So a while back I posted about my MIA bearing endplay checking fixture/tool/jig/WTF it's called. At the time, the first one I had made had gone awol and had apparently been missing for some time although, because I had not been building or servicing any wheels, the absence had gone un-notiiced. In retrospect it could have gotten lost anytime prior to the turn of the millenium or the construction of my shop. Not sure what ever became of it. As you are about to see, one of them is just slightly too large to just turn sideways and vanish.
So these two shots are of my newly finished replacement bearing endplay checking fixture, Mark Two, I think I did post pictures a few pages ago of the plate sitting on the drill press table and clamped in position for the final bore to tolerance. The bit came in today. Took two weeks to get it and two minutes to complete the hole. The cut to length section of All Thread that I elected to use for my spindle was a 0-0 fit. How? Well, it turns out that 3/4" NC all thread is not 3/4 inch in major diameter; that is it is not ,750 on the micrometer dial. It is only .733. That, oddly enough, when I consulted my drilling card, turns out to be the same as 47/64 in the fractional world, and drill bits of that size are made and can be obtained, or ordered and obtained which is what I had to do. When I bored the hole to a final diameter of .733 and fitted the section of rod into it, they mated together perfectly. No flopsy/wobbly that would have to be dealt with to get the spindle to be straight in the hole.
The second shot clearly shows the bottom spindle nut. This is specially machined item, there are two, top and bottom, that are a combination of bearing spacer and nut and which shoulder up against the taper bearings when the wheel is loaded onto the spindle. The bottom one is permanent. It stays where it is. The spindle threads through it and the plate and comes to rest in a 3/4 NC 2H, aka Heavy Hex nut that is welded to to bottom. When a wrench is put to the spindle nut and it is snugged tight, it locks the spindle in place but still allows for it to be removed should a wheel with a wider hub have to be set in place and checked.
Flipping the tool over to expose the bottom clearly shows the mounting tab/ear that gets put into the vise and secured in place. It is the same thickness as the plate, actually a short section of the plate that was cut off during the sizing process for just that purpose. It is centered from side to side and the joint edge was chamfered before it was welded in place. The chamfer gave me some seriously deep penetration in order to get the strongest mechanical connection possible. i do not want the plate to snap free while I am running a wheel. I do not need that picture beside any of my definitions of a bad thing.
Also visible is the belly nut that I also welded in place. I like the heavy hex nuts for this kind of exercise. I can set the welder for 1/4 plate and pour the heat to it and get the penetration that I need without deforming or melting the nut. The only precaution needed is to take a flap wheel or grinder to the faces to shave off the cad plating that they come with from the factory. While useful for rust inhibition, the stuff gives off fumes when hit with heat. Not pleasant and hard on the lungs.
For the sake of showing what this tool is meant to do, I elected to load the wheel that I will be doing the bearing preload and endplay check on, onto the spindle and set the upper spindle nut into position to display how it all fits together. There is no torque on the nut, because there is not internal sleeve spacer put in place between the bearings. That spacer is one of the reasons for having this tool; to take the measurements needed to learn exactly how long the spacer needs to be and then take them to the lathe to whittle one.
Finally, this is a three shot detail series showing how the upper spindle nut interacts with the bearing. In a real world test, the spacer mentioned above would be in place and the spindle nut run down to finger tight and then torqued to 55 foot/pounds; the same value used for the axle nut when the wheel is shod with a tire and put in service. The presence of the torque is necessary to get the correct value or reading once a dial indicator is set up and zeroed. Endplay is measured in thousandths and can be set tight enough that .010 is considered sloppy by some builders. HD offers a range for the spec they provide; something to do with variations in the casting and machining of the wheels. This particular unit is date coded 1974 according to the digit suffix on the part number although it could be younger. The part numbers tend to stay constant until an upgrade or change in application is introduced. More than a couple of them around that are not going to get discussed. That is a topic for a bunch of us greybeards while digging through greasy and rusty piles of bike parts at a swap meet.
So anyway, the tool itself is complete and ready for service. You might have noted the holes at the tab end of the plate. They were there to begin with but I think I am going to make a leash or tether for this one to keep it from wandering off like its predecessor. Murphy's Law says that now I have made it, the old one will finally show up.
Nick
So these two shots are of my newly finished replacement bearing endplay checking fixture, Mark Two, I think I did post pictures a few pages ago of the plate sitting on the drill press table and clamped in position for the final bore to tolerance. The bit came in today. Took two weeks to get it and two minutes to complete the hole. The cut to length section of All Thread that I elected to use for my spindle was a 0-0 fit. How? Well, it turns out that 3/4" NC all thread is not 3/4 inch in major diameter; that is it is not ,750 on the micrometer dial. It is only .733. That, oddly enough, when I consulted my drilling card, turns out to be the same as 47/64 in the fractional world, and drill bits of that size are made and can be obtained, or ordered and obtained which is what I had to do. When I bored the hole to a final diameter of .733 and fitted the section of rod into it, they mated together perfectly. No flopsy/wobbly that would have to be dealt with to get the spindle to be straight in the hole.
The second shot clearly shows the bottom spindle nut. This is specially machined item, there are two, top and bottom, that are a combination of bearing spacer and nut and which shoulder up against the taper bearings when the wheel is loaded onto the spindle. The bottom one is permanent. It stays where it is. The spindle threads through it and the plate and comes to rest in a 3/4 NC 2H, aka Heavy Hex nut that is welded to to bottom. When a wrench is put to the spindle nut and it is snugged tight, it locks the spindle in place but still allows for it to be removed should a wheel with a wider hub have to be set in place and checked.
Flipping the tool over to expose the bottom clearly shows the mounting tab/ear that gets put into the vise and secured in place. It is the same thickness as the plate, actually a short section of the plate that was cut off during the sizing process for just that purpose. It is centered from side to side and the joint edge was chamfered before it was welded in place. The chamfer gave me some seriously deep penetration in order to get the strongest mechanical connection possible. i do not want the plate to snap free while I am running a wheel. I do not need that picture beside any of my definitions of a bad thing.
Also visible is the belly nut that I also welded in place. I like the heavy hex nuts for this kind of exercise. I can set the welder for 1/4 plate and pour the heat to it and get the penetration that I need without deforming or melting the nut. The only precaution needed is to take a flap wheel or grinder to the faces to shave off the cad plating that they come with from the factory. While useful for rust inhibition, the stuff gives off fumes when hit with heat. Not pleasant and hard on the lungs.
For the sake of showing what this tool is meant to do, I elected to load the wheel that I will be doing the bearing preload and endplay check on, onto the spindle and set the upper spindle nut into position to display how it all fits together. There is no torque on the nut, because there is not internal sleeve spacer put in place between the bearings. That spacer is one of the reasons for having this tool; to take the measurements needed to learn exactly how long the spacer needs to be and then take them to the lathe to whittle one.
Finally, this is a three shot detail series showing how the upper spindle nut interacts with the bearing. In a real world test, the spacer mentioned above would be in place and the spindle nut run down to finger tight and then torqued to 55 foot/pounds; the same value used for the axle nut when the wheel is shod with a tire and put in service. The presence of the torque is necessary to get the correct value or reading once a dial indicator is set up and zeroed. Endplay is measured in thousandths and can be set tight enough that .010 is considered sloppy by some builders. HD offers a range for the spec they provide; something to do with variations in the casting and machining of the wheels. This particular unit is date coded 1974 according to the digit suffix on the part number although it could be younger. The part numbers tend to stay constant until an upgrade or change in application is introduced. More than a couple of them around that are not going to get discussed. That is a topic for a bunch of us greybeards while digging through greasy and rusty piles of bike parts at a swap meet.
So anyway, the tool itself is complete and ready for service. You might have noted the holes at the tab end of the plate. They were there to begin with but I think I am going to make a leash or tether for this one to keep it from wandering off like its predecessor. Murphy's Law says that now I have made it, the old one will finally show up.
Nick
