What Did You Do Today (2017)

[Allan BParticipant @allanb]

They still do, we do most of the basic maintenance and checks on the machines, including freeing up a seized bush on a horizontal mill, but taking the whole headstock apart is a little more than a lessons work I think, and even without the power feed we need the lathe as they are in short supply as it is.

Allan

[Dave SpicerParticipant @davespicer27262]

The shear pin should be where the leadscrew exits the feedbox. No need to strip anything down. Can you rotate the leadscrew by hand, without the half nuts engaged.

You will see it rotating, but where the shaft exits the feedbox .

[Allan BParticipant @allanb]

Yes you can rotate the leadscrew by hand, and hear a nasty grinding noise from inside the gearbox at the same time, no matter what settings the leavers are in 🙁

[Dave SpicerParticipant @davespicer27262]

Doesn't sound healthy that, If there was a shear pin then some one may have fitted a hardened pin instead, it's done before. Can you find out the machine serial number?

[Allan BParticipant @allanb]

I can next week which is the next time I am in the machine shop, due to finance they have cut half a day out of out practical time, so we only get 6 hours a week.

Allan

[BazyleParticipant @bazyle]

Sky news has just shown the Chancellor pictured with a backdrop of a light blue turret mill .ETM 2VS. I wonder if he knows what it does or perhaps it was just 'something industrial' for effect inserted by the editorial team.

[John Stevenson 1Participant @johnstevenson1]

Should have been a lathe and then he can turn in his sleep.

OK I'll get me coat………………

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, yesterday evening I finished turning my new backplate for my slim 4 jaw. All it needs now is the holes for the chuck to be drilled and tapped, and some holes drilled for holding it down on the mill table. In all about 7lbs (approx. 3.2 Kg) of metal was removed, but it machined very nicely.

Regards Nick.

[HowiParticipant @howi]

Tried cutting my first gear today, tooth profile bl***y awful, I think I must have set the depth of cut wrong.

Cutting an 80 tooth clock gear, 82.7mm outside diameter with a 2.7mm depth of cut using a mod1 cutter.

Teeth are pointed rather than typical gear tooth shape, is there a simple formula for calculating depth of cut?

I have 3 mod 1 cutters that cover the range of gears I require. I do not want to waste any more brass if I can help it, it is far too expensive.

[EmgeeParticipant @emgee]

Howi, DOC usually engraved on the cutter, go to this page by JS, all the info you need.

http://www.metalwebnews.com/howto/gear/gear1.html

Emgee

Edited By Emgee on 18/03/2017 10:21:52

[Martin WParticipant @martinw]

Hi

There is a table for for Mod 1 gears here which gives all the information regarding sizes and tooth depths.

Martin W

PS

The above link gives  total tooth depth of 2.16mm but on looking at another site this is for gears with a pressure angle of 14.5 deg and this changes to a total tooth depth of 2.25mm for gear with a pressure angle of 20 and 25 deg. So for an 80 tooth gear, assuming apressure angle of 20 deg, the blank diameter will be 82mm with a cut depth of 2.25mm.

Edited By Martin W on 18/03/2017 11:14:51

[roy entwistleParticipant @royentwistle24699]

Howi Clock wheel teeth usually are pointed Don't forget that clock wheel teeth are cycloidal. You usually only have one cutter for wheels but several for pinions

Roy

[Martin WParticipant @martinw]

Howi

If you are cutting cycloidal gears then the profile will, as Roy says, will be pointed. There is a diagram and calculations here. The blank diameter for Mod 1 cycloidal geras is given as,for an 80 tooth wheel,  82.76mm with a total tooth depth of between 2.45mm to 2.95mm depending on whether it's short or standard form. As these figures are very close to those you are using then I suspect that you are cutting cycloidal gears and as such the teeth look long when compared to normal gears (involute).

Hupe this helps

Martin W

PS

My previous post was for standard involute gear so would probably not be correct for your application.

Edited By Martin W on 18/03/2017 13:00:28

[Martin ConnellyParticipant @martinconnelly55370]

I was asked to square up the ends of some 2 1/2" sch40 316L stainless for a trailer axle and modify some stub axles to fit in the ends with a "hammer" fit. Holes were added to allow for some welding away from the thin lip and a fillet will be added all round the end of the pipe. Someone else will be welding it.

Martin

[Nick_GParticipant @nick_g]

.

Went to my mates to borrow a chunky angle plate off him so I can bore out for the main bearings on an engine.

He was doing a batch of threading. – This machine dates back to the WW2 era. I don't think it's been cleaned. ……….. EVER.!

Nick

[HowiParticipant @howi]

thank you to everyone who replied, Martin W – thanks, the depth of cut of 2.25mm looks to be the right depth value i should have used. at least my electronic rotary table worked a treat, I think the gear is salvageable so will crack on with the rest.

once again many thanks

Howard

[David TaylorParticipant @davidtaylor63402]

I made the oil pots for the tops of the slidebars of the loco I'm building. Was a nice easy job once I had a system worked out.

[Speedy Builder5Participant @speedybuilder5]

Got around to making one of the Christmas stocking fillers – I built a loco in one day !!!

[Martin WParticipant @martinw]

Hi Speedy

Looking forward to seeing it in steam !!

Martin W

[Michael GilliganParticipant @michaelgilligan61133]

Not sure quite what to make of this:

**LINK**

The Science Museum’s model ship collection, in a new light

… It's a valiant artistic effort; but what it tells us about the Science Museum is sad, to say the least.

MichaelG.

[John Stevenson 1Participant @johnstevenson1]

They might as well set fire to them because they will never be seen again, like a lot of the displays.

I was there 4 years ago and totally disgusted. The top floor which used to be set aside for flight now has been gutted and holds 3 large desks with 3 computers on each desk where the public can look at alternative energy sources.

 

??????????????

 

It's a freeking museum for Christs sake and half of these 'exhibits' aren't even made or viable. Anyone can sit at home and search the same thing out and not have a whole floor wasted.

 

I wanted to see Babbage's Differential Engine which is supposedly on display and built with public funds so part of it is mine.

Looked all over, found the small section that has been on display for years. Found his brain in a glass jar [ shouldn't that be in the Natural History Museum down the street? It's not like it is part of a Babbage display, it just sits in a jar surrounded by other exhibits not even related ]

 

Finally went to reception to ask. Some 20 year old something that judging by all the piercings had fallen face first into a fishing tackle box, had no idea what i was talking about. So she had to look it up on her computer.

"We have a section on display "

 

"Seen it I'm looking for the whole thing, can't miss it as its 10' x 10' x 10' "

 

"We have his brain on display on floor 2 "

 

"Glad someone has one "

 

Had to return home and Google it to find out it was on tour around the country but the Science Museum didn't know.

 

Pathetic. Now the Birmingham museum of Science has closed we only have MOSI in Manchester as a proper museum, but for how long until some Arty Farty new director decides to try to make a name for himself.

 

Edited By John Stevenson on 22/03/2017 00:14:20

[thaiguzziParticipant @thaiguzzi]

LOL

Fallen face first into a fishing tackle box…

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Stevenson on 22/03/2017 00:12:46:

… we only have MOSI in Manchester as a proper museum …

.

Treasure your memories, John … I think you might be disappointed if you returm to MOSI

… It has changed a lot in recent years

MichaelG.

.

http://msimanchester.org.uk

http://msimanchester.org.uk/whats-on

Edited By Michael Gilligan on 22/03/2017 06:59:37

[PeroParticipant @pero]

There seem to be common threads running through a lot of museums around the world at the moment:

• We have a lot more material than we can ever hope to display (fair enough) but we want still more (presumably that we can also hide away and never display).
• It is all ours and we propose to limit, restrict or prevent your access to the material even if it is in public ownership. (Private museums can of course manage the material they have acquired as they wish.)
• All material shall be preserved exactly as it is on the date of acquisition no matter how decrepit, as if the date of acquisition is in any way significant. I believe most craftsmen would be insulted to see their work displayed in anything but pristine condition. Personally I support the full restoration of items unless there is demonstrated significance to condition at a specific date, e.g. the desk in 1066 at which Nelson received the Kaiser's surrender after the battle of Waterloo.

If the practice of allowing historical items to continue to deteriorate (a la many historical buildings and monuments) human history will disappear at an ever increasing rate, no need for the terrorists to do it for us.

As for the photographic display of historical ship models – I like what I have seen but put it in an art gallery where it belongs, it has no relevance in a science museum. Then employ some scientific photographers to photograph the collection and put the results onto the internet where they are accessible to all.

The above comments are the views (and rants) of the poster for which no one else can be blamed.

Pero

[JAParticipant @ja]

Posted by Michael Gilligan on 21/03/2017 23:41:45:

Not sure quite what to make of this:

**LINK**

The Science Museum’s model ship collection, in a new light

… It's a valiant artistic effort; but what it tells us about the Science Museum is sad, to say the least.

MichaelG.

I am sure that most of you know of Science Museum's archive for large items at Wroughton near Swindon. Thirty or so years ago it used to open to the public on some summer Sundays. However it has been firmly closed to the public for over ten years.

If I had the energy I would try to get a petition to Parliament going to at least get them to debate what they are doing about a great national collection. I cannot understand the mind set of museum curators who do not want to show their museum exhibits. Yes, I know the popular mantra – there is no money, our exhibits must interact with the public, we must educate our visitors and all that, but…..

Written with childhood memories of pushing buttons and twiddling knobs at was once a great museum.

JA

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