Best to check the speed with a cheap laserspeed meter with new bearings it will be arround the 1440-1450 rpm on 50 hz at first start up.
This speed will be changing a little bit by temp. with the laser you can check the motor first if it stays stable ,after mounting you can check it with belt and steppulley .
If it is not stable check the steppulley bearings ,these can give speed problems.
Concerning the new bearings it important to polish the shaft as good as possible, and good cleaning mosttimes there is some wear on it.
For check the runout time for the motor without belt must be more then 15 seconds and secure after adjustment the four mounting bolts well .
The motors get hot. Often about 70 C. If you get a piece of wood about 2 x 2 x 150 cm getly tap the rotating motor shaft when hot. Do it from all directions. This will help the alignment.
Phosphor bronze bearings are tidal. The heat causes oil to flow from the felt pads if fitted into the phosphor bronze sponge like structure. The phosphor bronze is formed in a mold then pressed. The mold is exact so as to fit correctly. The good news is even the cheapest are very good. This makes a joke of surface finishes on the shaft. Perception is it reduces noise. If it did the bearing would be too tight. Most likely it aids oil distributution and ensures someone checked for how round it is. 6 micron is OK.
Phosphor bronze bearings are tidal. The heat causes oil to flow from the felt pads if fitted into the phosphor bronze sponge like structure. The phosphor bronze is formed in a mold then pressed. The mold is exact so as to fit correctly. The good news is even the cheapest are very good. This makes a joke of surface finishes on the shaft. Perception is it reduces noise. If it did the bearing would be too tight. Most likely it aids oil distributution and ensures someone checked for how round it is. 6 micron is OK.
The E50 motor temp.is arround 45 degrees outside, my own experience tells me surface finish shaft is important for steady speed .Agree if there is noise the bearing is to tight .
You can always tell a true engineer, they talk in mm and inches at the same time . The reason is simple. When you order metal it often comes from Canada. A typical order is 2 x 1 x 1/4 " x 4M long ( Ideal L section for TO3 mounting if 70 mm long and TO3 at 45 deg offset. Use .7071 to get co-ordinates ). The 4M comes from it will fit in a Ford Transit. Most engineers are happier with 0.001" if from USA or UK. It also helps in other ways. 1 x 2 " will machine to 25 x 50 mm nicely and costs less usually. I think it also helps engineers to do this multi tasking/thinking. I am mostly happier with metric. However for houses I prefer feet. As much as it matters 1 sq metre is 10 sq feet. 8 feet as much as it matters is 2.5 metres. There is an urban myth about a crashed Mars lander where inches and mm got mixed up. I doubt it. That's the story they are telling.
The finish is a strange question. I have done much work on it including furrows like a ploughed field. The furrow is the very best! It seems what is most imprortant is how round. The oil is 90% what is happening as my best guess. The furrows hold it and insist it does it's job. Alas the gentleman in Bratislava who did that has vanished. Roman Drozda where are you? Funny thing is a friend introduced us. I was not to talk of the Check republic or assume Roman spoke English. On meeting Roman in better English than me said come look at the elctricity meters in my house. He got my number I think ? When my friend said " Roman I didn't know you spoke English " Roman said " You never asked "! Fuel injector engineer. I asked him for fuel injector style shafts. Roman did it his way. I was so upset. Took them to Oxford University sceince labs and was told I was an idiot. They were the work of a genius.
If you have a Variac you might get the motor to 60C. This usually is fine. 253V seems OK. The USA can be 130V ( 260 V ). Garrard built to 270V. By mistake a 301 was run at 470 V for 5 hours ( 236 V into 115V windings ). It was so hot as to be goodness knows what. After cooling down it was OK! Don't try it yourself.
For the E50 motor 253 volt is way to much speed goes up and beyond brake reg. 240 V and more in the UK can give problems too as I read on PinkFish .
For myself I use 200-210 volt supply voltage without compromising
drive .
I'm using approximately 110V - 112V and above that the brake action is too noisy. I've tried the 125 - 150V tap on 121V supply, but the table looses its soul.
The motor in the MKII currently takes longer than 15 seconds to coast down and is quiet, my problem with it is that it takes about 20 minutes to get up to stable speed from cold. (replaced motor bearings)
The motor in the older 124 also coasts down > 15 seconds and is quiet, running at the same 112V it takes less than 2 minutes to get up to stable speed from cold. (And much is closer to speed to start with - original motor bearings)
For those of us on 60Hz I guess the motor speed Volken referred to should be around 1728 - 1740 rpm.
The motor in the MKII currently takes longer than 15 seconds to coast down and is quiet, my problem with it is that it takes about 20 minutes to get up to stable speed from cold. (replaced motor bearings)
The motor in the older 124 also coasts down > 15 seconds and is quiet, running at the same 112V it takes less than 2 minutes to get up to stable speed from cold. (And much is closer to speed to start with - original motor bearings)
For those of us on 60Hz I guess the motor speed Volken referred to should be around 1728 - 1740 rpm.
15 seconds is ok , the new bearing must run free when you give it a spin with your hand on the shaft , no friction at all.
Sometimes its better to take the motor apart and clean the bearings , and check the shaft accurately on wear extra polishing
The first motors were I replaced the bearings had sometimes problems with the speed this was always a shaft /bearing and cleaning problem .
Kevinkr, I looked back, but couldn't find a post on your older motor (I'm sure it's there somewhere). To clarify, exactly what state is the older motor in? Running exactly as you got it or serviced in the same manner as the one with new bearings? The same lubricant? While the original bushings were retained, were any other moving parts in the motor replaced (the ball bearing/thrust pad)?
The "stable speed" you're referencing - under full load? If that's it, then every other part of the drive train would have to be suspect, correct? If other parts got new bushings, that could be significant. I say this because my one botched attempt to replace the idler wheel bushing resulted in it being far too tight and boy did that mess things up. In particular, gaining speed stability took a looong time!
The voltage I refered to was to heat the motor for aligning. I think 220V is likely to be best for TD124, Early 301's about 205 V if converted to oil in the bearings. Early 401's 245V, later 301 and 401 215 V.
From this comes the early 301 are best folklaw. The Japanese have 100 V. Thus an early 301 suits them best. 301 serial no > 60000 are better I find. 401 was a bit of a mistake at first. Garrard tried too hard to reduce rumble which made them sligtly under powered. These say 12 watts on the rating plate. Later 401's said 16 watts as the 301. These are the better ones. I never tried a 401 motor in a 301. It think it would be very good. The spring chassis is the same.
Interesting - so the idea is to get the motor hotter than normal operating temperature during the alignment process? Forgive me. I'm not an engineer so while I understand this would expand both the rotor and the bushings, I'm not clear on what exactly would be accomplished by doing so.
I do my final alignment with the motor installed in the table and fully warmed up.. I usually listen for the least amount of noise and try to minimize vibration. I have a mechanics stethoscope I use when I am really feeling motivated..
The motor is always noisier with a belt installed, and in fact excessive belt tension will result in a considerable increase in noise and pulls the motor hard against its mounts which also (and audibly through a stethoscope) increases noise transmitted into the chassis.
My personal feeling is that most current belts are too tight even allowing for stretch over first hours of use. The OEM belts (all probably well stretched if still good) fit less tightly. Nothing performs quite as well as a NOS belt IMLE.
The motor is always noisier with a belt installed, and in fact excessive belt tension will result in a considerable increase in noise and pulls the motor hard against its mounts which also (and audibly through a stethoscope) increases noise transmitted into the chassis.
My personal feeling is that most current belts are too tight even allowing for stretch over first hours of use. The OEM belts (all probably well stretched if still good) fit less tightly. Nothing performs quite as well as a NOS belt IMLE.
Oh no I have a 401 with the 12W motor..Have not got it running yet.
Me too. My 16 watt one lives in Germany now with ex Thorens lady Martina Shoener.
I will run mine at 250 V perhaps ? I can find a 16 watt coil at the workshop if I try. Martina rebuilds Jaguar engines, I trust her to pamper it. The sad thing for Thorens Germany is they have no idea what war work they did. Garrard is easy. Mostly anything including bits for bombers. Only 201's were made in small quanitiies during the war. 4500 ladies were found similar work. The 301 might have had a head start due to this. The 201 was the one in mind as no other production was running. The Churchill centreless grinder was government bought and forgotten. The Garrard spindles were detonator pins which Garrard had plenty of. The 401 shaft is shorter as the 9/32" centre spindle ( 7.1 mm as 7.14 is too tight ) is longer. This was so as to use the same material. The other explanation is the Churchill was specific to this length. If so Garrard possibly designed the pin to serve as a spindle after the war? My 501 spindle is 401/301 hybrid. After Roman Drozda dissapeared SME made them. They were the only ones we trusted. When asked what we wanted we said " as if for yourselves". That got the reply " that's clear ". I hope they don't mind me saying it, great people. Other engineers will never be told that they are not as good as 1955 engineering. SME know it and can still do it. Subtly the Garrard was in some ways better. Not ways that matter. SME fine machine and tumble. That is fine. 1900's RR were better. Only problem was no exact interchangable parts. All were hand lapped and fitted.
Getting the motor hot to set the bearings should be fine. If not something is slightly wrong.
Seems Churchill got a patent in 1931 on this machine.This is how it works
Churchill Center Less Grinding Machine
Center less grinding is a machining process that uses abrasive cutting to remove material from a workpiece. Center less grinding differs from centered grinding operations in that no spindle or fixture is used to locate and secure the workpiece; the workpiece is secured between two rotary grinding wheels, and the speed of their rotation relative to each other determines the rate at which material is removed from the workpiece. Center less grinding is typically used over more conventional grinding processes for operations where many parts must be processed in a short
time.
And here we see a simple version on it https://www.youtube.com/watch?v=3Foc0ia7-Tg
KEF ( name of thew grinder ) as in the speakers was the old name of a company bought by Raymond Cooke a Yorkshireman. The bank manager had never heard of Wharfedale speakers. In despiration Mr C said he had bought the old Kent Engineering Foundries site. The manager had heard of them. So KEF it was. Loricraft also. It was his wife's lace bobbin business. Terry got a cheque and paid it into the business.
Raymond Cooke left Wharfedale over the use of plastic. Mr Briggs prefered paper. Me also. Mr B took Mr C to the Quad ( ELS 57 ) room and said" We are all going to the workhouse if these suceed " . The point being plastic was not better than ESL. I paraphrase a little.
Raymond Cooke left Wharfedale over the use of plastic. Mr Briggs prefered paper. Me also. Mr B took Mr C to the Quad ( ELS 57 ) room and said" We are all going to the workhouse if these suceed " . The point being plastic was not better than ESL. I paraphrase a little.
And this spindle from SMD UK ?
Made in the UK this spindle is dimensionally an exact copy of the original Garrard 301 spindle. It is manufactured from a high carbon, high chromium tool steel grade offering very high wear resistance and toughness. After the spindle is CNC machined it is vacuum hardened to HRC 55 - 60.
Once hardened the spindle is precision ground to the original diameter a nominal 0.4825" +/- 0.0002" (12.255mm +/- 5 microns) that's an incredible tolerance to achieve (see below "Making Sense of Microns"). Finally the spindle is subject to ceramic polishing to give that polished look of the original.
Most of that is not very imporatant. The No 1 is 0.0001" of 90 degrees at the bottom ( 0.00254 mm ) . The surface finish was 6 micron and hardness 55 Rockwell C . The latter is poor by modern standards ( 64 is typical ) . 6 micron can be taken down to 1 micron. Not imporatant, but nice. Even how round is not very important as long as it is inside specs. The centreless grinder although a mass production tool is the right tool. It is possible if ground on centres to get it right. As we were advised for a Garrard spindle better do it the Garrard way. We offered a guy a big order for them at £18 a piece ( 1000 ). In the end he turned it down as he could no meet the spec. SME could at many times that price. Rega are less than £1 so they really know how to do it. The Rega is a good bearing albeit a bit small. If I remember it is made from an aircraft component ( SKF roller element ). Rega make the outer. That takes a week to set up the tooling. Once set thousands can be made and quickly. That is down to clearance and test to the end result. Having done the same things I am sure they were telling the story exactly as they do it. The tool is an adjustable reamer. It has two lock screws and a blade. The problem is getting it exactly right. Another way is to buy an oversized reamer and grind it. The critical thing is to know when to stop. The Rega bearing is made with a standard cheap drill. The errors are averaged out. The ball falls dead centre. The reamer removes typically 0.3 mm.
E50 Motor Bearing Red Alert
I decided today would be the day I would pull apart my TD-124 MKII and see if I could resolve some of the recent issues.
I got ambitious and pulled the motor, I am somewhat miffed to have to report that the motor bearings I installed 4 years ago are not what I thought they were. Be very careful purchasing parts on eBay, particularly ones sourced here in the USA. (Make sure to verify they are made of sintered bronze)
The bearings are also COMPLETELY dry, and study with a loupe is pretty conclusive that these bearings are not made of sintered bronze. Fortunately I kept the original bearings and have cleaned them, heated them to drive out the old oil and they are now sitting in a hot oil bath which is slowly cooling down. These bearings have virtually no wear since the table was not run for 40yrs and I doubt it saw more than 100 hrs of use with its original owner. (I am the second owner of this table)
This explains the massive difference in performance between this motor and the one in my other table where in a fit of cheapness I decided to keep the original bearings.
All I can say is that my knowledge has increased considerably since I got this table and I knew immediately looking at these motor bearings that they were not right.
Fortunately the motor shaft is OK, not a lot of evidence of wear.
I decided today would be the day I would pull apart my TD-124 MKII and see if I could resolve some of the recent issues.
I got ambitious and pulled the motor, I am somewhat miffed to have to report that the motor bearings I installed 4 years ago are not what I thought they were. Be very careful purchasing parts on eBay, particularly ones sourced here in the USA. (Make sure to verify they are made of sintered bronze)
The bearings are also COMPLETELY dry, and study with a loupe is pretty conclusive that these bearings are not made of sintered bronze. Fortunately I kept the original bearings and have cleaned them, heated them to drive out the old oil and they are now sitting in a hot oil bath which is slowly cooling down. These bearings have virtually no wear since the table was not run for 40yrs and I doubt it saw more than 100 hrs of use with its original owner. (I am the second owner of this table)
This explains the massive difference in performance between this motor and the one in my other table where in a fit of cheapness I decided to keep the original bearings.
All I can say is that my knowledge has increased considerably since I got this table and I knew immediately looking at these motor bearings that they were not right.
Fortunately the motor shaft is OK, not a lot of evidence of wear.
