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- Nov 23, 2014
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- 2,606
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
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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