Advice on moving an Archdale radial drill

[Simon Williams 3Participant @simonwilliams3]

DC Injection braking:

Firstly thank you for a positive reply. There are several ways of doing this, and it depends on what motor is fitted and what supply is going to be used.

DC braking is provided by some VSD drives as a built in feature which can be selected as part of the set-up parameters. I've got several Telemecanique Altivar drives which offer this facility. But that assumes you were going to go the VSD route. Otherwise you can buy a safety module which fits into the motor circuit to provide DC braking as a specific function. Essentially all it does is introduce DC current into the motor windings briefly after switch off, which acts like electric treacle and makes it very difficult for the motor to turn.

You can also buy a microswitch which mounts on the spindle head, with a telescopic "radio aerial" poking into the work area. If the microswitch is tripped the supply to the motor is switched off, and the braking effect is automatically applied. If set up right it can bring the spindle to a very smart stop.

To help in suggesting something suitable, could you post details of where you are (first three digits of postcode is ideal) 'cos someone with appropriate experience may be able to help hands on.

Also ideally a picture of the spindle motor rating plate to show kilowatt rating, supply voltage and full load current, also motor windings configuration. If not a picture can you post this information here?

What supply do you have at your workshop location (three phase/single phase?) and voltage, also current rating.

Does the machine have more than one motor – does it have a motor to wind the head up and down the column?

Have you got a control panel supplied with the machine? If so can we have a picture of the front of it.

Looking forward to hearing further, best rgds Simon

[Andrew ByronParticipant @andrewbyron13518]

Posted by Simon Williams 3 on 02/06/2021 19:41:47:

DC Injection braking:

Firstly thank you for a positive reply. There are several ways of doing this, and it depends on what motor is fitted and what supply is going to be used.

DC braking is provided by some VSD drives as a built in feature which can be selected as part of the set-up parameters. I've got several Telemecanique Altivar drives which offer this facility. But that assumes you were going to go the VSD route. Otherwise you can buy a safety module which fits into the motor circuit to provide DC braking as a specific function. Essentially all it does is introduce DC current into the motor windings briefly after switch off, which acts like electric treacle and makes it very difficult for the motor to turn.

You can also buy a microswitch which mounts on the spindle head, with a telescopic "radio aerial" poking into the work area. If the microswitch is tripped the supply to the motor is switched off, and the braking effect is automatically applied. If set up right it can bring the spindle to a very smart stop.

To help in suggesting something suitable, could you post details of where you are (first three digits of postcode is ideal) 'cos someone with appropriate experience may be able to help hands on.

Also ideally a picture of the spindle motor rating plate to show kilowatt rating, supply voltage and full load current, also motor windings configuration. If not a picture can you post this information here?

What supply do you have at your workshop location (three phase/single phase?) and voltage, also current rating.

Does the machine have more than one motor – does it have a motor to wind the head up and down the column?

Have you got a control panel supplied with the machine? If so can we have a picture of the front of it.

Looking forward to hearing further, best rgds Simon

so something like this?

i've seen those type of microswitches on machines, presumably they're designed to trip if the workpiece spins on the table.

I'm on a three phase supply i'll look at the breaker in the distro board to get an idea of the current rating. I've just backed to drill into the workshop on the trailer for now as i want to lift it off when there's two of us here but i shall be hopefully doing that tomorrow so i'll get the info off the drill then, there's just a singhle period DOL starter which i presume works the spindle and possibly also the coolant pump, i'm not sure if the coolant pump is working but i can't see a separate switch for it.

it was the right way up when i took it, but you get the idea, this are pictures showing the complete machine.

[Simon Williams 3Participant @simonwilliams3]

Andrew – that Crompton DC Injection brake certainly looks like the right sort of thing, Data sheet courtesy of Mr Google here.

Would need to check motor ratings for compatibility, but don't think much of the price. I'd expect to get a secondhand mainstream VSD for that sort of money, with variable speed as well as DC braking. Always supposing the main drive motor is dual voltage 220/400 volts. Some of these old motors weren't, and not all of them like running off a VSD anyway because the motor construction has to accept high frequency currents.

Having said all that, if you get your arm caught in the mangle that Crompton gismo will be the best £200 you ever invested.

I worked for a guy a long time ago who got hit in the face on a Maskiner geared head radial drill of about the same size and vintage as this one, he had two false front teeth. He never told me the whole story.

[Andrew ByronParticipant @andrewbyron13518]

Having said all that, if you get your arm caught in the mangle that Crompton gismo will be the best £200 you ever invested.

I worked for a guy a long time ago who got hit in the face on a Maskiner geared head radial drill of about the same size and vintage as this one, he had two false front teeth. He never told me the whole story.

My main job is farming, and it's often the case that when accidents happen to people it's because of complacency. These things are only dangerous if you fail to respect them, that said, with the best will in the world, there's always that time when you're in a hurry and think oh, it'll be ok. I've got a good machine vice for this and it certainly came with enough clamps to hold the workpiece steady, and in theory i won't be drilling anything in this that isn't properly secured, and i've got two free standing pillar drills for smaller work, one with an MT2 arbour and another with a 13mm jacobs chuck which can be used for smaller jobs.

The Crompton box was the cheapest i could find with a cursory search and i thought , bu**er that, it's more than i paid for the drill, but your final point is a very good one, if ever i made a mistake it would be very cheap indeed.

What i will probably do is work out what it needs to do the job and look out for something suitable at the right price. Having looked into it a bit following your suggestion it certainly sounds like a good safety feature to have on the drill, so thanks for the input.

[vic francisParticipant @vicfrancis]

Hi , well done 👌on moving such a beast! Ok it is a very good thing about spindle breaking in case of the work breaking free; however I would bolt a safety stop fixing on the bed , using more than one tee slot as well… I did see a video ; whereby the long bar material being drilled ( large hole) snagged broke free and hit the operator ,mid torso. Like a scything motion, only stopping when at the main column…Very sadly it was fatal. If he had a mechanical safety stop he would have survived, and bought time… I have seen a few milling damaged tables with tee slots broken, and often wondered what happened….

So safe working and Please show us what work you can do on such a fine versatile machine? Maybe fullsize traction engine parts??

ps it looks more than 1.2 tons!!

Vic

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, in my old maintenance job that I had, all the drilling machines had injection breaking fitted and these had to be used even when whatever you were drilling was clamped down. However, curly swarf was always a pain as it would hit the trigger and the brake would cut in very often while drilling through thick plate, this was avoided by using chipbreaker drills. e.g. Chipbreaker Drills.

Regards Nick.

Edited By Nicholas Farr on 04/06/2021 07:46:21

[Ex contributorParticipant @mgnbuk]

The company that I started my apprenticeship at in 1977 had several radial arm drills – as a heavy duty valve manufacturing plant there were a lot of flange bolt holes to drill. There were a couple of semi-automatic multi-spindle drills, but most flanges were drilled on the radials with guide plates clamped to the flange containing hardened bushes – no marking out or pilot drilling, just straight in the bush with the finished size drill followed by a countersink on the front & a back counterboring tool to touch up the back face.

All were fitted with wand operated Jet Brakes (DC injection brakes) & one of my early tasks was to regularly check that the wands were undamaged & that the spindle was properly braked to a stop when the wands were touched. IIRC the spindle stopped in less than a revolution when the wands were tripped. I also have a recollection that it was a legal requirement for radial drills to be fitted with such devices, so I am a bit suprised that an ex-industrial machine doe not have one.

"Nuisance" tripping due to long curly swarf when the wands were set close was an issue, though the machines usually restarted with a press of the button when the swarf was cleared. On one occasion that I recall, this didn't happen – the machine would not restart & I was sent to investigate. Turned out that the motor had restarted, but the drill wasn't going round – the motor shaft had sheared off inside the drive end bearing at a circlip groove. DC injection braking can be pretty brutal !

Nigel B.

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