Here is a list of all the postings Howard Lewis has made in our forums. Click on a thread name to jump to the thread.
|Thread: Bridge Rectifiers|
Second for comments about voltage regulation. A supposedly 12V power supply for a OO gauge train was 18V open circuit, did no good to the electronic controller connected to it!
Is there a high resistance (poor/corroded) connection any where in the circuit? The current draw will cause a voltage drop through that, although it ought to start feeling warm, if that is the case.
Just a thought
|Thread: Quick Adjusting Drill Depth Stop for RF-20/25 Mill?|
A bit too late now, but was going to suggest a 1/2" or 12mm round with a short thread on the lower end, for fixing, and a moveable stop. But you've just done that with the M8 studding!
|Thread: Model Engineer – Editorial direction|
Neil summed it up quite well.
Cannot comment on M E as not a reader. Am M E W subscriber. Not all articles do interest me, but sometimes, like JS, a return to an earlier Issue provides inspiration or the solution to a problem.
(Not having CAD, do not read the articles, but many others things are interesting/useful, at some time. As are the Workshop Practice books, G H Thomas, Sparey etc)
Reading back issues is like this Forum, addictive, and informative.
This Forum is a great asset, you learn about things that come in useful later, (Some are in the "Not many people know that" category, but no knowledge is totally wasted)
Note to editors, if needed, You won't please all the people, all of the time. One man's meat is another man's poission, (deliberate spelling mistake/pun) and all that.
The measure will be, if the magazine content is wrong, sales will decrease. If you get it more or less right, sales will increase.
|Thread: Taps and Dies|
My choice tends to be The tap and Die Company, expensive but GOOD. Tracy are quite good, and if there is a problem never get a query, just an immediate replacement.
Won't touch Carbon Steel now, seem to break too easily, always HSS or T &D Cos HQS.
Quality tends to be cheaper in the long run.
|Thread: First lathe|
For what my opinion is worth, in the future you may find that you want to machine something a bit larger.
If you have the space and the capital, my advice would be to buy a larger machine, (all other things such as quality, being equal). As someone said to me, "You can do small work on a big lathe, but not the other way round"; despite the splendid work that many folk do do on small machines.
Mini lathes tend to have plastic gears, (Arc sell metal gear conversions). The Chester Conquest manual advises against roughing cuts greater than 0.010" (0.25mm). My worry over converting to metal gears, (much as I am tempted so to do) is that you might then find the next weakest link in the chain, and it could be an expensive one, such as control board or motor!
My mini is a "standby" machine, (for when I don't want to disturb a job set up in the larger lathe) bought from a chap who bought it and then found it too small for what he wanted to do. My Myford ML7 with a 2MT headstock was too restrictive. I M O 3MT is much more useable, hence my preference for a larger machine.
Hope that this is of some help.
|Thread: Quick Change tool post advice|
Like J S, as an Apprentice, one of the first things that we were taught was to feed steadily, using both hands
I use the Apron Handwheel, or the Topslide Handwheel, as required. Topslide has to be used when turning short tapers, such as trimming up centres, or making holders for ER collets.
My far eastern lathe has Handwheels, thank goodness, preferable to the ball handles on smaller Myford ML7 which preceded it.
To remove bell ended toolpost clamp screws is a pain, since it involves trying to hold the screw stationary whilst filing, in situ, on every one, until they can be removed and tidied up properly. Best remedied as soon as noticed, before becoming a major problem.. Stitch in time and all that!
|Thread: Myford super 7 cross slide and oil gun|
I bought a genuine Myford oil gun. From new it leaked everywhere, more oil on machine and me than where it was required.
Bought a Reilang, money very well spent. It does not leak, and puts the oil where you want it go, and will pump no matter what angle its at!.
Edited By Howard Lewis on 09/03/2016 17:01:15
|Thread: Miss Britain III|
The thing that surprised me when I saw it was, just how spindly the crankshaft was.
Nevertheless, the Lion saved many lives powering WW2 Air Sea Rescue launches.
Great British engineering that is no more, sadly.
|Thread: What Did You Do Today (2016)|
F W I W, I use a pastry brush to clean swarf off the lathe, where the dustpan brush won't reach.
(Sometimes, cheap paint brushes will do this job quite well)
For Taps and Dies, an old tooth brush is very handy for cleaning before putting away.
Empty food tins, cleaned, are useful for filling with swarf (Well packed down with a piece of 1.5" /38mm bar)
For fine swarf, a stick magnet in a copper tube with a closed end, is handy for retrieving and transferring into the tin. Unfortunately, only works with ferrous materials, wish it did with brass or ali!
Then just before completely full, (packed down) add the lid and hammer over the edges, before dumping into the recycling. (Not tight, just careful y'ken)
Edited By Howard Lewis on 09/03/2016 16:26:57
|Thread: Models stolen, Lancashire|
Am sorry to read this, not good for the blood pressure.
(DON'T get me started on what should be done to such thieves. For once Sharia law does look appealing)
Too late to be much help in this case, but may help others to avoid such event.
If your garage door is of the Up and Over type, the diagonal reinforcements only have pop rivets on one side.
Apparently, it is a popular ploy to flex the door, so as to spring past the latch at the top. Placing another 3/16 (4.5mm) pop rivet on the other side of the top hat section reinforcement will strengthen the door, and make unauthrised entry less easy.
If you access the garage via another door, so that the main door is only opened as and when required, drill a hole through the moving latch, above the catch plate, and insert a pin, or even a bolt and nut. It does not need to be big, 3/16" / 2 BA / M4 will quite sufficient, (They won't shear that easily). This will prevent the latch being disengaged from the catchplate.
The central lock, is often carried on a plate which is pop rivetted into the door. If the four rivets are drilled out, a hand can be inserted to pull down the wire that is connected to the catch, REplace at least two of thos rivets with dome headed bolts with nuts on the inside. If possible use self locking nuts or anaerobic sealant to prevent the nuts loosening.
No dome headed bolts? Turn off the hexagon, and radius the head.
If you make it difficult, the unmentionables, will find somewhere easier to burgle.
A security light may help, as long as it doesn't provide light for them to do their worst.
If the garage has a side door, it would be worth making sure that the lock is 5 lever, to be difficult to pick.
(For my shop I specified a five lever, but in the event, the door came with a six lever lock, which is even harder to pick)
Hope that some of this may be of some help.
|Thread: I screwed up!|
Experience allows you to recognise the mistake, as soon as you make it again.
Having been foolish again, I had to remove the Apron to remove the damaged traverse shaft/gear.
Thanks to Geoff for all his guidance, which gave me the courage to have a go at it
Was none too sure about genuine replacement parts, since the original seemed to bend so easily, (despite a 5mm brass pin in the drive) so made my own replacement, eventually. Wasted a lot of time cutting the gear, because the chart in the Vertex HV6 manual was wrong (eventually made up a spreadsheet which showed up eight discrepancies / omissions) Started a thread on here about this.
Eventually cut a new gear, (blank Loctited into the new shaft). Works and feels better than before. Raised oil level in the Apron by turning up a nylon plug for the hole where the Handwheel gear goes into the Apron. Oil is now distributed to the upper gears by the handwheel being turned manually or under power. You know its working, 'cos it seeps past the shafts on the other gears!
When Apron was off, found found the screws for the Worm Housing were loose. Had to shorten and modify a 5mm Allen key to tighten them after Apron refitted. (found this out the hard way! A VERY slow job, but time well spent).
Also found out why the feed control was a bit too notchy, caused by the Leadscrew interlock, but soon cured.
Feedshaft and Leadscrew now both have 5mm brass shearpins, with 2.5mm drilling, so hopefully, in the event of a future pile up, the pin will shear before damage is done.
Now can restart work on the job that I piled up to begin with!
|Thread: Hello from Merseyside|
I made up a frame from 3 x 3 box section, welded together to make a portal frame, and used a 6 ton hydraulic jack as the power source. It was used to change a lot of Ford Cortina half shaft bearings.
Just be sure that the parts that you are pressing will not fly out sideways, if anything slips! And that you are exerting pressure on the parts that you should, otherwise you may well break something.
Making dollies to press bearings in or out is just simple turning, and makes life so much easier than "bodging"
|Thread: Imperial Drawbar for a Metric BF20 Mill|
+1 for making a 3/8 BSW drawbar. The one that came with my RF25 has the hexagon pinned to the top end.
So no reason why not to cut a 3/8BSW male on the end of a 3/8" or 19mm bar, and pin or weld a bit of hexagon bar on the other end, at the required distance.
(Not REALLY happy at hybridising threads, have come a cropper at times doing things like that)
And it is only a simple turning job to make a 3/8 BSW drawbar, anyway, so time well spent.
|Thread: Abuse of the word "free"|
Remember, it was a politician who said "When I said safe, I didn't mean safe". But how many of them do say what they mean?
Friends who don't have a TV were HOUNDED by the TV licence people , until they finally came to the house to search for the set, that MUST be there. Only then did they accept that there was no set.
"What very odd people, no TV!"
Winston Churchill said that there were liars, damned liars, and statisticians, he forgot marketing folk and politicians of all shapes and sizes.
There is no such thing as a free lunch. Someone has to pay for it!
Howard (Fully paid up cynic)
I think that you will find that R - R invented Wellseal, and Hylomar in their Research Department, many years ago.
Wellseal was used to seal the wet liner to the recess at the top of the cylinder block on the C Range engines. Messy (and smelly) stuff as it seemed that only trichlorethylene would dissolve it, to clean hands or tools, or anything else. For many years trich has been banned, because of the effect of breathing in the vapour.
At Perkins, Hylomar was used extensively for many years. Both are non setting jointing compounds, unlike Hermetite, which will set like concrete, if not harder, and has to be virtually chipped off.
If the machined surface is reasonably flat, and has a good finish, applying a sealant, such as Wellseal, Hylomar, or silicone rubber results in a metal/metal joint, with the sealant merely acting as a gap filler where the surfaces depart from ABSOLUTELY flat. Again, you need something fairly exotic as a solvent ,such as methyl chloride, for Hylomar. Silicone rubber is good, but beware of excess being squeezed out to block small passageways, such as steam ports if used on cylinder covers.
There are grades of Loctite, and probably other anaerobic sealants, that will do the same job.
|Thread: ML7 lathe|
You certainly do not want to load the machine by cutting metal whilst running in reverse. That is asking to unscrew the chuck, and damage to machine, and possibly you, that will result.
(My lathe looks like a newer version of Ian S C s, and has restraints for the screw on chuck)
Parting off using a back toolpost is better than using the front toolpost. The parting tool is mounted upside down, and the lathe is run in the normal forward direction. Capstan lathes, used in industry, nearly always had the parting tool, or form tools, mounted on a back toolpost. On my lathe, the back toolpost carries the parting tool and tools to front or back chamfer the work.
Running a lathe with a screw fit chuck (without restraints) is likely to be done only when running the screwcutting tool away from the chuck, to avoid disengaging the half nuts.
Edited By Howard Lewis on 03/03/2016 17:47:53
|Thread: What are these (from)?|
There is very little scrap material. Only when it is already swarf, or too small to hold for further processing, is it scrap.
It will always come in useful one day, (assuming that we have space enough, and live long enough to find a use for it) A friend has made a small oscillating engine from the legs of a 13 Amp plug. 3/8 BSP brass pugs are good raw material for small bushes, and so on.
|Thread: correct way to feed when milling|
As already said, climb milling is for rigid machines with no backlash, or backlash prevention.
The risk is that the cutter will grab the work and pull the two together, risking a broken cutter and scrap work piece.
For our Model Engineering world, it is not a good option. The workpiece should always travel towards the cutter teeth, so that the relative speed is increased, (climb milling gives decreased relative speed, because both are travelling in the same direction.)
|Thread: Feedscrew Material|
I thought that all cycle threads were 60 degree x 26 tpi.
20 tpi is a nice convenient thread for a feedscrew, since it gives 0.050"/rev. Sometimes, I use 1/2 UNF , since it is 20 tpi, for that very reason.
|Thread: Hydrogen embrittlement in steel?|
Also, why paint it black anyway?
Black is a good radiator of heat, so silver paint would radiate less heat, and so aid the external insulation.
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