Member postings for DiogenesII

According to the book, should be a 51102 (15x28X9) ball thrust bearing - try ArcEurotrade;

Arc Euro - Thrust Ball Bearings

Buy a new 3x18 metric taper pin.

Bob's your uncle.

See what it's like with the proper bearing in it, hopefully normal action will be restored...

Edited By DiogenesII on 09/03/2022 21:32:46

...I think every Ash tree in Gloucestershire got cut down before Christmas...

Thanks, Jason, that sounds good, will give it a go.

Thanks, Howard

The main object is to produce a good bearing surface, sizing being a secondary consideration. I'm currently +0.1mm over target 10mm, I need to increase corner radius / examine the score marks / apply a slip to my 'stuck-out' parting blade before comitting to another pass - interesting watching the lead corner 'pull-in' on either traverse!

I digress - yes, I need make it 'round', straight, and polished - I have a nice piece of HE15 with which to make a conrod, I have a measure of cconfidence that this will run acceptably on a steel journal provided everything is as it should be. (..on a model, of course..)

I'd be surprised if the leadscrew is bent, it's a chunky fine pitch 16mm dia thing and quite short.. ..tho' of course the human animal can always find new ways to break things..

If you need a new pin, probably best to buy a new mild steel one - it is there to retain the collar that acts against the thrust bearing, and has to resist the push & pull of the carriage when the saddle is being traversed.

Agree with Bazyle that it's a standard 1:50 'Metric Taper Pin 3x18mm', - 3x20 will fit but will probably need to be dressed back flush with the collar after fitting.. also his comment regarding getting the holes lined up in the right orientation before driving home..

It is described as 'grooved' in the manual because the original part is a drive-fit taper pin with an axially 'nicked' head that's meant to retain the collar on it's shaft as a more-or-less permanent assembly.

If it works loose you might end up having to use a chemical retainer to secure it.

Edited By DiogenesII on 07/03/2022 07:25:45

Edited By DiogenesII on 07/03/2022 07:27:41

Pin 28 should be fully 'home' in it's collar, not hanging out. It's purpose is to secure the collar to the leadscrew.

If it's not too badly damaged, it's okay to straighten it out and replace it - loosen off the nut and handwheel at the R/H end of the leadscrew and the carriage lock first to release any tension.

Once the pin is back in, re-fit the handwheel loosely (i.e. with ample end-float), and lightly nip up the locknut just to check that the leadscrew turns freely and without binding or rubbing on anything.

If you can't achieve free rotation at this stage, something else is amiss and will need sorting out.

Once everything feels free-but-sloppy, turn your attention to adjusting the handwheel to give the minimum of freeplay/backlash/endfloat, but without binding or becoming stiff to turn - it will not be possible to eliminate all backlash because some clearance is necessary for the parts to turn without binding.

It can be a pain to achieve correct adjustment, but it's worth persevering, and if you must, err on the side of too much freeplay rather than not enough.

The 'screw thread' pattern might be a seperate issue - is the gear train set up to give the finest feed possible - (0.08mm, I think) - 30 tooth (Z 30) on the back of the spindle, driving a Z75 which should be compounded with a Z20, which then drives the Z100 on the leadscrew...

There are a few 'hobbymat'  and 'MD65' threads on the forum, the machines are great, but have some quirks, you can use the search box at the top of the page to see previous discussions..

Edited By DiogenesII on 06/03/2022 19:32:51

I need to size and finish a big end journal between the webs of a one piece single throw crank for an IC engine.

The pin is 10mm x 10mm, the throw also.

Plan A is to make a spilt lap of the 'wash tongs' type

- What is a good width to make the lap to help avoid either barrelling or waisting of the pin?

- opinions in the literature seem to vary from 'accurately-finished full width' to 'narrow, work it up and down to remove high spots'.

I can see potential pitfalls in both of these methods, I'm sure that there is some happy middle ground.

As I already have some hours invested in the part, I'd rather not experiment myself if anyone has achieved consistent and trustworthy results from a particular design/dimension - there's little point re-inventing the wheel..

I'd love to hear from you.

Can you explain why please...

FWIW.. ..Begging DC's pardon, I think some of the numbers might also refer to insert dimension, tip radius and ?maybe ?grade? or could be another attribute? ... 'cos they seem to come in 9 or 15mm depth of cut i.e. 09(high) 02(thick) 08(tip rad) + other attributes, the 15's look like they are 15(high) 03 /4(thick) 08/16 (tip rad) etc, obsolete grades are hard to find and I'm out of my comfort zone here in any case.

The size of the inserts will be essential information if you want to get any further, tip rad & grade will depend on what you want to use them for / availability of same might dictate what you can use them for..

Might be worth dropping a line to this man via his Ebay store;

Ebay.co.uk - Dellunn

..I have no connection other than as a satisfied customer - he seems to know his stuff.. ..he's also a bit cheaper than Cromwell..

Edited By DiogenesII on 05/03/2022 19:13:19

Hello Adrian, welcome to the forum.

This thread explains how to upload pictures;

Uploading pictures

My late father carried out what I can only assume to be a life-long trial of Eclipse hacksaw frames by never, ever releasing the tension except to put a new blade in it every few years..

..when new the top of the grip was in line with the centre of the tube.. ..like DMB's, when I inherited it, it had a big extra nut between the wingnut and the frame, and the blade would still fall out if I shook it..

It's in the back of my mind that the relief on a lot of HSS taps is ground differently from that of CS taps as they are more likley to be used on Stainless steel and more 'difficult' materials - I think there's often a full-profile 'land' to give strength, but it can cause chips to jam - I only know this because I couldn't understand how I managed to bust two HSS ones in short order, both breaking whilst being being backed-out..

In response to comments in this thread, last night I put my Facom frame in the vise and spent a few minutes realigning it - I expected it to have some 'spring' and be difficult, but as it happened, it went back into shape easily and seems to have stayed there.

I fitted a new blade, nipped (rather than heaved) up the tension and all seems good, at least as good as ever was..

Having sliced a few thin slabs off the end of an EN3 bar and some bits of gauge plate by way of experimentation, I feel less inclined to screw the tension up as much as had previously been my habit..

PS - I can't mantion 'habit' without admitting that I overlooked the fact that fallability of judgement was one of the points that SOD was trying to make - I concede that one - apologies, Dave..

Starrett HSS £1.09 each if you buy 10..

Zoro - Starrett high speed steel hacksaw blades

Stick a dab of superglue / 638 on them

Haha, one of the reasons that I didn't give a link was because I recoiled in horror at their convoluted product-data-web-experience..

?this one

Wurth Cockpit Care Data

probably best bought from somewhere like here - Wurth seem to have gone 'trade only'..

Falcon Workshop Supplies - Ebay store

..not cheap, sorry..

More stuff to catch up on;

Mike - yes - or perhaps maybe - things seem less clear-cut today!. Also you shouldn't leave work clamped tight in a milling vice for long periods (just in case you are ever tempted to do so)

Dave, there is no doubt in my mind that certain products made in the past were of better quality than their equivalents are today - specialised grades of material were more widely available in the local economy, and labour was cheaper, meaning that some processes that were formerly economic are no longer so, and the use of some grades of material has declined because it is no longer cost-effective to employ it. Producers better understand their target market and subtle changes in consumer expectation mean that cost has become the primary driver in the retail market for domestic hand tools, whereas up until ? the 1970's ?, 'reputation, quality & durability' (or at least an illusion of those things) was - in the UK at that time many end-user's had had direct experience in one of the worlds centres of manufacturing.

An example - the garden spade / edging iron / pointing trowel - pre 1960's tooling has thin blades of forged carbon steel, the better quality one's are thinner, harder, and the socket or tang is contiguous with the main structure, though often in a different state of temper. The blades are thinner & harder and have the right degree of flexibility to avoid breakage and makes for a nicer working action.

As far as modern versions go, most are made of welded stainless steel - 1980's / 90's 'better' quality stuff from the likes of S&J, and WSword are thinner than post-millenial ones, tho' still essentially 'throw-away' - they fail with remarkable predictability at the joint of head and socket, the weld often failing.

Instead of improving the method of manufacture to obviate the problem, simply increasing the quantity of cheap material in the blade has been seen as the 'cure' - what's 'advanced' about that?

(Rude comment about Bulldog tools deleted).

I have more 60-70-year old spades than 1990's ones, although I have bought far more of the latter.

I'm 56.

Jimmie - by all means - I've gone back to a quality 'wire frame'..

I'm sure that sawing straight is pretty much a mixture of learned technique and practice - there's also something intuitive about it - I have no doubt that all three of us could cut to a very respectable line with our own saws, I think if we then all swapped, the results might be something less than impressive, certainly for the first cut. The same reason that no-one sharpens my knife, but me.

Since I wrote the last post, it occurs to me that blades were probably slightly better, in the better days of yore at least - having considered why I like to put tension on modern blades, it's probably because some of them are, well, less than perfect.

I have some 'own brand' all-hards from a major supplier, they're okay, but the cut is chattery and rippled unless stretched out to the max. I wonder whether the material is as hard, stiff, or more stretchy than old stock, and whether the teeth are as accurately ground or set..

Maybe I'll try an old stock Eclipse or Starrett blade in an 'old school' frame and compare..

Thanks;

..not sure why Starrett no longer seem to supply the 145 in the UK..

I think the '1 turn at a time' tensioning system is the same as the Facom, there's a stop-pin to prevent over tightening - your '+1' for the Bahco is duly noted, thank you.

I've had some success with frames that have just pulled the 'front leg' inwards at the bottom, less so with the kind of subtle lengthwise twisting and bowing that high-tension mechanisms seem to cause..

As a point of discussion, I must admit that on the principle that nearly all hand tooling had been brought to a state of perfection before the 1930's, maybe 'high-tension' is a red-herring / sales pitch - I can hardly believe that Thomas, Chaddock, Bradley at all wouldn't have invented it themselves if the benefits were there.. ..I bet all of these men used an Eclipse-type tubular or flat steel frame with a wingnut at the front..

Edited By DiogenesII on 27/02/2022 08:08:46