Safe ways to remove crimp marks on axle shaft ?

[quadad]

We just started on this year's cars and already stumbled. In getting the axles cleaned up prior to the axle press I am having trouble safely removing those (2 on one side, 3 on the other) crimp marks.

Both I and a couple of my boys can fairly well remove the burrs under the head, and even put an angle on the head, with a smaller (not smallest) triangular file in the drill press (bought a cheap, small drill press that's kid size). I have found many posts with neat ways of doing that (hole in cutoff saw, sand paper on paint stir stick, ...), but have not found as much dealing with these marks on the sides.

The crimp marks are really large. Last year (blissful ignorance) we did just use a flat file on them, but now that I am much more sensitive to the overall process (and growing competition at pack), I am more worried about taking off too much material or digging in around them, and I am looking for a better way. The good news is that we have LOTS of spare axles !

[Stan Pope]

Some ideas:

1. Look at nail and see if there is a "good sector" upon which the wheel can ride smoothly. You need more than the 30 degrees of shaft. To be safe look for more. If you find such an area, you can clean the ricges off willy-nilly! the bore should never see an indentation where the ridges were, so long as the nail is oriented accordingly in the slot/hole.

Smooth and polish to your preference.

Downside: you can not align by rotating the nail without risk of interference from the areas that you scrubbed.

2. Straighten the portion of the shaft below the ridges (that will also smooth out the shoulders near the point. Then chuck the nail and work as last year. You might approach the nail "stepwise": Chuck and turn off the first ridge. Repeat straightening exercise, including that part of the shaft you have now cleaned.. Chuck and turn off the next ridge. etc. When all the ridges are gone and the nail straightened as fully as you can, then address the head!

Smooth and polish to your preference.

Assess shaft diameter in the areas that you have worked. Is it irregular? Are the inner and outer ends at least as large as the area you worked? (Larger? Oops! A "grooved shaft"!)

This approach should leave you with more axle diameter than if you take all the ridges off after the first straightening. However, for my test fleet, that is what I did. I ued a lathe instead of a file and ended up removing a couple of thousandths of diameter. Not best, but I could produce nice cylinders and good head taper with no groove at the base of the taper. And, done this way, even the Cub-Scout-legal car lubed with PTFE was a car length (and more) faster than the fastest three pack racers last Saturday.

If you use a file to remove the ridges from the turning axle, don't "ride the file hard" down in between the ridges. You just want to take off the ridges, so control the file position. Gentle pressure, barely touching the nail at the ridges!

Had I started with emery cloth, I think I'd have taken more off the "good parts" of the shaft and still ended up with egg-shaped cross section.

Downside: These axles will have a slightly smaller shaft diameter. But full circumference is smooth

[knavekid]

We used a small triangular shaped file that only cuts on one surface and does not cut on the edges. I softly filed a few strokes on the ridges and then ran my thumbnail down the shaft to check progress. Eventually the ridges were gone without fear of taking significant material off of the shaft. This file also worked well for the burrs without digging into the axle shaft. Standard polishing methods followed.

[quadad]

OK, some good thoughts. Since a lathe is not in my near future, it sounds like some careful filing is. Since we have a lot of axles to work with (more than 5-6 x what are needed), I think I will have 'the crew' work on plenty of spares and then pick the best.

Now how to "pick the best" ? Should I take them all through sanding and polishing (probably not practical) and then run a 'spin test' ? Or should I just examine them "for damage" - I have a decent magnifier with light and a micrometer ? Or ... ?

[psycaz]

I would say, start with the most visible damaged.

Eliminate those.

Then as you progress through the polishing process, I'd separate more. You can keep checking the size to kind of group them together where they clean up at.

Hopefully you can have sets of 4 so all the axles will appear the same and have the same size when done.

[Stan Pope]

... Since a lathe is not in my near future, it sounds like some careful filing is.

"Lathe + file" is equivalent to "Drill press + file" or to "hand drill in a vice + file", provided that the axle is well centered.

Selection is the key. What is your "ultimate criterion?" How can you apply it?

[terryep]

I mount the nail in a Dremel and use a Barrette file.

[quadad]

Terryep,
I am not familiar with that kind of file, but saw the other post you had (with more pictures) on this subject. Nice idea with the flashing to prevent scratches.

What I have found so far (working 16-20 axles and eliminating that same number), is a HUGE difference in the size of these marks. I have axles from various kits, and a number (at least 60) from stock axle purchases (think they were $1 for a package of 10 last year). The worst have three tightly grouped, very heavy marks on one side and two thinner, more widely spaced marks on the opposite side. They cover 75 % of the axle between the two of them.

Alternately I have also found axles with no more than 3 total, very thin crimp marks, that take hardly any clean up. Whereas the former have been really hard to file down without disturbing the area between them (Stan's advice).

Now that I have done some number (using my pin vise, drill press and a few files), I am going to go back and re-read the various info sources I have before getting the kids going on these this year. (I need a pretty good system before unleashing my 3 boys on it.) One thing I am seeing is that finding what works for you (which includes trying out other's advice) and getting experience doing it that way, can really help make it go better and smoother.

So Terry, does your method work with these heavy duty crimp mark guys ? And is there something special about the file that you are using ?
- It can always be part of next year's plan !

[Stan Pope]

(( Welcome back, Terry!!! You've been gone way too long! ))

[nodakindy]

I mount the nail in a Dremel and use a Barrette file.

As a teenager who sharpened saw blades, knives, and such to pay for my first car I thought I had seen every file imaginable, but would have to say I am not familiar with this file. It almost looks to have a fine diamond like surface to it. Is this something you found at hardware store or did you order it online?

Regards,
Nodakindy

[nodakindy]

One thing I am seeing is that finding what works for you (which includes trying out other's advice) and getting experience doing it that way, can really help make it go better and smoother.

I couldn't agree more. This board has been very helpful to me. This is my second year of helping my grandkids with there cars and the many suggestions, links, and general experiences has saved much time and helped achieve great results as well. With this in mind I will add my two cents worth.

I too have found just having more axles to choose from makes things much easier so I just bought a lot of extras to go through. There cheap anyways so what the heck.

Then before we did anything to them we put them in drill and all looked at them together sorting them according to flaws relating to being concentric while spinning in the drill. This goes pretty fast. I have found their attention sort of wains after a half of an hour so I try to work often and quickly in lots of segments. We sorted through about 80 nails and separated them into 4 piles. A - being most flawless, B - good with flaws, C - OK, D discard or use for painting to fill axle holes or slots.

This gave each of the boys 10 axles to work with. Plenty for spares or in case of goofing up while working on them. There both only 7 so mistakes are par for the course. We then went through and filed bumpy flaws only and put nails in this handy tool to straighten them more.

It cracked me up watching these guys wacking this press. Be advised, let them hold this tool themselves if you have any love for your fingers at all. LOL

Once they were straightened we put them all back into drill to pick out most concentric again and divided into two groups. I had them start on worst of the two groups first so they would get a little practice before getting to the best axles. At 7 their hands are a little unsure so I found setting them in my lap and guiding theirs hands a little with the file helped their confidence.

Good luck in your races!

Regards,
Nodakindy

[Stan Pope]

Then before we did anything to them we put them in drill and all looked at them together sorting them according to flaws relating to being concentric while spinning in the drill.

Nice posting, Grandpa!

Many of the BSA axles (probably all of them) have some "shoulders" where the point is cut. I try to relieve these shoulders before the nail ever gets close to either a wheel or a chuck. The reasoning is that chucking an object that is "lumpy" will probably give really inconsistent results. Last year, the shoulders went away with a file. This year they went away with a ProAlxe Press.

Heeding the "words of the maker", the crimp marks stayed outside the press, aided by a "holding / locating fixture" formed from 2" of latex tubing (3/8" OD X 1/8" ID black stuff).

Because I found it difficult to chase the Press around on the back of my vice, I clamped the bottom of the Press into the vice. (Bifocals and chasing things around while hitting 'em with a hammer just don't mix well.) This enforced the plan to tap the Press gently using 1" strokes with a medium ball peen hammer while turning the nail rapidly with the latex tubing holder (20 or 30 degrees turn between strokes). Without applying too much science and only a little math, I settled on about 50 strokes.

Since the Press embraces the entire nail below the ridges, almost all of the treated nails should pass your "chuck and spin" test... straight from tip to ridges!

It goes fast, too. After a few nails, your hammer will sound like a woodpecker working a hollow tree! Biggest trouble is counting the strokes. But if you do groups of 12 or 16, pausing to change hold on tubing, it is really easy!

Last year this time I thought that the ProBody tool was the best of the bunch. I still think that it a good tool. But I've changed my mind about the ranking! The ProAxle Press tool fills a niche that doesn't seem to have any good alternatives!

[terryep]

Hello Stan, I'm back helping out with the cub pack once again.

What I thought was a Barrette file is actually a Cantsaw file.

http://www.farmhardware.com/SuperStore/ ... uctID=8862

Mine is a 10" but a 6" might be better. I use a brass shim between the file and the nail shaft so as not to file it while filing the taper on the head. The picture shows the end of the file, it has a "single cut" on all 3 sides.

[quadad]

Terry,

Looking at the picture, that looks great for filing the head angle. Do you use that same file to work on the crimp marks ?

If so, I am envisioning that you are creating some kind of quasi-mini lathe with your dremel setup.

[terryep]

First I take off the crimp marks near the point using a belt sander so I can chuck them in the Dremel. This file will take off the crimp near the head by sliding it into the head using a slow speed. After cant is formed I use some 600 sandpaper under the file to do a little smoothing of both shaft and under head. I try to remove as little as possible. Then polish with paste and a cloth at full speed. I'll pick the best side to face down for wheel hub contact.
Terry