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Member postings for Pete Rimmer

Here is a list of all the postings Pete Rimmer has made in our forums. Click on a thread name to jump to the thread.

Thread: Large Crane
04/04/2020 23:49:34

A job I did we used a 425tonnes capacity Sheerleg "Norma" out of Zebrugge to lift up to 400 tonnes on the river Medway. The Norma has since been scrapped but I bet that ship in the pic above could have picked her out of the water :D

Thread: Sourcing gunmetal for leadscrew nuts.
31/03/2020 07:45:27
Posted by Hopper on 31/03/2020 02:35:53:

Havent seen gunmetal advertised in years. When was the last time guns were made from yellow metal? LG2 bronze seems to be the modern equivalent. It contains tin, lead, zinc, nickel and iron if it is made to full spec -- but probably varies depending on manufacturer.

But if you want bronze go with LG2.

LG2 = Leaded Gunmetal

Thread: New DTI "Glass"
30/03/2020 18:26:45

An Etalon dial gauge is definitely worthy of repair.

I would make a new crystal from a welding mask lens cover. You can pick the screen covers up for peanuts as they are disposable and you'll get a few tries at it.

 

Edited By Pete Rimmer on 30/03/2020 18:27:32

Thread: Square thread cutting
30/03/2020 15:29:57

Nice one George, that has come out much better. I don;t know how they do it but they do it well!

Now, if you get really bored in your isolation and fancy doing the whole manual, send it to me and I'll make a very nice PDF for you.

Pete.

30/03/2020 14:18:22

George, I cleaned up your photo a bit. Not the best result but it's a bit easier if you ever want to print it out.

It would be nice to get a pic of the whole page if you could. If you took the pic with your smartphone there's a great app called CaMScanner that will automatically clean up photos to make them much more readable.

Pete.

29/03/2020 19:44:50

Hi George,

I was going to ask if it was a Little John. I have made a backplate for one of those and the dimensions looked familiar.

I don't recall it being particularly difficult to turn that thread. I would grind the end of a broken end mill to a square shape just deep enough to cut the thread depth and cross-drill a chunky piece of bar as a holder. Secure the bit with a grub screw and make sure it's turned slightly to match the helix angle. It should go fairly easily. Grind your tool a few thou wide rather than the exact width then you won't have any clearance problems. Turn the register exactly to the shoulder diameter first then thread it until the tool puts a shallow groove into the register so you have good clearance. A slightly loose fit on the thread is fine. Be sure to face the end on the same setup so the register, the threads and the seating face are all true to each other.

Good luck!

Pete.

Thread: Myford ML7 4mm Screw Cutting
29/03/2020 10:53:09
Posted by Hopper on 29/03/2020 02:34:47:

And is the helix angle even greater? The OP states a 4mm pitch thread on 33mm diameter. All things being proportional, wouldn't that be the same helix angle on the thread as cutting a 2mm pitch thread on a 16.5mm diameter? Which nobody would be concerned about.

The helix angle will be similar but the full depth 4mm pitch thread will be removing double the material of the 2mm pitch at double the rate for the same rpm = 4x the load on the lathe.

Thread: Inverter failure guidance
28/03/2020 20:40:11

Before you go too far, check any interlock switches. Foot bar, end door, chuck guard etc.

Thread: CovMac Lathes
28/03/2020 11:44:16

I have several sets of 4-jaw chuck jaws. No idea what they fit as they came in a bag with a load of others,

Measure your screw pitch, jaw width and slot width Thomas and I'll see if any of mine are close.

Thread: shopmade tool cutter grinder attachment
28/03/2020 08:51:41

Teriffic work Celso, as usual. However I'd have to question the concentricity of the collet taper to the spindle OD given that you had it held in the 3-jaw. I think you might find that you have to clock the OD in a 4-jaw and cut that taper again. Even tiny amounts of concentric error show up when you're sharpening cutters etc.

Thread: A sight for sore eyes
22/03/2020 21:39:46
Posted by Hopper on 22/03/2020 12:33:11:

Okay Boomers. laugh

Seriously, have you blokes been self-isolating for the past 30 years? In 2016 there were 296,000 women working in construction in the UK, according to the Office of National Stats. Still a small minority overall but hardly a new or strange thing. It's been going on since the 70s. It's nothing new and it's nothing particularly unusual any more.

I've been working in construction for more than 30 years and whilst there are many more women working 'in construction' now they are almost all in 'soft' jobs. For example:

Surveyors

Site engineers

Site managers

Project managers

Document controllers

Environmental managers

Safety managers

Compliance

Office/welfare support staff

I've seen a few on the tools, but only very few. Saw a female brick layer, and you get quite a few women in M&E installation. One of the best crane operators I've ever known was a Polish lady.

What I've never seen women doing on the tools in the whole of my working life is:

Driving any diggers or other mechanical plant

Working in demolition (on the tools)

Steel fixing

Steel erecting

Concrete gangs

Or any of the other heavy-labour jobs in construction. So yeah whilst they are 'in construction' they are not generally fulfilling the roles that you associate with the stereotypical brawny male, and that's by choice- it's not like the opportunity is not there - it's that the typical female physique is not suited to the heavier work and they don't want to present too masculine an image.

This isn't bigotry or sexism, it's my observations and in my mind women are perfectly welcome to work in any role and in any industry they choose. In construction they very much tend to choose the non-physical roles.

Thread: Lathe levelling
21/03/2020 17:38:37

Yes, the tall stack but narrow bed lathes suffer the most from twist plus of course they tend to be less rigid in the first place.

I don't advocate putting a level on the top of the saddle simply because it will only give you the angle of the saddle, not the way. Anyone who has scraped in the underside ways of a saddle would know that the biggest wear on a saddle is on the front way nearest the chuck - the wear there is going to be more than the wear in the actual bed and it's normal for saddle ways to be worn both ends and 'high' in the middle causing them to rock.

For a badly worn lathe that is cutting a taper you might use inducing a bit of twist as a get-you-by mind - some manufacturers actually specify setting a twist to remove taper.

Where it REALLY gets complicated is for lathes like Colchesters which have adjustable headstocks via the rear-end jacking screws. You could get into a horrible situation where you adjusted the headstock to correct for cutting taper in a part when thee cause was actually the bed has a twist. Now you have adjusted the headstock out of axial alignment with the tailstock so you'll be drilling off-centre and causing reamers to cut on one side.

If you're going to work on your lathe alignment the first thing you do - the very first thing, is level the bed.

Thread: A sight for sore eyes
21/03/2020 17:19:52
Posted by Steviegtr on 21/03/2020 16:49:34:

50Kg for who? Everyone? Or just certain sections of society? I have in front of me an invoice from my coal merchant which states "Take notice that you are to receive herewith, in sacks, and each sack containing 50 Kilos." I've had a quick look at the HSE website and am surprised to find that there are NO legal limits to manual handling of loads. There are diagrams which suggest limits, but these are NOT legal requirements.

That does surprise me.

The building game. I think if doing self build or one offs, maybe it does not count. I am watching daily here as everything is controlled, by crane lifting. Strange as I did a few courses on manual handling when working for blue chip companies. They insisted we all went on too many courses. Even back then they were quoting 25kg. Looking deeper it would seem as Peter says. No legal limit. So it must be down to the company who hire you. These houses are all Persimmon homes. So guess they implement the rules.

Steve.

Steve, the guidance for lifting is "whatever you feel comfortable with". Some people can quite comfortably lift 30-40kg loads all day, others could not lift 15kg. Age, size, physique and yes sex are all variables so a rule limiting weight to lift is not practicable.

The main requirement is that the operation be risk-assessed and that mechanical mean be used wherever possible. It's not acceptable for example to expect 3 men to shift 100 kilos where a forklift could do the same job.

P.S. there was a trial done some years ago where a supplier reduced cement bags to 15kg weight. All that happened is people carried 2x 15kg bags together instead of 1x25kg bag. It made the situation worse. Nowadays of course they are mostly 20kg bags.

Pete.

Thread: Lathe levelling
21/03/2020 16:40:12

Gary, you put a sensitive level at each end of the bed to make sure not that they are 'level' but that they are level with each other. Any pedestal lathe sitting on the floor but not levelled will almost certainly have a twist in the bed. If it's on castors even more likely.

Hopefully this sketch will show why you would level a lathe.

I've knocked up the above image and laid one over the other but rotated 1 degree to simulate an exaggerated twist in the bed. The images depict the saddle at one end of the ways and then at the other. If you look at the tip of the tool you'll see that it's closer to the 'work' at one end than at the other because the twist has rotated the whole assembly clockwise. This would cause you to cut a taper in your work.

 

Edited By Pete Rimmer on 21/03/2020 16:41:45

Thread: Coronavirus
21/03/2020 08:51:37
Posted by Ady1 on 21/03/2020 08:23:55:

And as usual most of the sacrificing in this war is being done by the youngsters in the form of financial armageddon

While the main net beneficiaries in this war are the oldies who live in relative financial luxury

I would spread the pain

Do something along the lines of a 50% reduction to every public and private pension in the land

This cash gets diverted into a war chest which helps with the national cost of this war

We're all in it together kinda thing

That could have far-reaching repercussions, not that I think it could ever happen the idea is preposterous.

Not only would you plunge millions who have lived their life responsibly, taking care of their financial future into hardship (people who are currently the last-resort backstop for a lot of people about to face becoming destitute) but you'd also remove the incentive for the following generations to make contributions towards their own future when they face the prospect of having THEIR pension pot snatched out from under them on a whim.

Thread: Renovating vice screw and nut
20/03/2020 18:08:43

You can use literally anything you want. Some M16 threaded rod and a long nut would be the most basic way. That's how the cheaper saws do it.

20/03/2020 13:15:48

If I were tackling that job I would simply turn a new nut from bronze and set it into the cast-iron nut with threadlock. Turn a round nut with a flange on one end and make sure that it's 'pulling' into the hole you bore in the cast iron nut when the vice is tightened. The threadlock will be more than sufficient to hold it for opening the jaw.

Unless the old screw is knife-edged it'll work for many thousands of cuts.

20/03/2020 12:38:14

Looks like you're right Clive. Looking at pics of other Q&S saws the moving jaw is furthest from the handle so the thread would indeed by RH.

20/03/2020 07:27:59

Whatever you do check it's not a left hand thread because it most likely is.

Thread: Face turning Bronze castings - strange surface finish
19/03/2020 09:33:37

If it's loose headstock bearings you could put a bit of load on it using the tailstock centre. Just get a bit of scrap ally or something and pop a centre drill hole in the face of it with your cordless. Grease up the flat face and the centre drill hole and use it as a rotating pressure pad.

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