Century Electric Motor 1HP: Rebuild and many questions

Pupuhd · Nov 29, 2015

I purchased this 1hp Century electric motor several years ago from a guy in the next town over. His price, a case of beer. No really, all he wanted was a case of a Canadian ales beer if I recall correctly. Long story short, this motor is intended for an upgrade for a 1974 Clausing 15" drill press that came with an under powered 1/2hp motor, and now I'm finally getting to rebuilding it. The PO stated he used it in his barn for a haylift of some sorts, hence the rust and pitting both on the exterior and interior.

Before getting any further into details of the rebuild, I have many questions and issues I see with this project. I will post them in BOLD so they can be spotted easier. First, vintage year, date of manufacture, approximate decade at least? I have two other Century electric motors: one circa 1930s, 1940s with the waffle style end bell. The other, a 3hp, possible circa 1950s. The later and current build have many features in common, however I wanted to know if some one here would have a better or clearer opinion as far as circa year or time period.

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The machine tag reads as follows:
CENTURY, CODE: H
SINGLE PHASE MOTOR
MODEL: CSN-207-BA6-5EA
HP: 1, RPM: 1750
CY: 60, VOLTS: 115/230, AMPS: 12/6
40 DEG. CONT. OPEN, SERIAL NO.: Z1
CENTURY ELECTRIC CO., ST. LOUIS, MO

The reason for my first inquiry above is because I've been making brass etched rebuild tags that I have already attached to a few of the rebuilds I have done to date. The tag will include my shop name, my full name, city, state, country. Below that blank spaces to be stamped with brief description, then DOM (Date Of Manufacture) and DOR (Date Of Rebuild).

I have many other questions/concerns requiring further explanations, details and possible sources for components. Thank you-David

EDIT: Soon after beginning this rebuild I decided that this motor will not be suitable for a drill press due to the fact it is design for horizontal installation, not vertical. This one will be assigned to a vintage Delta Wood/Metal Band Saw waiting for rebuild.

Pupuhd · Dec 4, 2015

While I hopefully get more input from you guys, I'll continue here with the dismantling. As mention before this motors previous life in a barn with a lot of exterior exposure is evident with the amount of rust inside of the motor connection box. The rust itself I can blast clean, however the rust has eaten through most of the bottom cover. Good news is that I have a found connection box to replace.

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The large nut holding the cover down gave me some trouble due to heavy rust, but a few hours of penetrating oil, it gave way. I was able to salvage the nut and lock washer for the replacement connection box.

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theoldwizard1 · Dec 4, 2015

There are several videos on rebuilding an electric motor. Here are just a couple.

Single Phase Electric Motor Diagnosis
Good basic explanation of electric motors.

Electric Motor Rebuild
On this one, I would have replaced the start and run capacitors.

Pupuhd · Dec 4, 2015

Next the capacitor was removed from the motor. You can see the deterioration on the capacitor case. One end cover is completely rusted through, while the center cover is out of shape.

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Here's where I need to post another important question. As you can see both the cover, end caps and the capacitor itself is pretty worn. This motor ran with no issues prior to tear down. However I wish to replace the old beatup capacitor with new and also get a new cover for it.

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Not knowing if the old capacitor is running 100% and absolutely no clue to the specs anywhere on it, except some writing. How can I determine the specs/size for a replacement capacitor? Is there a way to determine from the motor tag or test the capacitor using a simple multimeter?

I will most likely post this question in a separate post to get more attention to it with a link to this one for more details.

Pupuhd · Dec 20, 2015

The smaller parts were then removed, inspected and all put in a tray. End bell vent covers and screws were fine, just typical rust.

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Inside did not look too bad upon initial inspection.

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Next the aluminum Century logo cap. A little beat up, but hopefully salvageable.

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Before removing the end bells, I punched witness marks for later assembly. However in later photos you will see two other sets of punch marks which tells me this motor has been worked on at least once before if not more.

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Through bolts remove and again plenty signs of internal rust.

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These are the older found witness marks mentioned before.

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Gentle taps with a flat head screw driver and a plastic mallet around the perimeter, and the end bells separated with no issues.

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Here's a closer look at the centrifugal switch assembly. Rusty, but no visible damage.

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Rotor removed. This has plenty of rust through including the centrifugal switch assembly. I'm still trying to figure out how to carefully disassemble this switch to blast and paint the individual components.

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Inside of the stator is literally a rats nest. No remains found just a lot of debri in and around the stator and shaft end bell.

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Here's a look at the reverse side of the switch.

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Overall photo of all the major components disassembled.

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454ragtop · Dec 22, 2015

Might get more help over at OWWM.org in the electrical section, those guys do this sort of thing all the time.
HTH, Jim

Pupuhd · Dec 30, 2015

Before pressing out the bearings, I took careful measurements to how far in they sat.

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Back end is .282", while the shaft end is .355". Don't know if at assembly these measure will still hold true, depending on rotor slop.

Using a socket both bushings popped out with no issues on the shop press.

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Both bushings are identical, clean with no apparent damage.

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Inside you can clearly see the wool wick string. After spending sometime, I was able to remove 99% of it. All was dirty, some dry up oil clumps. I have been unable to locally find unstained wool yarn and also expensive for just one at about $6, so for under two dollars I got some wool roving. This stuff is still stained however not processed into yarn, sort of like fluffy mat. I'm hoping by pressing it in tight to the cavity around the bushings it'll help wick the motor oil.

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Brass ring on shaft end carefully removed.

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elsonarah · Dec 30, 2015

those guys do this sort of thing all the time.

Pupuhd · Dec 31, 2015

Only one Gits oil cup of two was still on the motor. This fell apart while removing it, looks like it was made from pot metal. Either way two new ones are on order.

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Next the inside dust cover was removed. This was held by four drive screws. At first I ground off the heads thinking these were installed in a blind hole. After blasting the end bell I saw that the holes were drilled through, I could've easily just punched them out from the outside. Oh well, maybe next time.

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Cleared out both excess oil holes located at four o'clock. These were completed clogged.

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Both end bells were cleaned with parts cleaner to remove any grease prior to blasting and also to clean out the the chambers were the wool wick was.

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Overall view of all the misc. hardware and fasteners to date. Some of these will be replaced with new, the rest cleaned, blasted and/or painted. The through bolts threads were cleaned up with a 5/16-18 die.

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Pupuhd · Dec 31, 2015

Preparation is everything as they say. First the lip around the end bell where it sits inside the center stator section of the motor was wire wheeled. Followed by taping off all areas that will remain bare metal.

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Before and after blasting. I used Black Diamond (Tractor Supply Co) to remove everything from the heavy rust to any original paint left.

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I spray painted the parts in batches due to the size of my homemade spray booth. It's too cold outside at this moment and my shop is too small to paint everything at once. Also with this spray booth connected to the Delta Air Cleaner filter unit, this made over-spray all over the shop a thing of the past.

First three light passes with gray primer, followed by three light passes of the finish paint. This covered the first coat. For the colors, I used Ford Gray Gloss Machine & Implement spray paint for all parts for and including the end bells. Gloss Black Rustoleum High Performance Enamel was used for the center section and parts of the motor.

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My favorite part of this project. Why? Because I can hear my wife muttering under her breath: and that is backing the parts in the oven.

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I've been experimenting with a recipe for baking the paint that works for me. As I start to put in the parts in the oven, I turn it up to 300 degrees. I then set the timer for one hour. The oven slowly gets to temperature during this one hour, no preheating. Afterwards, oven is turned off and parts are left to cool down for an hour or so. This process mostly cures the paint enough to handle without any tacky paint and proceed with a second coat of final paint. Again three light passes prevents heavy build up at once or run off/drips, followed by backing again.

First patch of parts are left hanging in the shop to cure properly the following days/weeks.

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sgs236 · Dec 31, 2015

Thanks for posting this. Lots of good information here.

Pupuhd · Jan 1, 2016

sgs236 said:
Thanks for posting this. Lots of good information here.

Thank you for the interest. I've gotten a lot of useful information, help and advise between this forum and OWWM. I'm just returning the gratitude and hope this helps someone down the line-David

Pupuhd · Jan 1, 2016

While waiting for a delivery of Glass Abrasive and Glass Bead media for the blasting cabinet, I decided to move onto the stater. As you'll see later I won't be using the Black Diamond media for this, however the glass medias to clean and peen all the surface and leave it a bright bare metal finish.

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On the fan end of the rotor are eight spacer washers, six fiber and two metal. On most newer or modern motors usually you'll find at least one spring washer to take up any lateral movement of the rotor during use. I'm assuming these eight washers on this Century motor compensate for any slop or lateral movement. The fiber washers to the left of the photo ride or rotate right up against the end of the bronze bearing bushing.

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Other end has a cup like washer with two metal washer behind it. The cup washer has two ears that prevent it from spinning. Also found what I believe to be a dust shield like material inside the cup washer. It was brittle and crumbled very easily, I'm thinking decades of dried oil.

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Pupuhd · Jan 3, 2016

The blasting glass media arrived. As mentioned before in an earlier post I originally thought about disassembling the centrifugal switch mechanism in order to blast and possibly paint most of the rotor. However after studying the rotor carefully I realize it would be nearly impossible to remove because it was pressed onto the shaft. I started researching into peening the rotor with glass beads to achieve a smooth and reflective bare metal finish, sort of like original.

I purchased the Glass Abrasive #100 and Glass Bead #9 from http://www.tacomacompany.com. The website is just a place holder with contact information at the bottom and two videos. They also have an Ebay store with most of their blasting products. I spoke with Mike there and explained my situation in regards to the rusted and pitted rotor. He "prescribed" the above two medias and I should be able to achieve my goal. He is very knowledgeable with blasting needs, I had earlier purchased a deluxe blasting kit from him which included blasting gun, regulator and foot switch. This kit improved my Harbor Freight blasting cabinet to an almost professional level. I'm able to blast parts quicker and with less air pressure and this is using my currently cheap 26 gallon Craftsman air compressor. The gun itself lets me continue to blast while the air compressor keeps running with little pressure loss.

Below are before photos of the rotor, you can clearly see the rust and heavy pitted areas at the switch mechanism, round plate behind it and fan part. The copper parts (if you can even tell they're copper) and center stack plates had light surface rust.

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The switch mechanism functioned, open and closed with no issues.

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First step was blasting with the Glass Abrasive #100. This took nearly an hour because of me getting tired leaning over the blasting cabinet that long. It was recommended the pressure be set a minimum 25psi, no more than 40psi. I started at twenty-five, however had to raise it to thirty due to the heavy rust. After this first blasting, all the rust was removed, it left the rotor a slight matted gray finish. Now you can see the copper and brass components.

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Final step was swapping out the previous media for the Glass Bead #9. Blasting the rotor now only took 15-20 minutes at 25psi pressure. Had to carefully do a section at a time since it was difficult to see the process behind the dusty blasting cabinet glass. Had to remove the rotor several times and inspect the progress.

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All I can say is WOW, I never realized you can get these results from glass beads. If I didn't do the blasting myself, I swear this rotor was spray painted with bright copper and bright silver paint. The reflective surfaces are from the camera flash. Every square inch has a reflective shine to it and silky smooth. NO NEED TO PAINT NOW!. I originally had taped off each end of the shafts thinking the blasting would ruin the machined surface, however wound up blasting these areas also.

Here's a closeup shot (same angle as above before) of the centrifugal switch mechanism. I still get a kick out of the results.....call me giddy.

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99LeCouch · Jan 3, 2016

Excellent work, and excellent documentation! Kudos to restoring this old motor to its original glory!

And, thanks for the links and description of how to achieve those results with a smaller compressor!

Pupuhd · Jan 6, 2016

Next step in the blasting was the center stator section of the motor. With this one I had to blast in three steps due to the heavy rust inside. First the Black Diamond media inside and out. I didn't bother taping anything off as long as I was careful not to blast the copper winding directly. However before anything I had to remove the manufactures plate on the side. The drive screws were too rusty to try and remove them and inaccessible from the inside. I had to carefully grind off the heads using a dremel with a cutoff wheel.

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Here are some before photos of the stator section. You can see the heavy rust near the top inside and stack plates.

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After blasting with the Black Diamond media. The streaks on the outside is the Electric Motor spray cleaner. I had to do this cleanup to remove all the dust and any media left behind before the next blasting step. Here all the rust inside and out has been removed. Some wires from the windings were hit near the inside between the motor section and the plates. Only the varnish coating(?) was removed, the wire itself was not damaged.

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The stack plates on the inside where the rotor would spin was not blasted with the Black Diamond media. This will be blasted in the next step.

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Now swapping out and cleaning out the blasting cabinet for Glass Abrasive #100, this changing of media takes ten to fifteen minutes. It involved bagging the old media, brushing everything down and vacuuming, back flushing the gun and putting in the new media while filtering it out. This is especially important since you don't want the Glass Abrasive and Glass Bead getting cross contaminated with any other media.

With this step I only blasted with the Glass Abrasve the inside of the stater wall and the plate stacks. Also blasted the centrifugal switch component. All this gave those areas a matte, almost satin look and feel, as before with the rotor.

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Again, swapping media and cleaning out the blasting cabinet for the Glass Bead #9. This step takes a little extra care and patients since no remains of the previous media can left behind. Here you can see the flash reflecting on the newly bead blasted plate stacks. The centrifugal switch assembly and inside walls now have the bright and smooth finish.

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These are brackets for the centrifugal switch assembly. Left is blasted with the Glass Abrasive, right is the next step with the Glass Bead. I hope the photo can pickup the differences in both.

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McBrownie · Jan 6, 2016

Nice write-up and a very interesting rebuild. Can't wait to see the finished product. :thumbup:

Packard V8 · Jan 6, 2016

His price, a case of beer. No really, all he wanted was a case of a Canadian ales beer if I recall correctly.

You overpaid. Demand the bottles back to at least get the deposit. ;>)

You're doing excellent work and will be proud of the result. At a modest per hour rate, you'll have a beautiful $1500 1-hp motor.

Having said that, I completely understand. Most of what we do here doesn't equate to an economic return. I just spent an hour cleaning and repairing a $3 air hammer and saw a guy selling one on craigslist for $5. But now it's really mine and I know what's inside it.

jack vines

smalltown · Jan 6, 2016

Nice job. I could never imagined you could blast the inside of the motor with anything without ruining it. Looking great so far.

P.S. Why doesn't the stator section come out of the case so you could blast the inside? I'm sure there is a good reason I just don't know it.

Pupuhd · Jan 6, 2016

Packard V8 said:
You overpaid. Demand the bottles back to at least get the deposit. ;>)

You're doing excellent work and will be proud of the result. At a modest per hour rate, you'll have a beautiful $1500 1-hp motor.

Having said that, I completely understand. Most of what we do here doesn't equate to an economic return. I just spent an hour cleaning and repairing a $3 air hammer and saw a guy selling one on craigslist for $5. But now it's really mine and I know what's inside it.

jack vines

Jack: True on that. I think the case of Canadian ale cost me $22 local price. I believe I'm nearly $100 in supplies and misc. parts needed. However like you stated "But now it's really mine and I know what's inside it."

smalltown said:
Nice job. I could never imagined you could blast the inside of the motor with anything without ruining it. Looking great so far.

P.S. Why doesn't the stator section come out of the case so you could blast the inside? I'm sure there is a good reason I just don't know it.

smalltown: I didn't think either. I was going to originally tape/cover the copper winding for blasting then use sand paper flap wheels to clean the plate stacks. I even purchased three in fine, medium and courde grit variety of them, but after learning about using Glass Beads to peen metal, I was confident in carefully taking this task in the blast cabinet.

The courser media will damage the copper winding and finish if not extremely careful when blasting near them. However with the Glass Abrasive and then Glass Bead I was able to blast directly onto the winding with no issue. At 25psi pressure, it cleaned any exposed copper wires, finish and even the cloth wrapping around the winding and lead wires.

No the stator itself cannot be removed from the center housing of the motor. It is pressed in at the factory. Impossible to remove without damage.

weg_guy · Jan 6, 2016

I have enjoyed reading your post. I like that you are trying to restore a old motor to its formal glory. Last year I did all the work except for the rewind, as I am not a motor winder, on a 40HP 460v low RPM (900 If I recall) bell and howell. It turned out really nice and hopefully will run another 80 years. I am currently reconditioning a 1,500KW Cat gen (gen only not the diesel part).

As you may have guessed I am a 3 phase electrical motor technician/mechanic by trade and I would respectfully like to offer you a few tips.

In the future do not bead blast the stator windings. All of the magnet wire is coated and you do not want to damage any of those coatings or see any bare wires so that you do not cause a turn to turn or a to ground short. Not having access to motor specific equipment like one would in a professional shop I would simply blow it out with compressed air or if you wanted to get really crazy you could try taking it to the car wash and washing it with a pressure washer (maybe not hit the windings directly full blast though) and then drying it in your oven if it will fit for 6 hours at 300F or slightly cooler. That is also what I would do for the rotor. Rotors are not nearly as sensitive as the stator however they are also not generaly bead blasted. Usually polishing it up and knocking off the rust with a wire wheel is sufficient.

After cleaning both the stator and the rotor the rotor would be masked off and hit with a heavy coating of red insulating varnish like this stuff:
http://www.grainger.com/product/SPRAYON-Red-Insulating-Varnish-1D276
We use a similar product from ESSEX that is pretty much the same thing.
And especially the stator would be hit with a heavy even coating of the same. If the laminations were as rusted as yours I would carefully hit it with die grinder with a sanding drum on it before hitting it with the heavy coating of varnish. If the air gap between the rotor and the stator is really tight I would do a lighter coating of insulating varnish on both stator and rotor.

Again I really enjoyed the write up and the pics and I hope you don't think I am criticizing you at all I mealy want to offer some tips.

Best of luck to you on your project and I hope you get it all running well again.

Pupuhd · Jan 7, 2016

weg_guy said:
I have enjoyed reading your post. I like that you are trying to restore a old motor to its formal glory. Last year I did all the work except for the rewind, as I am not a motor winder, on a 40HP 460v low RPM (900 If I recall) bell and howell. It turned out really nice and hopefully will run another 80 years. I am currently reconditioning a 1,500KW Cat gen (gen only not the diesel part).

As you may have guessed I am a 3 phase electrical motor technician/mechanic by trade and I would respectfully like to offer you a few tips.........

weg_guy: No, thank you very much for the advise and tips. Would I recommend blasting a stator, no I wouldn't. Every motor might be a different situation. In my case with the heavy rust, even flaking, I had very little avenues to pursue removing it. Also, I would never have blasted it with my old original HF blasting gun that came with the blasting cabinet. However with the upgrade gun from Tacoma Company, I was able get a concentrated small pattern at a very low psi of 25.

Of the many electric motors I have waiting for rebuild, this by far was the worst one condition wise. I may never have to blast another one, however if I chose to do it again, next time after Electric Motor cleaner I will apply Red Insulation to the winding prior to any blasting inside.

My post are now about 1-1/2 weeks behind the actual rebuild. I currently already have the motor assembled and running. Just as a note from your comment above, after blasting the stator I did apply Red Insulation to the winding. I didn't want to use the spray version, so I purchased a small can that can be brushed in more liberally and especially into tight and blind areas around the perimeter of the winding. I will soon post that progress.- David

Pupuhd · Jan 7, 2016

Next was painting the stator section of the motor. Here I tried a failed attempt to apply even coats of spray paint while it was prop upside down on four wood screws. Even though I tipped it over to spray the bottom, I could never get the spray can to spray ninety degrees to the surface. It always sprayed this area at an extreme angle and most of the atomize paint (over spray) in the air would land on it to cause a textured finish. The sides and top of this setup were fine.

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In the photo below you may be able to see the textured finish at the top by the hole for the capacitor wires, This area and the base top surface also had this issue.

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At this point I decided I could fix this later and proceeded with rewiring the old lead wires coming from the stator. I cut back the exterior cloth braided insulation to withing a half inch of the winding. Then cut back the inner insulation back to a point it was no longer brittle and free of cracks.

Next I spliced a new #14 copper stranded wire, followed by flux and solder.

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I put a small piece of regular heat shrink tubing to cover this soldered spice, followed by marine grade heat shrink tubing that spanned from the old cloth braided exterior insulation onto the new wire.

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This procedure was continued with the next capacitor wire and the four lead wires that would run into the junction box.

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As far as the color call-out for the four lead wires: T1, T2, T3, T4. I had the wires marked for 110V hookup prior to dis-assembly. I knew what wires for one winding were, T1 and T4, these were Black and White. The other two had me stumped for a while and after googling wire diagrams for this type of motor, I was able to ohm test and conclude which one was T2 (Red) and T3 (Blue) based on ohm's resistance value. I'm no expert here, so my theory could be all wrong. I just based my findings on some research.

Pupuhd · Jan 7, 2016

Below is the new old stock electric junction box I had laying in my parts bin. The original Century one was too far gone as far as rust to try to bring it back to life. This one had the correct radius and interior space, just had to do some grinding in the center to accept the threaded portion sticking out from the center stator motor section.

This newer box had all three knockouts removed. I had saved (yes I saved them thinking I would someday need them) knockouts from household steel electrical boxes and tack welded two spots to secure them on the left and right of the box. This will be blasted again one last time before paint.

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hunterguy86 · Jan 7, 2016

Nifty! Thanks for sharing!

Sent from my iPhone using Tapatalk

Roberts210 · Jan 7, 2016

Good job! Excellent work you are doing.

pistolpete1313 · Jan 8, 2016

The level of detail is great and I always enjoy learning from experts such as yourself and weg guy

McBrownie · Jan 8, 2016

Pupuhd said:
Below is the new old stock electric junction box I had laying in my parts bin. The original Century one was too far gone as far as rust to try to bring it back to life. This one had the correct radius and interior space, just had to do some grinding in the center to accept the threaded portion sticking out from the center stator motor section.

This newer box had all three knockouts removed. I had saved (yes I saved them thinking I would someday need them) knockouts from household steel electrical boxes and tack welded two spots to secure them on the left and right of the box. This will be blasted again one last time before paint.

Vindication!!!! I love it when I end up using something "useless" that I saved just in case I might need it someday.

Pupuhd · Jan 8, 2016

After rewiring it was time to repair the previous failed paint job. End was loosely masked off, lightly sanded both the top and base area, applied a second finish coat and baked. After drying the finish was now good.

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Concerns were brought up in regards to blasting the interior of the stator with the possibility of the copper winding and insulation getting damaged. This is true, I would not recommend doing this: Play At Your Own Risk. However I had a bit of confidence with the upgraded blasting kit and glass media I would succeed. In reality, I lucked out. As noted before some of the copper wire and insulation did get hit by the blasting. However as I write this post, the motor has been completed and been running for half an hour with no issues. In hind sight, I should have cleaned the interior with Electric Motor spray cleaner then applied Red Insulating Varnish before any blasting, if required.

With that said, covering the winding came next. From Amazon, I purchased MG Chemicals 4228 Red GLPT Insulating Varnish. A 7.6 oz can was $23. I decided to use the brushed version instead of spray because I was able to apply a one time heavy liberal coat and get into all the nooks and crannies of the winding. With both ends done, I only used half the can, not bad for around $11 a motor.

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The original grommet for the capacitor wires was rotted. From my stash I found the correct diameter one and just widened the groove to fit the thick wall stator section.

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New screws holed for the new capacitor cover were drilled and tapped. Take note of the installed grommet and thick Red Insulating Varnish applied. I don't think you would get such a good coverage with spray varnish. When applying the brush type, don't spread the dipped brush too thin. Allow the product to soak into all the cavities, you can always apply a second coat just soon after, This stuff dries quickly.

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Overall photo of all the center components to the motor: new 243-292 Ohms Capacitor (McMaster Carr, $6), salvaged capacitor cover and electric box.

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Pupuhd · Jan 8, 2016

The original data plate was cleaned and reinstalled with new drive screws. Since the new capacitor was a lot smaller than the cover itself, I used foam sheet good to keep it from rattling inside. Again more junk saved for another day, at least that's what I keep telling myself.

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I decided to restamp the important information on the plate such as Volts, HP, Amps, RPM, Cycle. The old stamp characters were hardly visible from nearly 60+ years. Original height were 3/32", only had 1/8" in my bag of goodies. It'll do piggy, it'll do.

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Assembled center section already for the rotor and end covers.

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Shield was attached to fan end cover with new #7 drive screws from McMaster Carr. While ordering, I purchased #4, #6 and #7 drive screws to cover a variety of projects. I believed these were around $4 for a box of one hundred.

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The bronze oil bushings were pressed half way. This allowed me to pack the bottom half of the oil cavity with the new wool wick. I couldn't locally find wool string, so I purchased a 3 oz package of Wool Roving at Hobby Lobby for under $2. "Roving is a long and narrow bundle of fiber. Rovings are produced during the process of making spun yarn from wool fleece, raw cotton, or other fibres. Their main use is as fibre prepared for spinning," This three ounce bag did both oil cavities exactly.

Once the bottom half was packed in tight, I press the bushings the rest of the way. The brass ring or collar at the shaft end I hammered back into shape and blasted with glass beads. One thing I did at this point is start soaking the installed wool wick with motor oil. The end covers had to stay up vertically so the oil wouldn't run out during the next steps.

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Pupuhd · Jan 8, 2016

Stator was next for final details. On the centrifugal switch end there was two spacer washers and this cupped shaped ring that rode up against the bronze oil bushing. This cupped shaped ring has two taps that lock onto the shaft. Inside the cup was a dirty hard brittle material, I believed this was originally a dust shield. So I decided to treat it as such. I used some 1/8 inch thick F-1 wool felt and cut a ring to fit inside the cup.

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As I was ready to dry fit the rotor into the stator and mount the end covers, I didn't like the way the centrifugal switch wires looked. I also found frade and cracked insulation. The old "might as well" hit me and decided to repair these wires. Same as before: clean old insulation, apply heat shrink tubing and new crimped eye connectors. I even installed the brass number tags back on.

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Before photo:

Don't anybody tell you "throw away that junk, you'll never use it". Perfect example, old vintage nuts, bolts and washers. Here I was able to find an exact 8-32 brass nut I needed to add to the above repair.

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Here's that assembly attached to the shaft end cover and a before photo from same angle. Don't know, but it brings a tear to my eye. Again call me giddy.

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Pupuhd · Jan 8, 2016

Back to the rotor, on the other end the fiber washers were installed.

While waiting for more supplies to be shipped, I took this opportunity to try my hand at some restoration. The aluminum cap with the Century logo which mounts at the end cover was badly beaten up and no color left.

Using the end of a half inch steel round stock, I clamped it vertically to my vise and use that as a miniature anvil. With a copper hammer and small punches, I carefully flatten the background and reshaped the large C. The squished sides were cut off and filed smooth. I then with cheaters applied red Testors enamel paint to the background.

Not perfect, but good enough for government work. I shouldn't say that too loud, I work for the state.

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My wife is getting use to my baking......delicious. NOT!

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McBrownie · Jan 8, 2016

I bet it didn't look that nice leaving the factory. Nice work!

Pupuhd · Jan 8, 2016

Supplies arrived finally from Amazon, the new Gits oil cups and ACF-50 anti-corrosion spray.

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I saw this product while watching a Youtube video on blasting a small engine with glass beads to peen it. They then sprayed ACF-50 to further protect and lubricate the finish. This stuff is like PB Penetrating spray on steroids: Protects, Penetrates, Lubricates. Meets Requirements for MIL-PRF-81309, Type II, BMS 3-23 (what ever that means). Pretty pricey at $25 shipped for a 13 oz. can. This will be used sparingly and I even saved the excess in a glass jar.

My thinking here was to spray the entire stator to both protect the peened finish and lubricate the centrifugal switch, since once assembled I would probably never have access to it.

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Excess wiped with paper towel, shaft end oiled and rotor installed with the one end cover in place. I had plenty of witness marks from previous owners to line it correctly. ****, isn't it?

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Next was to install the shaft end cover and through bolts with new nuts. Used locktite for this. At my favorite steel and surplus outfit, they sell fasteners by the pound. Was able to find over sized 5/16-18 nuts in bare metal that closely were the same scale as old ones. These were about under one dollar for half pound worth, I always buy extra. I had also peened these in the blast cabinet.

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While assembling I noticed the shaft didn't spin freely, it was stuck. After careful pondering I realized the wool felt dust shield was the issue, too thick. I removed one end and removed two of the fiber washers. This did the trick and the shaft rotated freely.

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kunkernator · Jan 8, 2016

Beautiful restoration. I never would have known to take so much care in researching what type of glass bead to use......

My girl asked me why I spent 30 mins reading a write up on an electric motor. Cause it is frekkin cool!

cptn_zippy · Jan 9, 2016

Just want to comment about the amazing work and clear writeup. Stuff like this is why I love GJ.

J

torqueman2002 · Jan 9, 2016

Thanks Pupuhd!

I think it is a great write up, but you know that. I posted it on your OWWM thread.

:thumbup:

larryq · Jan 9, 2016

Great stuff, thanks for the amazing job and writeup. One question about 'drive screws'-- I'm looking to replace the faceplate on a couple of old grinders I'm restoring. Do you hammer these in, giving them the appearance of rivets?

Pupuhd · Jan 9, 2016

larryq said:
Great stuff, thanks for the amazing job and writeup. One question about 'drive screws'-- I'm looking to replace the faceplate on a couple of old grinders I'm restoring. Do you hammer these in, giving them the appearance of rivets?

Yes you hammer them in gently, they screw-in as you seat them. If possible get a soft hammer, brass or copper preferably, this will prevent any marring to the surface of the drive screw.

In my constant find of older and vintage tools, I came across this used copper hammer for about $5. Cleaned it up and refiled the head. In a flea market I came across a Brown & Sharpe center punch kit for $3. Coincidentally, it had a concave punch in the set, perfect for setting drive screws.

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I wound up ordering from McMaster Carr a variety of drive screws in #4, #6, #7 in the 1/4 in. and 5/16 in. lengths. This will cover most of my rebuilds.

Thanks-David

Pupuhd · Jan 9, 2016

At this point I began to install the remaining wool roving in the oil chambers around the bronze oil bushings. First jammed it to fill the sides then the top area. I compressed it down good especially at the top were it comes in contact with the shaft. This is the open part of the bushing. Before the new Gits oil cups were installed, more motor oil was added to soak the wool wick.

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I cut a disk from 1/8 in. F-1 wool felt to insert inside the aluminum Century logo end cap. My idea was for this to act as a dust shield and possibly absorb excess oil inside the chamber.

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Gits oil cups installed, I used a piece of wood and copper hammer to gently pound these in. The holes are 7/16 in. diameter, so it required Gits 00305 Oil Hole Covers and Cup, Style R Shoulder Drive Oil Hole Covers from Amazon for $11 each. I continued to oil it until it began to come out of the over-flow hole on the side and the brass collar.

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TIP: Paint does not like sharp 90 degree corners, it's a week point for possible chipping at this point. I forgot to follow something I learned a long time ago: caulk inside corners, slightly round over outside ones. I should have slightly chamfered or rounded the outside edge of the stator cast iron housing. When I went to put the cast iron end covers and gently tap into place, the black enamel paint started chipping where they seated together.

At this point in assembly, I took some of the original spray paint and put some in a cut motor oil quart container. With a small fine tip brush I touched up these areas. Motor oil container make a great parts container and for some reason because of the previous oil inside are smooth as butter. The black enamel paint just wiped off with little thinner, ready for the next oops.

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Century Electric Motor 1HP: Rebuild and many questions

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