It may well be PTFE is not suitable, in the next couple of days I'll run one up, I have 11 working SP-10's so no issue. In the meanwhile I trust PKI to do some research, in fact we may end up with a different material altogether ?
To my surprise the ball measures 7.147mm which is as near as 9/32" (7.14375) as we could get.
Dave
Visit from my son, deadline for an article, and (of course) the last weekend of the regular season for the NFL. Oh yeah, and four concerts in two weeks. I need rest. I'll get back to the SP10II project in two weeks or so.
In the meantime (and I'm an experimentalist, not a theoretician!), user501's choice of a filled Torlon looks like a really good idea. I would be leery of Teflon. I may have some tweaks on lubricants- Rocol has been an education for me!
Is that a tool to take the bearing cap off in the pic? Did you make it?
It may well be PTFE is not suitable, in the next couple of days I'll run one up, I have 11 working SP-10's so no issue. In the meanwhile I trust PKI to do some research, in fact we may end up with a different material altogether ?
To my surprise the ball measures 7.147mm which is as near as 9/32" (7.14375) as we could get.
Dave
Extremely well. It has some sensitivity to amine-based chemicals, but lubricating hydrocarbons are no issue even at high temperatures.
Yes it is ! A friend made it for me.
A question to PKI: I'm not fixated on PTFE but would like an expert opinion on the wear compared to Torlon ? If it's close I'll use PTFE as it is slipperier and potentially quieter?
Thanks
Dave
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Technics SP-10 Mk2A, a project by 6L6
Dave, from what I can see Torlon is superior in terms of mechanical qualities, however, PTFE has lower friction. What I was thinking and Google says it should be possible is to use synthetic Teflon plus graphite lubricants, so we can get the best of both worlds!
Again, I had no experience working with actual materials under real conditions, so I am just looking into all sorts of data sheets. Some additional practical knowledge can direct us a bit.
From what I can say looking into user510 experiments, there is no that much of a difference in sonic performance, I would be mostly focused on mechanical reliability.
Even if we look into friction data, the difference is in "dry numbers", if we add some lube things are leveling out.
Dave if you have a batch of these things produced already, use them. They should last for many years (there will be 3d printer using all sorts of plastic by that time.
P.s. I will keep looking... We should investigate all sorts of lubricants, I would say.
Dave, from what I can see Torlon is superior in terms of mechanical qualities, however, PTFE has lower friction. What I was thinking and Google says it should be possible is to use synthetic Teflon plus graphite lubricants, so we can get the best of both worlds!
Again, I had no experience working with actual materials under real conditions, so I am just looking into all sorts of data sheets. Some additional practical knowledge can direct us a bit.
From what I can say looking into user510 experiments, there is no that much of a difference in sonic performance, I would be mostly focused on mechanical reliability.
Even if we look into friction data, the difference is in "dry numbers", if we add some lube things are leveling out.
Dave if you have a batch of these things produced already, use them. They should last for many years (there will be 3d printer using all sorts of plastic by that time
. P.s. I will keep looking... We should investigate all sorts of lubricants, I would say.
Friction depends on the material that's being slid against the surface. There are some standard measurements, but they will not necessarily follow when one uses a different combination. And they will be VERY different for different grades and different fillers.
Here's a nice guide on Torlon:
http://www.hycompinc.com/PDFs/Torlon Design Manual.pdf
Here's a nice guide on Torlon:
http://www.hycompinc.com/PDFs/Torlon Design Manual.pdf
A petroleum oil for sure. Maybe an ester base. The secret will be in an additive package I have in mind... Some experimentation is in order for sure. I'll order up some of those Torlon jobs and (I hope!) get some measurements to prove out the optimum choice.
Feel free to email me to discuss- it's always useful for me to talk with other polymer guys.
Feel free to email me to discuss- it's always useful for me to talk with other polymer guys.
