Does Sequence of Polishing Operations Matter?

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BradyS71
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Re: Does Sequence of Polishing Operations Matter?

Post by BradyS71 »

here is a 50X pic of an Awana speed axle, un touched just to show the capabilities of the camera and scope. I just found out how to do 100X but there won't be a calibration bar as I would have to recalibrate the scope.

So I will bring some polished axles in but I think I can show what you want to see.

Let me know Stan.

Image
chromegsx
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Re: Does Sequence of Polishing Operations Matter?

Post by chromegsx »

I don't think 100x is going to get you what you want. See pics below. You can't really tell the difference between at sub micron levels at that scale. I took your picture and imported into my CAD, scaled it to the scale bar then placed pairs of lines using stan's numbers at each indicated micron distance. Then for the second pic I zoomed in by two to see what difference could be seen at 100x. What you will be able to see is the light refraction difference at the different micron levels though wich can be seen with the naked eye pretty well. Magnification always helps though.

Click the pics to get full scale views
50X
Image
100X
Image
BradyS71
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Re: Does Sequence of Polishing Operations Matter?

Post by BradyS71 »

Well like said there is always the SEM. I would be willing to stay late one night and get some images. That I can do 5-10K X on our old microscope. We are looking at new ones that will go 100,000X.
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Re: Does Sequence of Polishing Operations Matter?

Post by Speedster »

That's Impressive. I have a 45x scope and the raw Max V 4094 axle looks like those pictures. I decided to do a little test since I've been wondering about it. 3 axles were involved.

winderby - True to his word the BSA axle measured .080 after he was finished with his work. The axle showed some porosity where the wheel would ride but no where near a raw axle.

Max-V 4094 axle - Polished with Brasso only. Axle still measured .087, very shiny and seemed to show less porosity then before polishing. Can't explain that.

Max-V 4094 axle - sanded with 400, 1000, 1500, 2000, 2500, 3000 wet and polished with Brasso. I timed each sanding to 20 seconds. To my surprise the axle measured .086. I thought it would have been a lot less then that. The axle looked smooth, no porosity (at least with my scope) and very shiny. I don't know what this axle would look like under quality microscopes. If I reverse the sanding and go to , 2500, 2000 would it look the same as when I came the other way? Perhaps the powerful microscopes would show it.

My thoughts.
winderby axle - I prefer a larger diameter
4094 axle polished with Brasso only - I like the diameter. Is the wheel going to ride on a smooth surface only? Is the porosity relevant? Is this the fastest axle?
4094 axle sanded and polished - It looks smooth and shiny. Is it? I know .001 was lost. Did I also leave sharp edges that will cut through graphite quickly? Perhaps the powerful microscopes will show something.
Did I answer any questions or simply create new ones? Anyhow, it was fun.
Last edited by Speedster on Wed Feb 20, 2013 12:55 pm, edited 1 time in total.
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Stan Pope
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

I think that would do the job! Thank you.
I'll send you some axles.
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BradyS71
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Re: Does Sequence of Polishing Operations Matter?

Post by BradyS71 »

Okay Stan here is a quick and dirty axle sanding study,

Started with an Awana speed axle, 0.0985 inches in diameter
Image

Sanded with 400 grit wet sandpaper for 15 secs (counted, not using a timer) with axle chucked in a dremel at lowest speed. Note the deep gouges from manufacture that remain after the 400 grit. Probably started too fine.
Image

Sanded with 600 grit wet sandpaper for 15 secs, diameter is now 0.0975 inches
Image

Sanded with 800 grit wet paper for 15 sec, diameter is still 0.0975 inches
Image

Switched to 6 micro diamond paste for 15 sec.
Image

3 micron diamond paste for 15 sec.
Image

1 micron diamond paste for 15 sec.
Image

Switched to 0.3 micron alumina micropolish
Image

Finished with 0.05 micron alumina micropolish.
Image

So not exaclty sure if this is showing you what you want but I think that it shows there is a difference inbetween 400 grit 800 grit and 1 micron. Also the diameter didn't change after the 600 grit paper was used. All I know is I am going to be doing some speed testing with axles taken all the way to 0.05 micron polishing, the pics don't do it justice.
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Stan Pope
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

Nice work!

Questions:
1. Graphic "Awana Speed Axle, 0.03 micron pumice" labeled in text as "0.3 micron alumina micropolish". The latter is more consistent with sequence ... next finer is "0.05 micron". So, is it 0.3 or 0.03?
2. Is the "trash" across the middle of the pics, especially in 0.05 micron pic, "photographic artifacts", "detritus that would have been removed with more careful cleaning", or "surface imperfections"?
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Re: Does Sequence of Polishing Operations Matter?

Post by gpraceman »

Very cool photos. It is great to see the affect that each grit has. :bigups:
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BradyS71
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Re: Does Sequence of Polishing Operations Matter?

Post by BradyS71 »

Stan you sound just like my boss... its a typo, its supposed to be 0.3 micron :oops:

Also there are surface pits that weren't removed with the initial 400 grit sanding. Going forwards I would sand initially until all the pits were gone using probably 320 grit paper.

If you want to send some axles just let me know, and I can spend a bit more time trying to get better photos. Also I can swap the other lense in and got up to 100x.
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Stan Pope
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

BradyS71 wrote:Stan you sound just like my boss... its a typo, its supposed to be 0.3 micron :oops:
That makes total sense in the context ... and in the images!

The reason that I asked is that some other posters have described taking the sequence abruptly to "0.03 microns". I wonder if theirs are typos, too! :)
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Re: Does Sequence of Polishing Operations Matter?

Post by chromegsx »

Just checking in...Has there been any conclusion to this? More pictures using Stan's axles finished the opposite way?
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

chromegsx wrote:Just checking in...Has there been any conclusion to this? More pictures using Stan's axles finished the opposite way?
My progress has been hindered by some unexpected health issues ... I've been down with the
croup for about 3 weeks and a week ago, Bride was getting up for an early morning bathroom run and didn't get vertical enough ... fell and busted arm just below shoulder. So, I'm chief nurse as well as bottle washer! Seems like every 15 minutes I'm applyihg a cold pack, removing a cold pack, applying moist heat, removing moist heat, applying a sling, removing a sling, helping to bathroom, giving a shower, dressing, undressing, preping a meal, cleaning up after, .... well, you get the idea!
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Re: Does Sequence of Polishing Operations Matter?

Post by chromegsx »

So sorry to hear that Stan. Prayers to you and bride for quick healing.
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Stan Pope
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

chromegsx wrote:So sorry to hear that Stan. Prayers to you and bride for quick healing.
Thank you. I'm pretty much on the mend, but it will be a few weeks of pain before Bride is ready to ride again! She is a brittle diabetic with high insulin sensitivity, and can't keep food or liquids down in presence of every pain med we've tried. So the pain during recovery will be pretty dreadful.

She worked as a psychotherapist and in years past (about 30 years past), she worked with a group who did pain management. I hope that some of that learning is helping her deal with the pain in a non-medical way. Meanwhile, I give what TLC and sympathy as I can. I'm hoping that I'll start getting some "shop time" in a few days, since she is starting to walk again with only minimal assistance for balance.

Bride and I are growing old ... none too gracefully! :(
Stan
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Re: Does Sequence of Polishing Operations Matter?

Post by Stan Pope »

Brady sends these photos:

Sample G: Sequence=30, 15, 8 microns:
Image

Sample H: Sequence=30, 15, 8, 4, 2, 4, 8 microns:
Image

Preliminary interpretation:

It appears that neither sample shows effects of initial machining pass, so 30 micron was a reasonable starting grit.

Is the broad white band across the center of the pic due to saturation? Little information there, right? (Light source located on the line perpendicular to the striations and reflected into the camera because the surface is varying and not flat (in which case the light would almost all be reflected to the side of the camera lens and show dark.)

The top 0.25mm of the darker band just below (a) and the bottom 0.25mm of the darker band just above (b) are the best places to compare, right? Looking at the top margin of the (a), where it meets the white band, it appears that there are taller spikes in G than in H, suggesting that the roughening pass (moving from 2 microns to 4, 8, ...) doesn't produce as rough a surface. On the other hand, the area below those margins appear very similar. It is as though the finer polish sequence sheared off the tops of some spikes and the subsequent rougher passes did not have time to reestablish the variance.

Am I in the ballpark of correct interpretations? Anything grossly bad?
Stan
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