Chapter 4.9 – Center Pins and Drawbar PinThe final parts of the Tender Frame are the Center Pins and the Drawbar Pin. These are simple turnings and shouldn’t have taken too long. But being as talented as I am, I was able to make them take my full shop time today! Pretty impressive, eh?
OK, I did some other puttering around – sharpened some of the yard tools that my wife had asked me to and fixed the electric hedger. But after that, I started on my project!
I got all set up on the lathe and then remembered I’d left the change gears in a non-standard state. That was back when I did the springs for the truck - I needed a really course horizontal travel for the spring which required a gear change. So, I thought, “I’ve got plenty of time, why don’t I change them back now?”
So, I did. It just took longer than it should have. But in the end, I got it done. With the added bonus of breaking the gear change banjo (or Change Gear Pivot Bracket, as they call it in the Grizzly manual). This picture shows the change gears on my lathe. The three gears in a row there are all connected to the banjo – the bottom one is where it pivots and the next two up are mounted to the banjo.
It’s held in place by the nut you can see just below the middle gear (to the left of the lowest gear). And by a clamping screw that clamps it to the pivot point at the bottom.
And that’s where it broke. I was tightening the clamp at the pivot and suddenly, the screw turned way too easily. Apparently, I’d over tightened the screw and broke the casting? I didn’t know I could do that. I didn’t think I was exerting that much force, but clearly, I did.
After fretting about it for a bit, I decided to go ahead and use the lathe for today. The clamp around the pivot isn’t what provides the rigidity anyway – it’s the other nut that really clamps it into place. I’m thinking as long as there’s enough material to hold the banjo in place at the pivot point, I shouldn’t miss that clamping force from the pivot too much? Thoughts from anyone on this? Am I foolish for continuing to use the late with the banjo broken as such?
Regardless, I’m going to contact Grizzly and find out what it will cost to get a replacement banjo.
Anyway, after that exciting little mishap, the rest of the work went without hitch.
I started with the Drawbar Pin. This was made from 1/4" 12L14 rod. Using a 1/4" collet to hold it, I cut about 3/4” down to diameter (5/32”) then chamfered the end at 30
o using the cross slide.
I then slid the bar out another inch or so and brought the required length down to diameter.
And parted it off the rod. I also took this opportunity to chamfer the top of the pin with a file.
Now for the Center Pins. These were also made from the same 1/4" 12L14 rod. Kozo specifies these to be 0.245” to provide an easy sliding fit in a 1/4" reamed hole. So I skimmed off a few thou from the 1/4" bar and chamfered the end. Then I cut a 1/32” groove for an e-clip.
Next, I used a parting tool to cut a 1/8” groove in the pin for a set screw.
And parted it off.
And did it again.
Here’s the three parts I made today:
Showing the Darwbar Pin in place:
And the center pins. You can almost see one of the e-clips on the bottom of the rear center pin if you use your imagination!
Thanks for stopping by and taking a look.
Kim