Tiny Drill chuck

[Tomc938]

So I made may first brass cannon today. 1" long. I'm looking for some way to hold a very fine drill bit in my RF30 clone mill to cross drill the body for the trunnions.

The only thing I could think of was a pin vice mounted in a collet chuck.

Anyone have a better idea?

Thanks!

Tom

 

[YYCHM]

Make a bigger cannon

 

[Tomc938]

But I have all these tiny little cannon-balls I want to use up!

 

[DaveK]

So I made may first brass cannon today. 1" long. I'm looking for some way to hold a very fine drill bit in my RF30 clone mill to cross drill the body for the trunnions.

The only thing I could think of was a pin vice mounted in a collet chuck.

Anyone have a better idea?

Thanks!

Tom

Perhaps a small Albrecht chuck, ideally with a sensitive drill arbor. They can hold tiny bits and the sensitive drill arbor makes breaking tiny bits a little more difficult. Something like this :

Albrecht Chuck with 1/2" Tapping Shank (Inv.28352) | eBay

(Inv.28352).

www.ebay.com

The drill feed is by hand, holding the larger black knurled knob that is on bearings. The shank would be chucked on the RF30 with it's quill locked.

Here is the Sherline version, a bit more affordable.

Sherline Sensitive Drilling Attachment 1012 | eBay

On the shaft above the chuck is a knurled disk that is mounted in a ball bearing race so it can be used to lower the drill chuck. The shaft runs inside the bearing, so the disk doesn't turn as you pull it down.

www.ebay.com

There are Indian imports that are quite inexpensive (with corresponding quality IMO ... I have one and it'a a bit sloppy)

Dave

 

[Tomc938]

Perhaps a small Albrecht chuck, ideally with a sensitive drill arbor. They can hold tiny bits and the sensitive drill arbor makes breaking tiny bits a little more difficult. Something like this :

Albrecht Chuck with 1/2" Tapping Shank (Inv.28352) | eBay

(Inv.28352).

www.ebay.com

The drill feed is by hand, holding the larger black knurled knob that is on bearings. The shank would be chucked on the RF30 with it's quill locked.

Here is the Sherline version, a bit more affordable.

Sherline Sensitive Drilling Attachment 1012 | eBay

On the shaft above the chuck is a knurled disk that is mounted in a ball bearing race so it can be used to lower the drill chuck. The shaft runs inside the bearing, so the disk doesn't turn as you pull it down.

www.ebay.com

There are Indian imports that are quite inexpensive (with corresponding quality IMO ... I have one and it'a a bit sloppy)

Dave

That's exactly what I am looking for! When I saw the $26 USD price tag I was so excited. And then I saw that is the amount of the 12 equal payments.

Perhaps a project is in order......

 

[YYCHM]

Put drill bit in a roll pin and chuck the roll pin up?

I take it your drill chuck and collet set doesn't clamp small enough?

 

[DaveK]

That's exactly what I am looking for! When I saw the $26 USD price tag I was so excited. And then I saw that is the amount of the 12 equal payments.

Perhaps a project is in order......

lol ... ya, Albrecht chucks ain't cheap but I love them. Bought one a few years back and now have 4 I get used ones that have reasonable looking jaws off eBay, then rebuild them (takes an hour or two).

Here is the Indian version sans chuck.

Micro Motor Drill Chuck Clamping Range 0.3-4mm Taper Mounted Mini Drill Chuck | eBay

Find many great new & used options and get the best deals for Micro Motor Drill Chuck Clamping Range 0.3-4mm Taper Mounted Mini Drill Chuck at the best online prices at eBay! Free shipping for many products!

www.ebay.ca

Dave

 

[gerritv]

Pin vise, I have used that down to .6mm drills. In a ER16 collet in my case.

If you really want a chuck, then a Jacobs 0.4->4mm or so will do fine as well.
Gerrit

 

[Tom Kitta]

Some small drills have larger shanks. For a lot of drilling that needs to be precise I use collets.

This depends a lot on "how small" you want to go.

 

[Tom Kitta]

3.06C$ 11% OFF|Mini Drill Chuck 0.3-4mm Jto Taper Mounted + Key Lathe Chuck Pcb Mini Drill Press Applicable To Motor Shaft Connecting Rod 8 Mm - Power Tool Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

There seems to be plenty of small chucks available - now one just needs to find JT0 arbor.

or

Muye 4pcs 0.3-4mm Micro Motor Quick Change Drill Chuck Clamping 1/8"(3.17mm) Shaft Connecting Rod Brass Sleeve Hexagonal Wrench : Amazon.ca: Tools & Home Improvement

Muye 4pcs 0.3-4mm Micro Motor Quick Change Drill Chuck Clamping 1/8"(3.17mm) Shaft Connecting Rod Brass Sleeve Hexagonal Wrench : Amazon.ca: Tools & Home Improvement

www.amazon.ca

 

[PeterT]

How fine is fine?

I use these circuit board drills because the shanks are wider & consistent thus can use my accurate chuck or collet. They are carbide, so you need to treat them as such. You can get precision chucks in 0-X size so they can grip pretty small drill sizes, but good ones cost money.

I've never quite understood pin vises but in all honesty I don't have one. The jaws look fine but they never struck me as a particularly accurate OD body. Maybe I'm looking at the wrong ones?
Runout becomes very important as you go to small. Consider .001 TIR on a 1/16" drill is 1.6% of D. But say a #80 (0.0135") drill, same TIR represents 7.4% of D. That means much more off-axis wobble.
Anyways, a good reality check habit is to chuck a very accurate pin like needle bearing or precision dowel & see what the DTI says. When you grip something that grips something else & that whole assembly is held in another socket, tolerances can stack in the wrong direction. You can only know by measuring.

Small drills need high rpm & usually our machines max out much lower than ideal. If you can 'peck' drill, that's helpful.
That's why dentist drills are crazy high rpms & special bearings.

 

[RobinHood]

x 2 on using a collet. ER style are particularly useful for small drills. A 1mm collet will easily hold a 0.5mm drill.

x 2 on spindle speed - you’ll need lots of it for tiny drills.

 

[Tomc938]

Well, not being one that likes to wait around for things to arrive, and not wanting to part with large chunks of coin, this is what I came up with:



I had a Dremel with a bad motor. I was hanging on to it to fix it one day, but since then I have come upon two others. So I cut the end of the shaft off. The small chuck fit nicely in my larger chuck and I used the fine down feed on the quill and went VERY slowly though the body of the cannon. It actually worked very well! I did have less that 1/4" to go through and the material is (of course) brass.

The drill bit is a #56.

And here is the almost completed cannon. Made it out of 1/4" brazing rod. Just have to re-chuck it and turn the ball on the end. Then I have to figure out how I am going to make a carriage that small.



Thanks for the suggestions! It was a couple of posts that came together in my head and reminded me I had a small chuck already. Just had to figure out how to make it work.

 

[Tomc938]

This chuck is from the used Dremel I bought. I really should clean it up and re-knurl it.

 

[PeterT]

I've pondered buying an ER-8 collet system because my so called mini precision chuck is not so precision. But even ER-8 only goes down to 1mm (0.039"). The nut body is 10mm (0.394") which is nice & small but rather cylindrical shaped vs typical drill chuck tapered body & extended jaws. I guess it depends on the job if no tight spaces are involved. I would think a good quality ER would hold better runout than my chuck.

But that still leaves RPM. On my long list of crazy projects is a brushless RC motor held in an adapter arbor to fit a standard R8 collet. I can make that spin 30K no problem. The bearings & shaft runout are actually quite well suited (providing it hasn't tasted Mother Dirt LOL). What I haven't figured out is a good way to marry a collet system to what are typically 5-8mm output shafts without introducing runout in that area.

 

[Alexander]

ER8 is perfect. Then just mount that in your ER32 or ER40 tool holder. For a HSS drill runout won't be an issue.

 

[6.5 Fan]

That will be a nice looking canon when you finish it.

 

[Perry]

I've held a small bit in a pin vise and used it to drill a small hole in a brass blank being held in a larger collet. (on the lathe and the mill) Then crazy glued the drill bit into the brass. This will have the bit running true. The next issue as stated above is you will need a lot of speed.

 

[Mcgyver]

Tom, I like the solution you came up with - it should work well and you worked with what you had.

Small drills need high rpm & usually our machines max out much lower than ideal.

I'll be the dissenter on the speed thing. I think the speed notion comes from applying the cutting speed formula, but (for hss or carbon at least) that's just a theoretical maximum after which tool wear is non linear. Running below it is fine. I like speed for small drills, I have three high speed micro/sensitive drill presses that all see action, however I also drill them with a pin vise by hand or often very small holes in watchmakers lathe at say 1000 or 1500 rpm. Indeed, some of the smallests drills, say a .004" pivot hole, are often cut at hand power speeds - e.g. pivot drill lathes . Speed makes things go faster; but the cutting tool's performance and resultant hole can be just as good at a slow speed

 

[gerritv]

ER8 is perfect. Then just mount that in your ER32 or ER40 tool holder. For a HSS drill runout won't be an issue.

runout on a .5mm drill will most certainly be an issue if you don't want a tapered hole. As well, ultra precision collets are likey outside of the hobby scope price-wise.
For tiny drills I would now use WW collets, having been recently introduced to them. They come in .1mm increments.

Regardless, I no longer consider a #56 drill as small

Gerrit