A good toolpost drill design

Hi all

I find myself often having to cross drill or drill on a pcd on the lathe. I have been searching the forum and web for a good toolpost drill design.Up to now I have used a Dremmel type drill to fit on my Dickson tool post on my S7 but as everyone knows they run too fast and don’t have the torque required to do anything but a small hole. I have Steve Jordan’s ideas on YouTube but they seem unwieldy and top heavy. Has anyone pout there made a robust drill that can be speed adjustable and plenty of torque?

Chris

If you can find one and have deep pockets the the Quick Step mill is a nice tool for this sort of work. A spindle with a drive from a motor often using a round belt is another popular option. The Arrand spindle is sought after and fetches a good price but they often appear on eBay and sometimes a bargain price will be paid. The drive for the spindle will be whatever you want to build though.

Mike

Before I got my QSM I had made a very simple holder to fit the 47mm (?) collar on a drill gun fastened to the cross slide at centre height.

Even simpler, clamp a bar with suitable hole in the toolpost and use this to guide a handheld drill.

I made a toolpost drill form the quill of a cheap in my case free chinese drill press.The speed of the moter was 2000rpm so I thought it would make one and also do light grinding.I stripped the drill and cut down the column with the coller with three fixing holes for the base table column ,this I now use on the mill and the base I now use fastend to the drill columm to take a scissor jack for lifting my heavy drill table.The column that I had left was used up in projects and the motor is also used.So my point is a cheap drill press could be worth looking at.

Frank

Use an electric pistol drill, the type with the round section on the nose designed for a second handle to stick out sideways. Make a suitable bracket that fits one end in the tool post and the other having a large round hole to fit the nose of the pistol drill. Plus some kind of cut in the bracket with a clamping bolt so it clamps down on the drill body.

You can even fit a shaft with an eccentric on it to the trigger of a variable speed drill for "hands off" operation at the rpm of your choice.

If a hand held gun drill is too bulky, use a flexible drive cable attached to the drill with the chuck on the cable held in the too post. Should be suitable for drilling holes up to 6mm or slightly bigger.

Paul.

Edited By Paul Lousick on 20/01/2020 00:28:17

My plan for this is to take the motor and gearbox out of an old cordless drill. I've kept an old Bosch that the NiCad batteries died years ago fir just this purpose. Some need the case to hold parts together but this can be solved at various levels of neatness (hacking the handle off to machining a shiny new housing. It will run off a 12V supply with speed control modified to a rotary knob.

Robert G8RPI.

Here is my spindle drive I made recently. I had a motor left over from doing a mod to my Z axis on Chester 16V mill.

David

Hi Chris,

I only have a minilathe and I apopted a different approach using a flexible drive shaft to take power to the cross-slide, see:

**LINK**

I only fitted a 4 mm chuck but if I made it again I would fit a 6 mm chuck as there is more than sufficient power.

Mike

I made mine from a plain shank er11 collet holder, a pair of angular contact bearings and a 200w 240v treadmill motor.

Rod

ER11 spindle motor mounted on a vertical slide. I bought the motor, mounting block, power supply and collets for £90, and spent about 10 minutes drilling and tapping 8 M6 holes to mount it to either face of the slide. That means it will mill and drill with, or along the lathe axis and at any angle to it.

This is how they didikt in the old days, 'Potts Spindle' castings still available.

I made this out of an old pistol drill, I fitted the epicyclic gearbox in the steel block, the motor is in the old spice container. Drills well, doesn't mill very well due to end play.

A bit more discussion on these Here

Thanks for the suggestion Guys.

I guess it comes down to either a Flexible shaft design or go for a motor mounted above the spindle to provide power. I like your modification Mike .

Rod does the treadmill motor have plenty of torque at lower revs?

Neil:

I had no idea that anyone stocked the Potts castings still.

who might that be?

Mike

Nifty idea, I have some in the bathroom cabinet...........

Used to be available from Hemingway, but I think it's been discontinued, although they sell castings for two other Potts projects.

If you can weld, it wouldn't be hard to fabricate and you might actually get a better result.

Neil

Silly billy!

Hi all

I have an arrangement using an Arrand ball bearing spindle and it works quite well for small holes up to about 4 mm.

For larger holes it's worth reflecting that it takes the same power to drill a hole in the lathe as it does in a drill press, and quite a large motor is needed to drill holes of (say) 6 mm diameter or more, especially in steel. Anything much less than 1/4 HP may seem underpowered and very slow, and 1/2 HP is much better.

Rod

Problem with this approach is that most cordless drills, and generally all the lower costs ones, have a rather low high speed rpm top end - typically 1200 to 1500rpm and that tends to be a bit low for the smaller drill sizes, below 3mm perhaps. Also, the front bearing is not the greatest, and neither is the chuck, all giving rather poor runout performance.