Less is More? Polishing Too Much

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picard1963
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Re: Less is More? Polishing Too Much

Post by picard1963 »

Well, we are in a position to set the track up for an extended period of time and do some testing. It's a new MW Freedom Aluminum with a K2 timer. We bought an extra 8' section so that would be a "50 foot" track (i measured 46.5' with a soft tape, pin-to-FL).......For perspective, our top time in our actual race was 3.7352 (see top-10 min times from GPRM file below). We don't have any experience with this length of track (District race is the more common 42'). Are we in left field running this extended length?

Car# Heats Avg Min Max Std Dev
29 6 3.76805 3.7352 3.817 0.02915611
14 6 3.78135 3.7552 3.7952 0.01643213
39 6 3.782883 3.7673 3.801 0.01199023
22 6 3.825567 3.7978 3.8668 0.02496563
16 6 3.874833 3.8116 3.9818 0.06673113
24 6 3.877067 3.8172 3.9364 0.0459473
7 6 3.858717 3.8223 3.8931 0.0263619
1 6 3.856917 3.8232 3.8932 0.02246904
25 6 3.886767 3.8379 3.9406 0.03884784
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Stan Pope
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Re: Less is More? Polishing Too Much

Post by Stan Pope »

sporty wrote:Now, there is something stand left out. That I have mentioned before.

the 12,000 regular micro mesh, wears to 1 micron. even tho rated at 2 micron, it will wear and to 1 micron. And typically it does not take long to get to the 1 micron rating.

Thats why i most often will call 12,000 grit 1 micron. I did testing to also prove that it went to 1 micron.
Finally got some "shop time" during the past few days. Worked a series of axles to various degrees of polish.

Started out with a 3/8"X3" strips of various grits, beginning with 30 micron and ending with 2 micron, stepping 30, 15, 8, 4, 2. Then continued with diamond polish at 1, 0.5 and 0.25 microns. 30 and 15 were wet/dry emery paper; 8, 4, and 2 were MicroMesh.

In the course of stepping from 30, 15, ..., I observed the state of the strips after one and two axles. All of the strips seemed to lose substantial "cutting capability" after one axle. It did not appear that any of these stabilized after wear to a predictable or useful "effective grit", e.g. that the 30 micron paper wore down to and stabilized at about 15 (or some other specific value) microns! Some pictures coming from Brady may shed some light on this, although wear was not the purpose of the study.

A description of the method of "testing to also prove that it went to 1 micron" would make interesting reading for us!
Stan
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picard1963
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Re: Less is More? Polishing Too Much

Post by picard1963 »

Correction: it is a 48' 'Freedom Series'.....not 50' as previously stated.

Stan: were you able (or intend) to apply graphite at each of the grit steps? This is what we would like to determine. Without any science or testing to start off with, does the notion of "less polished surfaces" acting like "velcro" for some big-flake graphite sound like even something work talking about? :idk:

p
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Stan Pope
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Re: Less is More? Polishing Too Much

Post by Stan Pope »

picard1963 wrote:Correction: it is a 48' 'Freedom Series'.....not 50' as previously stated.

Stan: were you able (or intend) to apply graphite at each of the grit steps? This is what we would like to determine. Without any science or testing to start off with, does the notion of "less polished surfaces" acting like "velcro" for some big-flake graphite sound like even something work talking about? :idk:

p
That is in the plans. The current wait for pix from Brady (just put the axles in the mail yesterday, so I'm the holdup, not Brady) is intended to validate plans published here a few weeks ago to do as you indicate. My plan was to start at high polish (0.25 micron), then step down X2 per step (0.5 micron, 1 micron, ...), using the same wheel. Since the number of runs at each polish level is rather high, I was concerned that starting at 30 micron and stepping to 15, 8, ... might wear the bore excessively and invalidate the results. I raised the question here as to whether polishing in reverse sequence would produce friction surfaces comparable to those produced when polishing normally. No definitive response, so .... I will look at pix from Brady and run one case, 8 micron: A) sequence 30, 15, 8 and B) 30, 15, 8, 4, 2, 4, 8, through a loaded spin test sequence.

Meanwhile, I'm scavenging some lens from a discarded camera to help with a sensor to upgrade the loaded spin test arrangement to include effects of startup "stiction" and time to various finish line distances.
Stan
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picard1963
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Re: Less is More? Polishing Too Much

Post by picard1963 »

wow! Sounds great :bigups:

Good thinking on the "smoother-to-rougher" direction for bore integrity. Won't that still be a question as the axle "gets rougher"?

Thanks Stan!
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Stan Pope
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Re: Less is More? Polishing Too Much

Post by Stan Pope »

picard1963 wrote:wow! Sounds great :bigups:

Good thinking on the "smoother-to-rougher" direction for bore integrity. Won't that still be a question as the axle "gets rougher"?

Thanks Stan!
Yes, there is still a possibility, but the effects should be more limited. I suspect that bore wear from axles with 2 micron polish will be much, much less than wear from axles with 30 micron polish, and that the wear will accumulate much more slowly working finer to coarser than vice versa. I really don't want to prep a fresh wheel with a 0.098" bore for each grit case!

To help qualify results, the plan does include a "fresh" wheel for a second run at either 8 or 15 micron.
Stan
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Re: Less is More? Polishing Too Much

Post by knotthed »

firstplaceloser wrote: Now I know there are many multiple factors in play such as the other cars were faster than test day, we didn't do something properly during the prep process, yada, yada, yada. But what brought the question to mind is I know the other cars axles weren't prepped to the degree, meaning to the fine grit sandpaper, like mine or picards were and they beat us. Also that the test day axles were faster, which lead to this debate.
You are correct that there are many factors in play, but the least I would concern myself with is the other cars being faster than on test day. You should focus on your car being faster.

From an outsiders point of view, I certainly would be questioning alignment. I don't see any mention of checking alignment on test day versus race day. This can have a huge impact on performance. It would be my opinion that you could have the best wheel and axle prep in the world and if your alignment is out, you will be slow!

Can you comment on pre and post alignment/drift?
Rear wheels not touching center rail?
Rear wheels migrating to nail heads or touching body?
Any wobbles, side to side motion down the track?

FWIW,
I offered our pack a test/tune day this year and I was quite suprised at a few things. One was how the few people that showed up had some major problems with their cars (Fundamentals! - weight placement, overspray on wheels, burrs on axles, on and on.) We replaced wheels and did test run before tuning, then tuned alignment and did runs, I was surprised at the times without any axle or wheel prep - they were quite good in my opinion. We didn't have enought time to start from the beginning to correct all the problems, but it was enough to get these boys in the trophies at our pack and they will continue on to districts.
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sporty
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Re: Less is More? Polishing Too Much

Post by sporty »

Replying to Stan.

I posted this a few times but not recently.

Using micromesh regular, 12,000, not mx.

After using it. I would then take a new piece of 1 micron rate, the plastic strips. and found it did nothing.

It would not further polish my axles, after using the 12,000. I had to skip to the 1/2 micron, to see or tell a differance.

I think much of this was all discussed on here 2 or 3 years ago, Surely 2010.

There is even video clips of me doing it and how I hold it, ect on here. If someone has the time to go find it and share it with you. If you are wanting that kind of detail and information.

Also, I compared to mothers mag polish which the last member I recall, was also rated at 1 micron. and I seen no differance comparing that also.

I use the micro mesh regular for plastic on the axles, I have some of the MX, still new, but I never liked how it worked on the axles. It jsut did not go as fine. I could see scratched in the axle at 12,000.

But for some reason the regular, I did not.

Which did you use, the regular micro mesh or the mx ? or did you test and try both ? from micro surface.com is where I get mine from. no where else.

Hope this helps you in your study.

Sporty
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firstplaceloser
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Re: Less is More? Polishing Too Much

Post by firstplaceloser »

knotthead,

Alignment was about the same.
I couldn't see about the rear axles at district because we couldn't get real close to the track. On race day it did not touch the center rail.
Rear wheels were touching on both because I didnt cant either.
Both days the car didn't wobble.

I was running slower was because I weighed heavy at district and had to take some weight out. That was the main reason. I thought my prep work would still be able overcome that. Of course that wasn't the case. Then the times that the other cars are turning knowing their axles werent prepped as good as mine or picard's lead to the orignal debate. I,like you, think those less prepped times were pretty good.

By the way I had two other cars that ran within .001 of each other in the open race (first and second) All three cars were setup exactly the same (thin, extended wheel base, 3/4 cog to rear wheel, 3 wheeler, axles and wheels prepped the same) Which car do you think was the slowest of all three? :burningmad: The fastest car in the open class would have placed third in the den and maybe third overall.

What I am learning is that many things have changed since I raced 25 years ago. I had pretty good sucess back then but thanks to this site I know now that I don't know jack. This year and last year I was reluctant to make a rail rider or cant my axles. Again thanks to this site I bet you can't guess what my next car will be :D. I also have a few more questions (well ok a lot) that I am going to research on here and ask a few more too. You guys are great about helping out!!!
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Re: Less is More? Polishing Too Much

Post by knotthed »

I have learned in the last couple years that some good pictures will go along ways after the race is over. Take good pictures of the fast cars on the tables. front back side, what ever you can get with a good zoom if possible!

You can then take a look a the pics later to decipher little details. Were the wheels machined/lightened, etc... axles canted, these are all things you can pick up on from pics.

How did you test your alignment? do you have any numbers or just thinking they were the same?
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Stan Pope
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Re: Less is More? Polishing Too Much

Post by Stan Pope »

sporty wrote:...
Using micromesh regular, 12,000, not mx.

After using it. I would then take a new piece of 1 micron rate, the plastic strips. and found it did nothing.

It would not further polish my axles, after using the 12,000. I had to skip to the 1/2 micron, to see or tell a differance.
...
I use the micro mesh regular for plastic on the axles, I have some of the MX, still new, but I never liked how it worked on the axles. It jsut did not go as fine. I could see scratched in the axle at 12,000.
...
Thanks. Creeping senility has erased all memory of those old postings! :(

For viewing polishing results, I am compounding 4 lens and having difficulty getting my eye close enough to the axles in the lathe chuck to keep grease off my nose and cheeks! Even so, visual comparisons have been inconclusive. Maybe I need younger eyes like yours! Or maybe I need to get my eyes calibrated to interpret what I see. OTOH, a bit of grease smeared on my face is okay ... it makes my Bride think I've been doing something productive. :)

I purchased MX (to 4 micron) and Regular Micro Mesh (to 2 micron) from SIS a couple years ago. I think that I have a lifetime supply. For recent tests, I used 4 and 8 micron MX leading to 2 micron Regular. And followed with diamond polish at 1, 0.5 and 0.25 micron.

The coming photos from Brady will show whether my polishing technique is good or bad. If it is bad, then his photos should help me improve.
Stan
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firstplaceloser
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Re: Less is More? Polishing Too Much

Post by firstplaceloser »

Thats a great idea. I will do that for sure.

I do know that the two cars the beat me at district were built similar to mine. We are all pretty good friends and I checked them out pretty good on practice day. I didn't notice any cant. I know that may have changed from one day to the next too. The rules keep us from doing anything much to the wheels (No machining or sanding)

They both drifted about 2"in to the left in 4 feet. Since they were the same I don't think that was the difference. Keep in mind though I didn't build a rail rider. I could't get any of my cars to track straight and at the time I didn't want to bend a front axle. I know now that is ok to do. Honestly I thought they would act like a rail rider and be ok.

In addition to what I normally do I know I need to build a railrider and cant the wheels. Also I need to work on my wheel and axle prep for the next car.

Anything else I am missing? I have some other questions that are way off topic and will post another thread about those. If I need to now someone let me know. :? Still new here. Don't want to mess up Mr. Pope. I am following that closely. :bigups:
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Stan Pope
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Re: Less is More? Polishing Too Much

Post by Stan Pope »

firstplaceloser wrote:...
Don't want to mess up Mr. Pope. I am following that closely. :bigups:
Some things to watch:
1. pix from Brady
2. follow-on multi-polish study
3. bent axle alignment video showing how to do bent axle alignment. Few folks seem to "get it" from the write-up that I posted a few years ago. (Sometimes I wonder, though, if I should lead those by the hand who won't invest their time to dig out useful information. The process is fast and accurate, and leads to correct alignment for rail guided operation ... rear wheels off the rail AND tracking correctly together whether the DFW is indented or not!.)
Stan
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Re: Less is More? Polishing Too Much

Post by BradyS71 »

Pics will be coming monday-tuesday will send to Stan first.
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Re: Less is More? Polishing Too Much

Post by picard1963 »

Stan, cool write-up. Have printed to include in "the notebook".

What pictures? Is that to see if you have your "smoothest" starting point before "roughing them up"?

p.
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