My 1910 Mitchell "parts car" project

[JV Puleo]

All of this could be done without the milling machine and the rotary table. It might not be quite as precise, but the differences would probably not be visible to the human eye. I'd just coat the surface with dye chem... draw the circles with a sharp protractor and see how much high school geometry you can remember. I'm guessing you've got chain sprockets to do. I find it makes a huge difference to draw the whole thing out on paper, full size, to get the measurements and even then I find myself making changes on the fly.

 

[JV Puleo]

Does your drill press have a hole in the center? If not, you'll have to think of a way to block the work piece up and bolt it tight. It is very important that the piece be held securely... I managed to slash my leg open drilling a thin piece of metal many years ago when the drill caught a burr and spun the piece. It's astonishing how much torque these old, slow drills generate.

 

[Luv2Wrench]

Yeah, I saw a picture of a guy with a busted eye socket/nose/face in general from something coming loose in his drill press.  I didn't need much more explanation on the dangers after that. 

The part in question is the friction disc (the one attached to the prop shaft).  I don't have a photo handy but it is just a circle with some holes in various places around it.  I don't have a hole in the DP table but I would have the work mounted and clamped anyway so not an issue.   I will make a simple index type mount so that I can get the holes at a consistent distance from center and more less at the same angles.  The actual angles and the actual distance is not a big concern, the same distance and same angle is the concern.  It should be pretty straightforward and seeing how you break things down, build tools/clamps/etc, is an inspiration and makes the impossible seem much less impossible. 

[JV Puleo]

I've always thought that a simple indexing fixture could be made from a gear. You'd need one with either the same number of teeth as the number of holes or a multiple of the number of holes. As long as the work piece is mounted on some sort of axle it can revolve on, all that is necessary to make the holes uniform is a solid support for the piece. Alignment is easy as you have two circles, both with fixed center points. The arc of the circle will always pass under the spindle of the drill at the same angle. Its dividing the arc uniformly that poses a problem... hence my gear idea.

[JV Puleo]

Having finished the decorative holes in the gears, I have two more drilling jobs to do before I start milling the reliefs in the gear faces. First, I needed to drill the hub flanges for their mounting studs.

 

 

The holes in the flanges get threaded. The corresponding holes in the gears will get milled into radial slots covering about 15 degrees and making it possible to "fine tune" the position of the timing gear after it is installed. I then drilled out the three holes in the aluminum fixture the gear is sitting on. I'll use this as a tool to hold the hub when I thread the holes in the flange.

 

 

I used a drill the same size as the hole to locate the flange and fixture directly under the spindle – then used the drill press as a threading guide to make sure the holes were straight.

 

 

The last drilling job was center holes for the brass threaded inserts that go into the crankshaft gears. I'll drill, counterbore and thread these holes on the drill press when the inserts are ready.

 

 

I finished with starting on the inserts. The brass bolts are made of 270... an alloy that is strong but does not machine as well as the common 360 I usually use. That's not a serious problem but it takes longer to make them. I had three done by the end of the day and my back was telling me I'd had enough. I will probably finish the crank gear blanks tomorrow.

 

Edited July 5, 2017 by JV Puleo
typo (see edit history)

[JV Puleo]

As simple as this job was... once again I underestimated how long it would take. Each bolt had to be drilled...

 

 

After which, I threaded them. The threads were started using the lathe to keep things straight. Because they have such a thin wall thickness, it is critical that the thread be straight. This brass is tough to thread so I only started the thread here. When they were in five or six turns, I took the bolt out and put it in a vise where I could use a bigger tap wrench with a lot more leverage.

 

 

Next I had to turn down the heads. This proved trickier than I anticipated because the thin wall thickness of the drilled bolt leaves relatively little strength. In order to stiffen the bolt I put a stainless screw in it, center drilled to match the tail stock. That way, it was both stiffened and supported on the outside end.

 

 

After all that... actually turning them down went quickly. This is another job where 80% of the time goes into the setup.

 

 

The final step was to drill, counterbore and thread a hole in one of the gear blanks and try the inserts. It went in, tighter than I had expected, probably because it is almost impossible to keep everything perfectly concentric. Nevertheless, what irregularities there are will be invisible to the naked eye.

 

Tomorrow I will put in the last five inserts and face the blanks to the proper thickness.

Edited July 5, 2017 by JV Puleo (see edit history)

[Luv2Wrench]

Wow.. so you threaded the *inside* of the bolt?     I in turn ordered my first HSS blanks so I'm just a *little* behind you.

I got a video I need to send you as well... I was able to get a MT3->MT2 adapter secured into the tailstock... as such, I'm now the proud owner of a tailstock that accepts MT2.  I've already got a MT2 chuck and I've ordered some center drills.  Your thread is inspiring!!

 

 

Edited July 5, 2017 by Luv2Wrench (see edit history)

[JV Puleo]

All I did was turn the bolts into threaded inserts... after you've been doing this for a time, you'll start to notice all sorts of ways to "make something out of something else."

 

Do you know what your headstock spindle taper is? I was thinking that you could really use a collet set... the best solution is to get an adapter that takes 5C collets. The adapters can be expensive but the collets are cheap and readily available. In any case... I have a complete collet set with drawbar and adapter for my Hendey Tie Bar that I'd loan you until you can get a better setup... I just wonder if the spindle taper is the same.

 

You are probably better off using a tail stock live center with an MT3 taper... the bigger the taper, the more surface area there is and the less it will slip although taper size isn't so important with the centers as it is with drilling. That said, you'll need the adaptors down to MT1 to use taper shank drills so nothing is wasted. Get a drill chuck with the biggest taper shank that will fit.

 

jp

Edited July 5, 2017 by JV Puleo (see edit history)

[Luv2Wrench]

I looked at the spindle last night and I could not tell what the taper is.  The opening is 1.25" and I could not discern a taper in the first 5".  The other end of the spindle is 1" but that is nearly 24" away so I'm not sure that really contributes to the taper.  My guess is that there was something that went into the spindle that had the taper.  It looks like a 5C collet is pretty big, I wonder if that would work in this spindle?   As always, a very generous offer from you to help, and I'm very appreciative. 

 

The tailstock is not a real MT3 taper but rather I believe it has been adapted (hacked) to hold a MT3 to MT2 adapter.  I'll send you the video and I think it will make sense at that point.   I could most likely use an MT3 live center but I would need to modify it a bit to mount securely in the tailstock. 

[JV Puleo]

I will check the parts when I get int the shop. Maybe I should send you the adapter to try in the spindle.

I had a similar issue with my 1880s Prentice Bros tail stock - it was a jarno taper. I (very carefully) centered a #3 morse taper reamer in the chuck and gently fed it on to the reamer, using lots of oil and going very slowly. It worked a charm but I think I spent an entire day on it. If you could put a MT reamer in a collet it would be a cinch to get it perfectly straight. I like this idea!

 

j

Edited July 5, 2017 by JV Puleo
typos (see edit history)

[Spinneyhill]

If one uses an adapter to put MT 2 tool into MT3 (or MT4), how do you get the adapter out again? I am thinking of something like an MT2 collet with a drawbar.

[JV Puleo]

Most MT adapters are long, have a tang at the back and a slot for a wedge to dislodge the tool. Some are shorter and have two flats to take a wrench. Those can be a problem if you want to get the tool out of the adapter but it can usually be done by hitting the end with a plastic hammer. Collets are less of a problem... the collet itself is dislodged by pushing the drawbar forward. The adapter is knocked out with a "knock out bar"... I made one of DOM tubing and put an aluminum end on it so it doesn't mar the pieces in the spindle.

 

Further... for collets you need a short adapter with an open back. I'll photograph one tomorrow.

 

jp

Edited July 6, 2017 by JV Puleo
Addition & typos (see edit history)

[JV Puleo]

Here is the blank with the holes drilled, counterbored and threaded...

 

 

When the inserts are in, I put it back in the lathe to turn both faces and the diameter to the finished size.

 

 

This what they look like finished. Obviously, they still need the teeth cut. It needs a key way as well but I am reluctant to put that in until I've fitted the gear to the crank. I think they should be lapped out about .001 to .0015. That is a fussy operation and the lapping may round the corners of the key way so it is best left to last. Neither are difficult and there is little chance I'll screw that up and ruin the part.

 

[Luv2Wrench]

Wow, that looks fantastic! 

[JV Puleo]

For Spinneyhill... this is the sort of adapter that would work with collets. I believe these are shorter than MT3 collets so the collet would pass through leaving room to dislodge out with a knock-out bar. The one on the chuck is MT4 to MT3.

 

 

I had some errands to run today but between them was able to finish a couple of items. First, I finished the second crank shaft gear blank. Then, since the lathe set up for this, I refaced the timing gear hubs. I'd left the flanges 3/8" thick, intending to put studs in. I wanted to turn the face after the studs were inserted but, in thinking about it, realized that would cause a problem when it came to attaching it to the camshaft. This hub will, effectively, be a part of the cam.

 

 

Here they are finished... The original gears were attached with a woodruff key and a tapered pin. The result was that, in order to do anything to the gear, you had to remove the cam from the engine. For a lot of reasons I wasn't happy with this so I've adopted the separate hub. This idea isn't original to me, I found it described in the PM Heldt, 1911 engineering text, albeit as a feature of expensive cars.

 

 

Tomorrow I will mill the reliefs in the faces of the timing gears. For this, I'm using a special end mill, 1" in diameter with a .250 radius. I bought three new 1" end mills on ebay and sent them to a tool grinder. It turned out more expensive than I'd anticipated but the three mills should see me through this job and the connecting rods that I'll get to later this summer. Both require radius cuts for appearance and because they are much stronger than a simple square cut. I re-zeroed the mill and set up the rotary table before quitting for the evening.

 

 

 

Edited July 7, 2017 by JV Puleo (see edit history)

[Guest BillP]

This is to me, fascinating work. The energy of the mind goes directly through the lathe, through the mill, to the piece and then to the engine.

[JV Puleo]

Aside from unloading my "new" second-hand jointer and proof reading an article, I managed to spend most of the day in the shop. Having set the timing gear blanks up for milling last night, I started on them. I'm not thrilled with my clamps – although they actually didn't create any problem – I suspect because the plug in the center of the gear prevented any side-to-side movement. All they had to do was hold the piece down. This job created a lot of chips... hot ones, a few of which found their way down my shirt. It's not very pleasant but comes with the territory.

 

 

The relief is .250 deep on each side. I made four passes at .050, then two at .020 and the last at .010. There are some little chatter marks around the edges, not as apparent in real life as in this photo. The clamps held fine but there was a very small amount of vibration in the rotary table. None of this is critical, or even important, and there is a good chance the marks will polish out easily. I finished milling all three gears by the end of the day.

 

 

The center section now gets turned. The gear face is 7/8" but the centers will be .375 thick. I'll do the next step in the lathe with the blank mounted on a face plate. I've had lathes for 40 years now, all of which had a face plate and this will be the first time I've actually used one.

Edited July 7, 2017 by JV Puleo (see edit history)

[JV Puleo]

It didn't rain today – as forecast, so I mowed this morning but still had time to get into the shop to start again on the gears. After a wuick run to Lowes to get two more 10mm bolts I set the test blank up on the face plate.

 

 

I used the centering tool I'd made for the rotary table to get it perfectly in the center of the face plate. This worked just about perfectly and I was able to remove 1/4" of surface across the gear.

 

 

When polished, I should be able to eliminate the machining marks left by the end mill. Although it does not look it in the photo, the surface is actually flat. The lathe leaves a much smoother surface.

Edited July 8, 2017 by JV Puleo (see edit history)

[Luv2Wrench]

Very interesting to see the final product after seeing all the pieces and steps that went into it.

 

BTW... what is the swing on that lathe? 

 

[JV Puleo]

Nominal 15". It will actually take about 17" depending on whether you need the saddle to pass under the work piece.

 

[JV Puleo]

I finished relieving the centers of all the gear blanks today. There is one milling operation left, the adjustment slots. These are 3/8" slots, each one of which covers 30 degrees. The gear will be held to the hub with cap screws or studs and, when installed, it will be possible to "fine tune" it's precise relationship to the crankshaft. I think this is important because we have no official timing information and, even if we did, it would probably be inappropriate to today's fuel and the slightly raised compression ratio. The location of the gear, concentric with the camshaft, is controlled by the hole in the center. These slots are 1/16" larger than the retaining screws. Their only purpose is to attache the gear to the hub securely.

 

 

Here is the finished product. There are still a couple more minor steps before the blanks go out to have the teeth cut.

 

[JustDave]

• beautiful work,keep it coming im learning everyday,     dave

[F&J]

Hi Joe, I just went to the local scrap recycle place in Columbia CT, named JSR  or  AKA "Johns scrap recycling"

 

The have some machine shop stuff for sale:  Two monster millers with 6 foot beds, with a huge CNC control box/station to run both. Got to be 8.5 feet tall to the tip up there.

 

Then a rack full of collet chucks which can be bought by the single piece or more, sold as scrap weight, not what it is valued as in a tool.  This is dirt-cheap pricing if you see something there.  These will NOT be scrapped, but the two huge machines may get cut up today. 

 

then a small specialized grinder ??? that one will not be scrapped, and sold by weight...they gave a close guess at $500. 

 

It is 5 minutes from here so I can go there with you if needed.

 

 

 

[JV Puleo]

Wow... I think the grinder is a "Tool & Cutter" grinder — for sharpening milling cutters. I'd love to have one of the big verticals but they are too big to fit through the doors of my shop - which is in the basement of our book warehouse. The only way I could get something like that in is to dismantle it and, even then, I'm not sure I could. I barely got the Brown & Sharpe in and it was dismantled.

 

What a great scrap yard though and thanks very much for thinking of me. If either was a "#2" size (they are probably #3s) I'd be on it in a heartbeat.

 

jp

[JV Puleo]

While I waited for a few small bits from McMaster Carr, I made some special washers for the timing gear hubs. I realize making your own washers is a bit over-the-top, but I wanted these to be of a specific size that is not readily available. First, I turned down some 1" 12L14 to .875 (only because I didn't have any that size to start with).

 

 

Then drilled and reamed it to 5/16

 

 

I'd intended that they be .100 thick so, to get this exactly, I surface ground them. This will give me a perfectly flat surface. The idea behind these is that they, and the studs that will eventually be screwed into the hub, are what holds the adjustment of the gear in place against shifting from the pressure generated by compression and the valve springs. It is, therefore, important that this interface be as precise as I can possibly make it.

 

 

While I was doing this, it occurred to me that I should chamfer the edges of the 1/2" holes in the gear... they'll look better and it will remove a little more weight without effecting strength. The problem is doing it uniformly, so I ordered a two piece shaft collar and fit is as a stop to the spindle on my small drill press. This is an old, and not terribly precise machine I generally use for odds & ends...it doesn't have to be precise in this case because the countersink I'll use is self centering.

 

 

That worked so well, I was almost shocked. I was then able to fit a hub to a gear, put it back in the lathe and turn the OD to be absolutely concentric with the hub. All of the gears ran with very little runout. On a job like this, where several pieces are involved, a tiny amount of runout is inevitable so I was very pleased with how close they came out.

 

 

So... that is it for the time being on the timing gears. I emailed my gear-cutting friend to ask if he was still up for the job. If he isn't, I'll find someone else. here are the two sets of gears along with the "set-up" gears for both sizes and the originals I copied. The new gears will be slightly more than 1/2 the weight of the old ones. There are still a few more steps before they can be called "finished" but those should wait until after the teeth have been cut. The button-head Allen screws are temporary. I intend to put studs in the hubs and use locking nuts but I think that the studs will make fixing the hub to the camshaft more complicated so I will wait until after that is done to insert them. You can see both the front and back of the timing gear & hub on the right below. On the back, the hub is flush with the outside edge of the gear face.

 

 

Next, I'll finish the crankshaft hub that I started, changed and now need to get back to.

Edited July 14, 2017 by JV Puleo
typos & corrections (see edit history)

[Luv2Wrench]

Looks fantastic, as usual.  Do you have a couple of pictures of the engine such that we can visualize where these items fit into the whole?  If not your engine, then maybe one similar?

[JV Puleo]

Strangely enough... no, I don't. I've never seen one complete or heard one run. It looked like this when I got it.

(The jugs were in the big wooden box bolted to the chassis in the first photo in this thread)

 

 

 

I do have some photos of a similar car, apparently a 1911, or at least one with the later version of the same engine. When my engine is done, only the jugs, crankcase, crankshaft, sump, flywheel and timing gear covers will still be there. Many of the smaller parts, including the exhaust manifold, were missing and most of the others worn to a shred, bent or broken. It had clearly suffered the attentions of a very heavy-handed would-be "mechanic." What he didn't break, he lost. I've already made new cam followers, valve cages, rockers etc. Fortunately, the chassis is in better shape, although still missing some things.

 

 

Your can see the big timing gear at the front of this engine. The covers are off – or missing.

 

Edited July 14, 2017 by JV Puleo
typos & corrections (see edit history)

[JV Puleo]

The gears are now on their way to my friend in Arizona who will cut the teeth. He's a little busy at the moment so it may be 3 or 4 weeks before they are ready. Now I will finish the crankshaft hub and sheave and, because I like to have at least two or three jobs running at the same time, I am starting on the tooling to finish machine the pistons.

[JustDave]

Hello Jv,I have a question with all the aluminum being used won't you need the weight for torque in the motor will the aluminum rods pistons gears etc be really light or is that what your going for,by the way phenomenal workmanship,   Dave

 

Edited July 16, 2017 by JustDave (see edit history)

[JV Puleo]

The idea that the engine "needs" the weight is a myth. Actually, the lighter everything is, the less stress there is on the crankshaft, bearings and every other moving part allowing more of the power generated by the detonation of the charge to be transmitted to the wheels. My goal is to reduce reciprocating weight while while keeping everything in balance and maintaining strength. There are a few places on this car where I'll actually add weight. Lots of engine parts were simply too heavy, not so much because they didn't understand what was best, but because heavy parts were often cheap parts. The situation was reversed on the chassis where they often scrimped on materials and made things too light. You will also hear that the cars "need" a heavy flywheel... that isn't really true although in a case like mine it is unavoidable because the cone clutch is part of the flywheel. That was something that was misunderstood at the time, Engineers were heavily influenced by steam engine practice which was far more generally understood. Just about everyone who was designing a motor in 1910 studied engineering before the advent of the automobile. Modern engines develop far more horsepower and run at much greater speeds with relatively tiny flywheels.

 

Think of the lengths they went to to lighten early race cars... drilling the chassis and about every possible part, sometimes weakening them to the point of breaking. Effectively, if every moving part of which there are multiples... like pistons and connecting rods – are identical in weight, those parts will be in balance. With other parts - like the gears I just made, the critical element is keeping them as light as possible and as uniform as possible - hence the careful spacing of the holes. It wouldn't do to drill them free-hand and have some close together while other were spread out. 

[JustDave]

Now that you explained it it makes better sense,I guess in my last life I must have been a steam engine mechanic,if the rods pistons etc are lightened will you have to take weight off the flywheel or will it be ok as is,still watching and still learning.  Dave

[JV Puleo]

As this job continues, I had to put the big chuck back on the lathe so I decided to do all the current jobs that needed it.

First... I started on the tooling to finish machine the pistons. I roughed the pistons out two years ago but dropped stopped for two reasons... I couldn't turn the final diameter until I knew what the bore would be and the problem of locating the wrist pin holes - something that looks easy until you try to do it. They have to be perfectly located in the center of the bosses and you have to be able to do that completely blind. This is looking down into the piston. The walls aren't as thick as they look - the photo is overexposed and you can't see the ridge around the lower end of the piston that provides a guide surface. I have 5 blanks and I know they are very close to uniform because 4 of the 5 weigh exactly the same amount, to the gram. The 5th is only about 5 grams heavier,

 

 

I made was this device to measure the exact distance from the base of the piston to the edge of the wrist pin boss. I'll push the central piece down until it touches and measure the depth with a depth micrometer.

 

 

Then, I made another piece that will be part of the fixture that will hold the piston on the face plate. It's a piece of 4-1/2 inch bar with a 2" hole in the center. The first step was to bore it to 1.990 and ream the hole to 2".

 

 

I then did the same thing with the new sheave. In this case the hole is 2.370 so I had to bore it. I was pleased it came out perfect. Here you see it, with the original big sheave, on the guide fixture I made last week. This will allow me to locate, drill and tap the holes so the two parts screw together.

 

 

Last up was the new hub. This is a piece of Stressproof I bought on ebay. Needless to say, steel takes longer so I started with a 3/8" hole. I will keep increasing the size until I can get my boring bar in, then bore it to 1.485 and ream it 1.5".

 

[JV Puleo]

The next few steps...

The piece that will be the "new & improved" crankshaft hub was drilled with increasing larger holes up to just under 1-1/4" – the largest drill I have. I then bored it to about 1.485, 15 thousandths or 1/64" less than 1-1/2".

 

 

The next step was to finish ream it at 1-1/2." The reamer is one I bought on ebay. A new one would have been very expensive. I've found that industrial tooling like this is one of the few things that is consistently available at knock-down prices, probably because there is a lot of it and not that many small shops and hobbyists to buy it. In any case, it is probably .001 large – a clearance fit rather than exactly 1-1/2". In this case, that proved perfect, saving me the tedious task of honing the bore out to slip on to the crank. The fit is now almost perfect.

 

 

Before going further with this, I decided to do an experiment. This is the first gear blank I made. I got the diameter wrong because I used the diameter for a 44-tooth, 12 DP spur gear, not realizing that the helical gears are slightly larger. Because I managed to get the V-groove for the belts wrong on two occasions, I thought it best to make certain I could cut the groove correctly. I decided to make this gear blank into a sheave. It worked, and this time I got the angle correct. I will probably use the sheave on a generator or alternator but that part of the project is a long way down the road.

 

 

I then mounted an expanding mandrel. Because the bore of the new hub is slightly oversize, the piece won't press onto a conventional lathe mandrel. I only bought the expanding mandrel set a few weeks ago and already can't imagine how I got along without it.

 

 

The outside was turned to 2-1/2", then one end was turned to 2.370", the inside diameter of the two sheaves I salvaged from the old hub by boring out the threads. The idea was to save the big sheave and to make a new, smaller one. At the last minute, I decided to try and re-cut the groove in the smaller sheave as well as the big one. It actually worked, so I won't need to make a new one and I'm off the hook on locating the three threaded holes that attach the sheaves to each other.

 

 

The last thing I did today was convert the alignment tool I'd made into a broach bushing. Ordinarily,  you would never make one of these from aluminum but this is a one-time-use tool so I think it will be fine. Except, once again I broke my own rule and tried to do something fussy when my back hurt and I was tired. I managed to get the groove slightly off center. I'll do it again tomorrow. It isn't a major problem, just a wasted hour. A second groove in this piece will not keep it from working and, when it's done, it'll probably be going into the scrap bin in any case.

 

Edited July 22, 2017 by JV Puleo (see edit history)

[hddennis]

JV, are you going to cam grind those pistons? I ask because as a teenager 50 years ago I had a machine shop turn a set of "semi" pistons for me and they turned them round and when I sent them to my engine rebuilder he said they were ruined because they were round and not "cam ground". Luckily I was able to get a second set but it was a costly mistake.

Howard Dennis

 

https://www.jalopyjournal.com/forum/threads/cam-ground-pistons.538613/

[JV Puleo]

No, I'm not. The reasons are fairly technical but, simplified a bit, cam grinding is a way of making thin wall, split skirt pistons conform to the bore despite thermal expansion. These pistons don't have split skirts and they have reasonably thick cast walls so cam grinding would not accomplish anything as long as there is sufficient clearance. I don't think it was even invented until the 20s and maybe later because the early aluminum pistons were also cast.

 

What engine were your pistons for? One of the problems I constantly encounter is that lots of collectors – and "old-time" mechanics – are full of collected "lore" while having no notion of the physics or the history of what they are talking about and much of which is simply old wives tales. Depending on how old your engine was, you may have been right and the engine rebuilder wrong. Remember, this is a hand-cranked, 1910 engine. It is a lot different from most any engine only 10 years newer...

[hddennis]

No Problem, Just passing on my experience from long ago with a highly respected automotive machine shop, established before your engine was built, who did my first rebuild on a 1932 Plymouth which had a motor almost identical to my current project a  1917 Maxwell. Later they did my 426 Hemi's. 

 

Unlike some I respect what the oldtimers accomplished and try to learn from them as much as I can because I don't believe I know everything nor do I think modern ways are absolutely always the best when dealing with century old machines.  

 

Howard Dennis

Purveyor of Folklore

Shade Tree Mechanic

[JV Puleo]

I'm not sure what I was thinking but the slot in the bushing was off-center. In a case like this, that is a critical error so, Sunday morning, I went back to the shop and did it again. This time it came out right.

 

 

To use this, I pushed the bushing into the bore and then put a 1/4" key way broach in the slot. I set the broach with an arbor press. It isn't strong enough (nor is it bolted down) to push the broach through. It is important to get the broach straight. They are hard and therefore brittle and easily bent or broken. They are also expensive although this is from a relatively cheap import set I bought on sale because the box they came in was damaged. I don't use them often but they are a lifesaver when you need them. There other ways to do this, all of which are more complicated.

 

 

I finished broaching with my "shop made" 20-ton press. In order to get the depth, It was necessary to push the broach through 3 times, putting shims between it and the bushing in order to deepen the notch.

 

 

The result was quite satisfactory...

 

 

This morning I cut the seat for a Woodruff key. This is relatively easy to do but it is very important that the seat be in the exact center of the round section (as it is equally important that the key way be in the center of the hole) or the key and its key way will not line up. In this case, they came out just about perfect although I will have to order some longer Woodruff keys.

 

 

The last step will be to drill and tap two 1/4-20 holes in the bottom of the v-groove of the smaller sheave. These will go through slightly into the hub. The set screws will be nearly invisible there and they will keep the hub from shifting backwards, towards the engine, while at the same time permitting it to be disassembled easily should that ever be necessary. I'll drill the holes at 120 degree angles from the key way.

 

[JV Puleo]

The last step with the sheave was to drill and tap the holes for the set screws. To do that, I wanted a long center drill as the holes should be drilled with the parts assembled. I had to wait for that. In the meantime I did some more work on the tooling I will use to finish the pistons. This plate is about 7" in diameter with a 2" hole in the center. It will be the base of the fixture I will attach to the faceplate to hold the pistons while I turn them to finished size and cut the ring grooves. All of these piston finishing tools need to be as precise as I can make them because it isn't practical to do each operation to each piston, one at the time. That would almost certainly result in some variations. I will have to be able to put the piston in the fixture, do the appropriate operation and then do the same thing to the next piston, so the ability to replace the part on the machine with precision is critical. This is only the "roughing". This plate will be drilled for the mounting holes and then faced again while attached to the faceplate.

 

 

When the center drill came in, I set the piece up in the drill press. Making the bits to hold the sheave & hub together, and this setup, took far more time than drilling the two holes did.

 

 

As you can see... the set screws are too long. I'll just order more, a little shorter. I make that sort of mistake frequently which is one reason I have an entire shelf full of McMaster Carr boxes of fasteners. The other is that I frequently have to buy 25 in order to get 3. Although, I can say that they do eventually get used and often enough I get something done quickly because I have the necessary bits on hand.

 

 

With this done, I went on to finish the hub. The first job was to trim the ends. The back half was trimmed to just a few thousandths longer than the thickness of the two sheaves. The front half was trimmed to .100 longer than the original. I did this for two reasons. I will probably move the hub back about 1/6" and, should it be slightly longer than the original in front, this will only serve to protect the end of the crankshaft/

 

 

With that done, it was time to fit the hub to the crankshaft. The fit now is very close but I want a sliding fit with no appreciable play but not needing to be pressed or driven on. Keep in mind that there is a seal in the front of the timing case and the only way to reach it, and renew it, is to remove this hub. The original piece was .006 or .008 too large – a sloppy fit that relied entirely on the key and a tapered pin to keep it in place. For this job I used a "Flexhone." These are not intended to remove metal but to finish the bore and, if I had needed to remove several thousandths it would have been a long and tedious process. As it was, the honing took about an hour. The beauty of this is that, even if it is time consuming, it is almost impossible to take too much metal out and ruin the piece.

 

 

A bit out of focus but here is the hub slipped on to the crankshaft. You can see that some nitwit, in the past, hammered on the end of the crank. This spread the end and complicated removing the original hub.

 

 

The next step is broaching the keyway in the hub. I actually finished that job today but had downloaded these photos, and emailed them to myself while taking a coffee break, before I started that job so they will have to wait for next time.

Edited July 31, 2017 by JV Puleo (see edit history)

[Luv2Wrench]

Looking great Joe!  I've got a whole shelf of "25 to get 3" from McMaster-Carr.   With their reasonable costs and (for me as I'm in GA) one-day shipping, I probably don't pay enough attention when ordering things... easy to do "trial and error" with them.

 

[JV Puleo]

I find their web site almost seductive. Almost every time I try to buy stuff locally, it's always a wait to get it in at which point I say "why bother" and just order the stuff from McMaster. Of course, sometimes that "buy the whole box" is cheaper than the local hardware store - or so close in price that why not have the extras. I can't tell how many times I've been thankful I had the odd fastener on the shelf and could get on with things without having to run out.

 

j