Does any one know how to mod SL1210 for high torque??
I have serched everywhere and cannot find the mod I can only find a place in america who can do it But the shipping from england to there and back is more than a brand new motor for me presto 8N. Does any one know how to mod the SL1210 drive circuit befor I blow it up??
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Re: Does any one know how to mod SL1210 for high torque??
Hi There amp docAmp Doc wrote:I have serched everywhere and cannot find the mod I can only find a place in america who can do it But the shipping from england to there and back is more than a brand new motor for me presto 8N. Does any one know how to mod the SL1210 drive circuit befor I blow it up??
I am not familiar with the motor on this lathe But have a view that may be ok
What would be wrong with a speed control out of variable speed drill They seem to maintain torque on motors from very low to full revs
I would assume that if the motor is a 4 pole it spins at 1440 RPM at 50 HZ If you are to use a speed control turn it until the you get the right speed The strobe should indicate the correct revolutions any way but you may get the torque out of the device when the table is loaded up since it would want to maintain speed It is worth some consideration I would have thought Here is a link to a chip with application notes that you may have a look at http://www.datasheet4u.com/html/U/2/0/U208B_TEMICSemiconductors.pdf.html
If you think that it may do the trick here is another link that gives a circuit board layout for that very chip which is a u208b made by Telefunken
http://www.spelektroniikka.fi/kuvat/triacd.pdf May be this is of some value to you
Cheers
Chris
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cuttercollector
- Posts: 431
- Joined: Sun Jun 11, 2006 4:49 pm
- Location: San Jose, CA
Hello, I freely admit I am stepping into an area I know nothing about here, but here I go anyway.
First, is it even possible?
Why would Technics limit the torque back from what the motor could produce?
What I am asking is is the torque just inherent in the size of the motor?
This is a direct drive table in the family of the 1200 series yes?
So it is a multi pole direct drive servo motor that runs at platter speed. Right?
I believe that the previous post for drill speed control devices is not applicable to this style of motor. The old ones pulsed the duty cycle of the AC line voltage rather like a light dimmer and were applicable to AC brush motors of plug in drills. The ones in DC battery drills, I think also pulse the waveform or duty cycle to control a servo function with feedback from the motor. It is true that that gives maximum torque at any given rpm, but does not provide speed stability.
I would guess what you are fighting using this turntable for a lathe cutting application is that it mometairily looses speed stability or becomes somewhat "jerky" in it's speed under cuttting conditions thus wrecking the cut. If it is "almost there" what about something to make the platter heavier for more flywheel effect and stability?
Hmm, also what about just setting it up so it is running on slightly higher voltage than rated? Won't change the speed - that tries to maitain lock as best it can, but it would give it more power. Perhaps the actual motor voltage in is highly regulated anyway. It also might cause more heat and you could potentially shorten the life, but I still think the key is in the motor somehow developing more power.
Forgive me if I have missed the point entirely here.
First, is it even possible?
Why would Technics limit the torque back from what the motor could produce?
What I am asking is is the torque just inherent in the size of the motor?
This is a direct drive table in the family of the 1200 series yes?
So it is a multi pole direct drive servo motor that runs at platter speed. Right?
I believe that the previous post for drill speed control devices is not applicable to this style of motor. The old ones pulsed the duty cycle of the AC line voltage rather like a light dimmer and were applicable to AC brush motors of plug in drills. The ones in DC battery drills, I think also pulse the waveform or duty cycle to control a servo function with feedback from the motor. It is true that that gives maximum torque at any given rpm, but does not provide speed stability.
I would guess what you are fighting using this turntable for a lathe cutting application is that it mometairily looses speed stability or becomes somewhat "jerky" in it's speed under cuttting conditions thus wrecking the cut. If it is "almost there" what about something to make the platter heavier for more flywheel effect and stability?
Hmm, also what about just setting it up so it is running on slightly higher voltage than rated? Won't change the speed - that tries to maitain lock as best it can, but it would give it more power. Perhaps the actual motor voltage in is highly regulated anyway. It also might cause more heat and you could potentially shorten the life, but I still think the key is in the motor somehow developing more power.
Forgive me if I have missed the point entirely here.
The old 1950 110v motor run but its noisy.I also use I 240/110v transformer big heavy thing. I could just change motor but the rubber idler wheels are 33 1/3 and 78 and shrunk,hard. So talked to a friend who designs and builds custom factory machines got him to work out I a technics would have the torque to be stable he said "just about" and why not just use the motor setup and mod circuit to push abit more power thats why I could do with the mod planing to remove drive board and machining platter to mount to the heavy 8N platter should just fit nice Between base and platter also give 33 1/3 and 45 and digital stabilty without the transformer.Il let you know what happerns 
!Work or Bang Time!
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cuttercollector
- Posts: 431
- Joined: Sun Jun 11, 2006 4:49 pm
- Location: San Jose, CA
vinylium introduced the technics sp1200/1210 resistor modification when the kingston dubplate cutter came to the market 2001.
the main goal was to increase the stability of the phase regulator.
the phase regulator is not very strong in the original condition.
technics uses a current regulator for the main work and the phase regulator on top with much smaller regulation capabiltity.
it helps, especially for accetate. but it is not enough to cut into really hard stuff.
for that you need a hardware upgrade. which we started to develop but never finished...hehehe... sometimes maybe..
f.
the main goal was to increase the stability of the phase regulator.
the phase regulator is not very strong in the original condition.
technics uses a current regulator for the main work and the phase regulator on top with much smaller regulation capabiltity.
it helps, especially for accetate. but it is not enough to cut into really hard stuff.
for that you need a hardware upgrade. which we started to develop but never finished...hehehe... sometimes maybe..
f.
I have found a dc brushless motor at 50W and controler electronics to replace the original motor and idler wheels. Am going to mount in the same place as original to keep the apperence same. Thanks for the info motorino and flozki .you have helped me loads!!!! would not be possable without people like yourselves!!!! Thanks again 
!Work or Bang Time!