Scale Models - View Single Post - Suitable tooling for Micro Milling Machine

**GEEDUBBYA** · 25-01-2007

Howdy Guys,

Ok, I have been abit lax in keeping up with this thread since I began working really odd hours at work. However, I have made "ICT's" (Improvised cutting tools) lol on more than one occassion for my Dremel Rotary tool.
Now being a machinist, I have access to some tools most ppl wouldnt have, but, these little bits can be made with nothing more than a coat hanger wire small diameter steel rod, a file or bench grinder and a little patience.
My drawing below shows how to make a simple "cutting bit for a rotary tool" , and not having realized your problem with "chip clearance until just a minute ago, with a few minor alterations, these home made bits can be made with a "chip breaker" which is merely a small groove in the upper part of the cutting surface (along the shank of the "bit").
Please remember if this bit is to be used in a rotary type tool, the stock material needs to be as straight as possible...especially at high speeds. Otherwise you may be visiting your local Dr. to have it removed from under your skin. And as always, wear eye protection when using any cutting bits.
The "bits" I have built in the past have usually been made of drill stem material from broken drill bits, however, wire from a coat hanger will work for use on plastic. Brazing rods or welding rods can also be used if availible.

As I said, a "chip breaker" can be easily made by cutting a "notch" along the cutting edge of the Shank of the bit (right side shown in dark grey in drawing above, about 1/2 way in face of cutting edge).
As stated above, this is the same principal as used in making a screw self tapping, using a file or grinder, you merely cut away an area with a 90 degree face (for cutting metal). However, in a self tapping screw application, no chip breaker is required due to the threads of the screw preforming that function.

I hope this makes sense and if it does, I hope it helps.

Have a good day,

Greg

25-01-2007	#20 (permalink)
GEEDUBBYA Moderator Join Date: Jan 2005 Location: Pine Bluff, Arkansas Real Name: Greg My Models: model planes tanks and helicopters as well as missiles and rockets Visit GEEDUBBYA's Gallery Posts: 1,015 Images: 329	*Howdy Guys,* Ok, I have been abit lax in keeping up with this thread since I began working really odd hours at work. However, I have made "ICT's" (Improvised cutting tools) lol on more than one occassion for my Dremel Rotary tool. Now being a machinist, I have access to some tools most ppl wouldnt have, but, these little bits can be made with nothing more than a coat hanger wire small diameter steel rod, a file or bench grinder and a little patience. My drawing below shows how to make a simple "cutting bit for a rotary tool" , and not having realized your problem with "chip clearance until just a minute ago, with a few minor alterations, these home made bits can be made with a "chip breaker" which is merely a small groove in the upper part of the cutting surface (along the shank of the "bit"). Please remember if this bit is to be used in a rotary type tool, the stock material needs to be as straight as possible...especially at high speeds. Otherwise you may be visiting your local Dr. to have it removed from under your skin. And as always, wear eye protection when using any cutting bits. The "bits" I have built in the past have usually been made of drill stem material from broken drill bits, however, wire from a coat hanger will work for use on plastic. Brazing rods or welding rods can also be used if availible. As I said, a "chip breaker" can be easily made by cutting a "notch" along the cutting edge of the Shank of the bit (right side shown in dark grey in drawing above, about 1/2 way in face of cutting edge). As stated above, this is the same principal as used in making a screw self tapping, using a file or grinder, you merely cut away an area with a 90 degree face (for cutting metal). However, in a self tapping screw application, no chip breaker is required due to the threads of the screw preforming that function. *I hope this makes sense and if it does, I hope it helps.* *Have a good day,* *Greg*