Wot I dun at the weekend

Peter, If you have no luck up your way you could try Dieselec 01746

712265 Ditton priors Shrops. They might be a little out of the way from you, they're more mid to south shrops. I go up there every couple of weeks so could drop off or collect bits for you if you can get them to me some how.

Regards Gary M

"Peter Scales" wrote (snip):-

'twas I - thanks!

Most of us like this kind of vicarious joining in.

Let's keep it up!

Regards,

J. Kim Siddorn,

In message , Peter Scales writes

I have now had the chance to get the flywheel off(!) and have a good look at shaft and wheel bore keyways. The key is an odd size, 0.560" across. I suppose this was a 9/16" key at 0.5625" nominal when it started life. The shaft extension keyway where the flywheel wasn't is also 0.560" across and the key is a good push fit there. Close to the main bearing, the keyway slot has "fretted" (or rather the key has rattled in the keyway and eroded the slot) and the width of the keyway is 0.562". The width of the keyway in the flywheel bore is also around that figure. So, altogether there is about 3 thou of lateral slop in the key/keyway fit. That is never going to hold tight, I doubt.

A friend of mine has suggested shimming it for a temporary fix, until I can source and fit a bigger key. I wondered if a broken length of steel measuring tape would do the job - it seems to be around the 6 thou mark? I could hone it thinner on an oilstone. Suggestions anyone?

I guess I will also need to widen the shaft extension keyway with a bit of judicious filing when I come to fit a bigger key, otherwise I will never get it into the slot....

Ah, the joys of old iron!

All the best

Pete

BTDT - Just get a slightly wider key and oilstone it to fit. OTOH, your worst problem may be the taper of the shaft and flywheel, you should be able to get a good solid fit without the key. Is something stopping you getting the flywheel on far enough for a solid interference fit ?. Do you have something nasty like an incorrect flywheel with the wrong bore size ?.

The key is only supposed to locate the flywheel on the shaft, the torque loads should be taken by the interference fit of the taper.

The evil bodge option is to hammer it on as tight as possible then arcweld the shaft to the flywheel. I did that once on an old VW Combi in Rhodesia after replacing the flywheel key a half dozen times. It was still going strong 4 years later when it went off a mountain road in Swaziland in rather spectacular fashion. The remains are probably still rusting away at the bottom of the drop.

In message , Chris Newport writes

The shaft and flywheel bores are parallel on this engine. The flywheels are approximately 2 feet in diameter, the face width is approx. 4 inches, the rim thickness about the same, and the web must be about an inch. I'd guess the weight of one at around 300lb, or more than me, by a good bit. The flywheel is held stationary with respect to the shaft by a gib head key, which is tapered along its top surface and mates with a matching taper in the flywheel keyway. This particular key is 3 3/4" long on the tapered section.

My plan is, as you suggest, to get a wider key and fit it by filing and stoning. I was looking for a temporary expedient to get me going while I source a bigger key.

No taper (except on the key and wheel keyway), see above.

AAAHH! NOOO! Anathema! Besides which, I have absolutely no desire to see the flywheel and shaft drop off together due to cracking in the hardened heat-affected zone of the weld. Being chased into Cheshire by

300lb of revolving cast iron is an experience I am not willing to have (I live in Shropshire). It strikes me that it has the potential to really take up the slack in the underwear.

Mind you, Plastic Metal did cross my mind :-) And one kind soul has suggested that Loctite may do a suitable product....

VW Combis I can probably get more of, Lister CS 12/2s are a bit harder to come by. But thanks for the idea :-)

All the best

Pete

If you can get over the hersy of listening to guy fawkes...........

back in the day, if the tapers are clean and matched, a liberal dusting of powdered french chalk, then hammer (large lump of 4 x 2 or heavier) the flywheel on.

do it right and you'll need a puller to get it off again.

belt and braces a two halves bolt together clamp like the big end of a con rod and some shim washers will hold it on

none of this means modifying or bastardising anything.

That'll probably be the famous '20 thou Loctite', which I purchased from a bearing supplier many years ago. No idea if they still make it. Used to know a plant field service engineer who swore by it too, used it on Earthmovers etc.. I used it a couple of times to secure motorcycle plain bearings which had 'spun' in an aluminium casting (timing cover etc). It worked at the time. Very useful when you can't get a spare undamaged part from a breaker.

Not sure I'd be willing to trust it with a 300lb flywheel though...

Gyppo

I've asked the company if they have a product they recommend - more news as it happens.

regards,

Kim Siddorn,

In message , J D Craggs writes

I have been looking at Loctite 641, with thoughts about 638 or 603 instead, but 641 can be 'undone', which would be better. I really only need '3 thou Loctite'.

Indeed. I actually calculated the weight tonight, using a value of 7g per cc for cast iron, and came up with almost exactly 100Kg, or 110Kg if you use 7.7g for cast steel. That'd be 220 to 242lbs, so my 300lb estimate was a bit pessimistic. I also regret to say that this figure makes the flywheel weigh just about the same as me :-( I still don't want to be chased by it, though.

All the best

Pete

I've always had good results with Loctite compounds & when I was in the 'bike trade had a phone number I'd ring & talk to a very knowing lady who knew the product range inside out & upside down. Obviously, they couldn't fix everything, but that was thirty years ago - they probably can now!

I asked about a 150 kilo flywheel on a single cylinder engine in occasional use with three thou slop in the mainshaft keyway. I had this from Loctite direct this morning - obviously they think their product is up to the job ;o))

I would look at Loctite 641 or Loctite 270 if you need to get the flywheel off again. These are removable grade retaining products.

Loctite 641 is an industrial grade, known as Bearing Fit, available from Industrial suppliers like BSL, Cromwell, RS Loctite 271 is an Automotive grade, known as Stud n Bearing fit, available from Halfords and other garage suppliers.

Because you only have the one to do, I would be more inclined towards the

271 as this is in small tubes and bottles.

One important factor is to make sure that the bond is clean, this will effect the bond strength if the joint is oily or corroded.

Please contact me if you need any help (information help rather then with a spanner!).

Best regards

Peter Martin-Flaven Application Engineer Henkel Loctite Adhesives Limited snipped-for-privacy@uk.henkel.com

If the flywheel is 2ft diameter = about 6ft circuference. At 1000rpm the rim is going 6000 ft per min = 100 ft per sec == about

65mph.

I don't blame you not wanting to be chased by that.

A good safety addition is to tap the end of the shaft axially and bolt a large washer or plate onto it. If all else fails, this should stop the flywheel leaving the engine. It helps if the thread is LH or RH as apprpriate to stop it being undone by a clever flywheel.

John

Many years ago, I worked for Rolls-Royce cars. Spares were always available for any car they ever built & we supplied a set of kingpins, bushes etc - a full rebuild kit for the steering on a 20/25.

The wheelnuts were handed & - you've guessed it - the owner-driver contrived to fit them on the wrong sides.

Inevitably, the nuts undid themselves & the wheels dropped off, depositing the car on its chassis rails with a resounding thump to the considerable chagrin of the driver.

When he came in to tell us of it, he went out of his way to say how impressed he was that both wheels departed their stub axles at EXACTLY the same moment. This he saw as a tribute to the exactness of Rolls-Royce engineering.

Regards,

J. Kim Siddorn,

Presumably it's also a tribute to his driving that the cornering forces were so exactly balanced between left and right.

A good friend recently asked if I had a 1" BSF tap he could borrow. Apart from starting me on the job of cataloguing all my taps and dies, it also identified that fact that I had somehow aquired a complete set of 1" BSF taps, taper, second and plug in both left and right hand threads. One day I might aquire the left hand bolts to suit. Perhaps it's the answer to the question "what do you get for the engineer who has everything?". Answer - a left handed set.

John

which reminds me, i should get on with catalogueing my helicoil inserts and taps. it's a shame to sit on bags of inserts that someone could better employ. sammmm

Just been on the Rocol Industrial Adhesives website and for anyone who can fulfill all fields required, claim a freebie!

Regards, DJC

Good Heavens, I had a look but they expect me to have a job!!

As a purely temporary measure, I have in the past thickened a key by adding a layer of solder to the key sides - self sized when hammered in and lasted until a new key could be obtained.

John Ambler Sussex, UK Return E-mails to snipped-for-privacy@skiprat.net