Full tear down and Rebuild of a 10EE Round Dial

[Cal Haines]

The knobs, sight glass bezels and dials are definately made of different alloys. The latter will not stay polished. I had my dials chrome plated and they look great. Here's what they looked like 12 years ago:

The photo doesn't capture how shiny the bezel is. I intentionally didn't try to remove the dings. I think that the scars are part of the old girl's long service.

The dial was filled by painting it with semi-gloss aerosol paint, then wiping the high spot clean with a chunk of an old T-shirt, dampened with mineral spirits and stretched over a block of wood.

I wish that I'd clear-coated the knobs. 12 years later, the knobs are a dull gray with very little shine left. The bezels look like I polished them yesterday.

Cal

 

[beckerkumm]

Cal, what is the lever ? I like your pain on the dial. I was wondering what to do on mine with the pebbled surface in the background. I usually wait for the paint to dry and then sand off the embossed parts but your idea looks like it is less work . Dave

 

[Cal Haines]

The lever basically acts like a clutch by lifting the tumbler gear off of the cone gears, so that the gearbox position can be changed via the middle knob. Older round-dial gearboxes had a T-handle that is pushed in to lift the tumbler gear and rotated to change cone gears.

Cal

 

[beckerkumm]

My CVA has the T handle but the arm inside the box to hold the handle out and engage the gears is broken. I was hoping for an alternative method. Dave

 

[GrantGunderson]

The knobs, sight glass bezels and dials are definately made of different alloys. The latter will not stay polished. I had my dials chrome plated and they look great. Here's what they looked like 12 years ago:
View attachment 370500
The photo doesn't capture how shiny the bezel is. I intentionally didn't try to remove the dings. I think that the scars are part of the old girl's long service.

The dial was filled by painting it with semi-gloss aerosol paint, then wiping the high spot clean with a chunk of an old T-shirt, dampened with mineral spirits and stretched over a block of wood.

I wish that I'd clear-coated the knobs. 12 years later, the knobs are a dull gray with very little shine left. The bezels look like I polished them yesterday.

Cal

That turned out great! My plan is to get all of the knobs, and the dial / plaques , Art Deco trim chromed, but we will see how pricey that is. I'm hoping its not too prohibitive. If it is, I will clear coat them with the 2K poly... but that may yellow a bit over time.

 

[GrantGunderson]

Time to put the TravAdial back together.

The black paint with the clear coat turned out pretty well.. the white not so much.... I think that can had been sitting around way too long. I am also getting spoiled with the finish I am getting out of the IWATA gun.

First step is to lube the bearing and gears. I was going to use my ARRI cineflex camera oil for for this. That stuff was insanely good for camera gears, but somehow the cap for the vile cracked and apparently it all spilt out on the shelf. Thankfully I keep all of my oil / lubricants sitting on top of pig mats, so no major mess. So instead I used some really light dupoont grease with teflon in it.

On assembly, I find it really helps if you can lay everything out in order, as it forces you to think about the sequence ahead of time.

The case alignment pins go back in the case first.

Next I assembled the travel wheel / main metal gear with the friction spring and the plastic gear that goes bellow it.

I then lined up the spring tension alignment holes and inserted a 1/64th drill bit to hold it in place.

The 4 shim washers go on next, followed by the external snap ring. With snap rings, I always like to try to rotate them in their groove after installation to ensure they are fully seated.

The lower center plastic gear goes into the case first.

The the travel wheel / main gear combo gets inserted. Note the drill bit I used to hold the alignment holes for the spring tension goes through the alignment hole in the case. Dont remove the drill bit until the case is fully assembled.

The upper center gear goes on next, with the brass gear facing down.

 

[GrantGunderson]

The shaft for the dial needle gets inserted next.

The shim stack goes on the center gear followed by its small external snap ring.

Everything is now back in the case.
The two half of the case get matted and all 6 #1 head Phillips screws get screwed down.

The drill bit holding the alignment holes in place can now be removed.

The large retaining ring goes on the dial base.

The wave washer drops into the back of the dial..I put the service and my initials in.... curious to see when it needs service again.

Dial gets pressed on, until the retaining ring snaps in place. The Needle gets pressed on to the shaft followed by the lens getting pressed on.

The guts get put back into the knob in this order.

Make sure the set screw is actually aligned with the access hole.

 

[GrantGunderson]

Finally put in the internal snapring.

I used a lacquer stick to fill in the indicator mark for the knob, as well as for the knob markings.

I then clear coated the knob and thats where I ran into problems. The l white paint reacted with the clear, despite the white paint being from the same paint system. I found you can order replacement knobs / dial here. If the knob / faded dial ends up annoying me enough I'll probably order new ones. I still need to paint the bracket for it before I can install it.

 

[GrantGunderson]

The Art Deco accent bars for the access panel of my lathe where made of cast iron, since its a war machine... hell I'm surprised they even bothered with the accents during the war.

After stripping the paint form them, I hit them with some 40 grit sandpaper to see what I am actually dealing with. (Cal, thin bars appear to be EE5734, the wider bars look like EE2785) The castings are extremely rough, pitted and none of the edges are true. There is no way I will be able to sand and polish these in there given state and not have them come out super wavy / inconsistent. So there is only really two options forward, either machine new ones out of ½" AL bar or machine the rough castings. At this point it was 4:30, the only metal supply shop in town closes at 5 and I dont have any suitable bar in this size on hand. So not wanting to be that guy that shows up right at closing, I decide to move forward with machining the castings. I've never machined cast iron before, and knowing what I know now, next time I'd just make new ones! I'm not a fan at all of machining cast iron as it leaves fine dust that seems to get everywhere!

The bars have rounded edges on all sides, and the mounting tabs on the back are also rounded. Note the factory was far from constant in drilling the mounting holes, so they will only properly fit back in the correct spot. The 3 bars for the front access panel are the same hole to hole dimension. The bar for the access panel under the start switch is longer hole to hole, despite all of the bars being the same overall length. Also, holes are not symmetrical to the ends on each end. Each set is drilled with one set of holes closer to one end. I also found that while the holes are are close to being centered they are all off center by the same amount.

So I have two problems, how to clamp these to mill them, but also how do I do it more efficiently and make each set symmetrical?

My solution was to cut a scarp piece of ½" bar to length.

I then drilled and tapped it on one end.

I then secured a bar from the first set on one end, and then used a transfer punch to mark the distance to the other hole. The mill took care of the centering.

I now have a jig, so I can just swap the parts out for each cutting operation. First I need to clean up the sides. I am using a .250" radius cutter for this, and machined all of the right ends first.

Ok, thats way better. I now have straight ends with a constant curve. I'm not worried about the top edge yet, as that will get taken care of latter.
I used some dykem to mark the parts, so I could see what material I was actually removing. I then machined all of the front edges first. This pick is after the second pass on this part, you can see from the dykem how far out it is.

After I got the fronts cleaned up, I then took the same amount off of the back edges. Those ended up needing one more, pass, so I did a final pass on the fronts, before finishing with all of the left hand ends as oriented in the mill. all in all I took .060 off of each edge. I now have 4 constant and parraell sides with even radiuses. Tomorrow, I will do the bar for under the start switch, and then will finish milling these by machining all of the tops to the same thickness.

In hindsite, if I was to do it over again, I would just make them from scratch out of aluminum. I think that might actually be faster. I had to take really light cuts in order to prevent chatter as they where only being supported from two points, relatively far apart... plus machining cast iron is damn messy compared to AL, Steel or Brass!

 

[GrantGunderson]

Several of those actually have a NON decorative function. They divert chips or splash from easy entry to the cooling slots under them as a sort of simple labyrinth deflector.

I noticed that on the back panel and on the head stock end ones. I'll tackle the head stock ones latter as I need to get those panels on the machine first to see how they will align together as those came from two separate machines, with neither being my machine.

 

[murphatthepoint]

I noticed that on the back panel and on the head stock end ones. I'll tackle the head stock ones latter as I need to get those panels on the machine first to see how they will align together as those came from two separate machines, with neither being my machine.

.

I got the paint shipped off of the access panel today.
View attachment 370420
So they are ready to be sanded for the Epoxy primer.
View attachment 370421
The knobs where still pretty filthy after soaking in lacquer thinner all afternoon. Note all of the dings in them.
View attachment 370422
It would be really nice to have a disk or belt sander, but I have neither, so I clamped my Festool Rotex 150 into my vice and used it as a disk sander. Don't mind me.... I'm just over here polishing my knob. HA!
View attachment 370423
Knobs after 400 grit
View attachment 370424
Knobs after 500 girt
View attachment 370425
Knobs after 4000 grit
View attachment 370426
I then hit them with my Baldor buffer, first with Red compound then with Blue.


They turned out pretty damn nice!

Grant
I have been following along with your post since the beginning, very helpful to me since I have a 1939 round dial I’ve been working on for a few years. I redid all my chrome knobs and the Art Deco bars on the removable covers. A couple of chrome knobs I couldn’t get out so I will use your process of the higher grits and then buffing with the different colors.
also, the top of my apron is a little beat up. I was considering having a machinist run it on a mill or surface grinder but I prefer your painting it to match the color of the lathe. I also learned about your process of hitting the taper pin on the large end, filing the burr of the small end and then knocking it out. Fine work and keep it coming. You are very detailed in describing the work. Thanks

Jim Murphy

 

[GrantGunderson]

.

Grant
I have been following along with your post since the beginning, very helpful to me since I have a 1939 round dial I’ve been working on for a few years. I redid all my chrome knobs and the Art Deco bars on the removable covers. A couple of chrome knobs I couldn’t get out so I will use your process of the higher grits and then buffing with the different colors.
also, the top of my apron is a little beat up. I was considering having a machinist run it on a mill or surface grinder but I prefer your painting it to match the color of the lathe. I also learned about your process of hitting the taper pin on the large end, filing the burr of the small end and then knocking it out. Fine work and keep it coming. You are very detailed in describing the work. Thanks

Jim Murphy

Thanks! I think Thermite had some good options here a well. If the paint ends up getting too beat up, maybe I'll try hand scraping...


I ended up doing a work trip up to Revelstoke, so finally back to working on the accent bars.

Turns out the factory drilled holes, are damn close to the correct hole size for a 6M tap (not exact, but close enough). So I tapped them to 6M.


This allowed me to mount them to the same AL bar as before, but from the backside, so that I could face them with a carbide insert mill.

I wedged a piece of wood between the plates and the AL bar to help reduce chatter in the middle. Far from ideal, but it worked.

Here you can see, that the bars where far from having the same thickness top to bottom. So it took quite a few passes to get them even and flat.

And then disaster strikes. I had to take so much off of the front to get them somewhat flat, I ended up milling open a few internal cavities in the casting. Well shit. I suppose those voids could get filled prior to chroming, but this point I was DONE with milling cast iron. In fact it would have to be a damn good reason to get me to do it again, as it resulted in a fine black dust on everything in my garage. Worse than wood dust. So I spent an entire day cleaning the mill, and the rest of the shop. I even dragged the rubber floor matts into the driveway to pressure wash to keep fro meh black powder getting dragged into the house (the wife would kill me if it got on the new carpet!).

Needing a break from working on the accent plates, I decide to start working on the access panels.

I wire brushed the cams that hold the panels on, then blued and oiled them.

I had previously used lacquer thinner to get most of the paint off the access panels. So all that was left was to hit them with a cupped brass wire brush in the grinder to get the rest of the paint remnants off.

That made quick work of it.

Several of the mounting pins where proud of the panel. My first attempt was to see if I could press them in flat with my arbor press. They wouldn't move. Ok Good. I dont want loose pins to ruin the paint latter.

They got ground flush using a flap disk. I also tried to knock down any of the more obvious high spots on the panels.

A company called high-temp sells these silicone painting plugs and caps. They are designed for use powder-coating, but they make it really easy to make sure you dont get paint into critical areas, and its easier and quicker than masking, Plus they are reusable.

 

[GrantGunderson]

With the temps being unseasonably hot here, the paint cured quite fast. My painting tent was like a sauna! Both sides of the panels got a coat of self etching epoxy primer. The backsides got the same single stage polyurethane paint that I used on the interior of the lathe. I really like that single stage primer, and for someone that doesn't want to do the additional steps I am doing with the exterior of the lathe, I think it would be a great option.

Silicone plugs and caps removed. That was easy. I then covered the inside of the panel with painters tape, and put the first coat of Bondo on the exterior side. It was so hot and humid, I could barely get a panel done before it kicked. I'll have to wait to do the second coat of Bondo until the temps get better.

Back to accent plates. I decide to make new ones using AL bars, and for a cleaner look I am going to use blind holes to mount them, so no front fasteners. I started by facing all of the bars with the mill.

I was getting a ton of chatter on the ends where the bars stuck out from the sides of the vise. So I ran down to Grizzly and picked up two sets of machinist jacks.

I put one on each end, using a thin piece of cork between it and the bar stock and then made them finger tight. Not sure if there is a better way of setting this up, if so I am all ears. I did notice doing this, I get a bit of deflection the area above the jacks is very slightly higher than the section in the vise. Not critical for these parts, but I bet there is a more accurate way of setting this up.

Regardless, it took care of the chatter issue and you can see a big difference in the surface finish here.

All of the bars then got drilled with a ⅜" deep hole and bottom tapped. Using the vise stop made quick work of this.

Once again using the vise stop I rough milled the ends of the backsides of each piece and then milled the sides. The nice thing is once you set it up for each width, you can do all of the sides without moving. I aunt too concerned with surface finish here as you will never see this side on the lathe.

I then bolted each accent bar to some scrap stock, to allow me to clamp the pieces into the vise and then used a rounding mill with a ¼" radius to do all of the side profiles.

I used my Mirka hand sander to sand all of the pieces with 320, 400 and then 600 grit.

I then used some of the RED compound on the Baldor buffer and gave them all a quick polish. It turned out pretty good, so I didn't bother moving onto the blue compound. We will see what the chrome shop says when I make it down there. Hopefully week after next as I have another summer bike shoot next week in Vegas I gotta do first.

 

[GrantGunderson]

My Vegas shoot went really well. We avoid the typical Vegas stuff, and spent all of our time up at Lee Canyon where the temps where in the Low 70's despite Vegas only being 45 minutes away and over 100.


The biking was better than expected and I think they are going to do quite well as a mountian bike destination. After getting caught up with work, family stuff, and general bike and shop maintenance is finally back to focusing on the lathe.

I got a McMaster order in with a few small supplies I have been needing to button up a few things.


I ordered two of these oil cups for the tail stock, as I was missing the factory button style caps.

They just press right in. Unfortunately one has a broken hinge so I'll need to get a replacement for the second one. I also ordered some
10-24X ½" snake-eye screws in stainless steal as the compound wheel was missing the proper screw.

I injected the threads with some Tef-Gel (my go to anti-seize these days) then screwed in the screw.

I used an adjustable pin spanner for this that I had left over from my days in camera repair. This looks way better than the SHCS that the previous owner had in its place.

I also ordered new hardware for the tailstock alignment screws. I went with 316 stainless for these. They are a ⅜-24 X 3" bolts.

They also got a good coating of the Tef-Gel before I installed them.

 

[GrantGunderson]

I also ordered a Siemens ESP200 Thermal Overload really for additional protection of the motor. I am leaving the factory heater protection in place, but this modern version is for piece of mind. Unlike the heater protectors this unit basically acts like a built in clamp meter. the 3 wires that feed power to the motor (T1, T2, T3 (#3)) each get feed through one of the holes in the unit. Then you connect wires from the #95 and #96 terminals on the unit into main contactor coil circuit. The idea is when this unit gets tripped, it breaks the power circuit that energizes the coil, and in turn shuts the lathe off.

To connect it to the starter, I removed the jumper going from the stock heater protection to the coil.

So in theory, if the motor is overloaded (drawing too much current) either system is capable of shutting the system down. Since there is no room to mount the unit in the existing area of the main contactor, I am remotely mounting it in the same box that is housing the capacitors. This resides in the compartment on the back of the lathe where a coolant pump would typically be installed. So I removed the T1 and T2 wires that feed the motor panel from the contactor.

Underneath the contactor is a ½" pipe plug. Its originally there for running power to an optional coolant pump, so its the logical way to run the T1, T2 and the switching wires for the thermal overload.
a ⅜ ratchet was perfect for removing the plug.

I then ran watertight conduit to the box on the back of the lathe. This should ideally keep the wires free from oil and other contaminants.

I am using the "all metal" version of the watertight conduit connectors. These are way more robust, as an internal nipple gets screwed into the conduit, and it then works just like a typically compression fitting. Where as the plastic style just relies on the friction of the tube to hold it in. Worth the extra $1 in my opinion.

The overload has these square style ports that you feed the switch wires into. While you could just push the bare wire in and clamp it down, the proper way is to use a wire ferrule.

Slide it over the stripped end of the cable, with the bare wires flush with the end.

I then use a square ratcheting crimper.

 

[GrantGunderson]

The square ratcheting crimper leaves these ridges into the now box formed cable end. These priovide for better clamping with the units clamp screw.

Now that I am hopefully done with needing access to the main contactor area I chased, then injected the bolt holes for the cover with some Tef-Gel.

I had to grind down the diameter of the heads of the new stainless SHCS to get them to fit.

All buttoned up.

Ideally it would have been nice to have a larger box for this, but I am using the largest one I could find that would still fit the space in the back of the lathe. This is it before I hooked the T1, T2 and #3 leads from the motor through the overload and terminated to the terminal block inside of the box that the T1, T2 lines hooks to from the contactor as well as the start / run capacitor circuit. Feeling confident that I had kept all of the wires straight with the my labeling, it was time to test it.

Humm, sustained 52 amps on T1 and only 117.5V one T3 something is obviously wrong. In my prior testing, I was only getting 40ish amps on immediate startup before it almost instantly dropped down to 9.5amps and T3 read 503VAC before. I am using a larger run cap to hopefully reduce that 500VAC number, that doesn't explain this. I then used the continuity feature of the meter to verify I had T1, T2 and #3 leads from the motor to the capacitor box correct. Turns out I had reversed T2 and #3. Shit. I guess thats what I get for finishing that portion of the wiring late at night. I then verified that I had the wires correct from the main contactor, and the start circuits correctly wired and tried another test.

Ok, T3 is now reading 503.6V, so same as I had in prior testing, so thats ok, but T1 is now reading 68.9 Amps!!! Something is still clearly wrong. I shut the lathe down quickly and proceeded with one more test, but this time with the clamp meter on L1 feeding the lathe from the 30 amp breaker in breaker box, it read the same. Something is clearly not right. Looking at the circuity, its pretty clear that when I had T2 and #3 reversed I had the high voltage on the wrong side of the potential relay thats supposed to cut the start cap out of the circuit. I'm fairly certain I fried the relay, so ordered a replacement. I then tested the resistance of each of the motors oils and got 0.7Ω and 0.9Ω values on the various coils. Exact same as I had in prior testing, ok thats good. I then megged the motor again testing each coil to ground, as well as testing each coil to each coil. All of the tests with the Megger resulted in >4000MΩ so the motor test fine. I also verified that it spins freely by hand so its not locked up. What is puzzling is that with that much current being drawn it didnt trip the 30amp breaker on the sub panel, nor the 50 amp breaker that feeds the sub panel. It also didnt trip either of the 30 amp fuses in the disconnect, nor did it trigger either of the motor overloads. I then tested the fluke clamp meter on the individual leads that power my Bridgeport's motor, and got reasonable values, so I am fairly certain the clamp meter is working properly. I then verified the capacitors with the Fluke 117 and both read the same amount of capacitance and prior to testing, so I beige they are still good. So I think I have checked off the various possibilities, so next plan is to re-test when the new relay arrives. Hopefully on Monday.

 

[Mr_CNC_guy]

It is possible that your 3 phase motor has a shorted turn. You can test for this by applying a lower voltage AC to each winding one at a time. Measure the current, which should be the same for each winding. The lower voltage avoids the risk of overheating the winding.

For example, apply 120 volts AC to each winding for long enough to measure the current. A shorted turn acts to greatly lower the inductance of the winding and will therefore increase the current.

 

[GrantGunderson]

It is possible that your 3 phase motor has a shorted turn. You can test for this by applying a lower voltage AC to each winding one at a time. Measure the current, which should be the same for each winding. The lower voltage avoids the risk of overheating the winding.

For example, apply 120 volts AC to each winding for long enough to measure the current. A shorted turn acts to greatly lower the inductance of the winding and will therefore increase the current.

The Megger should have picked up if there was a shorted turn as that’s its purpose. I tested each coil to ground as well as each coil to coil and all tested good.

 

[CarbideTip]

No, the megger will NOT find shorted turns!
The megger test is primarily of the insulation to ground. Perhaps I should explain what is meant. A shorted turn is where one loop of a coil makes contact with the same coil earlier or later in the winding. There is no connection to ground. When the magnetic field is generated by the remaining turns the shorted section is coupled by transformer action but the 'secondary' has a dead short. So the current drawn by the winding goes up a lot and the shorted turn(s) get hot.
I think you tested the winding resistance too. Just one or two turns shorted will not show as the resistance change is very small.

HTH. Good luck. I'm following this thread with interest, and so far you're doing a great job!

 

[GrantGunderson]

No, the megger will NOT find shorted turns!
The megger test is primarily of the insulation to ground. Perhaps I should explain what is meant. A shorted turn is where one loop of a coil makes contact with the same coil earlier or later in the winding. There is no connection to ground. When the magnetic field is generated by the remaining turns the shorted section is coupled by transformer action but the 'secondary' has a dead short. So the current drawn by the winding goes up a lot and the shorted turn(s) get hot.
I think you tested the winding resistance too. Just one or two turns shorted will not show as the resistance change is very small.

HTH. Good luck. I'm following this thread with interest, and so far you're doing a great job!

Thank you for the clarification! I'll give it a test here this am, as soon as I get the slab of pork belly I'm making into bacon on the smoker.