- Joined
- Jul 28, 2017
- Messages
- 2,565
There you go -- I did learn something new!
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Horizontal fly cutter
- Thread starter dewbane
- Start date
- Joined
- Mar 2, 2018
- Messages
- 232
It seems like "fly cutter" is just one of those annoyingly vague terms. Another one that comes to mind is "bill." A bill can be a piece of paper telling you how much you owe, it can be a proposed piece of legislation, it can be the brim of a baseball cap, it can be a duck's beak, it can be a piece of paper money, and a bunch of other stuff.
So at least I didn't make a bill for my lathe. Then nobody would possibly be able to guess what it was for!
- Joined
- Apr 29, 2019
- Messages
- 2,252
Int the one photo before bluing there is a drop of water near center that makes it look like the slot is way off center. If you zoom way in you can see that the slot is only a couple thou off center and it is off on the good side. I would much rather be shy of center than over center.
If you think about the forces during cutting it does not matter which side the set screws are on. The commercial fly cutters all have the set screws on the side with less material to drill through. It saves time and money in the drilling and tapping operations. In use there will be near equal force on the screw at one end of the cutter and the other end will be forced against the tool body.
If you are having a hard time visualizing this make up something with a slot that is twice as wide as the cutter and apply pressure in the direction of cut to see where the tool moves in the slot. it will turn until it is touching the opposite corners at each end of the slot. now if you put in a set screw to hold down the one end the force will be on the setscrew and the far side of the slot. So it does not really matter which side the screws are in, the thin side is just easier to do.
I know you want pretty, but Stainless hardware is pretty soft and may not hold as well as a steel setscrew. The SS screw tip will flatten under the tightening load. Stainless fasteners also have the nasty habit of thread galling where the screw threads literally weld themselvs to the hole threads. I only use SS fasteners when absolutly needed for some special situation like a very corrosive environment.
If you think about the forces during cutting it does not matter which side the set screws are on. The commercial fly cutters all have the set screws on the side with less material to drill through. It saves time and money in the drilling and tapping operations. In use there will be near equal force on the screw at one end of the cutter and the other end will be forced against the tool body.
If you are having a hard time visualizing this make up something with a slot that is twice as wide as the cutter and apply pressure in the direction of cut to see where the tool moves in the slot. it will turn until it is touching the opposite corners at each end of the slot. now if you put in a set screw to hold down the one end the force will be on the setscrew and the far side of the slot. So it does not really matter which side the screws are in, the thin side is just easier to do.
I know you want pretty, but Stainless hardware is pretty soft and may not hold as well as a steel setscrew. The SS screw tip will flatten under the tightening load. Stainless fasteners also have the nasty habit of thread galling where the screw threads literally weld themselvs to the hole threads. I only use SS fasteners when absolutly needed for some special situation like a very corrosive environment.