The long truck nail measures about 1 3/8" from under the head to the blunt end. I ground the head off the nail by turning the nail against the grinding wheel and then ground the end to a point after the head was gone. The nail was then installed in a drill and the diameter reduced to .086 with a file. Using the smooth nail should save the tools and keep from breaking #44 drill bits.
Get rid of the steel spacer on the axle guide tool. It will damage the hub very easily. Have your scout hold a notched, plastic, credit car in place while you push the nail in.
Don't forget your 40% off coupon for a single item from Hobby Lobby. They have a 3 ounce package of incremental 3/8" tungsten cylinders for about $26.00. For these particular cylinders all you need is a 3/8" drill bit.
Truck nails can be purchased from Maximum Velocity.
I find the 1 3/8" long 18 wheeler axles to be very soft and bend easy being zinc coated and steel.
Might be tough for most to file down the (0.087) axle shaft to ( .086) as well.
Would a 2 1/4" .086 hardened drill rod work better for this application ?
https://timesavers.com/i-9995054-drill- ... 2-1-4.html
However, you made me think. I took a #44 drill bit that is .086 (maybe) , put the threaded end in the drill and the bit did not wobble. That will allow the smooth end to go into the wood about 9/16". Even if the threaded area of the bit went into the tool 1/8" or so it's not going to damage the tool enough to make any difference. I checked the Vermont Gage, .0965, that came with the concentricity gage from Derby Evolution. The caliper measured that correctly. I have 8 #44 drill bits ( they break easily in the hands of a child ) and they all measured .0845. I have no explanation for that. So, I think the bottom line here is simply to buy a #44 drill bit from one of the vendors and use it to spread axle slots without damaging the aluminum tools.
Shipping is necessary but it's expensive. Use Hobby Lobby's 40% Off one item when you can. No where else can you get 3 ounces of 3/8" incremental tungsten cylinders for about $14.00 and drill the holes with a 3/8" drill bit. I have a nice stock of these cylinders and am able to pass the savings on to the folks at our workshops who want to try using tungsten. We don't require them to buy all 3 ounces. We give away a 4 ounce 3/8" lead rod.