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Post by turbokinetic on Oct 25, 2018 3:10:59 GMT
Fixing this beast. It's in amazing condition, given how many years it has been in existence.
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The motor is very complex. The mechanism at the front is the governor. This is what changes the motor from repulsion mode (Startup) to induction mode (Running).
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In the past, the motor has been severely over-oiled. This has led to the brushes and commutator becoming coated in grease and grime. That will cause sparking and smoke when it starts.
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A quick polish job later, it looks a lot better!
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Now the parts are reassembled.
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I see a "3 yr" button. Wonder if that's 3 years between oiling, or if it was 3 year warranty?
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Wanna hear it run?
The cabinet is in such good shape and original condition. Hopefully I can just do a mechanical repair and not have to tear into the cabinet at all!
Interestingly, it has a one cylinder compressor and 1/5 HP motor, whereas my similar but larger model has a two cylinder compressor and larger motor. |
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Post by Travis on Oct 25, 2018 3:22:15 GMT
David,
You have a larger evaporator as did this parts machine you used to fix yours. I have a feeling only the smallest models had a single cylinder compressor.
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Post by turbokinetic on Oct 25, 2018 3:35:51 GMT
David, You have a larger evaporator as did this parts machine you used to fix yours. I have a feeling only the smallest models had a single cylinder compressor. Yep.... I can make THREE trays of ice at a time! 
I have an idea that the twin compressor will run smoother, since it has two evenly spaced, small compression strokes per flywheel rotation - and the single cyl has one large compression pulse per rotation.
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Post by ckfan on Oct 25, 2018 12:10:31 GMT
Wow, it sounds so cool! So was this the motor that had pot metal chewed up to bits inside, the one that was original to the fridge? If so, how did you fix it?
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Post by birkie on Oct 25, 2018 12:28:31 GMT
Nice! This one spins up so fast. I don't think I've heard a repulsion start motor this small before.
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Post by turbokinetic on Oct 25, 2018 13:57:30 GMT
Wow, it sounds so cool! So was this the motor that had pot metal chewed up to bits inside, the one that was original to the fridge? If so, how did you fix it? Hi Ray. I realize none of us really had time to study the parts we picked up from Lou. There are two sizes of motors we got. The original one (that had the broken weights at Travis's place) is a 1/5 HP size. One of the spares that came from Lou's garage was the same model; and the other spare was a larger 1/4 HP motor. The spare smaller motor also had broken weights. They appeared intact looking inside the motor, but when I took the front off the motor, they broke when touched lightly. The larger motor has a different mechanism design. It has steel weights which were still in perfect shape. Travis's fridge (which I started this thread about) can use the larger motor. It is about 2 inches longer than the original. Otherwise it looks about the same. I will have to get one of the shorter motors working for Lou's smaller 1933 Frigidaire. That fridge doesn't have room for a longer motor to be installed. It has a 1/5 HP motor, which I expect will also have broken weights. The biggest problem I see with repairing the 1/5 HP motors is nondestructive disassembly of the rotor. I can't see any feasible way to get the weights out, or new ones in. It almost seems that the rotor winding was put in place after the weight pins were driven in. If that's the case, it may be something which will require a lot of $ at a specialist motor shop. Nice! This one spins up so fast. I don't think I've heard a repulsion start motor this small before.
It does spin up fast! I've only got one repulsion start motor of my own. It's a huge 2 HP Century. It does take a lot longer to spin up, that's for sure! Once the compressor is connected it should take a little longer to start. Also, the brush position can be changed to alter the startup torque. Since this is more or less a show piece; we may adjust it so that it has a little longer and more "industrial" sound to it! 
This brings to mind my favorite electric motor startup of all time:
www.youtube.com/watch?v=fNuI6keQXYA
That motor was built when an operator really had to "operate" the machine, not just push buttons!
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Post by Travis on Oct 25, 2018 15:12:23 GMT
David,
I thought the 33 Frigidaire had the newer style motor. I could be mistaken. I have another source for motors if the need arises.
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Post by turbokinetic on Oct 25, 2018 15:16:42 GMT
David, I thought the 33 Frigidaire had the newer style motor. I could be mistaken. I have another source for motors if the need arises. I'm reasonably sure the 33 has the same 1/5 HP motor. If it is indeed newer it could have the steel weights. I will try to find out today. I want to get the "opened system" cleaned out and stabilized from SO2 corrosion before I go out of town again. The 1933 is still sealed up so I don't want to disturb it until I know that time is available to complete the repairs at one go. Hopefully I can see the front of the motor. |
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Post by Travis on Oct 25, 2018 15:54:47 GMT
I think we're going to find that the first type of RI motors used pot metal weights and the newer used steel. I suspect that the unit David got from me would have had the first type of RI motor originally.
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Post by turbokinetic on Oct 25, 2018 16:14:59 GMT
I think we're going to find that the first type of RI motors used pot metal weights and the newer used steel. I suspect that the unit David got from me would have had the first type of RI motor originally.
Definitely. It probably flew apart decades ago and the modern capacitor start motor was a replacement. While it is rock-solid reliable (especially with the PTC start relay) it is lacking the vintage "bling" of a large copper commutator, the brush noise at startup, and the faint whiff of ozone each time it starts!
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Post by turbokinetic on Oct 26, 2018 4:18:48 GMT
So, made a little progress on this today.
Got the compressor skid ready for washing tomorrow. It was raining and lightning today and I didn't want to get zotted out in the yard in an electrical storm! .JPG)
Then cleaned up the control parts and refurbished some of the "decorative" items. .JPG)
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Post by turbokinetic on Oct 27, 2018 3:36:18 GMT
In the interest of not letting SO2 sit in the parts mixed with air, and corrode them - I proceeded to tear down the compressor, and investigate what will be necessary to install a new seal.
After washing, it went on the bench... .JPG)
A little cleaner than it was last time a picture was taken. .JPG)
Off with its head! A lot of carbon in there... and SO2 PHWEW it stinks!
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So crudded up!
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Yowsers.... and it smells as bad as it looks, I have to add.
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The remains of the shaft seal were equally horrendous.
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Thankully, the piston is just fine!
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The parts laid out. Eccentric, shaft, strap, and piston
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The compressor was very low on oil. The shaft seal obviously burned out from lack of oil.
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This is a scrap seal from a current model GM car A/C compressor. I'm using it for a test fit and will install a new one once the details are sorted out.
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.The polished metal ring is what I made to adapt the Delphi seal to the Frigidaire compressor. It clamps in between the 4-bolt flange and the compressor body. It hahs an o-ring groove to compress an o-ring against the new seal.
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Parts stack-up.
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Seal on the shaft with o-ring around it.
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Completed test-assembly.
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This is the new seal which will be installed.
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So, I will need to remove the broken bolts from the compressor crankcase. Two were already broken, and one broke when I started taking it apart. Apparently they were brittle. Will replace all of the crankcase bolts as a precaution since these seem to have some material flaw.
Also, the shaft is already exactly the same size as the Delphi compressor shaft for which the new seal is designed. Because of this, I won't be able to "turn down" the shaft and get a fresh layer of metal as I did with the twin cylinder pump in my Frigidaire. This shaft will require a Speedi-Sleeve to be installed in the seal area. Will have to get that next time the stores are open. These are generally available, but sometimes they have to be ordered. That may put the project on hold for a few weeks.
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Post by elec573 on Oct 27, 2018 5:11:19 GMT
Can’t believe how nice that cabinet looks! I’m sure you we’ll get the refrigeration parts looking as nice. Nice work!
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Post by ckfan on Oct 27, 2018 12:26:25 GMT
It really amazes me how much carbon build up there is in there. Do you think that’s due to it being ran low on oil for a long while?
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Post by turbokinetic on Oct 27, 2018 13:43:14 GMT
Can’t believe how nice that cabinet looks! I’m sure you we’ll get the refrigeration parts looking as nice. Nice work! It is quite nice! Travis found it in this condition. All we did was carefully load it up and not ding or chip it during the process! It was definitely in "as-is, unbastardized" shape. When it stopped working (or started leaking SO2) they closed the compressor isolation valves and walked away from it. Nothing appeared to have been touched in decades. It really amazes me how much carbon build up there is in there. Do you think that’s due to it being ran low on oil for a long while? It is a lot of carbon! When I tore down my Frigidaire twin cylinder compressor, it had only light staining of carbon on the valves. That one had a lot of oil still in the system. It seems that the old oils in use at this time were not thermally stable; and especially not when mixed with SO2. The heat of compression would coke up the oil into the mess you see. It seems Frigidaire's design to combat this was to flush the valves with a high amount of oil to keep the carbon clear. The path of refrigerant goes from the suction valve, through the crankcase, up through the inlet reed in the piston, and then out the discharge valve. There's splash lubrication in the crankcase, so a lot of oil goes out with the gas. So, I have a feeling you're right in that low oil level reduced the flushing effect, and allowed the carbon buildup. There was just enough oil to coat the bearing journals, but not to splash up to the inside of the piston; and finally not enough to lubricate the shaft seal, which seized up and tore loose from its mounting. |
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