awesome!


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## jwmay (Oct 3, 2021)

Prepping for power feed. Not having much luck finding motivation through the week. Saturdays are family days, and Sundays are... well sometimes I can get something done. So this was all I accomplished. If you don't count breaking a tooth off my slitting saw blade, drilling out the stuck bolt in the slitting saw arbor, fiddling with clamps interminably, remembering I have a vise right over there, mounting a vise, setting up the bandsaw for vertical use, searching for suitable material, searching for that stupid allen wrench again, chasing off a stray cat, grocery shopping, attempting to draw my parts with fusion.  Anyways, at least something got done. Ha!


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## 38super (Oct 3, 2021)

thin slitting saws have a bad habit of wrinkling, causing a bind and a tooth pop.  Lube and slow feed/speed.  think of the lost tooth as an interrupted cut.


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## jwmay (Oct 10, 2021)

X axis works. As with everything I do, it's far from perfect. But it works. I'll have to trim off some extra eventually. The brackets couldn't be mirror images because of the factory power feed coolant tray having bolts in it that the other side didn't. So it is what it is. But it works, and that's the most important thing about having a DRO I suppose. In another reality, I would use these first brackets to get valuable measurements that would help me make a less novice looking install. But in this reality, this is pretty much as far as it goes.


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## jwmay (Nov 6, 2021)

Well I haven't worked on the old girl in over a month. But today I gently eased her into the shop. Maybe it's ok to keep both mills...it sure seems like the space isn't an issue. Plus what if something catastrophic were to happen to one of them? I might need the other one for repair work. That devil on my shoulder is working overtime today it seems.


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## Alcap (Nov 6, 2021)

You have a very nice shop


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## brino (Nov 6, 2021)

@jwmay 

Hi, I just found this thread.

You have made great progress. 
It is wonderful to see this mill being so well cared for!

It sure looks like there's room for two mills.......you really should keep both.....




Have you made any chips with it yet?

What DRO did you choose? Any feedback on it?

Thanks,
-brino


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## Alcap (Nov 7, 2021)

I’ll second keeping both like brino !  I started a few years ago setting up my shop , already had a small bench top lathe and bought a Clausing 5914 lathe and 8520 mill . I wanted a drill press when a old Jet 15 mill/drill for $160 about a mile away . Thought I would use it for those roughing jobs , things that might be harder on the 8520 .  I bought a 10” Phase 2 rotary table for a can’t pass price . I used that a few times on the Jet because thought keeping the heavy weight off the 8520 would keep wear on the knee screw a little less  .  I would if the job required more presision then I might expect with the Jet . Your round column is much newer and probably very good shape you’ll have 2 options for different set ups that you can go to !


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## jwmay (Nov 7, 2021)

Alcap said:


> You have a very nice shop


Thank you! I spend alot of time trying to put things where they're needed. It's the best space I've ever had. As it sits, (which is already different than pictured) puts nearly everything within one step of the machine that uses it most. I get much satisfaction from a well ordered workspace. 


brino said:


> Have you made any chips with it yet?
> 
> What DRO did you choose? Any feedback on it?


I haven't made any chips.  With a known good machine already set up, this mill kind of turned into an off season project. I want to get the DRO and power feed completed first. Then I read about another person who had a bad bearing in the head that wiped out the spindle.   Working with an obsolete machine, that has basically no replacement parts available, I'm being extra careful I guess. 
I bought the Toauto DRO from an Ebay vendor. It's a two axis unit, which I think will be enough. It still isn't fully installed though, so no word on how good or bad it might be. 
I brought my wife out to the shop after I got it in place, and SHE said ," I can't even tell any difference. I think it would be ok to keep both." I nearly fell over. So with the only other voter in the house onboard...I guess I can keep both! 
I'm getting long winded now. But the ironic thing about this is how much better my RC mill is than I knew. I had given up on it. I was spending my free time searching for a Millrite, and working out logistics for moving a knee mill cross country. Then I changed jobs, where I was given some training by a professional machinist. After a month with him, the RC mill started to shine . So now I have this knee mill, and I'm in no rush to use it. While there are definitely some good things about having a knee, the RC machine is darned capable too. It seems I was blaming my failures/difficulties on the machine. After a few weeks of professional mentorship, my own shortcomings had been laid bare, and the RC machine was chomping steel like it never had before! Lol 
The learning never stops around here!


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## jwmay (Nov 14, 2021)

DRO is installed and working. Looks like it's crooked from this angle. I didn't notice that when I was out there. Anyways, it's as accurate as the dials, so that's as good as I'll ever need it. I trammed the head to within a half thousandth over 3 inches. I don't really know if that's good enough or not. I hope so, because it's tedious. On to the power feed!


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## jwmay (Nov 20, 2021)

Today's improvement.


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## jwmelvin (Nov 20, 2021)

Good stuff.


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## Weldingrod1 (Nov 24, 2021)

Nice work!

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