The Cub Scout axles - those raised bumps on the shaft

[Stan Pope]

Current Cub Scout axles have some raised bumps on one side of the shaft right about where the hub would rest. What, if anything, do you folks do with them?

My first thought is that they might be useful. Would they make a good bearing surface for the wheels to ride on? That is on my list of "things to check out" but hasn't gotten to the top yet. (See other thread about measurement method.)

So far, I just guide to check for reasonable straightness, shave the raised soulders by the point, dress under the head, polish the axles with jeweler's rouge and talc, and orient the bumps toward the top of the car. (It was good enough for Grandson's Council championship car with no close heats, but is it really best?)

[Jewel]

I file down the bumps at the chisel points at the end of the axle. Then put the axles in a collet in a lathe, and check for straightness. I then take a light cut of about 2 thousandths and polish with Semichrome and or Mothers Metal Polish after sanding. I remove the ridges near the top of nail head, they look to be a liability but I might be missing an opportunity to do a little better, they could hold some lubricant.

Next year I may try drilling a center point at the end of the nail head and then hold the axle head using a center on the lathe for support. The goal is to make a cut without causing the nail to deflect and go out of straightness. I could then apply firm polishing pressure on the lathe without the worry of losing straightness. I am very concerned about straightness at this time because I had some flaws with my car that made it hard to align really well. I won the race I was in, but I know I can do much better. I hope that having really straight axles and axle holes will make LBW alignment with good car tracking straightness something that can be achieved very well.

What is the best way to use Jewelers Rouge and Talc? What grade of Jewelers rouge do you use?

[Da Graphite Kid]

Okay guys, let me show my ignorance here: there are different grades of jeweler’s rouge? The only grade I’ve seen and used comes in a Dremel kit. I’ve found that I get smoother results (verified with use of a microscope) with Mother’s Chrome Polish. Is there a grade of jeweler’s rouge that would produce better results than Mother’s? Is talc better to use?

Normally we leave the bumps in. We don’t have access to a lathe and would most likely reduce the axle diameter trying to get the bumps out anyway. I will make sure that we mark their position on the axles this year as orienting them to the top sounds like a good idea. By the way, I don’t remember if or how much of these bumps are left after using the Pro-Axle Tool, maybe none? Randy, do you or Bill know?


Da Graphite Kid

[RACER X]

The bumps are compressed to almost nothing if they are not dressed off before using the Pro Axle Tool but we recommend a light dressing of the axle to start with.

I have been using a small aircraft file to lightly dress off the bumps and seam ridges under the head before I start on the axle. I did this even before the axle press just to prevent any deflection in the lathe.

What are most of you doing for axle treatment, grooving or slotting or just leaving them straight?

[Mike Parrish]

I have grooved my axles in the past, but have had equally good results with de-burring and high polishing.

Mike

[Stan Pope]

Okay guys, let me show my ignorance here: there are different grades of jeweler’s rouge? The only grade I’ve seen and used comes in a Dremel kit. I’ve found that I get smoother results (verified with use of a microscope) with Mother’s Chrome Polish. Is there a grade of jeweler’s rouge that would produce better results than Mother’s? Is talc better to use? Da Graphite Kid

There may be different grade of rouge for ferrus metals. I've not seen them in my favorite hardware store. There are different rouge's for other materials, such as plastic. Or you could use "rubbing compound".

My next step is "talc", a very fine pumice, on a damp cloth strip. There might be a usefule intermediate (between rouge and talc) step, but I'm not aware of any.

If I'm feeling really patient that day, I'll put graphite on a damp cloth strip as the last step.

I have not subjected any of these to formal test. They are part of a test protocol that I'm developing, but "so many opportunities, so little time!" None of the "tests" that I've read about seem to have enough sensitivity or repeatability to produce reliable comparisons. Cost or availability of instrumentation is a big issue for most of us.

[Barga Racing]

This year we used some stuff called micro mesh. It is supposed to be finer than any polishing compound. It is like one micron and I read in one of their ads that polishing compound is about 3 microns. The US Air Force uses it to polish the scratches out of F14 fighter canopies. I honestly don't know that it helped any more than the Mothers but it should have. It is a cloth with silicon an diamond chips permanantly bonded to it. It does leave a nice finish on the axles. I have also tried grooving the axles which cuts out the bumps. If we don't cut grooves we usually use a very fine file and barely remove the ridges. This year we may try to leave them as to not reduce the axle diameter.

[TurtlePowered]

I would think with the raised bumps, it would automaticly throw off the alignment since the nail would not be sitting straight in the drill pressed axel hole.

[Stan Pope]

I would think with the raised bumps, it would automaticly throw off the alignment since the nail would not be sitting straight in the drill pressed axel hole.

The bumps referred to are the ones within 3/8" of the nail head. The bumps resulting from cutting the point also need to be dealt with for several reasons, including the one you give.

[TurtlePowered]

I would think with the raised bumps, it would automaticly throw off the alignment since the nail would not be sitting straight in the drill pressed axel hole.

The bumps referred to are the ones within 3/8" of the nail head. The bumps resulting from cutting the point also need to be dealt with for several reasons, including the one you give.

Yes, those were the 3 ridges I was reffering to. One side they are much more visible but they do continue on the other side. If the ridges were on the up side, wouldn't that be like grooving axels if the wheel were to ride on the ridges? If the ridges were on bottom, close to the wood, I would think it would throw the axel off true since the ridge would act like a fulcrum.