I thought I would share my work to date. I've taken lots of pictures to share with friends. Progress is on hold for now due to life intervening, but I will get back to it soon.
Dave
Dave
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According to solidworks the platter weights 38 lbs. The platter is Delrin and the weights are class 1 brass weights I saved from the recycling bin.
I decided to add some magnets to attempt some mag lev. If not to hold the entire mass, at least to reduce wear on the thrust bearing. That is the next step.
Dave
I decided to add some magnets to attempt some mag lev. If not to hold the entire mass, at least to reduce wear on the thrust bearing. That is the next step.
Dave
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At this point, I don't have plans to balance it. I did all of the turning in one setup, so I know that all the dimensions from the press fit of the bearing out at true. I centered the platter on the rotary table and from there milled all 24 weights. From my runout measurements, this thing is dead on. The only question now would be how consistent is the density of the plastic. At this point to balance it would mean making a fixture, removing the bearing and pressing in the fixture to verify the balance. I'm not sure it is worth it.
It looks like that Clausing is almost big enough for this project...😀
I used to own a Teres. It started out as a 135 all acrylic. Then I put the lead shot loaded platter (upgrade exchange program) on it. That was a pretty big upgrade over the standard weight platter.
As for balance, I think all Chris and his brother did was to verify the weight of shot put in each milled pocket of their platters. The precision of the machining operations was enough to otherwise guarantee good balance to the rotating mass of the platter.
What do you plan on using for a drive motor? DC with vhs tape belt, or perhaps silk cord. Or perhaps the Verus Wheel drive?
Btw, I've used the Verus for a time and wrote a review of it here:
Verus Motor Upgrade
Please keep us posted. This should be fun.
-Steve
I used to own a Teres. It started out as a 135 all acrylic. Then I put the lead shot loaded platter (upgrade exchange program) on it. That was a pretty big upgrade over the standard weight platter.
As for balance, I think all Chris and his brother did was to verify the weight of shot put in each milled pocket of their platters. The precision of the machining operations was enough to otherwise guarantee good balance to the rotating mass of the platter.
What do you plan on using for a drive motor? DC with vhs tape belt, or perhaps silk cord. Or perhaps the Verus Wheel drive?
Btw, I've used the Verus for a time and wrote a review of it here:
Verus Motor Upgrade
Please keep us posted. This should be fun.
-Steve
I have a maxon motor with a mark kelly motor controller. It will run off a massively over sized battery salvaged from another work scrap salvage. I am thinking thread, but I have a pulley for tape as well.
For a tonearm I have a nottingham space arm. I picked it up for real cheap a few years back. I'd like to do a linear air bearing arm at some point, but I think will be the second arm on this table. 😎
For a tonearm I have a nottingham space arm. I picked it up for real cheap a few years back. I'd like to do a linear air bearing arm at some point, but I think will be the second arm on this table. 😎
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Mine had the A-Max 110189. I had several upgrades of the controller. Which was of the original Manfred design. This controller, while providing a rather neat on/off feature was probably the weakness and cause for the laid-back sound qualities of the deck. I presume the Mark Kelley controller should impart a very different character. The motor itself has power. I think I once figured that at 33-1/3rd platter rpm, my motor was outputting 8watts.
Please note that the reason I call my old Teres "laid back" is because when I got a TD124, I discovered what the opposite of laid back is.😉
Another thing I learned about the A-Max. It requires periodic oiling. If not, the motor starves for lube. Not good. Figure once a year, re-oil its bushings.
-Steve
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Good to know. Thanks for the tip on maintenance. I'm sure there are plenty of others who could use the same tip.
Theoreticaly you are right about balance, this is not a casting but solid material.
I would still check it though.
You can do a quick and dirty balance by placing 3 springs under a test plinth with your bearing bolted to it.
Start moving the 3 springs (Y arangement) equally closer and closer increasing sensitivity, toward the center bearing and simply watching the outer rim spining the platter by hand.
I did this on a 1" acrylic with lead rimed grove and had to adjust accordingly.
The sonic difference was incredible before and after!
This simple technique will eliminate any assumptions
Looking forward to your completed design!
Regards
David
I would still check it though.
You can do a quick and dirty balance by placing 3 springs under a test plinth with your bearing bolted to it.
Start moving the 3 springs (Y arangement) equally closer and closer increasing sensitivity, toward the center bearing and simply watching the outer rim spining the platter by hand.
I did this on a 1" acrylic with lead rimed grove and had to adjust accordingly.
The sonic difference was incredible before and after!
This simple technique will eliminate any assumptions
Looking forward to your completed design!
Regards
David
THANK YOU STEVE!!!
I have the Maxon A-Max motor with Mark Kelly's motor controller and your tip has really helped!
Cheers
Frank M
I have the Maxon A-Max motor with Mark Kelly's motor controller and your tip has really helped!
Cheers
Frank M
Except the assumptions that you springs have identical perfection linear deflection for any given load....
IMO the spring technique should work well. It will either vibrate or it won't. Even if the k of the springs is different you'll know when good balance is achieved. I was thinking it could also be done static, doing up some fixture like a bubble tire balance machine. You just have to get the cg in the right place to have sensitivity.
Hi Steve, you mention re -oiling for maxon motor. My turntable maxon motor has been running for a few years now without re-lubbing. Do you mean re-grease of the bushings?.
Mine had the A-Max 110189. I had several upgrades of the controller. Which was of the original Manfred design. This controller, while providing a rather neat on/off feature was probably the weakness and cause for the laid-back sound qualities of the deck. I presume the Mark Kelley controller should impart a very different character. The motor itself has power. I think I once figured that at 33-1/3rd platter rpm, my motor was outputting 8watts.
Please note that the reason I call my old Teres "laid back" is because when I got a TD124, I discovered what the opposite of laid back is.😉
Another thing I learned about the A-Max. It requires periodic oiling. If not, the motor starves for lube. Not good. Figure once a year, re-oil its bushings.
-Steve
Quan
Yes bushings. See item 13 in the illustration: But not grease. Oil. Electric motor oil. approximately 20 wt.
-Steve
Thank you Steve, pardon me i can't see any recess for oiling. Do you just use a small pipet to drop the oil in? And how much roughly. I tried to open my motor last night but really stuff up those small screws badly.Huh.
Quan
Quan
There is only access to one of the bushings. The one at the pulley end. This is oiled by dripping onto the shaft and allowing gravity to pull the lube in. I've no idea how to get oil the the other end without a complete motor disassembly.
I do know that the upper bushing can go dry. It has on me, anyway. And when I lubed the one bushing, the motor began operating normally again.
-Steve
Thank you Steve the picture posted got me confused as it showed the other end of the motor😀.
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Yes. This photo shows the commutator and brushes. The grease is for the precious metal brushes. Platinum, I believe.
In order to gain access to the bushing and shaft just below, the motor must be further dismembered. I never bothered. Instead, I got into TD124's. Those are more maintenance friendly.
-Steve
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