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My 1910 Mitchell "parts car" project


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Another day of odds & ends...

I tried the technique that TonyAus suggested earlier to make a plug to go in the end of the new spindle for the valve grinder. This will have to be ground to size and I suspect they will need something on one end to attach a dog to. It had  to be a tight press fit. The compound was angled at 50-degrees - at which point .001 on the dial equally .0005 infeed. It worked pretty well but I still have a hard time using the small dial. I think that, in combination with a larger dial, it will be a real winner.

 

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I put it in the lathe to turn on centers...I want to take it down to about .015 larger than the finished size. My major problem here is that the lathe turns a slight taper. It's not important with short parts, or parts held in the head stock but long parts that need to be perfectly straight are a problem. The taper would not effect most car parts but it's not acceptable for a precision spindle.

 

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While I'm waiting on the new front wheel bearings I started on the new compound lead screw...first by taking measurements and making a drawing.

 

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While it's not a real drawing, it's good enough for my purposes...

The biggest challenge here is making the new graduated dial. For that, I've designed another tool that I'll use in conjunction with the small dividing head to engrave the graduated lines.

 

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I didn't get very far with this...rather than doing one and then the other, I'm making the parts for both as it seems expedient depending on how the machines are set up. I did bore the new hand wheel (which isn't in the drawing)...

 

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Edited by JV Puleo (see edit history)
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I am grinding away at this but it would be pointless to show any of the pictures until I get a little more done. As is it, it would make little sense. I did discover I'd made an error in the design though. Fortunately, I thought of a quick fix.

Edited by JV Puleo (see edit history)
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These are parts for a took I've designed to engrave the lines on a graduated dial. I will use this in conjunction with a dividing head.

The first part is a sleeve, 1-1/2" OD and 1-1/4" ID. I didn't have a suitable piece of tubing to start with so I made this from a piece of "mystery metal" - in this case it was formerly a piece of a railroad switch/

 

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It wasn't the best choice. I had a difficult time getting any sort of acceptable finish. It will work but it could be better.

Then I made the piece that will rotate inside this. It's 1-1/4 OD, 3/4 ID with one end turned down to 1"

 

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The large end was counterbored to .950

 

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And threaded 1"-20

 

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Next, I took an acme thread nut, turned it down to 1" and threaded it 1"-20

 

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It was screwed in with locktite...so we have a sleeve with a holder for a nut that will be turned with a hand wheel.

 

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There is a lot of experimenting going with this. It's much the same as will be needed when I make the new lead screw but it's all new to me. For instance, using an expanding mandrel to hole the nut that I threaded proved to be a poor choice. When screwed in, it's clear that it isn't perfectly straight. Tomorrow I will see if I can remove it and make another (I bought 2 nuts precisely because I anticipated something might go wrong.)

 

 

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More bits of the dial engraving tool today...I used a block of aluminum, 2" x 3", drilled and reamed a 1" hole in ti.

 

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Then counterbored one end to 1-1/2"

 

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It also gets a 1/4" slot in the top. The "ram" has a full length key way and this will hold the key that keeps it from rotating.

 

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And, if you are wondering where all this is leading, I did a rough & ready assembly to show how it works. Turning the hand wheel will force the 1" bar forward. It will have a sharpened tool in the end to engrave the lines...this will be facing the dividing head so I can rotate the dial, engrave a line, then move to the next graduation. Of course, I won't know if it works well until I'm done so all this is somewhat speculative.

 

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I had a busy weekend and, wasn't able to get into the shop. Supposedly, two little pieces I need for the dial engraving tool were supposed to arrive Monday. They didn't...so I find myself trying to do the odd bits of three different jobs that I have the materials for. I made a 1-1/4 - 12 threading gauge. This is for a piece of the lathe I'll be replacing. The problem here is that I need the lathe together to make the parts so I took it apart, measured what I had to replicate and then put it back together.

 

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After I took that photo, the piece slipped on the mandrel. In threading, that ruins it since it is virtually impossible to put it back exactly where it was. If it happened on the first or second cut you can keep going but, in this case, it happened on the last cut. So, I started over holding the piece in the chuck. the gauge itself came out pretty good.

 

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Then, because it was still early I started to make another lathe part. This will be the block that will hold the lead screw nut for the compound...it's 1-1/2" square

 

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With a threaded hole in the center and one end turned to a 1" circle...

 

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I didn't quite finish, preferring to leave the precise part for when I'm not tired...

The parts I was waiting came in today so I can get back to the engraving tool. I'd prefer to work on one thing at a time but sometimes it isn't possible. Ultimately, no time was really waster (except for the mistakes) since all these parts will have to be made to finish the job.

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Posted (edited)

It was a reasonably productive day today...after I'd finished turning the 1" projection on the square block I trimmed the other end.

 

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This piece goes inside the compound. Eventually, it will be bored and a 3/4-10 bronze acme nut inserted but that can't be done until the other parts are made. In this case, alignment is absolutely critical. The original part is a roughly finished cast iron block. I'm sure they had fixtures to do this with but, without them, I have to be very careful in positioning the hole.

 

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Then back to the engraving tool. I started by turning down a bronze thrust washer to fit...this will block the "ram" from coming back too far.

 

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I also trimmed both ends of the outer sleeve so that everything now lines up.

 

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I gave up on my "turned down & threaded" acme nuts and just bought a brass acme nut...the type that is made for this sort of job. It had a 1" OD so I threaded it 1"-20.

 

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While alignment wasn't perfect, it was much better. It was then screwed into it's holder with Loctite and the end faced off.

 

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Last up today was the "ram"...a piece of 1" keyed stock. I drilled and reamed one end 5/8"

 

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And slipped in a 5" piece of the acme rod. Actually, I super glued it in - that should hold it while I drill and ream for a tapered pin but it was near the end of the day and I was starting to make errors so I called it quits until tomorrow.

 

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In addition to being useful, this project is serving as practice for others I've put off...I've learned quite a bit doing this so whatever errors were made hardly count if they prevent an error when I'm working on something more demanding.

Edited by JV Puleo (see edit history)
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First thing this morning I discovered another error I'd made - nothing earth shattering but it's another part I'll have to make over. This has been a real "two steps forward, one step back" project but it is turning out as I'd hoped. After that I put a pin through the "ram" and screw to keep it solid and then drilled and tapped the hand wheel. I had to give this one some thought because the chuck I use in the mill is too wide to go down past the rim of the wheel. I used this long center drill to start the hole.

 

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After that, it was a piece of cake...

 

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I've been losing parts all day so I assembled this - that way I can't lose the small parts. The acme thread collar on the end of the screw is the stop so that the ram will always advance the exact same distance. The only real flaw in this design is that I should have used a LH thread screw but I couldn't find a LH collar. The only result of this is that it advances by turning it counterclockwise but since I'm the one who will be using it, that hardly matters.

 

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So, while I wait on another aluminum block...I started on the dial and the piece that screws into the compound.

 

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The piece in the saw, above, and another like it will replace the dial and the piece that the dial runs against and is screwed into the compound...

 

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Both get drilled and reamed to 3/4". This is to facilitate making them...both also will eventually get bushings to reduce the ID.

 

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The second piece - the graduated dial - gets counterbored and I'm not going to make the same mistake I made with the engraving tool - I counterbored it in place before removing it from the chuck. It turned out that I had the proper tool to do this but simply didn't remember until I looked this morning. If I'd looked earlier I could have saved myself my last error.

 

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The first piece then gets turned down to 1-1/4" for a little more than 1/2".

 

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I managed to get about 2/3 of it down but one of my friends showed up today to use the shop so I ended up helping him...besides, it isn't a good idea to do fussy work when you're talking.

 

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On 10/7/2021 at 5:25 PM, JV Puleo said:

 

 

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The only real flaw in this design is that I should have used a LH thread screw but I couldn't find a LH collar. The only result of this is that it advances by turning it counterclockwise but since I'm the one who will be using it, that hardly matters.

 

 

While walking around at Hershey I came across a really nice 6” jaw, swivel base vise that had a feed wheel just like what your using to replace the usual ball ended slide bar. It too had the feed screw replaced and also tightened when turning the wheel to the left. Definitely a modification made by a machinist.

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I finished turning it down to 1-1/4 this morning.

 

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Then put it on an expanding mandrel to face the end off to the correct length.

 

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Then put it back on the solid mandrel to cut a chamfer on the front edge and put in the relief for the end of the thread.

 

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Threading it was made a bit tricky by the diameter of the flange. There is very little room for the threading tool. I got around that by using a smaller one that is really for a smaller lathe.

 

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After figuring that out, the threading went quite well. I checked it with the gauge I'd made last week.

 

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Then it went back on the expanding mandrel to be faced off to 1/2" thick.

 

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So, that is that piece mostly done. It still needs an oil hole and a hole for a pin spanner but I can't do that until I've screwed it in and know where the top is.

 

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I completely forgot today was a holiday but, fortunately, didn't set the alarm off like I usually do...

I started by trimming what will be the graduated dial to the proper length. I must have mis-measured something because it was about 3/8" too thick. As it is, I'm making it thicker than the original.

 

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Then I got to thinking about the order of the jobs that still need to be done. Because I'm actually using the machine that I'm making the parts for, I have to try to get everything done that I can before I take it apart again. One piece I'll have to make is a threaded collar so I made the turning fixture that will hold it while I'm working on it.

 

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The thread is 9/16-18 (the original is 5/8) but in order to make these parts I have to change a few of the measurements.

 

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I need two collars to hold the new lead screw in place, one of which is threaded. The holding fixture above was used to make the first one. As simple as this looks, it has to be extremely precise, with the threaded hole exactly concentric with the OD.

 

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The second collar, which isn't threaded, was more of a problem because there was no good way to hold it. I used some rusty steel bar from my stock of "machine rolling" bars because I could afford to waste some.

 

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The idea was to do the OD, one end and the hole without taking the piece out of the machine.

 

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Then saw it off and finish the rough end. Both of these still need set screw holes and the larger one has to be drilled so I can use a pin spanner on it.

 

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Last up today was the acme nut. This has to be turned down to 1" and threaded.

 

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I got it to the point where it is ready to thread but decided it was best to leave it for the morning.

 

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I'll finish that tomorrow and go on to the actual lead screw.

 

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Also, the last set of bearings came in for the hubs so as soon as I finish this and get it operational I can go back to finishing those.

Edited by JV Puleo (see edit history)
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I usually hold the mandrel in a collet when I'm threading but this time set it up on centers because there was no collet that fit the fat end of the mandrel. It's good I did because just about everything that can go wrong, did go wrong - all the more nerve wracking because the acme nut cost abut $32 and I'd have to buy another one and wait for it. In the end, I did save it but the job that was supposed to take about 1/2 and hour to 4 hours.

 

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The thread is a little loose...but, it's only purpose is to hold the nut in the block and I'll use Locktite on the threads so it will be fine.

 

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With that done I went on to turning down the end of the lead screw...I'll be glad to finish this get back to car work. Machine tool work is much less forgiving!

 

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I finished turning down the end of the lead screw today, threaded it for the threaded collar and cut it off to finish the end.

 

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Aside from the seat for a woodruff key, this is now done.

 

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I had wanted to finish the nut it screws into and made this little drill guide...

 

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Only to discover I didn't have the center drill that fit it. So, I drilled and tapped set screw holes in the collars...

 

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It's amazing how much time these fussy little things - that you hardly think of when planning a job like this, take.

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Yes Joe. So frustrating as you are making parts to make a fixture.. to make a jig... to make a one off part then needing to repair the machine you are trying to make them on. I had to make a fixture plate to linebore rear spring perch blocks for my friends 1928 Buick. A 1/4" plate fixture was needed for the compound rest for my 10" S/B lathe. Except to center it I needed to excavate about .100" in the center of the plate for the outboard lugs to fasten it down level.

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 To undercut the center section of the plate I could use my 7" South Bend Shaper I bought at a school auction about 20 years ago and never got into setting it up. It had a 208V 3ph motor. I thought all I needed was to replace the motor with a 120V single phase unit. After clean up and fighting with wiring the 120V motor I got it operating. Much adjustmen needed... The tool post down feed screw collar was missing so I had to make that. Lock screws missing here and there that had to be made. But finnaly had a functioning machine it only took me 20 years!

Edited by dibarlaw
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That's a great fixture...and my shaper/planer - which I'm glad to have - came in about 3 years ago and I still haven't gotten around to setting it up. I will, eventually, probably when there is a job that can't be done any other way. They are great tools and much underappreciated.

Today I took the compound apart to begin fitting the pieces. The first one - that screws into the casting, fit just fine - as good as I could hope for.

 

It needs an oil hole, another pin spanner hole and a notch so that I can access the gib screw.

 

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Then I took the top off to access the nut. I had hoped this wouldn't be too difficult. No such luck.... basically, it took all day to fit this.

Here you see the old one and the new one. There is very little room inside the compound casting - a problem that was exacerbated by the fact that I was working blind.

 

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In the first place, the 1" projection I'd made was probably .0005 too large - there was no way to reduce it in the lathe so I lapped it in.

 

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Then I milled  a 45-degree chamfer on the bottom edges. I did this 3 times, each time going a little deeper.

 

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In the end, it was in and out of the machine a dozen times. The last step was to put some Prussian blue on the inside of the casting to see where it was rubbing. That worked but I probably have 6 hours in fitting this piece and I still have to drill & tap it.

 

I finished about 4PM so, rather than quit early I milled the notch in the first piece.

 

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If I get in tomorrow, I'll keep going with this. so far, despite the headaches, it is coming out pretty good...at least a far as I can tell!

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I came in for a short time today to work on the lathe and do one really fussy thing. I started by drilling an oil hole...which is also a hole for a pin spanner.

 

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The the piece went back in the compound and was tightened up. It is critical that the hole in the nut be perfectly centered with the hole in this piece. This isn't easy to calculate given its two separate parts. I screwed the piece in and tightened the gib so that there was no movement. Then inserted a sleeve into the center hole to take a #5 center drill (7/16" in diameter).

 

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I then used a 1/2" electric drill on the center drill. The sleeve, which is about 2" long, should keep it perfectly centered.

 

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It certainly looks right. Monday I'll set this up in the mill to drill, bore and tap a hole for the bronze nut.

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I wanted to do the next step when I was rested and thinking clearly...so this morning I set it up in the mill and very carefully centered the spindle on the center hole. I then drilled and bored it to .950 and threaded it 1''-20.

 

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Then screwed the bronze nut in with Locktite on the threads.

 

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I also fit the collar that is the stop at the end. On the original lead screw, this was one piece with the screw but, to do that, I'd have had to cut the acme threads as well and I doubt I could do an accurate enough jot. The original threads were probably ground. I don't know how this acme threaded rod is made but I do know I can't match the precision.

 

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Aside from a key seat and the graduations, these parts are nearly done so I went back to fixing the engraving tool. Like the nut, the idea was to do everything without moving the work piece. It was a close run thing because the reamer and the counterbore have Morse Taper shanks. I rarely use those in the mill but I got away with it this time.

 

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So...having done the tough part, I started to mill the slot in the top that will hold the key.

 

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And got about half way when the end mill broke...

 

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That was the only extra long 1/4" end mill I had...so I had to come with another way of doing it. Ironically enough, this is actually a better way but I was too lazy to set it up. I should have. It does a much better job and I could have avoided the difficult - almost impossible challenge of lining up the cutter with the slot that was already there. It's easy to get it close but we don't want this slot to be any more than a few thousandths larger than 1/4". In the end, I got it as close as I could thinking I had a 50/50 chance of getting it close enough.

 

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I was lucky...it looks as if it will be fine and all the parts slide in and move smoothly.

 

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 I worked on the engraving tool today...starting by milling another slot.

 

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It goes half way down the large counterbore. The idea is that this will act as a clamp to hole the pieces in place.

 

IMG_4891.JPG.2a90f68861585f2182419d0acfad5c41.JPG

 

It looks good, but the only way to tell if it works is to drill some holes.

 

IMG_4892.JPG.15f81a528c488cf27b6ac2f894852722.JPG

 

The two holes at the front will hole the key while the rear one clamps the wheel and screw mechanism n place.

 

IMG_4893.JPG.89a9ca392b23e04032ccac8c29210e17.JPG

 

So far, so good. Next, I'll make the key. There can't be any "wiggle" in this part since it will be used to engrave the graduated dial so I still have my fingers crossed that it will work.

 

IMG_4894.JPG.91b877a6dc2986c9e2c6a9348989356f.JPG

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I'm getting close now...I milled a piece for the key.

 

 

IMG_4895.JPG

 

Then marked it drill two holes.

 

IMG_4896.JPG.7eda718710d799063055c7dcea5ba342.JPG

 

The holes are 5/16 so as to not touch the through bolts...

 

IMG_4897.JPG.c06dd851806948c1aa753d01849fa924.JPG

 

I had to add some shims to adjust it and didn't push that too far. I got it close enough to be certain it will work properly but it has to come apart several more times before final assembly so it's pointless to go too far with the adjustment yet. The next step was to drill and ream a 7/16 hole in the end of the "ram".

 

IMG_4899.JPG.52401f453e5d1983eb47362f14483e26.JPG

 

And press in a square hole sleeve. These are a really neat little device that circumvents the need to broach a square hole. I get them from Green Bay Manufacturing, who also supplied the acme lead screw and nut.

 

IMG_4900.JPG.50be42d84b3bd6fc2cb7f7fcf472e9ed.JPG

 

Then I drilled and tapped the end for a set screw and slipped in a 1/4 HSS lathe bit. This will get ground to a 60-degree angle and serve as the engraving tool.

 

IMG_4901.JPG.dc004f145594c4624a7c549d8eb56af3.JPG

 

I'm waiting on some set screws to finish this up...then I have to calculate the optimum height, trim it and make a base that bolts to the mill table. In the meantime I set up this piece, a 3/4" rod that will take a 3/4-16 nut on one end. This is needed to take a final cut on the dial and the piece it mates with and to hold the dial in the dividing head to engrave the graduations.

 

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I set up the threading but it's 5:00 and my back hurts. I'll get back to this tomorrow morning.

 

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Edited by JV Puleo (see edit history)
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I finished the little threaded mandrel this morning...

 

IMG_4904.JPG.ffb2898fc8d1ce593056e08c532c17e1.JPG

 

And used it on the lathe to take a tiny bit - about .004 off the dial and the piece it mates with. This is so that they will have an absolutely identical OD.

 

IMG_4905.JPG.cec731f7326ffa63e9a424ca3498e50c.JPG

 

I also polished them on the lathe. Ordinarily, this isn't very important but in this case I want the engraved lines to be very clear.

 

IMG_4906.JPG.bbb834adb339a9617f038c04d2c011a9.JPG

 

With that done, I removed the chuck from the small dividing head and did a preliminary setup. You can now see how this is intended to work.

 

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I had to cut 1-5/8" off the aluminum block.

 

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And mill the bottom square. Actually, this long end mill didn't work very well. I don't think it was stiff enough for the 2" depth so I finished it with a different end mill.

 

IMG_4909.JPG.675996aec197cdd28f9e417c250a41ab.JPG

 

This piece needs a base to bolt it to the mill table so I started on that.

 

IMG_4910.JPG.0da9e214a5a8f3f693b6e532db30fb39.JPG

 

By which time my back was hurting so I set it up in the mill to put a slot in the center but I'll leave the milling for tomorrow.

 

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When I left last night I wasn't happy with the set-up for this last step but I was too tired to re-do it. so, I did so this morning and started milling the big slot.

 

IMG_4912.JPG.affc2c23d4b7a26ad5e67972b6cd5186.JPG

 

I took it down to a depth of .400

 

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And moved it over to finish the slot.

 

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It also needs an alignment block on the bottom and this has to match the width of the blocks that go on the dividing head. I usually leave them off because I use this head on the drill press and when I found them, I couldn't find one of the screws. B&S used all sorts of odd threads on their machine screws (and this dividing head probably pre-dates WWI) so replacing the screw is not an easy task. After about an hour of looking I finally found a hex head with the right thread. fortunately, these stick down into the slot on the mill table so they don't have to be flush on the bottom.

 

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The blocks are 5/8" wide so I milled a 5/8" slot on the bottom side of the base.

 

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Now I'll have to make a 5/8 "key to go in the slot...needless to say, I don't have a piece of 5/8" square stock so I'll make it out of a scrap of 1"

 

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