Need help regarding specialized drill bits

[md1400cs]

Hi everyone,

 

Please see pics. I want to be able to cut long grooves, such as those you see on this cathead (ignore red circles). I have a Dremel as well as a Dremel drill press.What are these specialized bits called? What I am doing is unacceptable.  I cut gooves, then add a block at the base. Very poor Hmmmm...., as you can see.

 

I've Googled it but can't find what I need. I can't locate the right kind of "straight" bits. I have some router bits, but all are with ball tips. Thanks in advance for any specific help.

 

Regards, Michael

[maaaslo]

Would you consider burning the groove out?

Just get the profile of that groove done out of some hard metal and then heat it over the flame. It should work. In joinery and carpentry this method is used sometimes...

[Gaetan Bordeleau]

You should  look for end mill micro size.

2 things to choose: end diameter and shank diameter.

[Sailcat]

Are you thinking about a Rotary Saw-type drill bit?  These kind of look like regular drill bits but are made out of harder metal to allow sideways cutting instead of just 'in line' drilling.

 

I believe Dremel actually has a range of these bits - a friend of mine used his Dremel to cut straight lines through wall tile using what looked like a thick drill bit.  But they're probably way more expensive and might not be available in the size you need.

 

And failing this, have you considered doing it by hand?  It's slower but there a lot more control over the situation, carving wise.

 

Good luck with finding what you need

[wefalck]

I guess you are looking for end- or slotting mills. What widith is the slot ? End-mills at a reasonable price go down to 1 mm diameter, but are actually made for metal. There is a limit to the depth of the slot, as the end-mills usually have only a useable length of 3-4 times the diameter. There are also two-fluted carbide end-mills with a diamond cut at the sides, but I believe they are only made down to 2 mm diameter.

 

You would need an x-y-table to be able to do the milling. Pushing end-mills through by hand will sooner or later result in their breakage.

 

Another method would be to drill several holes along the slot and then to chisel out the material in between. You would need to grind your own chisel from a piece of tool steel or modify a small cheap screwdriver. The blade of the chisel should be the width of the slot.

 

wefalck

[craigb]

1) End mill will do it no problem

2) Any rotary burr will work

3) you can often buy used dental drills (mini end mills sorta) on Ebay a bag at a time for cheap

 

3) My preferred method would just drill a hole at the end of each prospective slot and use a jeweler's saw to connect it into a slot

[md1400cs]

Thanks to all for your suggestions. It seems that end mill micro size bits are the answer. I will search for some that fit a Dremel. Here is a pic of what I needed. I was not unaware of these end mill bits. Again thanks for all of your help.

 

Regards, Michael

 

 

 

 

[Gaetan Bordeleau]

The fastest procedure is to use the end mill as a drill bit  and make a hole, advance half the distance of a hole, sink the end mill and so on. At the end, you can run from one end to the other  without fear to break the end mill. This procedure is fastest than to make many successives pass each one deeper than the other.

[wthilgen]

End Mills

[md1400cs]

The fastest procedure is to use the end mill as a drill bit  and make a hole, advance half the distance of a hole, sink the end mill and so on. At the end, you can run from one end to the other  without fear to break the end mill. This procedure is fastest than to make many successives pass each one deeper than the other.

Gaetan,

 

Thanks for your excellent advice. I will follow this once I acquire the bits.

 

Regards, Michael

[mtaylor]

Michael,

 

If you can't find end mills at a reasonable price, you can use a drill bit by grinding off the point. The other way is take a drill bit, flip it so the non-cutting end is sticking out of the chuck. Use a grinding stone and grind off about half the material on the bit from end to the cutters. You end up with a half-shaft but it works. I used this when I did the bitts on my Triton cross-section. The tip came to me via a former member.

[md1400cs]

Mark,

 

Thanks for that idea. Good to know.

 

Regards, Michael

[mtaylor]

By the way, Michael,  this is bit off topic,

 

The late Roma used to make his mill and router bits for the odd shapes of trim, etc. from nails.  He'd pound an area flat, grind and shape that area and them mount the nail in his mill or router.  

[WackoWolf]

Mark,

 

  I also remember someone else making them that way, I still have the pictures. I had gotten the pictures from MSW1 before the great crash. Thanks for also remembering this.