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Member postings for Howard Lewis

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: Audi recall
04/10/2016 21:29:03

At the start, I thought that John's calendar had gone wrong, and it should have been 1st April!

Agree about the connection between parking sensors and cruise control, but you can't see what make it is.

Or are retro rockets standard fitting these days? (far better than Anti Lock Brakes)

Sometimes you wonder why manufacturers bother to fit those shiny things on each side and inside; very few seem to use them for their apparent purpose.

Rant over!

Howard

Thread: Clarke CL500M - Belt Sizes?
04/10/2016 20:49:53

Thanks Michael,

I 'll bear what you've said in mind, once we get it up and running, and if the owner wants to go down those routes.

Howard

Thread: Greenly's Halton Tank
04/10/2016 20:25:40

At the Spalding Model Engineering Show, a couple of years ago, there was a very similar model exhibited, on I think, the Leicester Club stand, in Hall 1.

Howard

Thread: two stroke on gas
04/10/2016 19:11:38

The GM two stroke diesels were uniflow engines, where air entered the cylinder through ports in the liner, and the exhaust left via the poppet valve in the cylinder head. I think that the Foden two strokes may have been similar.

The Roots blower was purely to provide "blow down" for scavenging, rather than supercharging.

The Commer TS3, Napier Deltic, and Rolls Royce K Range engines, and possibly the larger Leyland engine (intended to power a Tank) by having opposed pistons operating in the bore, used one piston to control Inlet , and the other to control Exhaust. timings

Since the induction air did not pass through the crankcase, and specific powers were higher, a separate lubrication system was used.

The Rolls Royce C Range, and Perkins engines, that ran on gaseous fuels were not diesels, they were four strokes and used spark ignition. Most of the components below cylinder head level, other than pistons and rings, were common with the compression ignition parent.

SAAB two stroke petrols used a separate lub oil supply system, I believe, which allowed higher powers.

The Trojan and Sachs two strokes used a piston in a connected cylinder to provide scavenge air, (as did the Perkins Duplex - a two stroke diesel which never went into production). Quite a few two stroke diesels, used stepped pistons to provide scavenge air, but these were usually low speed units use for marine propuslion.

I can see no reason why, for low specific outputs, oil could not be admitted into the Induction tract under the Throttle for a Gas engine. (basically that is what the loop scavenge two stroke does by adding oil to the petrol).

Howard

Thread: Clarke CL500M - Belt Sizes?
04/10/2016 18:43:36

Shortly, am likely to helping a friend sort out problems on his second hand CL500M, so all this is of interest.

With regard to comments re too high a Spindle speed for screwcutting, I would have expected the Idler to be mounted the other way round, so that the belts run: Motor small/Idler large and Idler small/Spindle large.

Is there a reason why the idler cannot be fitted the other way round?

The tumbler reverse adaptation sounds interesting. Has anyone any details, please?

Howard

Thread: Digital Calipers - Can you rank these from the measurements?
28/09/2016 16:31:16

Interesting reading.

Total agreement with controlling temperature of "standard" and of the measuring device, and the importance of consistency in pressure applied /feel.

(Otherwise, why do large companies spend a lot of money on temperature and humidity controlled rooms for checking the accuracy of their measuring instruments?)

My practice with any measuring device is to wipe the jaws/anvils and check that Zero IS the reading, before taking each measurement. With callipers, I try to measure away from the tip, to minimise any effect of deflection. (My measuring kit, even the cheap LIDL digital calliper, is probably more accurate than my handiwork). I just look for consistency, and expect more from a dial or vernier calliper, and a reputable micrometer than from a DRO.

Strangely, this week, the DRO on the tailstock of my lathe began behaving erratically. Removing the battey and refitting after a delay did not work. Stripping and cleaning the slideways was no more effective, especially when it "froze"on 000.0. Having nothing to lose, I plucked up courage and removed the PCB and the Buttons. On the Zero area of the PCB was one speck of dirt. Once wiped off, and with everything reassembled, it seems to work satisfactorily, again.

Being a fully paid up Luddite, DROs are convenient, but mechanical devices inspire more confidence!

Howard

Thread: Delivery Problems
28/09/2016 15:58:14

After being made redundant; for six months I worked as a parcels courier for Interlink (A franchise operation).

Obviously, companies will vary, (as will each Depot and courier) in their efficiency and conscientiousness. Lack of care could result in damage to a consignment, at any stage of the process.

Everyday was a stressful 13 hour one, very often needing to be somewhere else 5 minutes ago, for a desperately urgent collection. Sometimes, the address was anything but clear, or obviously marked.

If a parcel was delivered a day late, it was only because an error by one of the couriers. Every item was scanned onto the vehicle, and off, with a handheld scanner, (PLUS a receipt signature) the results being downloaded at days end to confirm delivery.

Some deliveries were "timed", and theoretically had to be delivered by 0900. Try that when you have three, for destinations in places each some 15 -20 miles form the others! But barring the odd acceident, everything got there the same day as it arrived at the depot. The worst problem was folk who did not know the difference between Bourn in Cambridgeshire and Bourne in Lincolnshire, and then complained of delivery a day late!

Howard

Thread: Holding short lengths
28/09/2016 15:27:04

In an attempt to extend this thread to five pages, has anyone ever mentioned Bell Chucks?

For those who are not familiar, there are Internal and External versions, each one covering a range of sizes, in very small increments, capable of holding work as short as about 1/16" (1.5mm).

(Used a lot by the horological community, I believe) I obtained a set, (Not that I am capable of making a clock), but they come in useful for thinning washers. They would be ideal for the criminal offence of defacing coins of the Realm!

Mine, are Imperial, and will probably hold very short lengths, upto about 55mm dia .; depending on which of the multi stepped ones you use.

You just need to be careful not to run the tool into the very hard body.

Like so many tools, not used frequently, but invaluable for the odd unusual job, when it arises.

(I am sure that John S has many such bits and pieces for just such occasions in the course of his day job)

Howard

Thread: Clarke CL500M - Belt Sizes?
22/09/2016 16:59:24

The price quoted for the belts seems to be high, (or maybe I'm out of touch).

The manual , on line for the CL500M only quotes part nos, not belt details.

I would suggest buying from a local bearing/seal/belt stockist. (around here it is Anglia Bearing Company)

Brammer have branches all over UK.

With local suppliers you can be more certain of the quality than a cheap overseas source.

Don't forget to measure with the pulleys set for MINIMUM distance, so that there is space to allow adjustment for when the belt stretch.

If you already have belts that suit, keep a note of the belt details, for future reference, so that you can obtain them locally if you need them.

Possibly teaching granny etc, do ensure that the pulleys are in line. My Warco Economy Mill/Drill shredded the primary belt within 6 months, cos' the motor was misaligned. With the motor aligned, the replacement belt is still going strong after more than a dozen years!

Howard

Thread: steel for a project
19/09/2016 20:21:57

Some years ago, I made a four way Rear Toolpost for my lathe. The raw material was a 3 foot length of 3" x 1" BMS, (declared scrap by R & D). It was made to match the four way front toolpost.

Each of the five laminations was machined differently, and clamped together, internally, by three long Allen capscrews. The fourth position was used for a dowel to locate each orientation. It carries a parting tool and two chamfering tools (front and back chamfer).

1/2" bar was ideal for making the M10 Tool clamp screws.

The base is clamped onto the rear T slot of the Cross Slide, with two small dowels to locate it against the back of the Cross Slide.

Have also made two other 4 way toolposts, for friends from lumps of mild steel. One is on a Little John, the other on a Chester Cub.

As far as I know,like me, they have had no problems. So Mild Steel will do the job.

When machining cast Iron, I position a magnet under newspaper beneath the chuck. Aftrerwards, removing the newspaper allows the dust to be disposed off quite easily, and the lathe needs almost no cleaning up.

Howard

Thread: How should one protect ferrous tools?
19/09/2016 17:58:17

Insulating the shop is one way to avoid rust. My rather small wooden clad, framed and panelled shop has 50mm of glassfibre in walls and roof. The floor is 18mm ply on 8 x 2 inch bearers, which are/is closely surrounded on three sides.

Damp air is heavier than dry, so position a small vent as low down as possible, so that the moist air can escape.

Also, try to avoid sudden changes of temperature. If frost is forecast, I turn on a 60 W tubular heater, sited under the bench. After a couple of days, the shop does not feel cold, nor does metal feel cold to the touch. If I am working in there in low ambients, there is a 2Kw fan heater, fed through a thermostat.

Uninsulated Concrete walls seem to be especially prone to condensation. A friends workshop, with concrete walls and roof has glassfibre insulation, with a vapour barrier behind the internal cladding. He no longer has problems with rusting.

Howard

Thread: Why did you do that ?
19/09/2016 17:34:26

Always remember:

"Experience allows you to recognise the mistake the next time that you make it"

Part of learning something new each day!

Howard

Thread: Gate Progress RF45
19/09/2016 16:31:40

My machine is a RF25, for which I made an "extractorr" for tooling held in the 3MT spindle by the drawbar.

The nut holding the pulley to the spindle has a left hand thread. Remove and turn down the underside, to a suitable diameter, for just over the thickness of the plate mentioned below (not more than half the thickness of the nut) .

Take a piece of 1/4" or 6mm plate and bore out to just fit over the recently turned diameter on the nut.

Tap two holes, equally spaced about the centreline, Now, M6 would be the preferred, instead of my 1/4 BSF.

Place the plate on the diameter of the nut, refit it to the spindle, and tighten the nut.

Take another piece of plate, the same size as the first, and drill two holes, clearance for the thread chosen for the now captive plate, on the same centres.

Tap a hole in the centre of this plate, (I used 1/4 BSF). M6 would be more applicable nowadays.

Take / make two suitable long setscrews (I used 1/4 BSF studding with knurled "nuts" Loctited into place) and drop through the clearance holes. To keep the setscrews captive, a nut can be screwed on, under the plate.

Screw a suitable setscrew into the central tapping, to act as a forcing screw.

Slacken the drawbar by half to one turn..

Place the plate over the drawbar, and hand tighten the setscrews, equally, into the tappings in the captive plate.

Tighten the central forcing screw.

The Morse taper should now free. If it doesn't free off, a light tap on the head of the forcing screw should do the trick, avoiding the need to belabour the spindle bearings.

Remove the "extractor", and put away ready for next time.

Unscrew drawbar and remove tooling from the spindle.

Hope that this helps.

Howard

Thread: Green behind the ears
12/09/2016 22:11:31

Hi Richard!

Welcome. (i am a little further north, just off the A1 and A47)

You will get a lot of advice and knowledge here, (and some leg pulling).

When I first started, I was a Chronos customer, (still am from time to time), but mostly deal with Arc EuroTrade.

Ketan sometimes posts on here. he is a really fair minded bloke, and will help even when there is nothing in it for him as a trader.

Tooltips, I tend to buy from Jenny at J B Cutting Tools. Again, a pleasure to deal with, and is at most of the shows.

Try making a Tangential Tool Holder, it will be time well spent, and cheaper than buying one.

You can make a lot of tools and fixtures for that "one off" job, and save time and temper!

If you are not a member, do find your local M E Club and join. Again, you should get a lot of help and advice.

If you have a problem having someone come round and help, hands on, or saying "Bring it round, and we'll sort it out" is a HUGE help.

Enjoy yourself

Howard

Thread: Acceptable wear on leadscrews and nuts.
27/08/2016 10:25:35

Drip feed oilers, and spring loaded ball oilers are available from Arc EuroTrade, (Just a satisfied customer).

My genuine Myford oil gun left almost everything, including me, covered in oil. Not sure how much actually went where I wanted it to go.

Bought a Reilang, and years on am still MOST impressed. It was a good buy!

Howard

Thread: Setting Up a Workshop Special
18/08/2016 19:23:37

At the risk of restating the painfully obvious, surely there needs to be advice on

"What are you planning to do?" " How much can you/want to spend?" followed by advice on what to buy, where to buy.

Finally how to mount, it and set it up. AND, possibly suggestions on what accessories could be made, as opposed to buying, either as part of the learning process, or to economise. Plus some advice on what NOT to do once the machinery arrives, if it appears to have a problem.

Followed by plugs for joining a local club, and reading threads on this Forum, (ALWAYS a lot to learn here)

Howard

Thread: Fitting collets to a horizontal mill?
18/08/2016 19:09:01

Here is my four penn'orth, for what its worth.

If space is limited, in either Horizontal or Vertical mode, 2MT Finger Collets will maximise tool/workpiece space.

To release them, you will need to bash the end of the drawbar, once it has been slackened by about half a turn.(Unless you can make up some form of "pusher" for the drawabar, to spare the spindle bearings).

Finger collets for 2MT will go upto about 12mm, but are "one size" only, whether Imperial or Metric. Trying to use for other than the stated size will damage them. An ER collet chuck will take up space, but the collets will accept upto a 1mm variation in size, so can accomodate Metric or Imperial cutters, (or work in the lathe). ER20 goes up to 13mm, ER25 to 16mm, and ER32 (probably too big for your intended use) 20mm.

They may be expensive, but grip well, and run truer than a drill chuck.

Don't use helical endmills in a drill chuck. The Drill Chuck does not have as much grip as a collet (little more than line contact vs all round in a collet), and the helix will be trying to screw the cutter out of the drill chuck. You may get lucky, but one day, the cutter WILL move out, and mess up things!

H T H

Howard

Thread: Think I have burnt out my lathe motor
18/08/2016 18:16:33

If you can find the identification details on the board, you should be able to geta replacement from the importer.

You could try running the board identification past Ketan at ErcEuroTrade. He is very helpful, and ARC carry spares for the Seig C2 and C3, (they use DC brushed motors, but with different, non interchangeable, speed control boards) so you may get lucky.

Howard

Thread: My Unusual Tool
18/08/2016 18:08:09

If you do want to use it, why not make an adaptor to carry it, with a suitable taper to fit the Tailstock mandrel?

Or even more radical, mount it in a 4 Jaw , clock it for the shank to run true, and then reduce the diameter to something that your lathe can accept?

Howard

Thread: Speed controller Very slow!
18/08/2016 17:55:20

In the past, I have used a Variac to slow a cheap jigsaw, but with the knowledge that reduced speed = reduced power and seriously reduced cooling.

Speed reduction by voltage control is likely to increase current draw, more than expected, since at lower speeds, the motor's back emf will be reduced, resulting in a greater voltage drop across the motor.

The Power vs Speed relationship for a fan is non linear. Being similar to a marine propellor, it is probably to the power 2.8, so halving the speed probably reduces the flow of cooling air by a factor of between 7 and 8.

So only short periods of use, under light load, are feasible, if damage is to be avoided.

Howard

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