Vibrating bench drill

Hi guys,

I've gota small, cheap (probably the problem) bench top drill press (Ryobi handyman brand) - it vibrates a lot which hasn't been a real problem when I was using it for woodwork - but is a bit of a pain when I'm trying to drill accurately in metal.

From the investigation I've done the problem appears to be something in the drive train is unbalanced or uneven - the pulley attached to the drill stem is solid, but the drive motor and belt dance around a lot and the vibration carries through to the whole machine.

Is this typical of cheap drill-presses or have I got a dud?

Have you set the tension on your belt correctly

Bob

I dont know the particular model but it sounds as if it might just need a new, good quality, belt. If the pulleys themselves are running true (in two planes) and the belt is at the correct tension then there should not be any significant vibration.

A modern hobby type machine wont have the weight and mass of 50 year old pillar drill and its single phase motor will habe been engineered to the bone, but it should still be a usable machine.

Do some tests, run the motor without the belt, try loosening/tightening the belt, check pulley alignment before you condemn the machine.

Ian P

The belt can also take a 'set' if left under tension whilst the machine is not in use. This 'kink' can take a long time to work out of the belt. If you suspect this problem, try leaving it running for while to see if it improves, or just replace the belt.

I have a similar cheap drill. Found that the mounting hole in the belt pully was not on centre. If still under warranty, take it back an ask for a refund and buy something better.

I would echo the above. Check the alignment of the pulleys, using a straightedge across the tops, and make sure the spindles of the head and the motor are absolutely in line. The motor brackets are often weak pressings and the drive pulleys can be pulled out of line by too much belt tension. They may also be held by only one bolt and the weight of the motor makes them sag, out of line in the other direction then. Then set the belt tension to be enough to not slip, doesn't need to be board-tight.

The belts can be uneven, and may not be a good fit on the pulley, you can see this if you can run it with the cover open. Get a decent belt from a vehicles spares shop, or even better make up one yourself from the round belting available (whose name I forget, but you join it by melting it at the join point).

If attention to the drive fails, then you can look for more serious causes, but most rough running in the cheaper drills is caused by the drive train.

Phil

Further to above.

We are all assuming that you are using a good straight drill bit, well sharpened, and with the centre in the centre.

Pop mark the place, start the hole with a centre drill, then drill, and you will be sure of a good smooth start.

It's easy to overlook the obvious!

Phil

Many moons ago I owned a cheapo 5 speed "NuTool" pillar drill, you still see clones of this machine for sale today (Machine Mart and Wickes) it too used to vibrate dreadfully.

Stripped the "Z" section belt off it and you could see a lump in it where the cheap Tiawanese belt had been joined, changed the belt for one from the local motor factors and vibration much improved.

It's other problem was the amount of play in the quill which as it wore got to around 1/8" side to side movement when fully extended, to cure this I stripped it down and slotted the casting so that after fitting a pinch bolt I could adjust the quill play to a reasonable level.

Paul

Hi Jerry, I too wouls suggest belt 'set' might be a contributory factor. I'd always had some motor vibration on my Myford ML7, then changed the very old belt to one obtained from my local friendly motor factor, and the vibration simply went away. Now I always release the belt tension when I've finished turning.

I have a cheap second hand bench drill of early Ming dynasty, it vibrates/shudders like a crazy thing . In my case though it is the quill. If I extend the quill down as far as it will go, grab the chuck and wiggle it fore and aft I feel play, lots of it. I have never measured the amount but I bet it is something like a sixteenth of an inch - maybe more.

I also have another drill I bought new from ALDI and the quill play on that is even worse - from new!

The table on the early Ming drill was very concave and badly out of square so I removed it and replaced it with the table from the ALDI job (late Ming).

I do all the rough drilling with this and the more precise stuff is done on the WM16 mill.

For some years I have been looking out for a smallish second hand Meddings or a Fobco but no luck as yet - maybe they never made them that small.

Rik

Another thing that improved the performance of a Sealey drill I once had was to keep the drilling spindle well greased.

There's no provision for this, just wind it down and wipe the grease on.

Phil

Good idea Phil, I'll try that - it works on Sherpa kingpins, apparently!

Neil

Thanks very much guys - I'll double check the drive line alignment and the physical state of the drive belt - the type of vibration I'm getting is shaking the engine on it's mount, so the belt is an obvious culprit now that it's been pointed out

Thanks again!

A while back I was looking for a new decent drill since I had the old problem of a sloppy fit between the quill and drill head casting. All the usual suppliers seemed to have very similar Asian imports of dubious quality so I gave up the search. I ended up drilling and tapping a couple of holes near the bottom of the head casting at 120 degree spacing and fitting bronze pads to limit the sloppy fit. Seems to have worked for the time being, but time will tell if it is a long term solution.

Has anybody come across any supplier that sells decent quality drills at a higher but not unreasonable price?

Doug

Are the pully holes concentric, or if they are held in place by two grub screws, are the pullies tight on their shafts before they are tightened up, if not tight, they will get jacked of centre as they are tightened. If its the belt, and you can't get a good one, try a link type belt, if you can find one that will fit, the smallest I know is A section. Ian S C

I have what has been described as "An early Ming Dynasty" model.

This one is a Sealy, 12 speed Floor mount. I've had it for 25 years now, but two years after I purchased it, it developed bad vibrations. I contacted Sealy, who took it back, fitted new quill bearings & delivered it back, all free of charge! Not bad considering it was out of warranty.

25 years on, it stll performs perfectly, and incredibly, the chuck will still hold a 1mm drill perfectly concentric & accurately.

Maybe I was just lucky, but like the bandsaw I have, some Chinese imports seem O.K. I know that some importers, for instance Axminster, do make specification changes to the basic models, so I generally try & buy from a trusted supplier.

Dave.