Pulley Dimensions
Hi Vinyl-Addict,
I recommend the following pulley dimenisions. Use 11 mm for the pulley diameter; and 2 different crown heights: 6 mm (for turntables that have a pulley mounted close to the plinth) and 14 mm (for those turntables that require some clearance to the plinth - notably Linn).
These recommendations mirror the Orinin Live Brochure titled "Upgrade Power Supplies" - page 4 of 8. My assumption is that their market research has suggested that these pulley dimensions will meet the needs of the larger market for power supplies and controllers.
For what its worth, my custom turntable has a sub-platter where a large pulley like the one in your photo would not fit. It would contact the bottom and rim of the platter, because the platter rests over the sub-platter.
Hi Vinyl-Addict,
I recommend the following pulley dimenisions. Use 11 mm for the pulley diameter; and 2 different crown heights: 6 mm (for turntables that have a pulley mounted close to the plinth) and 14 mm (for those turntables that require some clearance to the plinth - notably Linn).
These recommendations mirror the Orinin Live Brochure titled "Upgrade Power Supplies" - page 4 of 8. My assumption is that their market research has suggested that these pulley dimensions will meet the needs of the larger market for power supplies and controllers.
For what its worth, my custom turntable has a sub-platter where a large pulley like the one in your photo would not fit. It would contact the bottom and rim of the platter, because the platter rests over the sub-platter.
Re: Pulley Dimensions
For the 110191 motor with the 12V controller the pulley to platter step up ratio MUST NOT be greater than 24 : 1 if you wish to include 45rpm. The controller was not designed to run this motor at speeds greater than 1000 rpm - it can be made to do so but that requires changes to the circuit and the power supply which preclude battery power. It is easier to use a lower volage motor such as the 110189.
Your 11mm pulley will give a max platter diameter of 264mm at 24 : 1 - OK for subplatter drive but no good for platter drive. If you wish to use a pulley of this diameter buy the 110189 motor rather than the 110191.
In addition, the speed variation due to belt creep gets worse as the pulley diameter is reduced - ceteris paribus the belt creep increases with the step up ratio.
The step up ratio should probably not be less than 12 : 1, if you want to use a low ratio use the 226764 motor.
JRags said:
For the 110191 motor with the 12V controller the pulley to platter step up ratio MUST NOT be greater than 24 : 1 if you wish to include 45rpm. The controller was not designed to run this motor at speeds greater than 1000 rpm - it can be made to do so but that requires changes to the circuit and the power supply which preclude battery power. It is easier to use a lower volage motor such as the 110189.
Your 11mm pulley will give a max platter diameter of 264mm at 24 : 1 - OK for subplatter drive but no good for platter drive. If you wish to use a pulley of this diameter buy the 110189 motor rather than the 110191.
In addition, the speed variation due to belt creep gets worse as the pulley diameter is reduced - ceteris paribus the belt creep increases with the step up ratio.
The step up ratio should probably not be less than 12 : 1, if you want to use a low ratio use the 226764 motor.
Payment alternatives?...
If there is any other way one could pay for the items, I would really like to know of it. The good guys at Paypal have kindly but firmly said "NO" to my custom (see exerpt from their reply below)
...We sincerely appreciate your interest in becoming a PayPal member.
Unfortunately, we are not yet providing services for the country or region
in question. Establishing our service in each new country or region
involves complex changes due to different regulations. We hope to be
expanding our availability, however, due to the complexities of global
expansion, we cannot give a timeframe for this. We are working hard and
look forward to expanding our services to additional countries and regions
in the future....
If there is any other way one could pay for the items, I would really like to know of it. The good guys at Paypal have kindly but firmly said "NO" to my custom (see exerpt from their reply below)
...We sincerely appreciate your interest in becoming a PayPal member.
Unfortunately, we are not yet providing services for the country or region
in question. Establishing our service in each new country or region
involves complex changes due to different regulations. We hope to be
expanding our availability, however, due to the complexities of global
expansion, we cannot give a timeframe for this. We are working hard and
look forward to expanding our services to additional countries and regions
in the future....
Re: Payment alternatives?...
You can always do a bank transfer to my account for the motor ( did you want a motor ? ) but the fee will probably be around $50, is in Norway anyways.
Are you mobile in Nairobi ? I might have a personal contact for you, to save you the fees. I'll check if its possible from my side.
GAgola said:
You can always do a bank transfer to my account for the motor ( did you want a motor ? ) but the fee will probably be around $50, is in Norway anyways.
Are you mobile in Nairobi ? I might have a personal contact for you, to save you the fees. I'll check if its possible from my side.
Could I order 1 motor & 1 pulley please? Its (they) are for LP12-should the pulley dimensions come into question.
Regarding concentricity problem- the best way around this issue it to ream/grind the pulleys bore to close tolerances/high finish (important) - at this point concentricity is a secondary issue. Then mount the machined pulley on a, very tight tolerance mandrel. Place the said mandrel between centres, clock the mandrel up, and then machine the pulley off the mandrel. However, maybe the cost of the mandrel is to a limiting factor.
Regarding concentricity problem- the best way around this issue it to ream/grind the pulleys bore to close tolerances/high finish (important) - at this point concentricity is a secondary issue. Then mount the machined pulley on a, very tight tolerance mandrel. Place the said mandrel between centres, clock the mandrel up, and then machine the pulley off the mandrel. However, maybe the cost of the mandrel is to a limiting factor.
Just a general warning
Guys...(and girls if there are)
It is better not publish your paypal address (or email address) anywhere on the internet.
if you have to do it like this..
john dot doe -at- domain dot com
There are robots on the internet that filter pages on the internet and send stuff that look like email addresses to their evil masters.
Thought I'd post this because I just got a mail from someone in this groupbuy who received a phising email
http://en.wikipedia.org/wiki/Phising
Guys...(and girls if there are)
It is better not publish your paypal address (or email address) anywhere on the internet.
if you have to do it like this..
john dot doe -at- domain dot com
There are robots on the internet that filter pages on the internet and send stuff that look like email addresses to their evil masters.
Thought I'd post this because I just got a mail from someone in this groupbuy who received a phising email
http://en.wikipedia.org/wiki/Phising
Hi John, great process if you're machining something with a larger bore but not necessary for this pulley. We used expanding mandrels everyday when I worked on the Alaskan pipeline pump project back in the 1970's.john2 said:
I have no problem with concentricity requirements using standard fundamental machining techniques. I think the problem a lot of garage machininsts run into is in thinking that simply reaming a close tolerance hole controls concentricity as well, not so.
For anyone wishing to build their own pulley for the Maxon motor discussed for this project, visit Maxon's website. They have documented all dimensions and tolerances there.
Pulley GroupBuy
Are we still moving toward a groupbuy on a pulley? Earlier, I had suggested 11 mm which is what Origin Live is using on their motors. Mark's well reasoned reply indicates this size is too small for platter driven turntables using the 110191 motor.
A few threads back someone suggested a range of 15-20 mm, with 17 mm maybe best. Either will work for me as long as the crown is not to high or too much wider. My subplatter is 208 mm. So 17 mm gives 407.8 rpm at 33 and 550.6 rpm at 45.
Is there any consensus on a course of action?
Are we still moving toward a groupbuy on a pulley? Earlier, I had suggested 11 mm which is what Origin Live is using on their motors. Mark's well reasoned reply indicates this size is too small for platter driven turntables using the 110191 motor.
A few threads back someone suggested a range of 15-20 mm, with 17 mm maybe best. Either will work for me as long as the crown is not to high or too much wider. My subplatter is 208 mm. So 17 mm gives 407.8 rpm at 33 and 550.6 rpm at 45.
Is there any consensus on a course of action?
Re: Pulley GroupBuy
I mentioned to Mark that I would be willing to make the pulleys but I think we are looking at a few issues here.
#1- There have been a few opinions on what size their specific pulley should be. Is it possible for everyone to agree on a "one size fits all" approach? Probably not since different platter diameters will mean different pulley diameters.
#2- What profile will the pulley be? Crowned, flat, tapered?
Any preference?
#3- What type of mounting scheme do you want to use? The pulley design can vary depending on this variable. I used a 1/4" thick mounting plate FWIW.
The group needs to figure out and agree on these 3 issues in order to proceed. It's possible to build "one offs" for everyone but the cost goes way up if that happens. I'm sure you can find someone willing to do the job for the group if you can solve these issues but it will be harder and more expensive to find a shop to machine several different designs.
JRags said:
I mentioned to Mark that I would be willing to make the pulleys but I think we are looking at a few issues here.
#1- There have been a few opinions on what size their specific pulley should be. Is it possible for everyone to agree on a "one size fits all" approach? Probably not since different platter diameters will mean different pulley diameters.
#2- What profile will the pulley be? Crowned, flat, tapered?
Any preference?
#3- What type of mounting scheme do you want to use? The pulley design can vary depending on this variable. I used a 1/4" thick mounting plate FWIW.
The group needs to figure out and agree on these 3 issues in order to proceed. It's possible to build "one offs" for everyone but the cost goes way up if that happens. I'm sure you can find someone willing to do the job for the group if you can solve these issues but it will be harder and more expensive to find a shop to machine several different designs.
Pulley GroupBuy
I vote one size fits all. We then can see how many members will sign up for the pulley. This was essentially the approach that was taken on the motor.
I suggest we go with a bronze, crowned pulley with a diameter Vinyl-Addict and Mark agree on. The quarter mounting plate could be optional but the pulley design would accommodate it. Then see how many members sign-up. If the number is sufficient to make it worthwhile for Vinyl-Addict, or some other machinist someone knows, then its a go. If not then we are on our own.
My two cents.
I vote one size fits all. We then can see how many members will sign up for the pulley. This was essentially the approach that was taken on the motor.
I suggest we go with a bronze, crowned pulley with a diameter Vinyl-Addict and Mark agree on. The quarter mounting plate could be optional but the pulley design would accommodate it. Then see how many members sign-up. If the number is sufficient to make it worthwhile for Vinyl-Addict, or some other machinist someone knows, then its a go. If not then we are on our own.
My two cents.
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