I finished up the new tape pulleys today each and everyone has been tested. Monday I will try a finish the string pulleys. These will not be anodized after I realized that all the pulleys I have that are good are not anodized. One fellow suggested that the process may have caused the problem since most likely the pulleys were strung on a copper wire through the center hole. According to him the process at first etches the aluminum slightly before it anodizes it. if the pulleys are supported by the said wire the etching and coating would be uneven due to the wire contact. This may have been the problem so I will not take that risk. Since the whole process was done on one operation it should have been fine and the present batch show the machining is good and everything runs true. New pulleys should be on their way this next week.
Greg Nuspel said:
excellent!
One question on the string pulleys... what diameter string to you feel will work best with the pulley design?
Greg Nuspel said:
Greg, It is very easy to mask the critical bore for the plater, that way there is no build up from anodizing. I do it all the time with the plater I use. He's anodized quite a few pulleys for me in the past and they work perfectly. The plater can also rack the pulley from any non critical area, you just have to tell them. If you don't tell them, they will choose the easiest method of racking them and sometimes it will cause a slight burr at the leading edge of a hole. Blind holes that are close tolerance should always be masked before anodizing. Thru holes are fine as far as consistent buildup, just for future reference. 😉
I really think the whole problem is that the young fellow who ran the parts changed one step on the process. He did as he was taught in school; drill, bore, ream. I had set it up for straight boring so my first set up parts were fine. If he had used a floating reamer holder for the reamer all would have been fine, but the shop had none. He thought he was improving the process since he had just come back from being trained this is the best way to achieve a proper bore size, unfortunately I was up at my desk programming a part in CAM when he did this. Problem is that the upper turret on the MacTurn was not running exactly true and with a small bore like this it does not take much to be off. It took him a while to admit he changed my program. So now he has learnt that school operates in a perfect world and we don't. It was good he told me finally what happened so I could straighten him out since the new machinist at that shop has very little more experience than the apprentice himself.
Greg Nuspel said:
Greg, That seems to be the norm these days, young guys starting out with no "real world" experience changing the process from what works to what "may work" without working knowledge. I'm glad you got to the bottom of it, sucks that you have to make them over but at least you know what went wrong.
Years ago I worked in a shop where I programmed multiple CNC machining centers for a variety of "personalities", needless to say, they liked to skip through the process as well. 🙁
Pulley ratio problem
Hi All,
Pleased to hear the pulley problem is resolved, mine had a wobble when trying it on a spare motor.
I have nearly finished the PCB build and was trying to work out what voltages i need to set, this is when i calculated the VPI platter has a diameter of 294mm; 294/17=17.29
how do i calculate rpm`s and voltages please?
Does this mean this controller is not suitable for this platter?
Could be a big problem for me, as no way of getting a Teres platter and bearing over in the UK?
Also i put the supplied 1k res in R24, is this needed for this motor?
Anyone have any ideas?
Many thanks
Webby
Hi All,
Pleased to hear the pulley problem is resolved, mine had a wobble when trying it on a spare motor.
I have nearly finished the PCB build and was trying to work out what voltages i need to set, this is when i calculated the VPI platter has a diameter of 294mm; 294/17=17.29
how do i calculate rpm`s and voltages please?
Does this mean this controller is not suitable for this platter?
Could be a big problem for me, as no way of getting a Teres platter and bearing over in the UK?
Also i put the supplied 1k res in R24, is this needed for this motor?
Anyone have any ideas?
Many thanks
Webby
Our mill here likes to do what we call crop circles. You have to watch it the first time through any program with your hand on the stop button. If it is supposed to do a 90 deg right turn it likes to turn left 270 deg. Ah the joys of technology, youth and ignorance.
PC Boards
Hi All,
I was watching the old thread (Mark Kelly) to try to find a PC controller board and then found this thread...late again. Does anyone have the old PC board, or one of the new ones? I have not purchased parts, so either will do (I already have a motor and pulley). Thanks. Jeff
Hi All,
I was watching the old thread (Mark Kelly) to try to find a PC controller board and then found this thread...late again. Does anyone have the old PC board, or one of the new ones? I have not purchased parts, so either will do (I already have a motor and pulley). Thanks. Jeff
Pulley ratio problem
I also have a VPI platter and the motor & controller combination in this GB work fine. As a starting point just used the dip switch settings listedin the documentation bundle, and yes I believe the resistor is required with the Maxon motor.
Paul
I also have a VPI platter and the motor & controller combination in this GB work fine. As a starting point just used the dip switch settings listedin the documentation bundle, and yes I believe the resistor is required with the Maxon motor.
Paul
Re: Pulley ratio problem
As far as I know Algar hasn't changed the basic design so the same calculation applies for speed setting. For accuracy you need to specify your belt thickness, assuming it is about 0.5mm then the speeds you require are 294.5 / 17.5 x 33.3 / 45 which is 561 / 757 RPM. Now divide these by the speed constant of the motor (121 RPM / volt) to get 4.64 / 6.26 volts.
I have an exel file which calculates dipswitch settings, I don't know if I can post it here. I'll run through the arithmetic if you like but it's a bit tedious. I calculate 01001010 / 01101100 for the speeds above.
The resistor across the motor windings improves the linearity of the current compensation circuit. Leave it in unless you have a specific reason to take it out.
webby said:
As far as I know Algar hasn't changed the basic design so the same calculation applies for speed setting. For accuracy you need to specify your belt thickness, assuming it is about 0.5mm then the speeds you require are 294.5 / 17.5 x 33.3 / 45 which is 561 / 757 RPM. Now divide these by the speed constant of the motor (121 RPM / volt) to get 4.64 / 6.26 volts.
I have an exel file which calculates dipswitch settings, I don't know if I can post it here. I'll run through the arithmetic if you like but it's a bit tedious. I calculate 01001010 / 01101100 for the speeds above.
The resistor across the motor windings improves the linearity of the current compensation circuit. Leave it in unless you have a specific reason to take it out.
Big Thanks to you
Thanks so much for the info, i will get on it today!
Just one last question please
do i still connect the motor in reverse polarity to X3 with the combined PCB?
Many Thanks and a big phew!
webby
Thanks so much for the info, i will get on it today!
Just one last question please
do i still connect the motor in reverse polarity to X3 with the combined PCB?
Many Thanks and a big phew!
webby
Was wondering what voltage battery are you using, I have trawled the posts but can't find a definitive answer. Is a 12v sla sufficient. Sorry if this is a dumb question, I just want to be sure. Another dumb one, but what are the spindle to tonearm base measurements for a standard 9" arm?
The combined PCB is not my design, so perhaps Algar_emi will chime in.
The motor connection should be pretty obvious - it will run backwards if the polarity is reversed.
The motor connection should be pretty obvious - it will run backwards if the polarity is reversed.
Connecting the battery
I've built mine and it's running fine (did my best to get the pulley aligned), but I did notice some speed instability that other builders may be interested in.
I had some boxes lying around so I thought I would use those, and to fit everything in I put the controller in one box then the transformer and batteries (or two batteries so they would fit better) in another box. To connect the transformer/batteries to the controller I used about 1m of Cat 5 solid core cable (which I also had lying about), using one pair for each connection.
Unfortunately it would seem the Cat 5 cable was not up to the task, and after replacing it with a more substantial cable all is well. Which has me thinking that Cat 5 may not be the best choice for connecting the motor either, although in this case there are 2 pairs for each connection.
Moral of the story "For anything that is carrying current use decent cable".
lastly when using a VPI platter I used the following dip switch settings, 33.3 RPM 11000101 and 45 RPM 00110001. I came to these settings using a very unscientific method, that is use those listed in the document bundle and see if the pots will do the rest (but note I am using the VPI rubber belt at the moment).
I will try Marks more scientific approach when I move to silk thread (harder to get than I first thought).
I've built mine and it's running fine (did my best to get the pulley aligned), but I did notice some speed instability that other builders may be interested in.
I had some boxes lying around so I thought I would use those, and to fit everything in I put the controller in one box then the transformer and batteries (or two batteries so they would fit better) in another box. To connect the transformer/batteries to the controller I used about 1m of Cat 5 solid core cable (which I also had lying about), using one pair for each connection.
Unfortunately it would seem the Cat 5 cable was not up to the task, and after replacing it with a more substantial cable all is well. Which has me thinking that Cat 5 may not be the best choice for connecting the motor either, although in this case there are 2 pairs for each connection.
Moral of the story "For anything that is carrying current use decent cable".
lastly when using a VPI platter I used the following dip switch settings, 33.3 RPM 11000101 and 45 RPM 00110001. I came to these settings using a very unscientific method, that is use those listed in the document bundle and see if the pots will do the rest (but note I am using the VPI rubber belt at the moment).
I will try Marks more scientific approach when I move to silk thread (harder to get than I first thought).
paudux:
I just bought a large roll of surgical silk that I plan to use. I have been thinking about selling off some of it, as like you said it was harder to find than I expected (and more expensive). If you're interested, just let me know 🙂
I just bought a large roll of surgical silk that I plan to use. I have been thinking about selling off some of it, as like you said it was harder to find than I expected (and more expensive). If you're interested, just let me know 🙂
Silk thread
I must admit I never thought of surgical silk, however I did find a shop with some machine silk in a lovely blue colour.
I looked through shelves and shelves of cotton and all types of synthentic thread in both sewing and craft shops, but in the end a lady from work pointed me to a small embroidery shop.
Cheers
I must admit I never thought of surgical silk, however I did find a shop with some machine silk in a lovely blue colour.
I looked through shelves and shelves of cotton and all types of synthentic thread in both sewing and craft shops, but in the end a lady from work pointed me to a small embroidery shop.
Cheers
Maxon Motor in an Oracle MK 3
I have been reading this thread with great interest and I'm hoping that someone in this group might be able to help me. The motor (DC) in my Oracle MK 3 is starting to fail and a direct replacement, to my knowledge, cannot be had. Oracle Inc. no longers supplies them. My question is, could the Maxon motor discussed in this thread be adapted for use in my Oracle? The motor pod is quite large, so I don't think that there would be any physical restrictions. It already has the Oracle DC motor controller.
If anyone could recommend a course of action to retro fit a Maxon motor to my Oracle, I would greatly appreciate it. I would imagine there are a number of Oracle owners who could benefit from an upgrade/repair such as this.
TIA,
Mark
I have been reading this thread with great interest and I'm hoping that someone in this group might be able to help me. The motor (DC) in my Oracle MK 3 is starting to fail and a direct replacement, to my knowledge, cannot be had. Oracle Inc. no longers supplies them. My question is, could the Maxon motor discussed in this thread be adapted for use in my Oracle? The motor pod is quite large, so I don't think that there would be any physical restrictions. It already has the Oracle DC motor controller.
If anyone could recommend a course of action to retro fit a Maxon motor to my Oracle, I would greatly appreciate it. I would imagine there are a number of Oracle owners who could benefit from an upgrade/repair such as this.
TIA,
Mark
Do you know the operating parameters of the Oracle motor and its controller? Without a detailed spec we're flying blind.
As a last resort: when the Oracle fails, send the controller and the old motor (including pulley) to me. I'll fix it and return it to you. I will charge you only for parts used and shipping, my labour is free as I'm learning.
I will then publish the details for the conversion on this site so other Oracle owners benefit.
As a last resort: when the Oracle fails, send the controller and the old motor (including pulley) to me. I'll fix it and return it to you. I will charge you only for parts used and shipping, my labour is free as I'm learning.
I will then publish the details for the conversion on this site so other Oracle owners benefit.
Hi. Being away from this GB for some time, really busy at work including a major re-organization, mortality in the family, life going on...
A few answers:
-Yes Mark, I didn't changed your original design, since it was working fine and also since some members wanted your original design, some other wanted my own version with the integrated charger and both small PCB combined. So, my own final version combined everything in just one PCB. Hence, your calculations still applied.
-The Yel and Red leds are very dim most of the time. Don't forget they are analog charge indicators, which mean they are not simply On/Off indicators, but vary in intensity with the battery charge level. The Red led will only be On really strong, if the battery is completely discharged. The rest of the time the Yel (Trickle Charge) will be bright for a short time, then dim again. The threshold levels are into the documentation.
-D56. Yes luvdunhill you're right. The schematic, version 2.0 is incorrect, D56 is a 1N4741A, not 51A. The correct part was included into the parts kit. The parts list and 11V voltage value are also correct. Thanks for pointing this error to me.
-Pulley installation and removal: The pulley mounting hole diameter is so tight compare to the motor shaft that you need to heat the pulley to install it. Once installed, it provides a perfect fit to the shaft. Hence in fact, it is better this way and not a problem.
Here an easy installation/removal procedure:
Really easy to do. Use an heatgun, then heat the pulley. Aluminum rate of thermal expansion is different than steel from the motor shaft. The pulley will expand, then will slide on the motor shaft really easily. Take care to heat only the pulley, not the motor top, that is made of plastic. Go by wave, oscillating the hot air from right to left.
It take about 5 min. to do. Take care not to burn yourself on the hot pulley in the process.
Use a piece of rag to touch the pulley. Heat the pulley again to remove it.
Thanks again Greg for all your hard work and greatly appreciated contribution.
A few answers:
-Yes Mark, I didn't changed your original design, since it was working fine and also since some members wanted your original design, some other wanted my own version with the integrated charger and both small PCB combined. So, my own final version combined everything in just one PCB. Hence, your calculations still applied.
-The Yel and Red leds are very dim most of the time. Don't forget they are analog charge indicators, which mean they are not simply On/Off indicators, but vary in intensity with the battery charge level. The Red led will only be On really strong, if the battery is completely discharged. The rest of the time the Yel (Trickle Charge) will be bright for a short time, then dim again. The threshold levels are into the documentation.
-D56. Yes luvdunhill you're right. The schematic, version 2.0 is incorrect, D56 is a 1N4741A, not 51A. The correct part was included into the parts kit. The parts list and 11V voltage value are also correct. Thanks for pointing this error to me.
-Pulley installation and removal: The pulley mounting hole diameter is so tight compare to the motor shaft that you need to heat the pulley to install it. Once installed, it provides a perfect fit to the shaft. Hence in fact, it is better this way and not a problem.
Here an easy installation/removal procedure:
Really easy to do. Use an heatgun, then heat the pulley. Aluminum rate of thermal expansion is different than steel from the motor shaft. The pulley will expand, then will slide on the motor shaft really easily. Take care to heat only the pulley, not the motor top, that is made of plastic. Go by wave, oscillating the hot air from right to left.
It take about 5 min. to do. Take care not to burn yourself on the hot pulley in the process.
Use a piece of rag to touch the pulley. Heat the pulley again to remove it.
Thanks again Greg for all your hard work and greatly appreciated contribution.