Here is a list of all the postings Hopper has made in our forums. Click on a thread name to jump to the thread.
|Thread: How to machine an ellipse|
Yet another way of doing it is with steel filing buttons made up, one large pair that fit over the centre part, and two small pairs that fit over a screw through each stud hole. Often the buttons need flats filing on the them where they meet so they fit the space. As often happens, takes way longer to make the buttons than to file the little bit of brass down to the resulting shape. But works well for multiple flanges. By rocking the file a bit, a good elliptical shape can be achieved, rather than the flat sides between the three radiuses. If you make the buttons from silver steel you can even harden them. Otherwise, I sometimes use mild steel and file carefully so as not to damage them. I don't have a mill so this method is handy for me.
Edited By Hopper on 17/07/2018 10:15:56
|Thread: Shingle bells|
Never heard of the vaccination for shingles. Good to know. My late wife had them once, and definitely they are something best avoided.
|Thread: Warco Mini lathe|
Might just be a matter of running a dead smooth flat file or a fine slipstone over the bed ways on all surfaces to knock down any burrs etc?
|Thread: A workholding question|
+2 on Rod's suggestion of the bespoke collet marked to match the chuck jaws for repeatability. "A split collet" consisting of any noggin end from the scrap box drilled to the size and split lengthways on one side with a hacksaw. I suppose you could bore the hole to finish size if you were of a fussier nature than myself.
|Thread: Another bush drilling question|
My ML7 had Oilite bushings, with no hole drilled through them. From the state of them, it would seem they were factory original. So new ones were installed and left undrilled. One drop of oil in the hole in the casting every time the lathe is used is enough to keep them topped up without making a mess.
I wonder if it makes any difference though? Oil goes in the hole and if undrilled, enters the matrix from the top surface of the bushing and spreads from there throughout the whole. If drilled, it goes through to the gap between shaft and bushing and enters the matrix from there. Possibly more loss of oil out the ends of the gap in the latter method but in practice probably much of a muchness really.
So Occam's Razor and all that good stuff, I opt for the simplest way and don't drill the bushings. This also hass the advantage that swarf particles falling in the oil hole can't get into the moving parts, being held back by the matrix.
Edited By Hopper on 17/07/2018 10:01:50
|Thread: Myford G/Box Gears help.|
Brian Wood, author of the excellent book Gearing Lathes for Screwcutting posts on here regularly so can probably tell you exactly what is going on when next he checks in. But a quick look at my copy of his book shows no mention of a 63T. He lists for a 1.00mm pitch a 34T mandrel wheel with the gearbox set to 36tpi. Probably no easier to obtain than a 63T though!
Myfords website lists teh following for metric conversion gears. Looks like your set has had a 65T substituted for the 63T.
METRIC CONVERSION SET 1481/1
Edited By Hopper on 17/07/2018 04:24:49
Edited By Hopper on 17/07/2018 04:27:14
|Thread: Political views within the forums|
Almost exactly what the head of IBM said about personal computers in the 1970s.
Abandon hope, all ye what enter here.
|Thread: Does anyone know of a project for someone looking to get in the hobby|
LOL, too modern for me!
His website (and the other one by Tom I posted) are both a great source of information for beginners (and not-so-beginners).
Elmers Wobbler engine here **LINK**
is a popular beginner's project.
|Thread: Rear toolpost for parting tool|
That's my rear toolpost. Glad you like it! But sadly I can't tell you much about it. It was apparently made by a previous owner of my Dad's old Drummond M-type. Looks to have been well made, possibly on a larger milling machine (foreign order at work maybe?).
It is based on the concept of the patented Norman tool post that came standard on the M-type, with the large diameter upright post and the toolholder that slides up and down it and clamps in position. I also have a Duplex/GHT-style rear toolpost topped with a fourway toolholder that holds the same parting tool and it works just as well.
But the old one does work very well, as the pic shows. I don't grind any back rake on parting tools, ever. Just use them flat. I do very lightly grind the top (er, bottom in this case) of the parting blade nice and flat as they sometimes come with a slight angle on that edge. That way, the tip is the same width as the rest of the blade. I do this with all of my several parting tools, all of which are mounted level with no back rake. They all work well.
I am currently (slowly) making a Duplex/GHT-style rear toolpost for our Myford that will have the parting blade held directly in the toolpost, just to simplify things. Using a T section blade from Eccentric Engineering. That will also be mounted level.
The search for the ultimate parting tool continues...
|Thread: Oilite Bearing with through oil hole|
I think, from reading the original brochure, they are talking more about mass production scenario where holding an edge for thousands of parts may be an issue. For home use on a one-off job, I would use HSS.
Generally speaking, yes carbide can be sharp. Solid carbide end mill cutters and reamers are sharp as.
I would ream your bushing to size and not drill an oil hole through it. Oil will soak into the bushing from the top, but dirt etc will be prevented from reaching the working surfaces. According to Oilite, reaming is OK, but not as good as single-point cutting. But for a low speed application like your saw, should suffice for the next 20 years or more of service in the home workshop.
From OiIite's own literature here **LINK**
"Machining Oilite presents no problems. There are
a few basic procedures that should be followed to
preserve the open-pore structure of the Oilite material
so it will retain its full self-lubricating qualities.
Cutting tools must be sharp. For this reason tungsten
carbide tooling is highly recommended since they
hold a cutting edge much longer. This preserves the
open-pore structure from which oil can flow freely.
A dull tool will smear the pores, greatly reducing the
self-lubricating qualities in the material.
Oilite bearings may be reamed provided a dead-
sharp cutting tool is used. However, reaming does
destroy porosity more than single point tooling.
Honing and grinding are never recommended on
Oilite bearings on any surface which will become
the bearing surface. These operations will smear the
pores and will not allow the oil to flow freely."
Edited By Hopper on 15/07/2018 11:03:52
|Thread: milling qestion|
Back when only spaceships had DROs we just did things the same way as now but used the graduated dials on the handwheels as our readout. Backlash was not an issue if you always moved the table in the same direction, backing off past the zone of backlash and re-approaching the job from the same direction if necessary. Even with a worn leadscrew, error is so infinitesimally small as to be way more accurate than marking out and centre punching etc.
Why does using handwheel graduations seem to have become impossible to do these days?
|Thread: New application of Mole Grips|
Gripping moles. That's why they hide underground these days. Prior to the advent of mole grips, they could be seen merrily skipping up and down footpaths everywhere in complete defiance of law and order.
Edited By Hopper on 14/07/2018 05:14:52
|Thread: Milling Set up question|
A lot of motorcycle reboring is done in bike shops by mechanics, not machinists, using a simple boring bar machine. Centring the bore before reboring is often pretty, ahem, basic. Often just basically a tapered fitting on the boring bar that fits into the mouth of the bore while the cylinder is clamped down on the table. The alignment does not have to be perfect. Within a thou or two would be plenty close enough. (There is plenty of side clearance on the gudgeon pin in one direction and almost infinite available variation fore and aft in the direction the crank rotates. Remember, the average engine is not "blueprinted" but relatively roughly put together under production tolerances.)
And, yes set up can be quite flimsy as cuts are small. Usually you are boring to 10 thou bigger than present, so five thou total depth of cut, or a bit less allowing for honing. So possibly done in one cut of four thou depth. Material is nice grade of cast iron so it machines beautifully.
|Thread: Political views within the forums|
I'm not OCD. I'm CDO.
It's the same thing, but the letters are in the correct alphabetical order.
|Thread: engaging back gear om Drummond M type lathe|
Welcome to the forum. There are quite a few of us M-type owners on here. Not sure which nut you are worried about falling into the works? If you mean the slot-headed screw on the front of the bull gear that you slacken to rotate the plate to engage/disengage the bull gear, it only needs to be loosened a quarter of a turn or less to allow the plate to be rotated around to the end of its slot. The screw is then retightened before starting the motor.
The main thing is to MAKE SURE the bull gear is disengaged from the pulley unit before engaging the back gear and starting the motor. When the bull gear is disengaged, but the back has not yet been disengaged, you should be able to turn the chuck or spindle by hand freely without the pulleys and belts moving. Once you can do that, engage teh back gear and start the motor.
|Thread: Political views within the forums|
Get a grip, guys. There was no politics of any serious nature posted in said airgun thread. A couple of light-hearted comments in the course of chit-chat re legislation that is relevant to the topic of the thread, and related matters does not constitute "politics". Besides, there's been more heated discussion than that on this forum on the topic of capital letters and apostrophes. (Please, nobody mention Irritable Old Gits!)
|Thread: Buying a lathe|
PS: If you look at the For Sale classifieds on the right hand side of this site's homepage, and click on the More For Sale Ads line at the bottom you will find a Myford for sale in there that might be worth a look. (I've no connection to the seller etc)
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