# Erector set part number 'P1133' motor terminal nut



## BGHansen (Aug 15, 2020)

Yeah, another reproduction Erector set part string. This one is a pretty simple part, Gilbert numbered it “P158” in 1913 – 1923 and “P1133” from 1924 – 1947: Motor terminal nut- 4-40 thread.

The A. C. Gilbert Company started selling Erector sets in 1913 and had a unique to that year motor. In 1914 they introduced a new pre-assembled motor (1913 motor was in kit form). Then in 1915, they introduced the P58 motor which was included in sets up through 1947.


The P58 motor included in Erector sets from 1915 - 1947.  These were battery or AC powered (up to ~12V AC).  Wires were held in place with 4-40 knurled nuts





Guys like seeing flames and sparks which are hard to photograph.  There are usually plenty of sparks coming from the brushes/commutator





Hard to believe there was a time when power was not transmitted to every house. Back at this time, many houses, especially in rural communities, did not have power lines running to them. Gilbert’s original motors were all AC/DC motors so kids could run them off a train transformer or batteries.

The P58 motor had four 4-40 knurled brass nuts for attaching a shunt and power from a transformer or batteries. It was a small part that was commonly lost. So, not a lot of demand, but enough demand to warrant making a few.

The nuts are made from ¼” diameter brass. They have a 4-40 threaded hole, are about 0.130” thick and are knurled. I make heavy use of drill bushings for the lathe work. Changing from a center drill to start a hole, then switching to a tap drill takes time, albeit not too bad with a keyless chuck, but does take a few extra seconds.

I started by making a drill bushing from ½” OD drill rod. Started by facing, center drilling and drilling a ¼” hole in the drill rod. Then followed up with a #42 drill. “The book” says use a #43, but a lot of these motors end up with some corrosion on the 4-40 screws so a step up on the tap drill makes for easier threading. Parted after drilling, flipped, and faced the opposite side. Lastly, hardened the bushing with a MAPP gas torch (and left it at full hard).


Pretty simple lathe job of facing, center drilling, drilling a 1/4" clearance hole so the bushing fits over the 1/4" brass, then drill a #42 hole for locating the tap drill on center.  Part, flip, face the opposite side and flame harden.
















In use, I chuck up the ¼” brass in a 5-C collet and a #42 drill bit in the tail stock. Slip the drill bushing over the #42 drill, set the tail stock close to the brass, slip the drill bushing over the brass and drill the #42 hole. The drill bushing holds the drill bit on center so I can skip the center drilling step.


Drill bushing in use.  Fire up the lathe, slip the bushing over the 1/4" brass, then drill the #42 tap hole.  The bushing holds the drill bit on center so I can skip the center drilling step.






After center drilling, I power tap the 4-40 hole with a Milwaukee M12 right angle drill motor. Again, saves a tool change on the tail stock to a spring center and tap wrench. Use a pinch-knurler with a diamond pattern per the original part. I find with brass after a while the knurls start to load up. Don’t know if this is the proper cleaning technique, but I use a file card to clean the knurls while it’s running. After knurling, part the nuts off to length.


Power tap with a Milwaukee cordless right angle motor.  I use the right angle motor so the tail stock doesn't have to be slid back as far out of the way.  After threading, knurl and part.









Parting leaves a nib on the end of the nut which I take off with a Scotchbrite wheel on a bench grinder. Naturally, not a lot to hold onto, so I made a tool to hold the nut for clean-up.

Started with a ¼” piece of CRS and turned a nib on the end that fits into a 4-40 threaded hole. This part would be a knock-out pin.


Turned a shoulder in 1/4" CRS that just slips into a 4-40 threaded hole




Then made a holder out of 5/8” aluminum (was in the chip pan of my Clausing). Drilled a ¼” through hole for the knock-out pin. I measured a knurled nut at 0.260” diameter, so drilled a 17/64” hole 1/8” deep to hole the knurled nut. Knurled the aluminum and parted. Flipped and faced the opposite side and drilled a 17/64” hole in that end also so it’s a double-ended tool.


Chucked up some at-hand 5/8" aluminum.  Faced, center drilled and drilled a 1/4" clearance hole.  Knurling grows the part some, so came back with a 17/64" drill bit so the nuts would drop into the holder.










In use, a nut is set in the hole with the nib out. Go to the Scotchbrite wheel and sand/polish it off, then knock out the nut.


Set the knurled nut in the holder and knock off the nib on a grinder with a Scotchbrite wheel.








I ended up making close to 20 per hour. These typically go for $2 - $3 each on eBay depending if 2 guys are battling or not. So no new lathe or mill, but they’ll fund a few odds and ends for my shop!








Thanks for looking,

Bruce


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## C-Bag (Aug 15, 2020)

Always learn something in your posts Bruce. Never used or seen a drill bushing used before. Most of the pics are deceptive because everything looks big. But only because I just did drill and tap some 4-40 set screws do I know first hand how tiny they are and how especially tiny the #42 bit is.

thanks for posting.


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## mikey (Aug 16, 2020)

Really nicely done and we'll documented, Bruce ... as usual!


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## markba633csi (Aug 16, 2020)

My Erection set was much newer- I never saw a motor like that.  They must have gone thru several periods of manufacture
-Mark


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## Tmate (Aug 16, 2020)

I got an Erector set for Christmas probably around 1948 or 49.  It came with a motor with an exposed gearbox in a metal frame.  As I recall it had a lever that came up from the frame to reverse direction.  The set cost $19.95 and you could make a Ferris wheel with it — at least I think you could.


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## hman (Aug 16, 2020)

Bruce -
I recall a blurb on the cover of a '60s vintage Mickey Spillane novel.  It went something like this:
"If you have a handful of books and one is by Spillane, you can either read it right away or save it for dessert."
Finding the title of one of your Erector Set posts on the Members Projects forum is like that for me.  Thanks for yet another one!


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## hman (Aug 16, 2020)

Correction to the above post:
After posting, I went and looked at all the Mickey Spillane books in my library, and couldn't find the blurb.  Figgered I'd lost and later replaced one or two of the books.  Then an hour or so later, I decided to look at my Donald Hamilton paperbacks.  Found the quote on the back of the 1964 (second printing) Fawcett Gold Medal copy of Hamilton's Murderers' Row:
"If you have half a dozen thrillers at hand and one of them is by Donald Hamilton, you can either grab it at once or save it for dessert." - N. Y. Herald Tribune.
Other than citing the wrong author, I'm surprised at how accurately I recalled the quote.  Interestingly, this quote also appears on some later Hamilton books, but attributed to "Book World."   Wikipedia lists "Book World" as the entertainment section of either the Chicago Tribune or the Washington Post, depending on the year.


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## BGHansen (Aug 16, 2020)

Tmate said:


> I got an Erector set for Christmas probably around 1948 or 49.  It came with a motor with an exposed gearbox in a metal frame.  As I recall it had a lever that came up from the frame to reverse direction.  The set cost $19.95 and you could make a Ferris wheel with it — at least I think you could.


Probably what was numbered an A49 motor.  There were many changes through the years.  I attached a PDF from a parts guidebook I wrote about 10 years ago showing the different motors used from 1933 - 1962.  Your set was probably a No. 8 1/2 set if it built the Ferris wheel although they sold a No. 9 1/2 (next largest set in 1948-49) and a No. 12 1/2 those years too.

Bruce


1948/49 No. 8 1/2




1948/49 No. 9 1/2



1948 No. 12 1/2


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## Tmate (Aug 16, 2020)

I think its fantastic that you have taken up Gilbert Erector Sets as what has obviously been a long term interest.  I used to lust after all the Gilbert stuff, including American Flyer trains.  I ended up with Lionel however.

There is a company, 8020 Inc., that sells what they call "the industrial erector set."  It uses aluminum extrusions and brackets to build pretty much whatever you want.  I posted this on another thread, but I built a complete 16' x 22' Lionel train layout using the stuff.


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## C-Bag (Aug 16, 2020)

I stumbled onto 80/20 in a local Craigslist ad. It was just the solution to what I had been struggling with for years. i love it’s flexibility but you definitely need deep pockets if you are buying new. Mine was used from an old DIY CNC router table that was scrapped. Got 75’ of 10 series 2”x2” plus tons of corners and braces for $175. There’s no way I could have afforded all that new.


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## Tmate (Aug 16, 2020)

The stuff is expensive!


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## Papa Charlie (Aug 16, 2020)

Nice work on the knurled nuts. Very well thought out process and tooling. My compliments.


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## C-Bag (Aug 16, 2020)

Never got Erector sets when I was a kid. Mostly I’m sure because my parents had seen what happened to the sets of stuff I got. My siblings felt it was their duty, sole purpose in life to scatter and destroy anything I had. Train sets never survived more than a week before something crucial disappeared. Same with slot cars.

I appreciate your through knowledge and explanations of the whole Erector world Bruce. It really does reflect what I think was the mindset at the time. LEGO was a pale reflection of that, almost a pixilated view of how to build and create.


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## Bi11Hudson (Aug 16, 2020)

My father was an "Am Damateur" inventer, using Erector set parts even when he was 81 (1987) to prototype ideas he was pursuing. No real sets as such, just parts people had in their basements left over from childhood. He loved the variable lengths that could be "adjusted" to fit most any dimension. I never had a set as a kid. . . too expensive. But after my younger brother was grown and money was a little more available, he gathered up parts wherever he could. "Gizmos R  Us", that's my Pop.

Hobby motor design has changed little over the years, mostly in the manufacturing process to cut costs. There are AC/DC universal motors and Permanent Magnet(PerMag) DC only motors. AC motors can be related to a sewing machine motor or a line powered drill or circular saw or any number of line powered appliances. Battery powered appliances will most likely be DC PerMag motors. The only differences in modern motors are the voltage ratings and assembly methods. 

My intent here is to advise that while sparking is normal, the less there is the more efficient the motor runs. At most, a sparkler(modern fireworks) puts out far more sparks than a universal motor. Small noise at the brush tips is the most you should ever see. If the "neutral plane" is set correctly, sparking shouldn't be seen with the lights on. The best example is a power drill. If you see that much, it's too much.

Neutral plane isn't easily adjusted on small (<2-3 HP) motors, but it can be done. The relationship between brush rigging and pole pieces is what controls it. If there is *serious* sparking, it most likely is the commutator "out of round", badly scarred, or "high mica", any of which involves disassembly to correct. Truing a comm is best left to folks that are used to truing copper. If it's just scarred, it can be stoned. For high mica, it *must* be undercut. 

Most small motors can be restored with these methods, especially "vintage" stuff like you are dealing with. High mica is the most difficult to deal with on small motors. It should be a minimum of 1/64th inch below the copper. Any deeper than 1/32" though and the cement used on old motors is weakened, often to the point of slinging the commutator segments out. At which point the motor becomes a small boat anchor. Learning is as much gaining the feel of the motor, but if you have any BER it's worth learning.

Bill Hudson​


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## BGHansen (Aug 16, 2020)

Little bit of trivia for all.  Every one of us has some "legacy" from the former A. C. Gilbert Company in our shops.  They invented and held the patent on enamel insulated wire.  Up until this invention/discovery, magnet wire was wrapped with cotton string for an insulator.

Bruce


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## hman (Aug 16, 2020)

WOW!!!  That's a VERY significant invention!


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## Bi11Hudson (Aug 16, 2020)

Now that is intriging. I've worked around electrical equipment even when I was in grammar school. And have run across the cloth insulation referred to on occasion. It still shows up on small lamps. (Grain of Wheat and smaller) I knew it was old technology, but wasn't aware of the significance. It wasn't a discovery, it was a true invention. The more modern version is (I think) G.E.'s "Glyptol".

.


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