George Thomas high speed drill.

[Martyn CozensParticipant @martyncozens74564]

Hi All. I have recently finished George Thomas’s high speed drilling head that fit to his tapping and staking tool kit.

As orginally designed the motor sits on the deck (bench) behind it and is driven by a long belt, which yest I could do but it makes it a bit of a faf everytime I come to set it up.

What I want to do is mount a motor on the drilling head as is done with a normal drilling machine, mmaking it simpler to use.

My problem is sourcing a suitable motor, the parvalux motor I have would be fine if mounted on the bench but is to big and heavy to mount on the head. I’ve looked till I’m going crosseyed on ebay and Amazon for something suitable but cannot find anything, also I’m not sure what size I would need, any advice or pointers would be very much appreciated.

Martyn C

[HopperParticipant @hopper]

Small sewing machine motor?

Small router spindle motor with speed controller? AKA CNC spindle motor or ER11 Spindle Motor on eBay.

[JasonBModerator @jasonb]

If you go down the spindle motor route it would probably be better to use that for the spindle rather than have it drive a separate spindle.

But one would work mounted pointing up at the back of the machine a bit like this with a simple clamp type arrangement to hold the spindle motor body which they often come with.

They do make a lot more noise than a sewing machine motor.

 

[Martyn CozensParticipant @martyncozens74564]

Hi All.

Thanks for the feedback, I did try a sewing machine motor but it was totally useless, no torque so when I put cutting pressure on it started to stall. Running small drills flat out (10,000 rpm ish) they would’nt cut. Oh and the vibration from the motor quite excessive. If I use a variable speed drive DC would be the cheapest if I could find a package suitable, but would I run into the same issues as the sewing machine motor no torque at about 2,000 to 3,000 rpm. I’m thinking I need something in the region of 200 to 300watts?

Martyn C

[bernard towersParticipant @bernardtowers37738]

Don’t understand the the bit about a faff to set up, been using mine in all modes for close to 30 years and if it take a whole minute to swap things round I could be exaggerating and lets face it how many times do you have to do it?

[John HaineParticipant @johnhaine32865]

Industrial sewing machine motor such as used by a few people here for small lathes?

https://www.jacksewing.co.uk/index.php?route=product/product&product_id=62

[Russell EberhardtParticipant @russelleberhardt48058]

Why not just fit one of these:

https://www.proxxon.com/en/micromot/28472.php

I have one fitted to the head of my little cnc mill, primarily for engraving, and find it very good. I have also used it for high speed drilling where the mill’s top speed is inadequate.

Russell

[Clive Brown 1Participant @clivebrown1]

As per Bernard Towers above. My UPT and drill-head are to the original GHT design, changeover is a matter of seconds. I do find the fairly long vertical belt-run a bit flappy when torque comes on, but it works OK for my needs.

Some of the speeds quoted above seem a bit high, the drill is, after all, plain bearings and the original maximum design speed is around 3500rpm IIRC. It was published as a sensitive drill rather than high-speed.

[John HaineParticipant @johnhaine32865]

Indeed, my CNC mill max speed of 5000 rpm and that’s really much too slow for small drills and cutters, I’d like 20,000.

[duncan webster 1Participant @duncanwebster1]

Someone must have designed a vertical slide arrangement to graft a Proxon onto a GHT pillar tool. The alternative is to arrange to lift the table, but then you’re adding mass so reducing senditivity

[John Haine]

On John Haine Said:

Indeed, my CNC mill max speed of 5000 rpm and that’s really much too slow for small drills and cutters, I’d like 20,000.

I understand the maths behind these super-high speeds, but I must question the necessity.

… generations of of watchmakers produced magnificent work using a hand bow.

Not arguing, just bewildered.

MichaelG.

.

Edit: Nice example … albeit only drilling a brass plate

https://youtu.be/UqXKpWYo3vI?feature=shared

.

 

[Roderick JenkinsParticipant @roderickjenkins93242]

These motors seem to be back in stock:

hebdenmotorbits on ebay

I use one to drive my lathe toolpost milling spindle and it would fit very nicely on the back of my Pillar tool

 

Rod

 

 

[John HaineParticipant @johnhaine32865]

The reason for high speed Michael is to minimise the tooth load.  All too easy to break small cutters rotating too slow.  E.g. for PCB isolation routing I have to limit the feedrate and it takes ages to make a board.

[Michael GilliganParticipant @michaelgilligan61133]

Fair enough, John

Thanks

MichaelG.

[JasonBModerator @jasonb]

And back in the day when their drill bits were probably just carbon steel they could not be run as fast as HSS or Carbide even if they had a fast elbow.

I recon he is getting over 1000rpm out of that setup.

 

If you say the pulley is 6mm dia and the travel of the bow 200mm that is 10 turns per pull

I can count about 18 pulls in 10 seconds so 108 pulls per min.

108 x 10 = 1080rpm.

 

[JasonBModerator @jasonb]

I’m actually wondereing where the Faff in changing over comes from. In all cases you will have to remove the tapping or straking tool and fir the sensitive drill. All the ones I have seen have the motor mounted to the base that the UPT is also mounted to. So the only extra requirement is to loop the belt under the motor pully which I can’t see taking more than a few seconds.

Most of the faff would seem to be the actual swapping between straking-tapping-drilling modes so having the motor on the drill won’t gain much.

What would be far better and save the inevitable faffing is to scrap the dog bone casting used at the top and have a double ended one, sprung index pin in the side and a couple of holes in the side of the column at the top for it to engage in. Then all you need do is pull out the pin and spin the head round to change modes. In that case a motor mounted directly above the drill spindle would work well and no need for all the pullies putting undue side loads on the bearings. Or better still beef up that end of the casting so the spindle motor becomes the quill and can be raised and lowered by the lever

With a setup like that you can leave the work clamped to the table while you drill the hole and then swing the tapping tool round and tap the hole that is directly under the tap.

[Roderick Jenkins]

On Roderick Jenkins Said:

These motors seem to be back in stock:

hebdenmotorbits on ebay

I use one to drive my lathe toolpost milling spindle and it would fit very nicely on the back of my Pillar tool

 

Rod

 

 

The controller in that ebay listing is deadly. exposed terminals and no earth.At least you put yours in a plastic enclosure.

[Russell EberhardtParticipant @russelleberhardt48058]

 

 

I understand the maths behind these super-high speeds, but I must question the necessity.

… generations of of watchmakers produced magnificent work using a hand bow.

Not arguing, just bewildered.

MichaelG.

.

Edit: Nice example … albeit only drilling a brass plate

https://youtu.be/UqXKpWYo3vI?feature=shared

.

 

 

 

My Great Great Grandfather, William Mannings of Steyning, was a watchmaker.  He probably had more workshop time than I could ever manage and more skill than I have.  He would have been amazed to see my CNC mill  drilling at high speed, engraving, or crossing out wheels.  If the technology was available in the early 1800s, I’m sure he would have adopted it.

Russell

[Antony PriceParticipant @antonyprice56876]

Hi Martyn

I maybe misunderstanding what advice you are looking for, but in the March 2024 MEW, there was an article, Fifty Years of George H Thomas Universal Pillar tool Part IV  where the author,  Warren Williams,  describes an “integral  variable speed drive for the sensitive drilling attachment”  … “using a 24V DC motor … fitted to millions of electric scooters”

Tony

[JasonBModerator @jasonb]

pic from that article

[derek hall 1Participant @derekhall1]

I built the GHT sensitive drill and drive it via a small 3ph parvalux motor and small inverter.

I don’t use it often but when I do the change over time is minutes.

It did take a bit of careful aligning to make sure the round belt didn’t keep coming off the pullies though.

I did also make the staking part as well but hardly ever use it. The tapping part of the tool though is always used and no way would I want to be without it.

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

On Roderick Jenkins Said:

These motors seem to be back in stock:

hebdenmotorbits on ebay

I use one to drive my lathe toolpost milling spindle and it would fit very nicely on the back of my Pillar tool

 

Rod

 

 

The controller in that ebay listing is deadly. exposed terminals and no earth.At least you put yours in a plastic enclosure.

 

I can’t imagine anybody would consider using the controller naked, if you see what I mean.

Rod

[Ian PParticipant @ianp]

I have some less than ideal electrical setups in my workshop but that motor and controller and mains lead being sold on ebay frightens me!

No warnings or advice on the listing to alert the purchaser that the motor wiring is a mains potential. I know there is label about earthing (as in Rod’s reply), but in one of the ebay pictures the earth lead is just shown unconnected.

We know that putting the controller in an enclosure is straightforward but how many buyers will properly protect the red/black motor wires from where they exit the motor endplate to the controller I wonder.

Ian P

[bernard towersParticipant @bernardtowers37738]

I made a miniature 4 jaw tapping chuck for mine which gives a nice positive drive for the taps but cant find the info at the moment.

[bernard towersParticipant @bernardtowers37738]

Tapping chuck design comes with the courtesy of Mikes Workshop.

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