Should it be bent? Meddings Content

I've got a Meddings LF1 mk2. I have noticed that the arms on the motor plate assembly are not at right angles to the plate. This means that the motor pulleys are not perfectly parallel to the pulleys on the spindle. This doesn't seem right to me so I've been shimming it with a couple of washers.

However, I have been wondering whether it is supposed to be bent.

On one hand both arms are bent pretty much the same amount so the plate is still square to the drill, just an angle if that makes sense.

On the other hand I think the drill may have been knocked over at some point. Which would explain the damage to the old motor casing.

Does anyone know for certain? Any thoughts welcome.

Is the plate upside down?- Could it have been done to counteract the tension of the belt.

Or has it happened due to over use of belt tension? it seems rather excessive, but seems to be rather accurately done.

William

I would say no defiantly not and if as you said the old motor was damaged then your supposition of the machine being dropped or ?? is more than likely.

Personally I would remove the mounting plate and straighten the two adjustment bars. I actually have an MF4 with the same adjustment system and it is at 90deg as one would expect

John

Can't imagine any reason why it would have originally been made that way. Belt wear, noise and possibly damage to bearings would be some of the effects of the pulleys being out of line.

More than likely the result of a fall.

Rob

With the mounting plate off, the bars may be removable and new ones made. I would be wary of straightening them in situ if the plate is cast iron.

If you google alignment of V belt pulleys you will see that it is important that the pulleys align as exactly as possible with each other in every plane!, We used long straight edges or even string, but even a small amount of misalignment causes noise, belt wear, overheating pulleys and pulley wear, and eventually bearing damage. That needs sorting!

I have a very similar Meddings machine, and very good it is too.

You are right - your machine has been damaged. The motor-mounting must be all true and square for two reasons.

- Firstly so the pulleys and belts align correctly.

- Secondly, I think your drill has a different motor-mounting to mine, but if yours also has a spring belt-tensioning arrangement, so it works correctly. (Mine has a warning-plate that the belt tension must not exceed that given by the spring.)

I'd dismantle the back end, and examine each component to determine which one(s) is / are damaged. The bars might be bent on their spigots in the plate. If the plate is mild-steel, that might be bent. It would not be too difficult to make replacements, in fact easier and more certain than trying to straighten the existing parts.

It could have been dropped but I would expect other damage to be apparent. Alternatively, it had been lifted badly, putting excessive strain on the motor mounting.

That original plate looks upside-down too - hence that adaptor between it and the motor. It's possible the set-up there is not helping by giving an extra cantilever effect.

+++

I've occasionally used mine as a tapping-head. Electricity off at the mains, belt slipped off, and turning the spindle by hand, using the chuck. The work held slightly loosely laterally to give a self-centring effect. One hand rotating the chuck, with a leather glove for protection from the sharp edges on the chuck; the other gently easing the quill down and up.

Thanks everyone, I thought as much.

There is no belt tensioner, just pull the motor back and tighten the allen screws. I don't think it was bent by the belt being too tight - cannot see any way that would happen without the belt going first. So damage it is.

The aluminium adapters are to convert from what ever mounting standard was used originally to the current MEC71 motor holes.

I plan to get new arms made up if I can find someone locally to do it for beer money.

The arms would then bolt directly to a plate with MEC71 holes in. The only current headache might be that the holes for the arms could be very close to the MEC71 holes.

Yes. That is the first thing I would change.

Strange!

Meddings would not paint their motors a different colour to the drill, and it’s mounting is strange. The pulleys should align and not be so far out vertically which will cause wear and noise levels

I think this is a bigger problem than the bent arms, which can be corrected with “ washers” under the motor mounting bolts

A simple fix. Shims have been used for levelling/lining up for generations! Even perfectionists use thin shims.

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Although not unknown ... it is rare for a machine manufacturer to custom-paint a motor

Have a look at Meddings’ current offerings : **LINK**

https://www.meddings.co.uk/drills-belt-drive/l1-mk-6-l2-mk4/

MichaelG.

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P.S. __ it seems clear that this motor is a replacement, and the job has been badly done

Your comment about pulley alignment is much more significant than the colour

Not the same model, but: The exploded view in this previous thread gives a good indication of how Meddings’ motor mounts are arranged : **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=118104

MichaelG.

To say that the pulleys are out of line, would be an understatement !

How could you use the machine like that ? That looks like a botched up job.

I would replace the bars if they are bent but also reposition the motor so that the pulleys line up correctly.

Short answer is No, it does not look right.

Take the motor off the motor plate, take a photo of the other side and upload here, looks like the steel bar in the casting in pressed in to the motor plate? If that is the case, press it out, and straighten it, they must come apart.

It doesn't even look bent, it looks like at its base it's become unseated on one side making it point off at an angle.

Woodlikesbikes - your first two photos are a no-brainer, that motor pulley is way out in just about every way possible.

Needs a major re-alignment, starting with a strip down of all the motor holding and tensioning parts and closely examining them, looking for un-natural bends or other damage and asking yourself if it was all assembled correctly before strip down.

And I would also bet that the motor is a replacement for the original too, which would lead me to suspect the machine has been dropped or suffered impact damage by some means, hence your problem.

It may be camera angle but in the first photo the steel rule also looks as if it might not be sitting level on the top of the quill pulley and rising up a tad towards the motor pulley.

It would be worthwhile checking the pulleys are turning round true, unlikely the shafts are bent but not unknown, but the pulleys themselves may be not sitting on the shafts squarely, worth a check.

As has been stated above, the pulleys must align perfectly both vertically and horizontally - thats your target! The quill pulley will be your reference providing it is, or when it is, true so all the adjustment comes at the motor end. You may find that you need to provide support under the motor while you are doing this and doing everything up, the motor gets heavily the longer you try and hold it up with one hand while tightening with the other, safer too.

Good luck - not at all difficult, just needs close attention to detail!!

Chris

It's clear from Michaels link that the motor plate is the correct way round, wasn't there a more suitable motor pattern than MEC71?

The alloy adapter is equally clearly not tall enough. If the mounting arms go right through the plate tap them out, just make sure the cast iron is fully supported. You may need to drill up the arm to weaken the hold of the casting

Judged by experience with a new RF 25, the belt will have a short life. Mine shredded within 6 months. Having aligned the motor, the replacement is still O K some 20 years on.

If the motor mountings on the plate are out of line, I would agree that the likely cause is that machine has been dropped at some time.

Whether you are prepared to risk the cast plate mby bending the bars back into line, or prefer to modifiy the mounting pads on the plate to align the motor is up to you.

Could you turn up some washers, to go between motor feet and the plate to realign it, and use longer bolts, and a least invasive recovery?

Howard

So with the careful use of a blow torch and vice I've managed to bend the arms back straight. I haven't measured everything perfectly yet, but it's looking pretty close if not bang on. I can always use a shim or two if needed.

Thanks to everyone who pointed out the plate was on upside down. This has turned out to be very helpful. I'm replacing the motor and was about to start making new adapter plates to fit. With the motor plate on the other way there is no need to make new adapters. I can just drill a new set of holes in the existing ones. This saves me quite a bit of work as it's the only pillar drill I've got access to.

And yes the drill is on at least it's third motor. And paint is new as of November. I'll put a proper post up with the refurb details soon.

You can usually slide the pulley up the motor shaft a bit too if you need that last bit of belt alignment. She must have done some work to wear out three motors. I have an ancient Australian-made Waldown drill press that is similar vintage and style and is my "go to" for drilling small precision holes, despite its size. Just a nice tight fitting quill and spindle make it a better quality machine than my much newer Chinese job that is now relegated to "roughing" after I found out it was drilling about 5 degrees off square due to manufacturing error. Well worth a bit of fettling to keep the old ones running when they do such a superior job.