Carriage Stop Body Part Three, Drilling the Holes

[@Patroand]

Patience and precision. I have to remember that all the time when I want to make a part ! Thanks Mr. Tom

[@TomsTechniques]

Thanks Robert. It also helps to build the part in your mind before making any chips. Tom

[@MyShopNotes]

Great vids Tom. Thanks for sharing your expertise. I'm totally new to machining on a mill and the things regarding part movement while milling have taught me much with respect to my attempts at milling so far. Thanks.

[@TomsTechniques]

Thanks Steve, I'm glad you are enjoying them. Tom

[@jimmilne19]

Very informative and well done video programs. I'm looking forward to the next episode! Have a nice holiday season!

[@TomsTechniques]

Thanks Jim and the same to you. Tom

[@rchopp]

Very well done I am truly enjoying these. Merry Christmas

[@TomsTechniques]

Thank you. Merry Christmas!

[@dennyskerb4992]

Thanks Tom, great video

[@TomsTechniques]

Thanks Dennis.

[@AliMirjamali]

Thanks and wish you a Merry Christmas Looking forward to watch the next installment for chamfering.

[@TomsTechniques]

Do you mean milling the radii? I hope to finish this part off later in the week. And a Merry Christmas to you! Tom

[@AliMirjamali]

Yes, you are right. Radius rather than chamfers. My mistake.

[@mikeadrover5173]

Outstanding Information! As always, thanks’ for taking the time to make this video! And I support this site. ~M~ Newbie

[@MilanDupal]

Thanks for precise machining video!

[@TomsTechniques]

Thanks for watching!

[@ckvasnic1]

Tom, Nice show. You are not using a center drill or pilot drill for the holes. When do you feel center drills and pilot drills be used? Thanks for sharing your time and talent. All the best. Chuck.

[@TomsTechniques]

Chuck, If the drill I am using is small, or not self centering (most of my drills are split point), I'll use a center drill. It's probably hard to see in the video, but I also pause a bit when I start the drill to see if it has a tendency to wander. A drill that has a full chisel point (not thinned) will always wander and should be spotted first. Thanks for watching. Tom

[@garygenerous8982]

Tom, first thank you for doing these very instructional and helpful videos and please continue doing what you do. I do have a question in regards to this episode if you don't mind. When you set up the part to drill the set screw hole you did not whack the part down with the nylon hammer to seat it on the parallels. Was this an error or does it really not matter with operations like that where you are drilling, reaming, and tapping all in the same instance and the hole does not have to be exactly vertical? I know this video is really rather old and you may not see this (I don't know if you still get notifications or not) but as I am just starting to get into machining any answer would be very helpful.

[@TomsTechniques]

Hi Gary, I normally only take the time to seat a part on the parallels for close tolerance features, such as milled surfaces or bored holes. For a set screw hole like that, it doesn't really need to be dead perpendicular to the surface. In reality, it's not really necessary to seat a part for any drilled hole, because a drilled hole is itself a low tolerance feature. Thanks for watching. Tom

[@Rugby23Kid]

Tom, may be a stupid question, but as the bulk of the material is mild steel, are you not concerned it will slowly rust? Excuse my naivety, I just noticed the billet you rough sawn from looked pretty corroded. I know this would probably only effect the aesthetics, but it would be a shame if so considering all the hard work put into it!?

[@TomsTechniques]

+Samuel MacGregor Most of the lathe and the accessories used on it is either cast iron or mild steel. This stuff spends its life covered with oil, so corrosion isn't normally an issue. Of course brackets and things could always be painted and moving parts blackened if desired. Tom

[@Rugby23Kid]

Cheers for the reply tom! Have been learning a lot watching your videos :)

[@MattsMotorz]

How come you drill it under size and then use a reamer? Why not use a drill bit of the same size as your finished hole?

[@TomsTechniques]

Drill bits do not drill round holes, they actually drill triangular holes. They also don't drill accurately sized holes. Even a perfectly ground drill bit will only drill within a few thousandths of size and it's even worse for larger sizes. Reamers produce very round, very precise holes, usually within one thousandth of an inch. Using reamers it is easy to make a hole .001" larger for a slip fit on a dowel pin or .001" smaller for a press fit. You can't do that with drills. Tom

[@MattsMotorz]

Toms Techniques Cool! Thanks for your great response!

[@loricastro3772]

Toms Techniques Forgive my ignorance (I am a self-taught) and my poor english, but how come round drill makes a triangular hole?

[@TomsTechniques]

Lori Castro The cutting edges never cut at exactly the same time, so they tend to walk around the hole. When one edge bites, the other swings around it instead of the point. In most cases, it's not really noticeable, but if you need a round, closely sized hole for a dowel pin, you need to drill undersize and then ream. Tom

[@Cadwaladr]

I'm curious as to how you deburr the 7/16 holes on the inside of the slot, or do you not need to?

[@TomsTechniques]

I have a blade type deburring tool like this that will reach the inside edge of those holes. Tom encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcT4j6oKdsCCIbAfDc3tj9RvdmCaM--wA7vYyDZAbw4kVBV3IDlQ