Glad you approve.When you said bandsaw, I was about to suggest 'parting it' on a lathe. Well...a drill press is pretty much a lathe standing on end--I approve of your makeshift solution!
Dang, I love creative solutions to unusual problems like this! That was a straight-up fun read! If I ever need to trim a rubber bushing down to size, I'm going to have to try this! That's just too cool!OK, this will be more of a 'how to' post than a progress report although it is both. If you have a Shock-Ease fork this may be of interest to you.
First locate part #20 in the patent drawing to see the rubber bushing.
View attachment 233628
After looking at the drawing it appears that the bushing is a basic cylinder shape or 'thick washer'. So today I visited my favorite auto parts store with fork in hand to see what I could find.
I have to point out that this parts store is locally owned and operated by an almost 80 year old man who spent his early years heavily involved with the local drag racing scene. I always patronize his store when I can without regard for 'a better price' at any of the chain stores. You simply cannot replace his years of knowledge. I get frustrated by unqualified counter jockeys at chain stores asking irrelevant questions like "what color is the interior?" when all I want is a distributer cap for my truck (but I digress). I hope that some of you are as lucky as I am to still have an actual owner operated Auto Parts Store or any local service store to visit. Like the old time bike shops, they are a dying breed.
Anyway, After I had asked to see a rubber freeze plug Hugh (the owner) was able to match up in his mind that an engine mount bushing for a 1955 through 1957 Chevy looked like a possible fit. The freeze plug did look just right except for the thickness, but after he walked to the shelf in the back and reemerged with the GM bushing in hand (that also looked like a good fit but for half the price), I handed over the three dollars and change and was on my way!
The only issue was with the thickness of the bushing. I'm sure that somewhere in the world there is a perfect fit sitting on a shelf but for now this would do. Hugh suggested splitting it in half with a band saw and steel mesh gloves but my own wheels began to turn and this is how I approached it:
I first stacked some washers in the space for the bushing on the fork to gauge how thick the bushing should be. Then I marked it on the bushing and pushed a carriage bolt through the center. The square part of the bolt was larger than the hole which gripped the rubber when it was forced in. I then chucked the bolt in my drill press.
Next I took a hack-saw blade and taped it down to two blocks of wood to make it level and placed the blocks on the drill table. The table was then cranked up to the point where the saw blade lined up with the cut line marks.
View attachment 233629
Stopping several times to add oil to the blade, I slowly pushed the blade against the bushing as it was spinning in the drill press. When it hit the bolt I stopped and ended up with the desired thickness!
View attachment 233630
When I got the fork, someone in the past had stuck an undersized rubber bushing along with a steel washer on each side to replace the original. It probably worked enough to get by at the time, but years later it too crushed and split becoming useless. Here is what I found compared to the newly modified Chevy bushing.
View attachment 233631
And finally here is the '55 Chevy bushing on the '37 Shelby fork!
View attachment 233637
If it turns out to be too thin after the weight of the bike is on it, I still have the thicker half left over that I can use to further dial in the correct size later on down the road. I hope this helps someone else looking to replace their Shock-Ease bushing.
Hey. There's a guy trapped in your table.Now that the plugs are out of the molds, I've trimmed them and started working on outfitting them with mounting brackets.
View attachment 234166
This is where the temporary line up jig makes its second appearance.
View attachment 234168
With everything in place, I bonded the brackets in place with fiberglass.
View attachment 234169
All of this is to dial in the fit on the frame and then return the plugs back into the molds to add scribe lines in the molds for trimming subsequent tanks down the line.
Vital need to know info. My shock ease fork is gonna need similar attention.Glad you approve.
I was inspired to use the 'vertical lathe' again today to finish up the fork rehab. In an earlier post I had added a temporary washer for the castle nut to rest on until I could make a proper shaped nut (see part #23 in the drawing below) and avoid having it digging into the fork.
The bottom of the nut is rounded creating a ball and socket between it and the fork. When the fork hinges from the pivot point (#8) the angle of the socket changes while the bolt pulls fairly straight down. Pretty clever engineering!
I used a jam nut against the castle nut to lock it down on a bolt. The head of the bolt was cut off so that I could chuck it up in the drill press. Then while the drill was spinning I use a flap wheel on my side grinder to take most of the metal off. That was followed with a file to finish shaping it.
View attachment 233745
I didn't realize until I just looked at this macro photo that I needed to finish with a dead smooth file. I'll do that tomorrow.
View attachment 233746
Here's how it fits in the fork socket.
View attachment 233747
*EDIT: I cleaned up the nut with a smooth file and some sand paper.
View attachment 233960
That's just Han, he's been there for a while.Hey. There's a guy trapped in your table.
Great! I'm still not 100% positive about the thickness of the bushing, but when I'm satisfied, I'll post the dimensions.Vital need to know info. My shock ease fork is gonna need similar attention.
Thanks Luke, it's nice having you around again!Loving the attention to detail you always bring TRM!