drill shopping--- what drill speed ?

[fairchild]

Ok-- im stating to drill shop----
I think I want the tinyist palm drill in 1/4 inch size---- CP-7300 looks like it would work--- its plain bearings- 2600 RPM- its pretty small-
I THINK I want a variable speed with a good controlable trigger...
Since it will be used mostly for # 2,#3 and #4 rivet holes--- the bits will be relatively small--- so I am thinking that a bit higher RPM would be helpfull.
I see lots of them that run 2600 - some at 3600 and a few at 4000 RPM.
What would be an ideal speed range for these small drill bit sizes ? Im assuming the starting point as you squeeze the trigger would increase proportionaly as
the top speed rating got bigger. Im thinking the "turn-on" speed might be important when starting a pilot hole ( that is not having it TOO fast ..... )

I have only used the cheap, ugly non-variable speed ones.... with an all or nothing trigger..... (not used friendly ! )

The cheapest sioux appears to be about 250$ at brown tool. CP-7300 about 140$ A used sioux would be fine if I could find one localy to inspect its
condition. I think i like the smallest "palm" style for rivet drilling.

Opinions ?

Tim

[N134RT]

The basic rule I learned from aircraft sheet metal class was, "Big bit, little speed. Little bit, big speed." That means a bigger diameter drill bit requires a slower speed to cut properly and not overheat. The opposite is required for a smaller bit. It's all about the speed of the cutter on the drill and the metal you are cutting. With this said, A drill motor with a quarter inch chuck and variable speed is a good all-around drill. Unfortunately, you will find with sheet metal work, the number of tools you need to do it properly are many, and expensive. I recommend checking out Aircraft Tool Supply for a drill motor. You want one with a, " teasing trigger" and a smooth, variable speed. If you can still get one with a Jacob's mfg. chuck and a conventional chuck key, that's best. The newer, keyless chucks are bulkier in size, and inferior IMHO. One more thing, buy an air control valve that screws into the air drill and allows you to fine tune the air to your drill. They are not expensive and are very useful in not only air drills, but rivet guns, too.

To answer your speed question, in general, a 1/4" drill motor will have a faster speed than a 1/2" drill motor. This is due to the larger drill bits needing a slower speed. The air control valve mentioned above helps greatly in fine tuning the speed of the drill. So, when you pull the trigger back fully to drill, the speed will be set for you. Rather than go just by drill rpm, use the chuck size to serve as a guide for the right drill motor to buy.

hope this helps.

[S Lathrop]

I have used these drills for years. I have both 2600 and 4000 rpm drills. http://www.panamericantool.com/

[fairchild]

thanks 134 and lath-
Yes-- there is some range of linear speed at the outer cutting edge thats somewhat constant for a given material. i have noticed most full size electric drills are kind of too slow
for bits in the range of 3/32 or 1/8. I will look again at pan-am.
Just for FYI---- is the pan american ball bearing or oilite bushing ? ---- so I am comparing apples to apples-----

[Bcone1381]

I acquired an old, beat up, used Mac air drill with a broken chuck a few years ago. The keyed chuck was broken when I got it and I replaced it with a keyless chuck. I don't even think about it much. I don't know what speed it is. I don't know what kind of bearing it has. I like the keyless the chuck. (edit...my drill's label says 2800 rpm)

My advice regarding drills
-Budget.....Make sure you don't spend so much on tools that none is left to buy materials.
-Use BoeLube when you drill no matter what kind of drill you buy.
-Buy a dozen drill bits of the common size you will need. I got mine from Pan American Tool place. Jobber Colbalt Bits...I dozen per pack. When a bit starts to wander, it gets replaced.
-I like going slow when I drill...in steel slower is better as heat is the drill bits enemy....seems to work for me also in Aluminum. But I know the upper end of the drill speed sounds cool...like a race car.


I can't believe how quick I can drill 4130 steel with a very slow moving drill and BoeLube. When the drill bit is warm, the Boelube melts and I give it a dip every hole I drill. A Sioux drill could not do it faster. (I know Sioux products are VERY nice...I used one once....just don't let the expensive drills prevent you from buying materials.)

[BTAZ]

A different thought....

I used an older 1/4" Rockwell air drill for most of the wing build(plus a few places I needed a right angle air drill I sourced from Ebay)

But once you move on to the fuselage, almost all drilling/reaming is in steel and are also typically larger holes(finishing at 3/16" and up) which require lower RPM and more torque. For this, my "go to" drill was my rechargeable drill, occasionally supplemented by a 1/2" electric for the biggest holes..

With the current smaller, lighter, Lithium powered, rechargeable drills, if I didn't already have an air drill and everything needed to go with it(decent air compressor with a water separator, lightweight air hose,the discipline to oil the tool at the start of the work session.etc.) , I would put my money into a quality rechargeable(or even two loaded with different size bits) and perhaps an extra battery or two.

Most of the required wing drilling are for small holes and thin material so drill just fine even at the lower top RPM of the battery drill. Generally, the thicker pieces(like splice plates and cap strips) can be pre-drilled on a drill press and then the spar match drilled as required.

You certainly won't miss dragging the air hose around the shop

[Gavin Chester]

If you are thinking electric, This one works well.
Makita #6501
4500 rpm.
It has a built in stop.

[Archer39J]

I just got one of these: DeWalt DWE1014. As I understand 2800 rpm should be sufficient, but I'll defer to the more experienced out there. For $60 it's not a bad deal...

[marcusofcotton]

I've done thousands of holes with the following very light weight and compact cordless. Buy a few 1/4" hex drive bit holders to fit #30 & # 40 long and short bits, cheap hex drive set of single flute countersinks for deburring. The impact doesn't come into play with the light loads. Easy on the arms/hands/wrists.

Makita XDT04RW 18V LXT® Lithium‑Ion Compact Cordless Impact Driver Kit (2.0Ah)

POWER : Variable speed (0-2,300 RPM & 0-3,200 IPM) provides 1,420 in.lbs. of Max Torque

• ERGONOMICS : Compact design at only 5-7/16" long

[schu]

I have the CP-7300R and it works great for me.

[geraldmorrissey]

If you plan on scratch building your wings, you will drill hundreds of holes. Go the extra few bucks and get a Sioux mini palm drill @3,600 RPM with a hose swivel. I love mine. Best chuck I've ever had on a pneumatic drill. It's fairly compact and light. It fits my hand perfectly and it's got a comfortable padded grip so it's easy on my hand/wrist.
just my .02
Gerry
Patrol #30

[bergy]

I've been sidetracked for a couple of days working on other projects. All these projects involve drilling lots of holes. I realize now that I need to invest in more drill bits.

Four or five years ago a bought a handful of small bits from a vendor at EAA OSH. These bits have been nothing short of wonderful. I don't think I have ever bent/broke/or had to sharpen one of them. Recently I helped a friend drill out a broken stud on the the front wheel of his Jeep. None of my old legacy-bit would touch it, so I tried one of my EAA Bearhawk bits and it came thru good as new. I tried to find the guy at OSH last summer and could not find him. I remembered that the guy was from Minnesota so I did some online searching and think I found him in Winnebago MN. I ordered a set of Moly-bits from him. Will see how they work.

I am now overwhelmed with specs and claims of drill-bit manufacturers. Anyone know the advantages/preferred-uses/etc for Cobalt/Moly/Titanium-Coated/etc alloys? What works best for aluminum/carbon-steel/stainless-steel/etc/? I think the ones I was using are Moly.

Anyone ever deal with DrillHog products? (Gotta be better than Harbor Freight)

[Bcone1381]

Bergy, I have a sneaking suspicion that you have the patience of Job and will sniff out an unbelievable deal on drill bits. I am different....When I am at OSH, I don't have the foresight, or am too frugal to get what I need when at 1/2 the price. Then, when I need it and I dont have the patience to shop much. I just want to get it done, and I am happy if I feel like I avoided getting ripped off. OSH sometimes gives me buyers remorse.

I was smart enough to buy all my drill bits a dozen at a time. I got cobalt jobber drill bits at Pan American Tool (based on a recommendation, and reasonable shopping around) the sizes I felt were commonly needed....for drilling -3, and -4 and -5 rivets. I have been very happy with them and will probably last me a lifetime. They last a long time, and even longer when I am faithful applying BoeLube on them. At the same time, I spent almost $100 on drill 7 dozen bits. They are great quality and last a long time.

Bergy, when you flush out that dirt cheap price on drill bits, let the others know so they can jump on it with you. I know I am too late....er um.....too early.

[fairchild]

Bergy--
I remember a guy from somewhere up north I met at sun-n-fun in the vendor area. he was selling some kind of new formulation of an alloy with carbide as 2 or 3 other
metals. he claimed it was much harder than straight carbide. I remember he said they were made in Russia. Regular carbide never seems very sharp but it will take heat to the point that the silver solder holding the inserts melt (1200F) ---- but mostly it does not loose its heat treat like steel for hard to drill materials.
I have liked titanium nitride coated high speed steel or cobalt steel. I was buying Bosh brand Ti-N bits. They seemed to be the best wearing bits for aluminum. Cobalt drills
are quite a bit harder than high speed- they can drill hardened steel well but being harder they break quite a bit easier. not sure if the extra hardness and greater fragility is
any help on sheet aluminum. But DEFINITELY - the Ti-N coating helps. The store stopped carrying bosh bits and switched to dewalt and i could tell right away they were
not as good as the bosh.

[bergy]

I've been having trouble drilling lots of 1/2" holes thru 3/4" of 304SS; bits do not last. I think my problem might be maintaining the correct pressure. Too much pressure and the drill-press belt wants to slip. Too little pressure and the drill gets dull.

I grew to love Bosch blades in my Milwaukee Sawzall on a project years ago. The Bosch blades ate up 3/4" grade-8 bolts like crazy. Competitor's blades would not last thru a single bolt.

[Bcone1381]

Bergy, I assume you are center punching and using some type of cutting oil. I am curious the results if you started with very small bit (to induce less torque on your drill press) and kept up the high pressure high on the bit.

I thought Post # 14 on this thread was particularly applicable. Dont skip over Post # 7.

http://www.vansairforce.com/community/showthread.php?t=77944