More drilling questions

[moke]

I have seen numerous threads recently on drilling on the lathe. I have a similar problem to those mentioned. Here is my tale of woe...

I have a Delta Midi. I started drilling with a One-way Chuck with pin jaws. I put the drill chuck in the tail stock and tighten it down, then tighten the side tightener until I can barely turn the drill into the piece..so there is no play. I use a starter drill...a number 3..I believe. I got a good, well centered hole, but often the other side would be off center. I don't understand that..if the bit was bad wouldn't I just get a bigger hole. I saw a thread about a month ago where I thought the answer he got was the drill bits, but I failed to point out earlier that I have always turned my blanks round. He was not......SO I thought it must be the chuck. I waited until PSI collet chucks were back in stock and got one of those. I still have some of the same problem....but not always. My 60 degree centers line up, so I don't think it is the lathe....now there issome play in my talistock before I tighten it down, but I assume that is normal. Any one got any ideas, obviously I am doing something wrong?

Secondly, it sounds like some of the people here buy a complete set of drill bits and just use them. Are you buying them in a 1/64 increment set and miking the tube and picking the closest bit? Who makes a good set? It seems to me buying a good set of bits will pay for itself by ruining less blanks. I have always just bought the bit and a set of bushings with a different style kit. So I have a huge hodge-podge of drill bits
HELP!!
Mike

 

[PenMan1]

Mike:
I turn my blanks round (between centers) to about 3/4 inch in diameter (I often "batch" this process so that all my blanks are ready for drilling). A good quality 3/4 inch open end wrench serves as my "caliper".

Once rounded, I them mount the blank in my Beall collet chuck with the 3/4 collet (the PSI collet chuck will work just as well). I mount the Jacobs drill chuck with the correct bit in the tailstock.

Then I use the center marker just as you do. I make a "sharpie" mark on the drill bit indicating the tube length. With my right hand, with the lathe running at I guess about 1700 RPMs, I crank the wheel on the tailstock to push the drill into the blank util it reaches my Sharpie mark on the drill bit. (sometimes I have to crank the wheel in reverse to clear the drill bit).

Since most of the pens I make require two different size holes (Jr's mostly) I then remove the blank and cut it to the length of the tuble with my bandsaw (there are HUNDREDS of ways to do this, including cutting it on the lathe with a parting knife).

Then I glue up the tube in the properly sized and squared ends blank. This is the most accurate drilling method I have found. Although I can think of 3 or 4 other ways that are almost as good.

Then I change to the other drill size and repeat this for the second half of the blank.

I'll be interested to see how others do this as this is only one of MANY ways to accomplish accurate drilling.

As for drill bits, I only buy the bits that I use for various pens (not sets), label them with the "known kits" that they make and USE THESE BITS ONLY FOR PEN MAKING. I guess I am a little bit of a "bit snob", but I only buy Colt 5 Star or ocasionally for the odd stuff, Norseman bits. They are a little pricy, so that's the reason I never use these as "shop" bits. For shop bits, I buy the HD or Lowes "specials".

 

[moke]

Hey Andy---
Thanks for the advice, I really like your new avatar too!!
mike

 

[PenMan1]

Hey Andy---
Thanks for the advice, I really like your new avatar too!!
mike

A fine upstanding Gentleman, with very good taste in jokes designed and manufactured this avitar especially for me. I owe him greatly. I'll PM you his address and maybe he will make a cool one for you, too:biggrin::biggrin::biggrin:

Thanks MIke!

 

[ldb2000]

I think it depends on the size of the bit being use to some extent . I have had this happen on a 7mm bit and the problem is flex in the bit . A 7mm bit will wiggle like a snake if if the hole goes off center for whatever reason and will exit the blank off center . A 3/8" bit is much stiffer and won't flex as much so it will drill an oversize hole instead . Why the 7mm bit goes off center is the real problem . If the bit has a slight bend it will enter the blank at an angle and as it goes further into the blank it will try to follow that same angle and will flex further as it goes deeper into the blank . Since the sides of the bit don't cut as efficiently as the tip does it won't enlarge the hole very much but the tip will continue cutting the hole at the same angle it started at and the bit will flex around to follow the hole . George was correct that a shorter bit will cut a straighter hole because there is less distance between the cutting tip and the shank being held in the chuck , hence less flex . This problem can also happen if the bit hits a denser spot in the blank that deflects it off center but to a much lesser degree because the centered hole will try to keep the bit from flexing . In this case the hole will still go off center and will be enlarged at the same time allowing the bit to flex more and go further off center .
The thicker or shorter the bit is the less flex it will have so use the shortest bit that will drill to the depth you need when drilling with thinner bits like 7mm . Note that a sharper bit won't help this problem either , in fact it will make it worse because it will cut a cleaner hole and cut faster then the sides of the bit can scrape bigger .

 

[moke]

Butch,
I had forgotten this from the last thread, but it really makes sense. I was just noticing last night that it was a long ways from the end of the bit to where the Jacobs meets the MT. I would like to get some of the shorter bits, do you guys know who makes a good set...I would think I would like them in 1/64ths...Didn't you say that you have a HF set?
Mike

 

[mredburn]

ALso you might want to check to make sure both sides of the drill tip are sharp if one side is slightly dull it will pull the drill off center. Put your long drill in the tail stock as you have described and see how much flex you have just by pushing on the end of the bit then extend it all the way out and do it again. there is more play there than you realize.

 

[PenMan1]

Mike:
The other nice thing about drilling the two tubes independently of each other is that the drill bit does not have to travel but half as far as if drilling the entire blank. By drilling each half at a time, in essence you cut the drill "run-out" in half.

Do I do this on every pen? NO, on a 7mm slim (which I don't really offer for sale) I drill on the drill press (still in halves) because as long as I am in the same zip code, I can still make a pen.

 

[ldb2000]

Yes I have the big set from HF but not the real cheap one , the $70 set . It's still cheap but is better then the real cheap one . I try to minimize any problems by only drilling about an inch before I move the tailstock and always check to make sure that the bit is starting the hole in the center of the blank .

 

[moke]

Andy--
I hope I didn't give you the wrong idea, I have never drilled both tubes at once...I only make cigars where that would even be an option, and that never even crossed my mind. I sometimes get this on a 2 inch tube...so I really am doing something wrong. Where do you get the Colt 5 star bits? What is pricey?
Mike

 

[ed4copies]

Andy,

Are you happy with the Colt bits on plastics? I am looking for a good answer to the "plastic drilling" question.

 

[PenMan1]

Andy--
I hope I didn't give you the wrong idea, I have never drilled both tubes at once...I only make cigars where that would even be an option, and that never even crossed my mind. I sometimes get this on a 2 inch tube...so I really am doing something wrong. Where do you get the Colt 5 star bits? What is pricey?
Mike

I get the 5 Stars from WoodCraft (which to me means WC, Rockler, Highland Hardware or whatever "BOX" woodworking store I happen to be near), Or you can buy them online (I like Amazon). A Colt 5 Star Pen Maker's 3/8 inch bit is $16. Others are a little more or a little less.

Wow! on a 10mm cigar "half", something IS wrong. Usually either wood grain or bit flex.

 

[PenMan1]

Andy,

Are you happy with the Colt bits on plastics? I am looking for a good answer to the "plastic drilling" question.

Ed:
I could write a dissertation on that simple little question, but I won't.
Let me just say that the Colt 5 Star Pen Maker's series is, to date, the best drills I have used.

Even then on some acrylics and PRs (Merlin's Magic, Alchemy, and Ancient Mars-Blanks you may or may not be familiar with:biggrin depending on the precision required for the piece I am making, I will sometime still drill a 3mm pilot hole. These blanks mentioned make BEAUTIFUL pens, but do require paying close attention when drilling.

I ALWAYS pilot drill on casein, bakelite and ebonite. I also use pam cooking spray on bakelite and ebonite.

 

[moke]

Andy--I have been turning a lot of Cobolloa, I have pretty good luck with resin. and I think Butch is really right about flex--by the time I get a bit in a Jacobs, it is at least 6 or 7 inches from the MT.

Guys--what those short bits called? I really want to try them.
Mike

 

[PenMan1]

Andy--I have been turning a lot of Cobolloa, I have pretty good luck with resin. and I think Butch is really right about flex--by the time I get a bit in a Jacobs, it is at least 6 or 7 inches from the MT.

Guys--what those short bits called? I really want to try them.
Mike

Colt 5 Star DOES make a set of "short" brad points (not the pen makers series) in metric. I use that little 7mm Colt BP bit(instead of a 'J" bit like many use) on wood with great success.

I'll find you a WC or Rockler link...
http://www.woodcraft.com/Catalog/Pr...28253&ss=d5161ade-883d-47c0-b521-d010a4c24499
The Pen Maker's "Set"

I didn't find the little BP I like so much, but all the HSS Colts are on clearence:
http://www.woodcraft.com/Search/Search.aspx?query=Colt%205%20Star%20brad%20point

 

[ldb2000]

The short bits George mentioned are "Machinist bits" here are some in SAE sizes but they don't have Metric ones though http://www.victornet.com/subdepartments/HS-Screw-Machine-Drills/1190.html These guys also have bits called "Fast spiral" that look promising but I haven't tried them yet , next time I order I Will though .

 

[Paul in OKC]

In the machinist world, short bits are 'screw machine' length. Regular length are known as 'jobber' length drills. Screw machine bits are short and stubby to reduce flex in a machining proccess.

 

[Russianwolf]

I have a "cheap" Titanium coated bit set (100 some odd piece set) and it does wonders. I have gotten in the habit of drilling a pilot hole with a nice sharp smaller diameter (shorter length) bit from the set and then coming back with the correct bit that I measure with calipers for the tube (I don't take the manufacture's recommendations any more). Some larger ones I'll do in several steps in sized bits.

I cut the blanks in half before drilling, as the more length sticking out of the chuck, the more room for wander (remember, wood moves). This can be especially bad in some larger diameter pens where the material will be thin. A little wander can crack the blank before you finish drilling.

I differ here from others as I will usually let the tailstock remain loose and move the entire setup by hand. I find I have more control this way as I need less time to reverse the bit out of the blank. If there is a vibration I can always lock the tailstock down, but I honestly don't run into that except in blanks that are not consistent in density, or shape.

I have one of the Norseman bits, and I will say that it is the best bit I've ever bought. The edge stays sharper longer than anything I've seen. But at $15 a pop, I couldn't afford a complete set to save my life.... Maybe my wife's life but only because I love her more than myself.

 

[PenMan1]

I

I cut the blanks in half before drilling, as the more length sticking out of the chuck, the more room for wander (remember, wood moves). This can be especially bad in some larger diameter pens where the material will be thin. A little wander can crack the blank before you finish drilling.

I have one of the Norseman bits, and I will say that it is the best bit I've ever bought. The edge stays sharper longer than anything I've seen. But at $15 a pop, I couldn't afford a complete set to save my life.... Maybe my wife's life but only because I love her more than myself.

By rounding the blank and using the Beall, you can stick just about all of the blank into the headstock and leave almost none of the blank sticking out.

When I can't find a specific size in the Colt, I use the Norseman. You explained why (price) I buy only the bits I need and not "sets"

 

[Dudley Young]

IMO a drill as small as a #3 would walk all over the place in grainy wood and most acrylics. You don't need a pilot hole. Just drill it the size you want in one process. I use all dedicated bits like Andy for my pens. I keep the drill in the drawer with the pen bushings for each pen. I use all good quality brad point drills and drill my blanks in the rough on the drill press using pen vice at 750 rpm. I always cut my blanks long and insert the tube on the opposite end if there is any blowout. Don't use a barrel trimmer much although I do have a set available. I square the ends on the belt sander. I use a deburing tool to clean up the end of the tube. That Works for me.

 

[PenMan1]

IMO a drill as small as a #3 would walk all over the place in grainy wood and most acrylics. You don't need a pilot hole. Just drill it the size you want in one process. I use all dedicated bits like Andy for my pens. I keep the drill in the drawer with the pen bushings for each pen. I use all good quality brad point drills and drill my blanks in the rough on the drill press using pen vice at 750 rpm. I always cut my blanks long and insert the tube on the opposite end if there is any blowout. Don't use a barrel trimmer much although I do have a set available. I square the ends on the belt sander. I use a deburing tool to clean up the end of the tube. That Works for me.

I have never used a 3mm on wood as I am sure it would walk everywhere. Mostly the 3 mm or 4 mm is to pre drill bakelite. Now, that Ed sells pilot-drilled bakelite this is no longer necessary. I find that it works very nicely on PR.

 

[Shannon]

Although I'm somewhat new to turning here is my process:

I drill square blanks on the press

I have a complete set of drill bits in 1/64 increment.

I don't worry about what drill bit is called for in the instructions. I find a bit that fits the INSIDE of the tube and drill with that and then check for fit. With wood, I 100% of the time need to drill with the next larger drill bit. I'm not really sure why but only 50% of the time I need to make the whole larger with acrylics.


Shannon

 

[Russianwolf]

IMO a drill as small as a #3 would walk all over the place in grainy wood and most acrylics. You don't need a pilot hole. Just drill it the size you want in one process. I use all dedicated bits like Andy for my pens. I keep the drill in the drawer with the pen bushings for each pen. I use all good quality brad point drills and drill my blanks in the rough on the drill press using pen vice at 750 rpm. I always cut my blanks long and insert the tube on the opposite end if there is any blowout. Don't use a barrel trimmer much although I do have a set available. I square the ends on the belt sander. I use a deburing tool to clean up the end of the tube. That Works for me.

a #3 centering bit and #3 drill bit are very different.

Drilling on the lathe, I've never had any issue with the bit walking on any wood or plastic as long as the end being drilled is flat/perpendicular to the bit.

 

[mtcsss]

Walking Bits

Drill bits will inherently walk in just about any material. Even on a metal lather drilling through steel. To get a perfectly centered hole from one end to the other I drill halfway through with a smaller size bit. Then turn the blank around and drill to the center from the other end. Then using the actual size bit, I drill all the way through and have a perfectly centered hole. This process is not usually necessary if you buy blanks large enough to accommodate the walk of the bit. I never drill anything smaller than 5/8" and usually use 3/4" blanks. Being a little off center does not usually matter. Just make sure you square the ends to the angle of the tube.

 

[PenMan1]

Drill bits will inherently walk in just about any material. Even on a metal lather drilling through steel. To get a perfectly centered hole from one end to the other I drill halfway through with a smaller size bit. Then turn the blank around and drill to the center from the other end. Then using the actual size bit, I drill all the way through and have a perfectly centered hole. This process is not usually necessary if you buy blanks large enough to accommodate the walk of the bit. I never drill anything smaller than 5/8" and usually use 3/4" blanks. Being a little off center does not usually matter. Just make sure you square the ends to the angle of the tube.

I have done something similar to this when drilling Corian (1/2 inch) and it really does work well! "unglued" Corian is just big enough to make a European style pen. But I can't turn it round and drill on the lathe (lose too much "meat"). But this method works very well on the drill press, too.

 

[soligen]

In the setup, having the centers exactly meet is not good enough. This means that the points touch at one location, which needs to be true, but also the axis on the drive and tail centers need need to be co-linear.

To test for co linear, chuck up a very short bit that is known to be straight and check the centers. Then chuck up the longest perfectly straight bit that you have and check the centers. If points align in both cases then you are co linear.

If you get a squeaking noise while drilling, then the side of the bit is rubbing the wall of the hole and you are likely not co-linear.

 

[moke]

All-
Thanks for all the great advice...this is truly what makes this website the best thing that ever happened to my pen making...so...

Dennis--I frequently hear squealing...it has sometimes driven the little woman out of the shop ..... I will check to see if it is co-linear ASAP--if it is not, what is the proper way to correct it.

Butch---Thanks for the website for the shorter drill bits...they are really cheap...I will order a set of those. How big should I go? Up to 1/2?

Mike--I have been using a #3 centering bit. My father was a Machinist the whole time I knew him. He is deceased, but I have all his stuff, a good dial caliper, tons of bits, little hammers etc evertything....except for his good Sarrett Mics, he sold those. So, if I understand you right, it does not hurt to use that centering bit, but really kind of a waste of time. Which reminds me, he must have had 5 brass headed little hammers, that he made, if I just tap, are those too rough for my Delta...just like to tap the Jacobs in, stuff like that?

Andy--I am going to see if the short bits correct my problem and if they don't I will order some Colts. I will PM you before I do. Do you think the words on your avatar need to be even bigger? Let me know.

Thanks again for everyones help....
Mike

 

[Russianwolf]

I wouldn't say the centering bit is a waste of time, just a different method of doing the same thing.

I usually start with a bit around the 1/4 inch/J/7mm size or smaller since I know I'll be using a bigger bit to finish off than that. I grab a bit I know is sharp, for that pilot hole. You are using the #3 centering bit for the same purpose, I'm just going deeper (sometimes to full depth, sometimes not depending on the pen I'm making)

I wouldn't start off with an A or 1/32nd since they are so small as to really be a waste of time for this.

For facing the blank, I put it in the chuck and use my skew to trim the end. This allows me to make the end concave slightly which I've had better results with than the absolutely flat face a mill/sander leaves. Before putting it in the chuck, I turn it between centers to make sure the blank is true to the tube, just in case the drilling wasn't perfect.

brass hammers are used to prevent marring when working other metals. I use a handmade wooden mallet in my shop to set the jacobs chuck in the tailstock if I think it needs it. I have a nice gouge in the side of my left thumb right now from the jacobs chuck coming loose and the bit seizing in the blank last week. The teeth that the key uses to tighten the bit were against my thumb and aren't very forgiving in that situation.

Again this is what I do since it works for me. Others use different techniques with just as good of results.

 

[soligen]

Mike, what do do depends on your lathe. I used metal HVAC tape as shims to adjust things. I still get some squeaking, but not as bad as when I started.

Its a finickey process, but I have a shopsmith. Hopefully a real lathe will be easier.

 

[IPD_Mrs]

Like many here I drill on the lathe as often as I can. Square blanks turned round to 3/4, insert into the collet and have at it. Two things worth mentioning here. First is heat when drilling. Many woods hate the heat and will retaliate down the road with a crack or two. When drilling, use your air compressor and blow air into the hole through the drill bit veins. This keeps the heat down, maybe 110-120 in ebony. Yes it is messy but well worth the effort. 40-50 PSI seems to do the trick. Sharp bits from the drill Dr. is a plus too.

The other thing is to mill the ends on the lathe. You get a cleaner mill, much safer than holding the blank in a hand drill and much faster.

 

[soligen]

I need to amend my process for checking the that head and tail of the lathe are co-linear. The process I suggested assumes the drive center is parralel in both pitch and yaw to your lathe rails. You can verify this first by doing the same procedure in reverse, putting the chuck and drill bits in the drive side. Not owning a real lathe, I cant suggest how to fix it if it's off, but if it is, I would think you would want to correct the drive side first, then the tail.