My 1910 Mitchell "parts car" project

[Gary_Ash]

The Little Machine Shop site has lots of reference info about machining and threading, including size tables for letter and number drills and tap drill sizes:

https://littlemachineshop.com/info/business_resources.php

 

More than you ever wanted to know about pilot holes for threading:

https://littlemachineshop.com/images/gallery/instructions/Pilot_Hole_Considerations_Rev-A.pdf

 

I finally broke down a couple of years ago and bought a complete set of quality titanium-nitride coated drill bits that include fractional inch bits 1/16 to 1/2 by 64ths, number bits 1-80 ( .228" down to .0135") and letter drill A-Z (.234" to .413").  The letter and number drill bits have very small steps in size and coupled with the fractional bits, you can drill exactly the size hole you want to within a few thousandths of an inch.  But, as the PDF about pilot holes explains, you can still have lots of strength even with 60%-75% thread depth and they are easier to tap, so maybe precision holes aren't that critical.  

 

I also bought a set of bits 17/32" to 1" in Silver and Deming format, 1/32" steps.  These have 1/2" shanks, 6" total length for each bit.  These are great in my Rong Fu mill/drill (like Grizzly) so I don't have to move the head up and down when I want a different hole size, quick to swap bits.  Unfortunately, I went cheap on the set and the bits get chewed up and dull easily.  I need to buy a quality set.  

[JV Puleo]

4 hours ago, Gary_Ash said:

 But, as the PDF about pilot holes explains, you can still have lots of strength even with 60%-75% thread depth and they are easier to tap, so maybe precision holes aren't that critical. 

So right! That why when tapping 10-24 I went up from a #25 to a #23 drill. A broken 10-24 tap is very near impossible to remove and when using the "perfect" size drill it's very easy to break one. Looking at the PDF Gary posted, I use #7 for 1/4-20 holes for a 75% thread and have never had a problem. I've been reasonably lucky where drills are concerned - having inherited piles of them from friends and, lately, my cousin. It's the result of having friends that are 20 years older than you are. Eventually, I have ended up with a lot of their stuff.

 

As to the half nuts...you'll remember I said I couldn't thread my piece of 1"-6 rod into the nut. I fiddled with this all afternoon — a mystery like this is, to me, really taxing. Finally, after about three hours I figured out what was wrong. It's almost laughable. The tap I borrowed came from a friend who had never used it...I didn't notice — and he didn't either — that is was a double-start tap! It's all under control now but I regret that it will delay Terry getting his lathe operational a little longer.

Edited December 14, 2021 by JV Puleo (see edit history)

[weathered1]

Joe are you saying you need a single start tap now?

[JV Puleo]

Yes...and I've managed to arrange one. It should be here in a week or two.

[JV Puleo]

The box of dom tubing for the hub sleeves finally arrived — actually on Wednesday but I'd started this project sorting out some of the huge number of small tools — especially taps and dies — that have proliferated on this job. It had gotten to the point that I often spent an hour looking for something I knew I had. I inherited the drawer units from my late cousin. I had to cut the stand down about 8" to get all three on it and not have it too tall.

 

 

The tubing...

 

 

And the first piece set up in the lathe. This is going to be a demanding job. The holes in the hubs aren't perfectly round and the ID of these sleeves has to be accurate to no more than a thousandth. I know it can be done but, as yet, I'm not sure I can do it.

 

 

This is why I interrupted the Mitchell work to make the new compound feed screw for the lathe and brought out the tool post grinder.

Edited December 17, 2021 by JV Puleo (see edit history)

[JV Puleo]

The bearing sleeve set up in the lathe...

 

 

The piece of tubing could have been an inch shorter. I bought this some time ago and miscalculated what I needed. The sleeve itself will only be 1-1/4" long when finished but it has to be longer so it can be pressed into the hub and then faced off. I set the compound at a 60-degree angle so that the dial would be direct reading — .001 on the dial removes that amount from the diameter. In retrospect, I'm not sure this was necessary. The OD sleeve itself is calculated to be .005 larger than the hole. I'll heat the hub before I insert it. The idea is to get a "shrink fit." The holes themselves are about .0015 out of round. I suspect the original bearings had an OD 4.75 and were a press fit. This should be slightly tighter but we don't want the sleeves to move at all once they are seated.

 

 

I was getting a good finish by taking small cuts so I kept it that way. It took longer but the OD does not have to be ground. In fact, if I can get this finish on the inside I may not have to grind at all. The ID will be 110mm — 4.330. I'll have to experiment a little with the boring tools because this is one off those jobs I dread. I'm just not all that good at boring really smooth holes and this DOM tubing is not all that cooperative.

[JV Puleo]

Boring the inside of the sleeve...

 

 

I tried two different heads for this boring tool, the second one worked reasonably well but as the hole got bigger I started having a bad vibration problem. The bar was too long but shortening it is a problem because about 3" of it would have to be turned down to 3/4" to fit in the tool holder. That's easy enough to do but I can't take the sleeve out of the chuck. I ended up taking the chuck off with the sleeve in place and using a collet to hole the bar while I worked on it.

 

 

Shortening the bar made a world of difference. In fact, the finish I was now getting on the inside was good enough so that I could forgoe grinding it.

 

 

I managed to hit the desired diameter, 4.330 (plus or minus a thousandth). The bearing race feels as if it will press in just fine.

I also cut a 45-degree angle on the end to match the inside of the hub.

 

 

Then took it out and turned it around. These pieces of tubing are probably an inch too long so cutting off the extra is a headache. I don't have a band saw and it's too large for the old Starett saw - besides, I'm very skeptical of clamping it. It's perfectly concentric now and I don't want to take a chance of making it egg shaped. I decided to machine the remainder off - a tedious, but not stressful job.

 

 

The first sleeve...I still need to trim about 1/4" inch off the length. It will press into the hub and then the protruding 1/4" will be taken off so it's perfectly flush with the back.

 

 

The next one should go faster since I've already discovered what my errors were.

[JV Puleo]

I trimmed the sleeve down and pressed the bearing race into the bottom end. I hasn't been pressed into the hub yet because there is a little more to do first but this will give you an idea of how it all works.

 

 

Then I took up the 2nd hub and measured it — having no confidence in the Mitchell company actually having made two pieces identical. It turned out the the hole in the second hub is both larger and tapered. I'm going to drill the hub for set screws that will bear on the sleeve and I made this sleeve a few thousandths larger.

 

 

I also got a better finish on this one although it involved making blue chips. It's a pain in the neck to work with because the chips are very hot and flying about as the piece turns.

 

 

Nevertheless, I hit my dimension and moved on to boring...

 

 

For some reason, the inside finish was not as good as the first piece but that's a small matter. All it does is hold the bearing race.

 

 

Then I put the angle on the bottom edge...

 

 

All that left is trimming it but that can wait until tomorrow.

[Terry Harper]

Joe,

 

Can you use a parting tool to trim off the majority of the extra length than face to final?

 

T

[JV Puleo]

I may try it but in the past I've found that this low-carbon steel DOM tubing is very "stringy". It doesn't machine easily at all. Added to that, my experience with using a parting tool on large diameters hasn't been encouraging. That said, it's worth a try.

 

 

[dibarlaw]

Joe:

 I empathize with your parting tool usage. I found out that trying to part off certain materials on my well used 10" South Bend it a trial at best. Cross feed screws /nuts being sloppy has been the issue for me.

[JV Puleo]

So far I've found that it works fine with aluminum, bronze and 12L14 steel up to about 2" in diameter. I've done much bigger, liking making 6" V-groove pulleys, but it was a real chore. another problem is that this big flat belt lathe doesn't have the turning torque that a geared head lathe has. That's fine for the way I use it 99% og the time and, for the most part, with belt driven lathes a better finish is more easily achieved but for cutting off a big diameter like this it will probably cause the tool to catch and the belt to slip.

Edited December 22, 2021 by JV Puleo (see edit history)

[Terry Harper]

Hello Joe,

 

It took me awhile to get the hang of using a parting tool. My lathe has a back gear so I have plenty of torque and very low RPM. (The lower the better!)

Having the tool as short and rigid as possible and working as close to the chuck as possible both help. I also apply lots of lubricant during the parting process.

 

With that said I have struggled with some materials to get a good finish when turning. I made a shaft awhile ago that no matter what I tried I simply could not get a good finish!  Like your DOM tubing its just wouldn't cut clean.

 

 

 

 

 

[Laughing Coyote]

23 minutes ago, Terry Harper said:

My lathe has a back gear so I have plenty of torque and very low RPM. (The lower the better!)

Having the tool as short and rigid as possible and working as close to the chuck as possible both help. I also apply lots of lubricant during the parting process.

Good tips Terry.  I part at 300 rpm with the parting tool tip just a bit below the center line. Lots of coolant.  I hear you about machining different metals and getting a bad finish.  For materials like that I use a cutter that has a more rounded tip and not a pointed one and adjust the speed and cut depth.

[JV Puleo]

I never thought to put the late in back gears for parting. I'll try that...

Today I finished the second sleeve. I can't say I'm really happy with it so rather than press forward with that I'll go on to some others (there are 16 in all). It stands to reason that I'll get better at this as I progress so I may go back and do the first ones over.

Edited December 22, 2021 by JV Puleo (see edit history)

[dibarlaw]

Joe:

 Because of the catching/stalling problem with my SB (even with back gear engaged) once I could start an accurate cut with the parting tool I would baby it untill it would chatter or catch. Back out the tool, run at higher speed and use a hand held hack saw in the same groove for some more depth and then use the parting tool for another period untill trouble again. A little tedious but it worked for me. The finish was a bit rough but we usualy leave enough of a length for final fininish facing. Parted off a 4" dia solid aluminum piece that I was making a replacement fan hub to accept sealed bearings for my 1925 Buicks  and a friends 1928 Buick.

[JV Puleo]

I've done the same thing. Making the front V-belt sheeve for the engine was a real chore (The Mitchell actually used V-belts although at the time they called them "trapezoidal belts"). I made them to take conventional V belts having no idea where you'd get the early type belt and I think the angle of the V is a pretty inconsequential detail. I find it isn't too bad when the wall thickness of the piece is only about 1/8" but any deeper and it takes forever. My real mistake was making those pieces much longer than I needed to but I have no good way to cut a 5" piece of DOM tubing to shorten them.

[JV Puleo]

Here's the second big sleeve for the rear hub. As you can see, it slides in part way. This is because the hole is tapered...I doubt intentionally, it's just sloppy work. The sleeves for the small end of the rear hub are much thinner - I think less than .100. Those will have to be ground so I'm forced to learn how to use the tool post grinder. I'm reserving judgement on whether I make the big sleeves over. They will work but I think I can do better. In any case, I'll keep on with this and make that decision depending on how well the rest of the job goes.

 

 

In fitting the bearings to the other end, I realized that the rounded fillet at the base of the original hole will keep the bearing from seating flat against the flange. This wasn't a problem with the big sleeve because it's so thick.

 

 

Also, the hole through the center is slightly too small for the roller bearing which projects slightly beyond the cup. So, I need to open the hole up about .150 and take off most of the fillet. For this I used my 1" boring bar and ran the lathe in back gears.

 

 

All this went smoothly and now the bearing and cup sit flat on the flange. I also managed to get both of them done today.

 

Edited December 26, 2021 by JV Puleo (see edit history)

[JV Puleo]

Fitting new bearings to the hubs is turning out to be a real challenge. It is clear that I'll have to grind the other sleeves so with that in mind I made a grinder mandrel. It's a piece of 1" ground bar threaded on one end 1"-20.

 

 

 

I started making a nut to thread on and, half way through thought of something better so I ended up with two nuts, one of which has a relief so it slips over the 1" shaft.

 

 

This is how it will go together. The sleeves will be centered on cones that will be reamed 1" so they slide over the mandrel. This probably isn't perfect but by being very careful in making them I think I can hold a close enough tolerance. However, I had to order the aluminum and that won't be here for another week.

 

 

I've also found that measuring the holes precisely enough to get a press fit is not easy. I have been using telescoping gauges and they work fine for about 98% of what I do but in this case I have to be accurate to the thousandth so I've ordered a bore indicator, hoping I can master it well enough to go forward. In the meantime, I'm making a second grinder mandrel much smaller than this one, for the new spindle I'm trying to make for my valve grinder.

[JV Puleo]

I'm pretty certain I can do the external grinding that will be needed but I have some reservations about the internal grinding. With that in mind, last night I posted a question of the Practical Machinist forum (it was a member of that group who originally recommended the AACA forum to me) regarding the large rear hub bearing. The spindle mikes 2.503, .003 larger than 2.5". I have a new set of bearings with a 2.5" ID that I would rather used than the metric bearings I started with. My question regarded  how to reduce the diameter of the bearing seat and one of the members — a long-time internet friend suggested using a cylinder hone to enlarge the bearing. A fantastic idea that I'd never though of. He's sending me the tool to try but I'm sure if he thinks it will work, it will. So...I'm now thinking of using the tool post grinder for the external surfaces of the sleeves and the hone for the internal ones. Both will allow me to work to a tolerance of .0005 which will be fine for any automobile application.

 

Because I'm waiting on some material for the grinding arbor for the hub sleeves I went ahead and finished a similar arbor to grind a new spindle for my valve grinder. This will be my third attempt but so far it looks good. The arbor itself is a piece of 5/8" stressproof ground stock, threaded on one end. I then made two more pieces out of 1" ground stock with a 5/8" reamed hole in the center.

 

 

One end gets a 60-degree taper on it.

 

 

And were then trimmed to 1-1/2" long.

 

 

The challenge here is that the hole, which is .0005 smaller than 20mm has to be concentric with the OD. This is one of those problems that is easier said than done because when it's done it can't run out any more than .001 and, hopefully, less. Hence the use of ground stock for the parts and the fact that they are all machined in collets. I don't know if this will work but it's the best solution I can think of. I'll be doing essentialy the identical thing for the bearing sleeves, albeit much larger.

 

 

The tapered ends are supposed to center on the hole. I will have to send this out to someone with a cylindrical grinder since I don't think I can do it on my lathe...the lathe cuts a very slight taper as a result of 100 years of wear. It's only a problem if you need a long part with an absolutely consistent diameter.

[TonyAus]

Have you tried offsetting the tailstock to compensate for the taper? This dodge can help if the work is held between centres.  However, it should be set up using the job in hand - differing work lenghts may strike varying wear points on the lathe bed.  A dial gauge set up the toolpost and run along the ground stock should give you guidance as to the offset required - half the distance, of course!   

[JV Puleo]

Yes...and I've gotten it very close - maybe .002-.003 in 10". I even have a test bar for that job - as well as a big grinder mandrel that I bought specifically to check the lathe with.

 

Unfortunately, I think the taper is coming from the height of tail stock rather than it's lateral adjustment. During the 15 years this lathe was outdoors the tail stock was laying on the ground and became the home of a colony of mice. On one side the V groove on the bottom is badly corroded from the mouse urine. I compensated for that by shimming between the top and bottom pieces of the tail stock but I've never been able to get it perfect and, who's to say it ever was perfect. This isn't a Hendey or Pratt & Whitney tool maker's lathe. It was well made to begin with but I simply don't know how good it was (though I assume it was better than it is now!)

 

If and when I ever get my planer operational, one of my future projects is to plane the underside V groove and make removable shims that could then be surface ground until I get it dead on. But, it's another big job and the need for it isn't really pressing.

 

The only pictures of the lathe when I started to bring it back...A better machine may have been in order but at the time I had, quite literally, no money - but I did have the lathe. It was outside because there was nowhere inside to put it and, quite frankly, it was a very bleak time in my life.

 

 

Edited December 31, 2021 by JV Puleo (see edit history)

[JV Puleo]

Fitting new bearings to the hubs is proving to be a much more complicated exercise than I'd anticipated. Boring out the sleeves to exactly .001 under the diameter of the bearing race is a challenge but I've solicited some advice from some machinist friends and they suggested honing. I've never done that sort of honing but it looks as if I'll be learning. In order to do the larger sleeves I will need a fixture to hold them and it has to allow for the hone to pass through them. I can hold the smaller sleeves in the 3-jaw chuck I use on the rotary table but the larger sleeves are a problem. With that in mind, I've designed a fixture made from this 8" slkuare piece of 1" aluminum.

 

 

With a 1-1/2" hole reamed in the center to position it on the rotary table.

 

 

I was fortunate in that I have these little edge clamps I made when I turning the timing gears so bolting it down, which I'd thought would be a big problem, turns out to have been easy.

 

 

I'll get back to this tomorrow after I run out to refill my oxygen tank — which ran out at 4:00 PM on December 31....not exactly the best time to get it refilled!

[JV Puleo]

After running out to get my tanks refilled this morning the acme tap I was waiting for arrived so I put the job on the mill aside to see if I could finally get a good thread. I started by boring out the 12L14 threaded nut I'd already made just enough for the tap to start. I was hoping the tap will pick up the threads I'd already cut making it easier to go through.

 

 

Thankfully, it did.

 

 

So I moved over to the mill table where I could use my huge tap wrench. Even with the threads cut half-way it takes a lot of torque to turn this.

 

 

But, it worked quite well. the threads look great and a piece of 1-6 acme rod threads right in.

 

 

I now need the mill to trim the ends of the half-nut holder so tomorrow I'll finish drilling the tool I started and then finish the half nuts. With any luck, this job will be done this week and I can send it back to Terry.

[Terry Harper]

Wow Joe! That is fantastic! Again, thank you so much for doing this! 

 

Best regards,

Terry

[chistech]

Joe’s the man! 

[edinmass]

 

YUP..

18 hours ago, JV Puleo said:

After running out to get my tanks refilled this morning the acme tap I was waiting for arrived so I put the job on the mill aside to see if I could finally get a good thread. I started by boring out the 12L14 threaded nut I'd already made just enough for the tap to start. I was hoping the tap will pick up the threads I'd already cut making it easier to go through.

 

 

Thankfully, it did.

 

 

So I moved over to the mill table where I could use my huge tap wrench. Even with the threads cut half-way it takes a lot of torque to turn this.

 

 

But, it worked quite well. the threads look great and a piece of 1-6 acme rod threads right in.

 

 

I now need the mill to trim the ends of the half-nut holder so tomorrow I'll finish drilling the tool I started and then finish the half nuts. With any luck, this job will be done this week and I can send it back to Terry.

 

 

Half nuts? Isn't everyone here totally nuts?  Just asking.........😉

[JV Puleo]

I'll be happy to own up to being nuts if it will get me a Stutz Bearcat...

 

I drilled center holes in the took I started the other day. I have to put in 12 holes in 3 concentric circles...

 

 

It's probably pointless to explain all this...you'll see how it works as I progress but so far, it's coming out as planned.

 

 

 

That freed the mill up so I set up the two half-nut castings to mill the ends flat.

 

 

When that was done, I put the nut in the lathe threaded on to a piece of 1-6 acme rod. Using that as the mandrel assures that the OD will be concentric with the threads.

 

 

Then put in grooves at either end. I like the idea of putting flanges on the ends but it's an interesting problem because you cut from right to left but you need a square corner on the right. To get that, I cut these grooves. They are about .005 deeper than the finished diameter. I'll have to find - or probably grind a tool to fit into the right-hand groove, but in this case a really good finish isn't desirable. A slightly rough finish will solder better.

 

Edited January 4, 2022 by JV Puleo (see edit history)

[JV Puleo]

I got a surprising amount done today...just the opposite of so many other days. I started by turning down the center of the acme nut. I tried something different here that I read about in one of my old machinist's books but have never done. I used what looks like a 1/4" wide parting tool. You can't take very deep cuts and it needed the grooves I made yesterday to start each cut but it actually worked very well.

 

 

When that was done I trimmed the ends so that the flanges will be .150 thick.

 

 

And there is the finished part...

 

 

I then clamped the pieces together to see how it fit...all ok so far.

 

 

I smeared the pieces with paste flux and set them up on the angle plate. This is because they must be in perfect alignment with the back side perfectly flush.

 

 

When it had hardened, I took it off and soldered the areas that I couldn't reach when it was on the plate, always keeping that welding clamp in place.

 

 

While it was cooling off, I drilled the holes in the aluminum plate I started on two days ago. This is going to be a clamping fixture to hole the spacer rings for the rear hub bearings.

 

 

Then I wire brushed the half-nut assembly...

 

 

And started setting it up to cut the two pieces apart. If I had a band saw that would have sufficed but I don't, and using a 1/8" slitting cutter will do a neater job in any case.

 

 

[JV Puleo]

Since I'd set it up last night all I had to do this morning was turn the machine on and start cutting. The cutter is a 5" x 1/8" slitting cutter. It turns at 80 RPM which makes this a slow job. The space between the two pieces is very slightly under 1/8" so it's cutting top and bottom as well as through the nut.

 

 

The other side was a little more tricky to set up. The big C clamp is there to prevent the top piece from moving when I get completely through.

 

 

It went quite smoothly although like all these jobs it's tension wracked until it's almost done.

 

 

I also had to drill an oil hole...

 

 

So...all done. In fact, I've already packed them up and mailed them. Terry should get them on or about Monday.

 

 

I'm quite pleased with how this came out. With flanges on both sides of the nut I can't see how they can come out...and if they did, all you'd have to do is clamp them together with a piece of acme threaded rod in the center and re-solder them.

 

With that done, I set up the clamp I'm making to hone the spacer rings for the rear hub bearings. There is a lot of special tooling in this job  — more than I'd anticipated but if it comes out right the extra work will be worth it.

 

Edited January 7, 2022 by JV Puleo (see edit history)

[Luv2Wrench]

Great job as always!  That is one heck of a saw.  My Hendey came with some that big and I can't wait to give one a try. 

[Terry Harper]

Joe, those look great! I can’t wait to try them out and get the old South Bend cutting threads!

 

i am so thankful for your skill, talent and time and generosity in taking this project on! 

thank you so much!

 

Best regards, always!

[JV Puleo]

23 minutes ago, Luv2Wrench said:

Great job as always!  That is one heck of a saw.  My Hendey came with some that big and I can't wait to give one a try. 

Remember...very slow speed and small cuts. The first time I used a saw like this I used much too much speed. It literally fractured and flew apart. It was startling, to say the least. I use an on-line speed and feed calculator and generally run it at the slowest possible speed. It takes time but does a really good job.

[Terry Harper]

16 minutes ago, JV Puleo said:

Remember...very slow speed and small cuts…..

Agree! My first slitting saw lasted all of   Five minutes…. Having learned the hard way my current set cuts wonderful and should last a long, long time. 

[JV Puleo]

The clamp I'm making to hold the bearing spacer rings for the rear hubs. It gets four 3/4" slots, 1/2" deep.

 

 

I often have a tough time getting a smooth surface milling aluminum but these came out pretty good.

 

 

Then I flipped it over and milled a 3/8" slot in the center of each 3/4" slot. Tomorrow I'll make the captured nuts that go in the big slot.

 

 

[JV Puleo]

Today I made 4 3/4" square nuts to go in the slots.

 

 

These are just shy of 1/2" thick so they will slide easily when the fixture is bolted down. I'll round the corners when I get a 5/16-24 cap screw to hold them.

 

 

And then put register lines on the top face of the fixture.

 

 

 

[JV Puleo]

I didn't have much time on Sunday but I did stop at the shop and round the corners of the sliding nuts I'd made. They are screwed onto an appropriately threaded bolt to hold them.

 

 

I'm waiting on more 3/4" square stock to finish this so I'm filling the time by making as much of the tooling I'll need for the rear hub sleeves. It turns out to be quite a lot. One of the problems with honing the sleeves is that the hones are really made for deep holes. They aren't easy to use when the piece is only about an inch wide. To get around this I want a "honing stand" for which I'll use my small, bench-top drill press. In order to do that, I have to be able to mount the fixtures. Today I took the drill press apart and put the base in the big drill press. I started by cleaning up the 1" hole in the center with a reamer.

 

 

Then made a centering plug...1" on the bottom and 1-1/2" on the top to match the hole in the center of the fixture.

 

 

That fits into the table.

 

 

I then put the fixture on, marked a hole, drilled and tapped it. I really don't approve of doing this with working machines but, in this case, I can't see where it will effect the function of the drill and I couldn't think of a better way to do it.

 

 

The fixture then bolts directly to the table with the center directly under the drill spindle.

 

 

This will accommodate the larger rings. To do the smaller ones I'll use the 3-jaw chuck I use on the rotary table. That also has a 1-1/2" hole in the center of its mounting plate so it was just a matter of locating the proper bolt holes in the table.

 

 

With that bolted down...

 

 

I reassembled the drill press. Tomorrow I plan to start on the centering discs for the grinder mandrel...the idea is to rough turn the sleeves. Then hone the inside to size and, finally, to use the tool post grinder to finish the OD...

[Terry Harper]

Fantastic work Joe!

 

Just as a follow-up... a box from Joe containing the carefully wrapped parts arrived today. I had a chance to install the repaired half nut and it works great! The old South Bend lathe is now ready to cut some threads thanks to Joe's incredible talent and generosity. A massive thank you!

 

Best regards,

 

Terry

 

 

[JV Puleo]

You will remember that I made a grinding arbor for the ODS of the bearing sleeves. Then I remembered that I already had one...a bigger one but much better for this job. It's 1-1/2" in diameter and, unlike mine, was actually made for that job in a professional capacity. So, I'll use that instead...but, in order to do so it needs a custom driver dog. The projection on the end where the dog is attached is only 1/2" wide and none of my conventional lathe dogs will fit.

 

I'm making it out of a piece of 1" thick scrap — part of a cobbled up power system for an overhead mill I owned in the past. I made a new setup and this piece went into the "not quite scrap" pile.

 

 

The hole in the end is 1.625 and needs to be about 1.265 so I'll make a bushing out of that piece of rusty mystery metal — also from my scrap pile.

 

It gets drilled and reamed to 1"

 

 

That allowed me to press it onto a mandrel and turn it down to a press fit for the hole.

 

 

Then I bored it out to the larger size and pressed it into the piece.

 

 

Next, I'll mill about 1/2 of the thickness off at the lower end...and shorten it as it's about twice as long as it needs to be.

 

[mikewest]

Joe , when we are  all dead and gone....the new owner of your Mitchell if is  a detective like we are, is gonna say MAN This car must be a PROTOTYPE  MITCHELL ! One thing for sure , he shouldn't have to fix anything!