drill speed reducer

Hello all

Has anybody ever used one of these, **LINK**

How robust or should I say strong are they, I want to cut 4 holes at 65mm dia, with a hole saw in 1/4 -1/2 inch mild steel plate, the drill I have is a Wolf big old 2 speed heavy duty drill, ,one of the old type that dont give in, but the speed on lowest setting is 430rpm, I sort of think this is still too fast?

Thanks

lee

As a ex electrician I have spent a fair bit of time with hole saws of various sizes chucked in drills. I am also familiar with those beefy Woof drills.

Are you thinking of using the drill hand held.? Because if you are, with a saw of that size in that thickness of plate I fear the only thing you will achieve is a broken wrist.

Nick

Not known as "gut busters" without good reason.

My dad always tells the story of how as a sparks in the 50s he would often have to drill steel tanks with a brace & bit.

Better to see if you can borrow a modern SDS+ drill with the hammer switched off the clutch will save you hurting yourself and the vari speed will take care of the rest.

J

I had one - a Rawlplug model. I made up a big aluminium shroud and handle for it so that I could get a decent grip on it when in use. It got used for drilling a lot of holes in the floors of Class 442 EMUs down at Bournemouth railway depot and it eventually wore out, having had a very hard life indeed. It was an excellent piece of kit.

Hello Nick

No,

I will not be trying to hold the drill in my hands, did all that sort of stuff years ago when we had not alot of choice really, na wont be doing that no more

No it will be securely fixed in a beefy drill stand

lee

What kind of hole saw is going to tackle 1/2 in plate? All the ones I've seen are for very thin metal or brick.

BTW a regular drill on a speed reducer is going to overheat unless you give it some long periods of running off load fast to give the fan a chance to move some air.

Lee,

To be honest, I don't think that speed-reducer stands a chance of doing the job you mention.

1/4" shank, driving a compact epicyclic unit

O.K. for sheet metal or GRP sheet, but it would be better to use a more suitable Drill. an electronic speed controller on the big Wolf.

MichaelG.

.

Edit: Just realised that you already have the Drill. 

Edited By Michael Gilligan on 09/12/2014 13:04:14

I know the torque of my, drill will chew through the steel plate quite easily, but I also know from past experience if the speed is too fast it messes up the hole saws teeth, I use Starrett hole saws which are brilliant for this job but they must be run slower, I contacted somebody who sells electronic moter speed controlers, but he said the ones he sells only reduces the voltage, I would get the speed down but Lose the torque

I have a top line so say heavy duty Matabo drill, but it heats up, light comes on and I cannot carry on till the light goes out,

thanks

lee

Edited By lee hawkins 1 on 09/12/2014 13:26:59

I tried to use a speed reducer in conjunction with a pillar drill and a 50mm hole saw. I found that I could not hold the outer of the reducer - hence no drive to the hole saw.

regards

John

Ok so it does not work anyway then

Thanks for posting

Could you borrow a magnetic drill, that would be the tool for the job.

Regards.

David.

Don't they normally have a tapped hole in for a torque reaction bar that can lodge against the drill pillar?

Neil

I did think about buying a mag drill, too pricey for me though,

I'll sort out some way to do it ,

Hi Lee,

mag drills are def the way 2 go.....they don't cost the earth 2 rent......plus a transformer..(all the modern one are 110v)

I bought mine as I got fed up with the worn out rentals or "it's out mate"..... it will cut the hole but u def need a sharp cutter.....if u go the rental route, shop about, some require u 2 buy ur own cutter £60-80 plus on flebay......other's just charge u for a re-grind on their's...remember loads of cutting fluid.....

Frank

Can you fit it in the lathe (in the gap), with the saw in the spindle? That way you'd have coolant and the right speed, both of which you need. The teeth on those hole saws are very fine and fill up with swarf very quickly so you need to do more pecking than a nervous hen(?), clearing the teeth out with a brush as you go.

I had some success notching pipes this way (with the pipes clamped to a vice in the top slide) and having used a hole saw on some 1/4" plate in the drill press, I'd be tempted to use the lathe next time if I didn't have a decent mill with a back gear and coolant.

Murray

Maybe I'm not adventurous enough but I wouldn't attempt to go through 1/2" steel with a hole-saw even on my 3/4 HP pillar drill on its slowest speed.

Apart from all else I would expect it to take literally hours given that a hole saw is one of the worst configurations of cutting tool since that there's no route for swarf removal and you have to withdraw it every few seconds. If you are the least bit tardy on that, it heats up with loss of cutting edge and the swarf welds itself to the blade making it even more difficult and time-consuming to remove.

I'd be very interested to hear how you get on.

Edited By Bandersnatch on 09/12/2014 18:23:37

Murray

I have not got a lathe, the holes in the steel Plate are for parts that will make up the legs of a lathe i am building,

This is why I am reluctant to fork out money for a Mag drill, ,want to save it for the lathe build,

I do have a home built milling machine would have done the job, that was working brilliantly until the shaft coupling snapped, I cant repaiir that yet, I bought two shaft couplings when I built the mill,left one of them around my brothers garage, but he is out of the country, wont be back for another month

thanks

lee

3/4 hp drill press would bump through it no problem with Starrett Dual Pitch hole saw, I have used them all the time over the years, their brilliant as long as the speed is not too high, this is my problem, my wolf drill will do the job but I know 430 rpm is too past

Regards

lee

Lee

Sounds like a case of "physician heal thyself", except that even the physician's tools are in need of repair. One step at a time. Good luck!

Murray

Could try using a lamp dimmer switch in line with the drill, many years ago I made a drill speed controller as a school project and the circuit was basically a dimmer switch.