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|
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.|
LG2 = Leaded Gunmetal
|Thread: New DTI "Glass"|
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|
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.
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.
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.
|Thread: Myford ML7 4mm Screw Cutting|
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|
Before you go too far, check any interlock switches. Foot bar, end door, chuck guard etc.
|Thread: CovMac Lathes|
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|
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|
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:
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)
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|
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|
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.
|Thread: Lathe levelling|
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
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|
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.
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.
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.
Whatever you do check it's not a left hand thread because it most likely is.
|Thread: Face turning Bronze castings - strange surface finish|
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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