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Index Model 645 Mill

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T.J, those spindle keys you ordered are going to cause problems later on in life. I would suggest not installing them in my opinion. They are not designed to drive the collet. They just hold the collet while you tighten the collet or arbor. I've been using my mill for over 12 years with out them. Don't miss them one bit. Ken
 

T. J.

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Gentlemen, the mill is back in business! I finished assembling the head and got it trammed in this afternoon.

image.jpeg
image.jpeg

I whittled on some scrap with an end mill before I ran out of shop time, just to be able to say I've finally made some chips! I've only had it 14 months...:oops: Of course, it's not completely done yet. I still have to clean up the table feed gear box and get it mounted. Then I need to make a new drive shaft. First though, I've got a very messy shop to straighten up:confused 3:
 

T. J.

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Here's a funny (now) side note to the mill project. The vise that came with the machine is a Kurt-style that was made in India. I cleaned it up the other day when I was getting close to being ready to use it. It's got a few dings and some pitting, but it will work for now. Two of the socket head cap screws that hold the jaw faces on were missing, so I stopped in town to get new ones: 1/2" x 1". I get home and they don't fit - bummer - I guess I measured wrong and they're metric. Next day, I make a trip to a Fastenal store and get two M12 bolts - they don't fit either! Now, I'm kinda mad. I can't be this bad at measuring. So I reconfirmed the diameter with 2 different calipers - .493". Then I got my thread pitch gauge out - 12 tpi. WHAT!?! What kinda screwed up outfit uses 1/2"-12 bolts instead of 1/2"-13? Those guys that made this thing in India must be...wait a minute...India was formerly British...

I look a little closer, then get out the Machinery's Handbook - sure enough, they're WHITWORTH threads! So now, I just ordered some online - $14.00 after making the minimum order and shipping. Not to mention the time making two wasted trips..
 
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Here's a funny (now) side note to the mill project. The vise that came with the machine is a Kurt-style that was made in India. I cleaned it up the other day when I was getting close to being ready to use it. It's got a few dings and some pitting, but it will work for now. Two of the socket head cap screws that hold the jaw faces on were missing, so I stopped in town to get new ones: 1/2" x 1". I get home and they don't fit - bummer - I guess I measured wrong and they're metric. Next day, I make a trip to a Fastenal store and get two M12 bolts - they don't fit either! Now, I'm kinda mad. I can't be this bad at measuring. So I reconfirmed the diameter with 2 different calipers - .493". Then I got my thread pitch gauge out - 12 tpi. WHAT!?! What kinda screwed up outfit uses 1/2"-12 bolts instead of 1/2"-13? Those guys that made this thing in India must be...wait a minute...India was formerly British...

I look a little closer, then get out the Machinery's Handbook - sure enough, they're WHITWORTH threads! So now, I just ordered some online - $14.00 after making the minimum order and shipping. Not to mention the time making two wasted trips..
I recall a few instances in my past where this came up. We just chased the thread with a 1/2-13 tap, installed the new screws, torqued them down and never looked back. Them old English built machines were finally pulled and scrapped out about ten years ago after a 30 plus years of running. So guess they held up....
 

NorseDave

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Looks good! I see that your mill has the breaker box mounted below the Index lettering on the side. Mine is mounted directly over top of the lettering :( Why would someone do that! You've got literally square feet of empty space on the side.

Your handles and controls are a lot shinier than mine.
 

T. J.

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Last weekend, I decided to tackle the table feed gear box.
IMG_0325.JPGIMG_0326.JPGIMG_0332.JPGIMG_0328.JPGIMG_0329.JPG
After finding the spindle feed fear box to have water in it, I expected the same with this one and I was correct. There was a little bit of rust on a couple of the gears, but nothing bad. IMG_0330.JPG
I disassembled the whole thing and got it all cleaned up.
IMG_0331.JPG
I got new bearings for it and I've got it most of the way back together as of now. But here is the bad news (you knew it was coming didn't you?). The worm gear is worn very badly. IMG_0334.JPG
I contacted W-I and a new one is $305. For that amount of money, I would rather try to adapt a Servo style power feed to the lead screw. Since I've already spent the money on the bearings for the gear box, I'm thinking I might just go ahead and try it like it is before I go another route.
 

middle.road

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Ah man, that sux to max.
Is there any hope that the 'worm' was a standard pitch and we could find a gear and adapt it to the original 'hub'?

on a side note, at least when you called W-I you received a positive though costly response.
Whenever I called them about a couple of items I needed for my Model 40 I ended up pounding sand.
 

T. J.

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I haven't taken any detailed measurements, but the gear is a 20 tooth and the worm is 3 tpi. That seems to be an unusual combination based on what I've found so far.

I have considered making one myself. The process would be to make a hob from drill rod, then use it to hob a bronze gear blank. I would need to obtain change gears for my lathe to cut 3 tpi (the coarsest thread my QCGB will do is 4 tpi). Then comes the problem of making a hexagonal hole through it (the bore is about 2" long). While I am sure I could overcome all of these issues, I'm not sure the reward is worth all of the investment. It seems like adapting a Servo style power feed to the lead screw would be fairly straightforward. I think I would just need to remove the gear housing from the right end of the table and fabricate a bracket to take its place with the proper hole pattern to mount the power feed. When completed, it would offer a couple of advantages over the original equipment - mainly infinitely variable feeds and rapid traverse.

Regarding Wells-Index, my dealings with them have been all positive other than the prices for a couple of items. I'm just glad they are still around to answer the phone and willing to help me with a machine they sold over 50 years ago!
 
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Yeah, the gear on mine is worn too, not as bad as yours. I second the idea of going with a servo drive to takes place. If you buy the servo brand, they may be able to supply the correct setup for the 645 mill. At least, they used to.
 
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One thing I like about Well Index mills, they use a number of stock gears in their design with a few specials like this one. You might be able to match up part of it to something stock out there. Highly unlikely, never know until you try.
 

T. J.

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A name brand Servo unit is more than I want to spend, but it looks like the Align (Taiwan) and ALGS (China) brands are reasonable options. There are several threads here on H-M talking about them.

The Boston Gear catalog is pretty detailed about their offerings. I just need to take some more detailed measurements on the gear when I get time.
 

T. J.

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Well, the gear may not be as much of an oddity as I thought. I took some measurements of the gear and made a drawing last night.
IMG_0339.JPG

While at first glance, the worm appears to be 3 tpi, measuring the distance between adjacent threads gives a lead of 0.305". After consulting Machinery's Handbook and the Boston Gear catalog, I did some calculations, I came up with this (also making some allowances for the fact that my measurements were taken from worn parts). The worm gear has a pitch diameter of 2 inches and diametral pitch of 10. This is a stock gear from BG:
http://www.bostongear.com/ecatalog?cid=worm_gears&id=GB1060A

My thoughts are that I could machine the gear teeth off of the original part down to a diameter of around 1". Then on the new gear, remove the protruding hub and bore it out to be a press fit onto the turned down section of the original part. It would probably need to be pinned in place. What do ya'll think? I've placed RFQ with Boston Gear, so we'll see how much it costs.
 
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ezduzit

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You should try to make this work. Your machine is more valuable with the stock drive system, no matter what must be done to repair it.
 

T. J.

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I got a quote on the part from Boston Gear through a local distributor today. It was $105.00. I guess that's not bad considering it's bronze.

For now, I'm going to finish assembling the power feed with the worn out gear and try it out. If it's not going to work, then I'll make the decision on which way to go from there.

I've gotta replace the bearings in the motor and then it will be ready to mount back on the mill. Then I will need to fix the drive shaft before I can test it.
 

middle.road

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One now wonders if any of the 'scrap' gear boxes that we have laying around, especially the Boston brand might just have one of these in it...

-EDIT- Added image. I can't believe I was able to run out into the shop and find this. Can't find the calipers from last night, but found this...
Have no idea where the cover is...
1517283733022.png
 
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D

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One now wonders if any of the 'scrap' gear boxes that we have laying around, especially the Boston brand might just have one of these in it...
Doubtful. But you never know.
 

T. J.

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T. J.

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The gear came in and it fits the worm perfectly. Here's a comparison between new and old:
image.jpegimage.jpeg
I could use some advise on how to secure the new gear to the old hub once I get them mated together. I was thinking two or three #10 socket head cap screws through the face of the gear into the large portion of the hub. Then I got to wondering if it would be a good idea to use something that would shear in the event of a crash (not that I would ever let that happen :cool:). What do ya'll think?
 
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That is super! I think it's going to take more than three 10# socket head cap screws. I would figure at least 4 just to make sure. Have a way to cut a matching hex in the gear? Doing that, three screws should be plenty. Red Loctite gear to the other piece and blue Loctite on the socket head cap screws.
 

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Here is a sketch of my plan:
IMG_0358.JPG

I was doing it this way to avoid having to cut the hex shaped bore into the gear. One dimension not on the drawing is the corner to corner distance on the hex is about 0.825". I was figuring on placing the screws adjacent to the flats on the hex, to give me a little more room. If you don't think three is enough, I may just go ahead and put in six.
 
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Put in six screws. Do you have a way to cut two small keyways in the gear and shaft? This item can see a lot of torque at times. Try six screws for now. If they get sheared off or loosen, you'll need to put a couple of keys in there. How about putting two H & G dowel pins in place of two of the screws. That should keep the gear from loosening the screws.
 

brino

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The gear came in and it fits the worm perfectly. Here's a comparison between new and old...... What do ya'll think?
I think the centre hole in the new one is all wrong......it needs to be some kind of wallowed out daisy-shape to match the old one. :D

But seriously.......
I like the idea of dowel pins.....but the "old hub" seems a little worn on the OD:
ScreenShot220.jpg

We don't have measurements of this:
ScreenShot219.jpg
versus this:
ScreenShot218c.jpg

It _looks_ like the old hub is bigger than the new hub......but it's hard to tell from here........

-brino
 

T. J.

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That portion of the old hub you have circled is unmachined casting. That section is just a spacer between the gear and the bearing journal to the left.

It _looks_ like the old hub is bigger than the new hub......but it's hard to tell from here..
You are correct, but the hub of the new gear will be removed.
 
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I might be a little late. I found a 3/4" hex broach in my toybox that I had forgotten all about. Your more than welcome to borrow it if you like.

Ken
 

T. J.

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You're not too late, as I haven't started on it yet. I really appreciate the offer, but I think I'll go a different route. As you can see from the photos, the bore is not a true hex. As Brino said, "daisy-shaped" might be more accurate. I don't think this is wear. I think it was purposely cut this way so that it bears on the flats of the driveshaft rather than on the corners.

I've been thinking a lot about how to go about this project. One thing that occurred to me last night, is that I could try to cut the hex in the new gear, and if it didn't work, I could go back to my original plan. I would start by drilling holes for the 6 corners, then hog out the middle with an end mill. The final shaping would be done with a file.
 
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That "daisy-shape" is wear, but that's ok. Still has lots of life. It'll last your lifetime since it don't have to work for a living anymore. Mine is more a true hex with some wear from what I remember. Too much crap to remove to get to that gear on my mill to look at it again.
 
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