What did you do Today 2018

[MuzzerParticipant @muzzer]

I finally got irked enough by the strange graunchy noise coming from the spindle of my CNC machine to actually do something about it. It's clearly not coming from the actual spindle bearings themselves, yet doesn't sound like the sort of noise motor bearings could make either. Have a listen here. The only way to fix it is to remove the motor and belt housing to have a closer look. There are other benefits to doing so: the belt looks as if it's not long for this world, the back gear assembly is one area I haven't overhauled and I would like to fit a shaft encoder to the spindle so that I can do rigid tapping at some point. Finally, there will come a point soon when I will need to extract the machine from the workshop through the roller doors that are only 7' high. This will require me to remove the motor / drawbar / belt housing etc, so it would be sensible to have a dry run up front. The workshop was built around the machine, so getting it in wasn't a problem.

The main issue is that the motor is big and heavy (50kg?) and is over 2m from ground level. And the belt housing isn't a lot smaller or lighter, being a large cast iron jobby.

Managed to extend the boom of the engine crane sufficiently to reach above the motor and bring it down in a controlled(!) fashion. Ditto the housing. No death, hospital visits or changes of underwear were required.

It's now clear that the funny noise was due to the perished belt which is hard and shiny in places. But what surprises me is that it has 60 degree faces on the vees. It measures about 11mm across the top of the vees. Has anyone seen 60 degree vee belts before? It's a new one on me. Having said that, the motor and spindle pulleys are clearly worn in places, so I may as well remachine them to a 60 degree profile.

The next step is to remove a couple of kg of heavy grease from the gear chamber, then degrease everything, check bearings, regrease and reassemble. Before regreasing, i will fit a couple of proximity sensors next to the main spindle gear. By placing these apart by 1/4 of the pitch of a tooth I should get a quadrature signal that indicates spindle direction as well as speed.

Murray

Edited By Muzzer on 08/01/2018 18:50:32

[ChrisHParticipant @chrish]

Journeyman John's picture of his slide rule and case looks very much like the slide rule I bought from the SU office at Plymouth College of Technology when I went there in 1962. We had to buy one (and a load of expensive text books that we also weren't told about before we got there) before we could start our OND course. The slide rule cost £3 I seem to remember. The two coloured plastic case was so distinctive. Had it for years and it served me very well before I left it on one ship or other. Now have my Dad's Faber Castel, if only I could remember how to use it.

Chris

[Mark RandParticipant @markrand96270]

Posted by Muzzer on 08/01/2018 18:48:06:

It's now clear that the funny noise was due to the perished belt which is hard and shiny in places. But what surprises me is that it has 60 degree faces on the vees. It measures about 11mm across the top of the vees. Has anyone seen 60 degree vee belts before? It's a new one on me. Having said that, the motor and spindle pulleys are clearly worn in places, so I may as well remachine them to a 60 degree profile.

Murray

Nah, it's not the worn belt. It's the cigarette card held against it with a clothes peg that's making the noise.

As to the belt angle, might be better to get the new belt before re-turning the sheaves, If you end up with a 40°, it'd be upsetting if you'd just turned the sheaves to match a 60° belt. ( when turning them, don't forget that the sheave angle is less than that of the belt, dependant on the pulley diameter)

[MuzzerParticipant @muzzer]

Sorry, that was a senior moment. I was planning to remachine it at 40 degrees, not 60! I've ordered a SPZ772 belt from beltingonline.com which should arrive before I've remachined the motor and spindle pulleys.

Managed to remove the motor pulley. The spindle assembly bearings pulled off easily enough but the gear and pulley seem to be pressed together. I've had to mount the assembly in the 4 jaw and although the gear end won't fit inside the body of the chuck, the stick out is fairly limited. The question is whether it's hardened or not ie can I use a simple HSS form tool or do I need to use carbide.

I looked closely at the shiny tops of the gear teeth, thinking this indicated where there was no wear. In fact, the shiny bits are ground, to take the bearing (which I have removed. The matt finish bits are a slightly smaller diameter. The gear is pressed into the pulley body, also contacting the shiny bits. There is a key and keyway in there too, to take the load.

Murray

Edited By Muzzer on 09/01/2018 12:21:12

[Andy CarruthersParticipant @andycarruthers33275]

Had a result from a local engineering firm, lots of offcuts for £50 which would have cost over £200 on eBay

Funny thing is, they treat the offcuts as scrap and throw them away

I had to ring a few places before I found this one – surprising that steel offcuts are so hard to come by in Scunthorpe…

[SamsarandaParticipant @samsaranda]

Going back to the dreary and disgusting subject of drains and sewage, a few years ago I was out one Sunday morning and my wife found that the kitchen sink wouldn’t drain and suspected a blockage in the communal sewer which runs across our rear garden. She asked one of our neighbours if they were experiencing a blockage as well so he being a Good Samaritan lifted various manholes to locate any problems. He found one manhole full to the brim but the next one downstream was clear so he got out his drain rods and proceeded to clear the obstruction. Our drains are buried quite deep, about 6 feet at that manhole, there are steel rings in there to enable climbing down. He climbed down the one downstream of the blockage and started prodding with his rods, you already have imagined what happened next, suddenly six foot head of sewage was released to hurtle into the empty chamber, well he wasn’t fast enough to beat the rising tide, apparently it was hilarious to see him scrambling up the rungs and out of the manhole but by that time he had been engulfed by the rising tide. Wasn’t his lucky day but we still have a laugh about that day, all that aside he is a very good neighbour, we have been neighbours now for 31 years. Dave W

[Richard S2Participant @richards2]

Posted by Muzzer on 09/01/2018 12:15:33:

The question is whether it's hardened or not ie can I use a simple HSS form tool or do I need to use carbide.

I looked closely at the shiny tops of the gear teeth, thinking this indicated where there was no wear. In fact, the shiny bits are ground. Murray

Not sure if you were also asking an open question to readers?.

To me, if it has been 'Ground' very close to the pulley 'V', then I would expect it to be hardened.

To confirm it, I would use a medium cut file to test the deflection from the surface in the 'V'. If the file stroke just slides over the surface and only polishes it, then it's also a hardened areal, so a TC Bit req'd, or grinding.

Lastly, if the stub shaft has been 'Centred' at the splined end, It would benefit from support with a Live Centre.

No 'egg sucking tuition' intended.

Regards

[MuzzerParticipant @muzzer]

No problem – as you guessed, the splined core is hardened but luckily the actual (outer) pulley is not. So I was able to make up a 40 degree form tool from a 1/2" HSS blank and set to. I ground the tool to give a large top rake by grinding a groove in the top surface and then honed it with a diamond tool.

The result was pretty good – lots of very fine "bum fluff" swarf during finishing but also some half decent swarf during the roughing part.

So job done – and even as we speak, the belt has been dispatched 1st class. However, before I get to reassemble everything I have a mass of old grease to scrape, wipe and degrease from the reduction gear mechanism. That'll take a while….

Murray

[OldironParticipant @oldiron]

SWMBO and myself were invited up to the Rolls Royce Heritage Centre in Derby to have a look through their archive collection of mechanical calculators & slide rules. Managed to put in a request for some of their duplicate items to add to our collection. Just waiting for approval from the powers to be now on when we can collect them.

We had a tour around all the engines and other paraphernalia which was fascinating. The centre is only open by invitation so most of the items have never been seen by the public at large. They must have at least one of every model of RR aero engine ever made. They also have a very large collection of aero models hand made by RR apprentices over many decades.

Managed to get a look through all the test equipment archives as well. The amount of stuff they had put away was huge. From massive granite & cast iron surface plates, micrometers, surface finish gauges to vernier calipers over 6 feet long the list goes on. I have never seen so many wooden boxes stacked up. All containing machinists tools and test equipment. It was disheartening to see so much equipment that will never be used again. Large amounts have been thrown out (ha) or have disappeared. They are going to try and place some of it in other museums eventually as they will never have the room to put it on display.

We were told that they have no idea of how much stuff they have and an ongoing task is to log and record it all.

All in all a good day out. Looking forward to going back up to collect some items.

regards

[mechman48Participant @mechman48]

Called into my local auction house today, picked up a decent cabinet for storage on a 'see & buy' day… £27 inc. commission + VAT. Will do for small stuff, taps dies etc when I reorganise garage.

George.

[John MCParticipant @johnmc39344]

Today I shortened 200 M8 bolts and used a Coventry die head to put a 5/16" BSF thread on the remaining plain part of the bolt.

This got me thinking, is a die head an obsolete piece of workshop equipment? Obsolete as is a shaper or planer in industry but never the less still useful for the model engineer. A local engineering business very occasionally borrows mine, having not replaced their worn out head some 30 years ago. They much prefer to use a throw away tip tools running at normal turning speeds for threading. last time they used my die head was to cut M10 threads on a part using the only "conventional" lathe (non-CNC) they now have, the reason being all the CNC lathes were busy!

John

[Mick B1Participant @mickb1]

Finished – I think – some bits for a Polish tank engine on a steam railway.

They screw into the valve chest on the outside cylinders, and I think they're lube injectors – 4 of the long 'uns and 2 of the short.

Screwcutting the thread in front of a gasket face was bit hairy at 180 rpm and 10 TPI, but I quite like the low torque of the higher speed range on the Warco – it's saved me damaging components more than once.

The thread is also puzzling – it's either 2,5 mm or 10 TPI, but the top diameter on the originals I was copying is 12 – 20 thou plus on 1 inch BSF. So after screwcutting, I finished off with a 1" BSF die opened to maximum. And what's extra odd is that a standard 1" BSF tap is a smooth finger-fit in the 'ole in the valve chamber. So far as I can see, there ain't no M26x2,5 standard thread. These locos have a complex history and I don't know whether the 1" BSF thread was original, though I believe some think it is.

Still, if it doesn't screw in, we'll just run the die down it with increasing closure until it does.

[Neil WyattModerator @neilwyatt]

Posted by Mark Rand on 08/01/2018 20:42:53:

Nah, it's not the worn belt. It's the cigarette card held against it with a clothes peg that's making the noise.

Brings back memories

Neil

[Mick HenshallParticipant @mickhenshall99321]

Yep everything comes in cycles, sorry if I spoke out of turn

Mick

[“Bill Hancox”Participant @billhancox]

Posted by mechman48 on 11/01/2018 12:03:30:

Called into my local auction house today, picked up a decent cabinet for storage on a 'see & buy' day… £27 inc. commission + VAT. Will do for small stuff, taps dies etc when I reorganise garage.
George.

Nice buy George. I am very envious. Being a competitive shooter, I was struck by the brand name on the cabinet. These are hard to come by and most often command high prices.

Bill

[DrDaveParticipant @drdave]

I managed to get a new pair of brushes for the DC motor in the mill on Friday. They were a tad thin (about 0.4mm thinner than the originals) so I was concerned that they might cause problems. Fitted yesterday & today spent milling a big block of ally into a small block of ally. No signs of trouble after a couple of hours work at near full speed. I’m a happy boy again.

Strangely, whilst the motor is German in an Austrian machine, the original brushes measured ¼” x 5/16”. Strange old world!

[mechman48Participant @mechman48]

Posted by "Bill Hancox" on 13/01/2018 01:48:11:

Posted by mechman48 on 11/01/2018 12:03:30:

Called into my local auction house today, picked up a decent cabinet for storage on a 'see & buy' day… £27 inc. commission + VAT. Will do for small stuff, taps dies etc when I reorganise garage.
George.

Nice buy George. I am very envious. Being a competitive shooter, I was struck by the brand name on the cabinet. These are hard to come by and most often command high prices.

Bill

​Thanks Bill

Yes these are expensive…

https://www.bisleydirect.co.uk/multidrawer/10-drawer

​I have seen them on eBay for as little as £43 ( inc. delivery ) but usually have cosmetic damage of some sort.

​Geo.

[ChrisHParticipant @chrish]

Not today but yesterday. Signed up new apprentice. 9 weeks old tomorrow. Supposed to be SWMBO's but she (new apprentice, not SWMBO) follows me around like a shadow so I can see her spending time in my shed yet.

Pictured asleep on the settee cuddled up next to SWMBO.

All together now, say AHhhhhhhhhhh.

Chris

[Mick B1Participant @mickb1]

Posted by Mick B1 on 12/01/2018 19:19:32:

Finished – I think – some bits for a Polish tank engine on a steam railway.

They screw into the valve chest on the outside cylinders, and I think they're lube injectors – 4 of the long 'uns and 2 of the short.

…

Still, if it doesn't screw in, we'll just run the die down it with increasing closure until it does.

Yep, 4 out of 6 fitted straight away – the other 2 needed one run of the die a thou or two tighter. I think I'll be making the pipe union cones and nuts once someone tells me the pipe diameter.

Edited By Mick B1 on 15/01/2018 14:14:25

[clogsParticipant @clogs]

clogsChris H,

always good to have a pup……….just lost an old friend of 13 years…….keep looking at pups now…….must not give in…….one of ours even as pup just sat on ur foot, 6 years on and still doing it…..he's now the leader of the pack…..

so the 3 other Border Collies will have to do………

clogs

[ChrisHParticipant @chrish]

clogs, good luck with the puppy hunt, we spent several weeks at it; our very first dog, a border collie, went at 12 years about 32 years ago now and we still miss him, was in fact the best we have had up till now, they are lovely intelligent dogs.

Chris

[JssParticipant @jss]

Say hello to crazy Maisie!

John.

Edited By Neil Wyatt on 16/01/2018 12:57:57

[Neil WyattModerator @neilwyatt]

Masie, meet Roxie…

[davebParticipant @daveb17630]

Ginger cat impersonating Rommel in Bridgeport column.

[MWParticipant @mw27036]

Posted by daveb on 16/01/2018 14:57:14:

Ginger cat impersonating Rommel in Bridgeport column.

I always thought he was the desert fox, but now he's a desert cat.

[Author]

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