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Member postings for Clive Foster

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

Thread: I may be stupid but
24/06/2022 00:19:59

Allegedly this practice reduces run out by helping balance the forces on the scroll so it moves closer to true centre.

It is said that any wear in the chuck allows the scroll to float slightly off centre causing run out.

I've never seen any figures of calculated run out associated with any degree of wear so am mor ethan a little skeptical. Maybe if a chuck is well worn.

A few brief tests showed no sensibly repeatable effects on the three jaws I use. But mine are in decent to very good condition with known history. I suspect supporting the work rather than relying on the lower jaw(s) to lift it onto centre helps control any imbalace. As does nip, rest, final tighten technique rather than simply pulling up in one go.

Life is too short to do proper, statistically significant tests backed up by wear measurements.

Any three jaw needing that level of playing to get decently acceptable results is, in my view, only fit for the bin. By its very nature a three jaw is of limited precision. Trying to do better than the concept allows is guilding the lilly in on uncertain terms. I understand the logic of a GripTrue and the various home brew equivalents but the faffing involved in setting up seems a vast waste of effort. Although certain limited circumstances can exploit such it doesn't alter the fact that you are trying to make an unsuitable tool work for the job in question.

Clive

Thread: Best way to run 400v 3ph motor on 220v
21/06/2022 18:06:10

Jak2G

For testing purposes simply connect the 440 volt motor to the 220 volt VFD. It will run just fine but power will be reduced to something between 1/2 and 2/3 rds of nominal nameplate output. Basically at 220 volts the motor enters its constant power region at 29 hz rather than 50 hz so it can't get up to full nameplate power.

As a surface grinder is more about free spinning than hard driving the reduced power may do just fine for you.

Inverter Drive Supermarket have a blog post explaining what is going on. Excellent, clear, information as usual from IDS. **LINK**

https://inverterdrive.com/HowTo/240V-Supply-to-a-400V-AC-Motor/

If you do decide to open up the motor to find the Star point and convert it you will find that NECO make a nice motor with the junction clearly accessible.

Clive

Thread: Welding on an old Startrite Motor
20/06/2022 09:47:42

Big hose clips like that do just fine holding up chimney liners and the like so you should be OK.

The big ones are cheap from building supply places and very useful for strapping stuff together when doing the common temporary the becomes permanent job. Handy for welding positioning too 'cos they don't melt like the plastic zip ties.

Couple or four of the big hose clips and a packet of the big, lever release, zip ties are an essentail foundation of any self respecting bodgers workshop.

Clive

Thread: Book on lathe operation ?
19/06/2022 09:45:00

Rich

Start by rooting around the internet and downloading one, or more of the books from older lathe makers who made smaller lathes for the training market. "How to Run a Lathe" is from SouthBend but similar from Atlas, Boxford, Hercus and others are all pretty much equivalent. Fundamentally a question of what style reads best for you.

If you expect to grind your own tools then grab SouthBend Bulletin Number 35, How to Grind Lathe Tool Cutter Bits, which is the best and most comprehensively consistent introduction to things I've yet found. Only 16 pages so its viable to print your own. Can be found on the 'net. Mine came via Scribd, a site I subscribe to.

The SouthBend Cutting tools data sheet is as good an introduction to angles an speed et al as can be found on one piece of paper. Only source I can find is **LINK**

http://vintagemachinery.org/pubs/detail.aspx?id=4834

Although the tools are shown mounted in Armstrong posts with built in rake the angles are correct for flat mount with the tip on centre height.

Bulletin 5910A on the use of the cutter bit grinding block is also interesting. Again Vintage machinery is the only source I can find **LINK**

http://vintagemachinery.org/pubs/detail.aspx?id=4831

Internet search will find various descriptions of how to make the beast and lists of dimensions should you fancy one as an early project. Its been on my "I really should" list for, um, er , 40 years!".

A cuttings speed graph, chart or nomogram is very useful. Especially for beginners. I've had the American Machinist Cutting Speed Chart no 30 stuck on the wall pretty much forever. Somewhat obsolete but being a nomogram its easy to see relative variations for different materials. Calculators are fine but they only give one data point so its hard to see how things fit together.

Downloads are great for basic reading and for printing out specific advice. Get a ring binder and a box of transparent wallets so you can keep printouts of useful "stuff" in the workshop in oily finger proof condition. But nothing beats a good book for reference. I've got "lots" but there are a few I always return to and know my way round. Style, presentation and having things explained in a way that suits you are important. I have a few that are frankly a waste of space for me yet others love them. I can see why opinions differ. For me the Sparey book suggested above has about 3 marginally useful pages!

When looking for a book its worth rooting around sites like Scribd to electronically have a quick flip through and short read before buying just as you would in a bookshop. I appreciate the potential copyright issues but its been very useful to me in spending my £30 or so on the right book for me. Hoovering up from recommendations and catalogues back in the day means I have hundreds of pounds worth of paper (in todays money) that, in retrospect, I didn't get value out of.

Abe books is a good resource for hard to find / used / cheaper as can be E-Bay if you wait and can stand wading through lists with lots of repeats.

Clive

 

Edited By Clive Foster on 19/06/2022 09:45:35

Thread: Mounting DRO scale on rough cast iron surface
17/06/2022 10:05:01

+1 for the sub plate suggestion from Pete. Takes a bit of thought and preparation to clamp the plate down onto to its bed of filler so the surface that the DRO scale will mount to it true to the head movement but its all simple stuff and when done it just works.

Jacking screws can work loose over years and shimming is even more tedious than getting a sub plate on. Thing I really don't like about those ideas is that you are working directly with a moderately expensive and not particularly strong component.

Pushing 50 years of butting heads with lawyer Murphy and the gremlin squad has convinced me that the first thing to consider when dealing with a non routine job is "what happens if it goes wrong".

The more money you have in the game the more important that gets.

Clean-up and sort out assistance for the rush headed can be salutary.

When I put the knee scale on my Bridgeport I bedded the one of the aluminium L sections out of the universal mount kit on body filler, with the aid of rather more brackets, clamps and shimmy bits than I'd expected to get it all true. To simplify clean up I lubricated the mating face of the L section so it could be lifted off after "moulding" the mating surface. I was unpleasantly surprised by just how uneven and out of line with the movements the finished surface was. Adcock Shipley did a good job of filling and smoothing their castings but the nice finish hid a surface that was, in my view, ultimately too uneven to risk direct mounting of a scale.

Clive

Thread: Query - Stub Mandrel's article on Workshop Power - MEW No.317
16/06/2022 10:23:21

Dave

Bit more research suggests its all to do with something called GAP.

According to Panasonic:-

"GAP stands for Generic Access Profile, this means that any GAP compatible handsets can be registered to any of our base systems and will allow you to receive incoming calls and to make outgoing calls. Other features and functions may be limited and cannot be guaranteed."

So I guess that means you can make and receive calls from any mix and match pair of GAP compatible phones and handsets but any other clever stuff may not work.

Sounds OK to me. In my book phones are for talking to folk too far away to hear you shouting.

Clive

16/06/2022 00:05:02

Dave

That BT repeater looks vey expensive compared to my memory of what I paid.

Assuming the DECT phone has a repeater mode any properly specified DECT repeater is supposed to be able to register and work with any DECT phone system. As far as the base station is concerned the repeater just looks like a handset and as far as the handset is concerned the repeater just looks like a base station so, in principle there are no issues. In practice there is adeal of jiggery pokery involved to ensure that the connection goes through either base station or repeater rather than try to go through both simultaneously. There can be a slight glitch in communications if you are on the move and the phone switches from repeater to base or back.

Summary of things with a short form note in the middle on how the registration process is supposed to work **LINK**

https://www.pmctelecom.co.uk/blog/how-do-dect-repeaters-range-extenders-work/

My no longer used off brand one is an RTX which certainly works with Siemens phones. By implication from that articel it shoild have no issues with BT ones.

Clive

15/06/2022 22:46:56

Greensands

Standard domestic market wireless telephone units are DECT (Digitally Enhanced Cordless Technology) systems which is very different from WiFi.

You can buy range extenders for these but they may take a bit of tracking down. £30 ish for off brand systems when I got mine. A bit more for on brand units designed to pair with specific phone sets.

They work quite well.

The off brand ones I originally bought to use with Siemens Gigaset phones worked fine out to my brothers garden office, about 18 yards, but struggled to reach further than just inside inside my workshop about 30 yards away. Replaced one with a pukka Siemens unit which is fine giving me a signal right to the end of the workshop, call it 40 yards.

Extenders are on second floor of a brick house next to the wall facing the office and workshop which are proper wooden buildings with cavity walls. Open air range is claimed to be over 100 meters.

I'm sure my second off brand one is still around somewhere, I've no use for it so if you fancy giving it a go you are welcome to have it for the price of the postage. Assuming I can find the instructions.

PM me if you are interested.

As I recall matters initial set-up was a bit challenging. Once it was all up and running it was obvious what the instructions for both phone and range extender were banging on about.

But not before.

Doesn't help that some of the things you have to do are time limited and if you over-run your allotted few second it all goes seriously pear shape.

Clive

Thread: DIN3113? - permitted max. jaw opening for 19mm
14/06/2022 19:29:43

Bill

Seems to be pretty much nothing useful freely available on the internet.

Best I could find was a sales catalogue from Gedore which on page 120-121 implies that the DIN 3110 tolerance on a 19 mm spanner is up to 0.3 mm oversize.

**LINK**

https://us.gedore.com/fileadmin/Kataloge/EN/116_151_05_Spanners_2017_EN.pdf

Which seems a lot and almost as much oversize as your spanner.

Interpreting a graph that is more pretty presentation than scientific Geodore claim to make theirs to no more than a touch over 0.1 mm oversize.

I actually have a Gedore 19 mm open ended spanner and that measures 19.11 mm using a micrometer so the claim may be well founded.

Digging deeper into my motley collection Elora and CK come out a bit under 19.2 mm whilst the various no name and lower end (Kamsa) ones are a bit over.

Clive

 

 

Edited By Clive Foster on 14/06/2022 19:29:56

Thread: Timing Belt
14/06/2022 18:59:23

Vic

Translucent belts are generally "stretchy" so they can be assembled onto pulley pairs at fixed centre distances and seem to carry a premium price. All too often they are specials of a non standard length with no direct equivalent in the normal black belts.

As your motor is adjustable a standard black belt will do fine so long as its a standard length. If I recall things correctly my Draper badged version of the smaller Record sander also had tension adjustment and was fitted with a black belt but the length was non standard so I still had to pay OEM prices.

Clive

14/06/2022 09:00:15

Vic

If you want to reverse engineer the belt you need to track down a belt manufacturers catalogue that gives the formulae to calculate belt length for a given centre to centre distance and type of belt. Last time I did this I used formulae from ContiTech HDT belt catalogue that I'd downloaded. I imagine Gates and others have equally useful catalogues.

Doesn't help that its often not clear from the pulleys which type of belt you have. Usually easy enough if you can eyeball a belt, use the magnifier or photo app on a smartphone to give a better view of a small tooth profile.

Hand held sanders, planers et al have fixed centre distances so the belts are self tensioned by stretching.

A standard near equivalent may not stretch correctly to give the right tension. As the tension is intended to be set by centre distance adjustment the standard belt can be stiffer.

Certainly the semi-transparent ones I got for my planer last year were somewhat more elastic than a standard belt of similar size. As in your case the makers official part price was expensive but diligent searching found two for two-thirds the price on E-Bay. On flogging through all the lists I found that there are only about 3 or 4 sizes of belts used on hand held planers. Presumably because most of them are pretty much different coloured iterations of same design from China Inc.

Clive

Thread: CAD - Accessories Worth Having?
13/06/2022 18:04:57

Also consider a "proper size" trackball instead of your mouse.

I've had Kensington ones since 2004 and the idea of going back to a mouse for CAD and spreadsheet work is scary enough to make my ears bleed!

Especially as my CAD program, Vectorworks, often has long distances between drawing and menu items coupled with long menus. Pre trackball I had serious issues with running the mouse off the mat mid transit. Even with the biggest mat I could find. Lifing and resetting the mouse to prepare for long moves got old fast.

Clive

Thread: Burnt Bridgeport power feed control board repair query
11/06/2022 19:37:52

Hi Taris

Sorry I no longer have any boards left. Passed them on to a guy willing to take pot luck on actually getting one to work. Which he managed. Unfortunately I've lost his contact details.

Realistically the originals are now so old that getting one to repair is chancy at best. Far as I know the pulse transformer details are not around so if that has gone you are stuffed. Maybe the professionals have the necessary information but professional repair will be expensive.

Best bet is to get a modern "90 volt nominal" DC servomotor control board and hook it up to the Bridgeport controls as per the Erskine system. A modern controller will work just as well, maybe a bit better.

If you don't have wiring details PM me your E-Mail and I can send you over my Erskine data pack which has everything you need to know and lots more. I also have a typical UK built Bridgeport wiring diagram in pdf if you need that too.

Clive

Thread: JUN-AIR Compressor
11/06/2022 16:45:41

Bob

I'd guess the part on the right you refer to is the safety valve. Knob / screw on top to set pressure.

That pinhole looks awfully like a drilled hole to me. Complete with characteristic rise round the edge due to a self tapping screw being bunged in. Rus pinholes are, in my experience, generally rather ragged in appearance.

Folk have been known to put self tapping screws into air tanks to hold cables et al.

I've given up on thinking "No one could be that daft.", regardless of the situation.

Clive

Thread: Curiosity about an Aldi belt sander
11/06/2022 11:49:00

The machine shown in the link from Nigel is a far better arranged design.

A little bit of creativity makes them much nicer to use.

Firstly a second strut on the other side so the table doesn't try to twist on you when belt sanding.

I would also add a plate under the belt unit curving up around the drums to help control the dust. As is it tends to go everywhere. Nicest if you can add an extractor fitting at the end to minimise the amount of scraping needed to clean dust off the shield / collection plate.

Takes a bit more work but it's useful to provide supports so the larger side table, and protractor, can be used when the belt is vertical. Usual arrangement of the economy versions only permits the small end fence to be used as a table in vertical mode.

I saw pictures of one fully kitted out with those and some other modifications after I'd got my Draper one. Having decided against getting an external motor one after careful consideration of the pro and cons of both styles.

Immediate reaction.

Ooops, bought the wrong one. Classic "screw up by the numbers".

Clive

Thread: Loose table on Fobco Star
11/06/2022 11:10:27

Luke

First thing to do is to verify that there is no build up of workshop dust, cruft or similar in the slot acting to prevent full closure of the tightening slot. I've seen such build ups that were almost as hard as the cast iron and pretty much invisible due to workshop "dust varnish" making everything almost the same colour.

From your description its only a few thou short of clamping using the handle so careful scraping out of the cruft should restore proper operation.

If things really are worn a little more flexibility can be gained by filing shallow grooves down the bore at around ± 120° to the slot using a small round file to avoid stress raisers. Shallow being the operative word. 10 to 20 thou with a 1/4" rat tail file will be more than enough.

Filing grooves really is a last resort tho'. If cleaning the slot improves the nip so its stable in rotation, but not quite enough to hold it up under drill loads it would be better to get creative with something to hlep support the table. Re-purposed car jack or similar perhaps. I always found sliding a heavy cast iron table up and down by hand more work than I cared for. Especially if there was a vice or job on top.

Clive

Edited By Clive Foster on 11/06/2022 11:11:03

Thread: Cutting tools
11/06/2022 09:51:36

Further notes on SouthBend Lathe Bulletin 35.

I just checked my copy and note that the grinder recommended by SouthBend has L shaped tool rests running round the side of the wheels. This allows the finishing touch up to be done on the side of the wheel giving a short straight surface just below the cutting edge and just above the bottom. Just a quick kiss so wear on the side of the wheel is negligible.

As the main shaping grind is done on the periphery of the wheel the actual ground surface is hollow. Putting the two narrow flats at top and bottom makes it easy to accurately hone the tool using a hand held stone or hone. Either for maximum sharpness when freshly ground or to restore its edge after some use. The two flats keep the hone aligned and the hollow clearance prevents rocking during the stroke.

When honing a flat sided tool the natural tendency is to rock the hone slightly as it moves across the tool rounding off the sharp edge. Which is rather the opposite of what's needed.

Like free hand sharpening a twist drill honing a flat sided tool is much trickier than it sounds from a basic description. It really doesn't help that folk who have learned to do either or both can no longer do it wrong, how ever hard they try, and a simple say "It's easy. Just like this." Grrr.

If you don't wan't to grind on the side of the wheel, or don't have suitable rests, its perfectly satisfactory to put the two flats at top and bottom on by hand using a stone or hone. Takes longer than on a grinder and generally the flats will be narrower so the tool won't go so long before it needs touching up. That's what I do using a set of diamond hones for puting the flats on and a fine stone for touch up.

Clive

Edited By Clive Foster on 11/06/2022 09:52:55

11/06/2022 09:14:56

Grinding your own tools has been mentioned.

Unfortunately descriptions of the actual techniques needed have never been well served in the Model Engineering publications. Whether books or magazines. Historically I guess it has been the assumption that most folk will be able to find someone to show them exactly how to do the job and train them in the nigh on imperceptible (to a novice) differences between getting a really sharp, durable tool and one that sort of works on a good day.

The best guide I've seen is the Bulletin no 35 from SouthBend Lathe "How To Grind lathe Tool Cutter Bits". 16 pages of clear, simple, instructions along with excellent diagrams of both tool planforms and use. A bit Ameri-centric in using Armstrong type tool holders for the illustrations which hold the tool bit pointing upwards so the actual angles you need to grind on the top of the bit will be different to those on a tool held flat. Its the angle relative to the work that matters so a tool held flat needs more angle ground on the top.

Can be downloaded from various places on the internet. For example :-

**LINK**

https://www.scribd.com/doc/55145100/How-to-Grind-Lathe-Tools

or, different edition of same thing in a more compact format.

**LINK**

https://www.scribd.com/document/456515606/Grinding-Lathe-Tool-Cutter-Bits-South-Bend

Sidebar on second link shows a whole host of other potentially useful documents. Boatloads of stuff on that site. Well worth my £40 (ish) subscription for all the extras beyond basic read'n download. Very useful for sorting out whether a book is actually worth buying or not.

The South Bend Lathe bulletins were primarily written to support school metal work classes and apprentice training schemes and remain highly relevant to folk like us.

Clive

Thread: Curiosity about an Aldi belt sander
10/06/2022 22:18:33

Johns motor is the same basic design as that in my Draper sander. Casting shapes may be a touch different but the semi open design is just as potentially vulnerable to sanding dust and debris if its allowed to build up.

Sanding / linishing dust was certainly what killed my first motor. Was horrified by how much had gotten in when I opened it up.

Made an effort to pull the bottom off and clean the second one out "fairly often" but by the time I passed it on it wasn't a very happy camper with starting issues and a tendency to slow down after a few minutes. Still running onb light duties and very occasional use for my friend. but he took it mostly because he had avery occasional need that didn't justify purchase.

Clive

10/06/2022 20:07:04

The Schepach one is essentially the same as the Draper sander I had. The actual dust extraction port on that was part of the plastic deflector unit moulding so sanding dust had no direct entry to the main body save by going around the divider in the port.

The Ferrex unit appears to have the extractor port hole in the upper rear of main body. The Aldi pictures doesn't show a flange or tube to attach the extractor. There is a larger aperture below that presumably connects direct to the main body. Its likely that there is a wall in the body casting between the motor and the area that sanding dust falls into which would limit dust ingress to the motor area. Imperfectly.

Neither design is good at preventing dust getting into the motor works.

Clive

Edited By Clive Foster on 10/06/2022 20:07:30

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