All the cotters in the Bonelle prints have them, if you have a copy. I have come to the conclusion they are not needed , but if I am wrong, I could always add them.
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Tool and cutter grinder build
- Thread starter Mark_f
- Start date
All the cotters in the Bonelle prints have them, if you have a copy. I have come to the conclusion they are not needed , but if I am wrong, I could always add them.
- Joined
- Aug 31, 2013
- Messages
- 321
Mark
I'm with you on that, I believe the slit and a pinch bolt would be sufficient. The only problem I see in the slit method is the grit can find a home in there. As a solution one could use RTV or silicon sealer in the color of your machine. When tightened the silicone would collapse and block any dust from entering. When loosened it would relax and look like normal but remaining closed from the dust.
Hope that was some help.
Nelson
I'm with you on that, I believe the slit and a pinch bolt would be sufficient. The only problem I see in the slit method is the grit can find a home in there. As a solution one could use RTV or silicon sealer in the color of your machine. When tightened the silicone would collapse and block any dust from entering. When loosened it would relax and look like normal but remaining closed from the dust.
Hope that was some help.
Nelson
+1
I made a vise stop as one of my first projects after I bought my mill
It locks w/ split cotters, and it's sitting on the shelf most of the time. When it comes time to bring it out, lining up the split cotter to get it mounted on the shaft is kind of a pain! I had not ever heard of using a slot and setscrew as a remedy. I may want to try that! I believe that I've seen someone solder a key in there for the cotter to slide on. A setscrew would be much easier than a soldered key. Still, you'll have to make sure that the cotters line up during assembly anyway. . . .
I guess it's one of those little details that set one tool apart from the others?
Jim
+1
I made a vise stop as one of my first projects after I bought my mill
It locks w/ split cotters, and it's sitting on the shelf most of the time. When it comes time to bring it out, lining up the split cotter to get it mounted on the shaft is kind of a pain! I had not ever heard of using a slot and setscrew as a remedy. I may want to try that! I believe that I've seen someone solder a key in there for the cotter to slide on. A setscrew would be much easier than a soldered key. Still, you'll have to make sure that the cotters line up during assembly anyway. . . .
I guess it's one of those little details that set one tool apart from the others?
Jim
This would solve your problem. But in my case, the cotters are always in place.
You mill a small short key way in the rear side of the cotter,and put a set screw with a lock nut in the piece. Adjust the set screw into the slot so it only locates the cotter but lets it move as needed. No more alignment problem.
Sorry,I have been gone for a while. I was down for the better part of a week with the flu and couldn't even get out of bed for several days. It is also too cold to go to the shop. The temperature has been from 10 degrees to -7 degrees. My little heater only keeps the shop about 20 degrees above ambient. I have been working inside for days on drawings. I am also looking for needed material pieces. Looked at Speedy Metals , but way too expensive once shipping is added. I ended up ordering a couple needed pieces from eBay. I have a couple ideas for the motor, but they are really out on the fringe of lunacy, so I will tell you about it if it works. I will get going again when the shop is warm enough to work in.
I"M BACK !!!!! I borrowed a heater for a few days so I could get some parts made. I wanted to start on the wheel head while I am waiting for material to get here to finish the tool holder. I made two designs for the wheel head. One was aluminum and the other was steel. I couldn't decide which one to use as they are both good. Since aluminum is easier to work with, I tried that first. I squared up a block of aluminum on my mill, then took it to the lathe and bored the hole for the column. My design calls for brass bearings in here , but if it works OK with out them , I'll leave them out. This photo shows using the 4 jaw chuck to bore the block . The hole is offset and not centered in the block.
I accidentally cut the bore .002" oversize. I hope it will still grip with the split cotter. We will see.
I put the block in my drill press and drill the hole for the split cotter. I step drilled until I got a .750" hole That has .125" interference into the bore.
I made the elevation block from aluminum and the column is steel. I had no brass for the split cotter so I made it from aluminum also. I turned a piece to just slide in the drilled hole and drilled it for the 1/4-20 locking screw, then put it on the mill and used a fly cutter to cut the notch. The cotter was then sawed in half and returned to the lathe where it was counter bored for a spring to go between the two halves.
This is the split cotter assembled with the steel screw and the spring.
The block is on the column and locked. Is very secure and I can't move it even with a mallet. The spring works just as it should when the cotter is loosened. Since this all worked so well , I guess I will use this design.
I next started on the wheel head arms that hold the spindle. They are made from 1/2" thick x 8" long aluminum bar 2 1/2" wide. They are bolted together so they can be machined as one. They will be mirror images of one another.
I used a fly cutter to bore the holes for the spindle.
The holes are bored and the end is split so the screws can draw the opening tight and clamp the spindle. I made a mistake reading my calipers and bored the holes .020" too big. If they won't close on my 2" bar stock for the spindle, I will have to get bigger stock and cut it down to fit. ( I'm glad I didn't make the spindle first.)
My 1/2"-10 acme lead screw came today for the elevation screw. I also ordered a backlash adjustable bronze nut for it . it should be here Monday. The motor should also show up Monday.
I accidentally cut the bore .002" oversize. I hope it will still grip with the split cotter. We will see.
I put the block in my drill press and drill the hole for the split cotter. I step drilled until I got a .750" hole That has .125" interference into the bore.
I made the elevation block from aluminum and the column is steel. I had no brass for the split cotter so I made it from aluminum also. I turned a piece to just slide in the drilled hole and drilled it for the 1/4-20 locking screw, then put it on the mill and used a fly cutter to cut the notch. The cotter was then sawed in half and returned to the lathe where it was counter bored for a spring to go between the two halves.
This is the split cotter assembled with the steel screw and the spring.
The block is on the column and locked. Is very secure and I can't move it even with a mallet. The spring works just as it should when the cotter is loosened. Since this all worked so well , I guess I will use this design.
I next started on the wheel head arms that hold the spindle. They are made from 1/2" thick x 8" long aluminum bar 2 1/2" wide. They are bolted together so they can be machined as one. They will be mirror images of one another.
I used a fly cutter to bore the holes for the spindle.
The holes are bored and the end is split so the screws can draw the opening tight and clamp the spindle. I made a mistake reading my calipers and bored the holes .020" too big. If they won't close on my 2" bar stock for the spindle, I will have to get bigger stock and cut it down to fit. ( I'm glad I didn't make the spindle first.)
My 1/2"-10 acme lead screw came today for the elevation screw. I also ordered a backlash adjustable bronze nut for it . it should be here Monday. The motor should also show up Monday.
- Joined
- Dec 22, 2012
- Messages
- 14