ArdWrknTrk Posted February 23, 2018 Share Posted February 23, 2018 Now I just need a milling machine...... I do have a drill press and bought an "X"-"Y" vise, I'll try milling with that.... Drill presses don't typically have bearings suitable for side loads. (or tables, or....) Just a warning not to destroy a tool trying to make it do something it was never designed for. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 23, 2018 Share Posted February 23, 2018 Just picked up a set of Milling cutters from Harbor freight. Broach? what is that? A broach is a tool that is pushed through a hole to form it to another shape. These are commonly used to cut keyways or make square, rectangular, or other polygonal shapes. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 23, 2018 Share Posted February 23, 2018 Just picked up a set of Milling cutters from Harbor freight. Broach? what is that? I'll let Jim speak to the broach question. But when you mill you want the end mill's working point to be as close to the chuck as is possible. So short mills put as far into the chuck as possible is best, and then put as much of the mill through the part as you can so you work at the top of the flutes. Too much leverage will cause problems, especially when using a drill chuck instead of a collet. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 23, 2018 Share Posted February 23, 2018 I'll let Jim speak to the broach question. But when you mill you want the end mill's working point to be as close to the chuck as is possible. So short mills put as far into the chuck as possible is best, and then put as much of the mill through the part as you can so you work at the top of the flutes. Too much leverage will cause problems, especially when using a drill chuck instead of a collet. Jim is right about the mill vs drill press. A mill's column has bearings designed to take both end and side loads. But most drill presses have bearings designed for end loading only. So you have to be very gentle and work very slowly, and with very little leverage. I've done it, but it isn't ideal at all. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 23, 2018 Share Posted February 23, 2018 I'll let Jim speak to the broach question. But when you mill you want the end mill's working point to be as close to the chuck as is possible. So short mills put as far into the chuck as possible is best, and then put as much of the mill through the part as you can so you work at the top of the flutes. Too much leverage will cause problems, especially when using a drill chuck instead of a collet. I just googled 'press broach' and came up with a bunch of YouTube videos. Imagine a square file with single cut teeth and a smooth pilot diameter on the end. When this is forced into a pilot hole the taper of the broach makes each tooth take a slightly bigger cut. You can use a arbor or hydraulic press but there are some rules of thumb re: # of teeth engaged depending on material thickness, lubrication, tooth form for CI, steel, red metals, aluminum, etc.. Link to comment Share on other sites More sharing options...
reamer Posted February 23, 2018 Author Share Posted February 23, 2018 I just googled 'press broach' and came up with a bunch of YouTube videos. Imagine a square file with single cut teeth and a smooth pilot diameter on the end. When this is forced into a pilot hole the taper of the broach makes each tooth take a slightly bigger cut. You can use a arbor or hydraulic press but there are some rules of thumb re: # of teeth engaged depending on material thickness, lubrication, tooth form for CI, steel, red metals, aluminum, etc.. Thanks Guys, All of this will be "kept in mind" Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 23, 2018 Share Posted February 23, 2018 Thanks Guys, All of this will be "kept in mind" What size is the square part of a bumper bolt? I went with stainless carriage bolts when I had to replace my bumper. Link to comment Share on other sites More sharing options...
85lebaront2 Posted February 23, 2018 Share Posted February 23, 2018 Thanks Guys, All of this will be "kept in mind" We had a square drill in the shipyard, it was a hollow square broach with a drill inside it, the drill was the size you wanted the resulting square hole to be and in a drill press or Bridgeport it would allow you to fairly quickly make square holes. Link to comment Share on other sites More sharing options...
reamer Posted February 25, 2018 Author Share Posted February 25, 2018 We had a square drill in the shipyard, it was a hollow square broach with a drill inside it, the drill was the size you wanted the resulting square hole to be and in a drill press or Bridgeport it would allow you to fairly quickly make square holes. Well that didn't work... 1/2" end mill in my floor-drill press, any side load and the chuck falls out of the "press fit" into the head. Must either by a bench-top milling machine, or figure another way to cut slotted holes.... Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 25, 2018 Share Posted February 25, 2018 Well that didn't work... 1/2" end mill in my floor-drill press, any side load and the chuck falls out of the "press fit" into the head. Must either by a bench-top milling machine, or figure another way to cut slotted holes.... Bummer! The broach may be a better approach as you can get a square hole. But, if you are considering going to a mill, let me tell you a bit about my experience with a 3N1 machine - Harbor Freight's #44142. It worked, but wasn't as useful as I expected. My learning was that a dedicated machine is better than an one-device-does-all. Also, whatever the cost of the machine you can expect to double it with the tooling you'll need. Maybe not right off the bat, but it won't be long. Link to comment Share on other sites More sharing options...
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