Here is a list of all the postings andrew lyner has made in our forums. Click on a thread name to jump to the thread.
|Thread: Band saw arm weight|
A real trip down memory lane. I imaging that 3D printing would not be a favourite.
I daren't do a smiley for fear of offending people.
Thanks for sticking with me, guys. My issue has been more with the way that the user manual presents its information. It would have been so easy to use a term like"arm weight, unsupported by the spring" instead of assuming that was obvious, But it's not all that obvious to someone who is looking for some definite advice / instructions. I get it now.
All the other factors like arm angle and length of cut in the workpiece are sort of obvious but I guess that the 'optimum' loading force is on a very broad curve so it's not too clear cut.
On the subject of the forum software, I hadn't previously come across those stupid 'automatic smileys'. It's a pointless facility because there are real smileys available. But that's just further example of the tiredness of the existing system. Things have changed a lot since the software was built - not least, the cost of data storage. ME could perhaps be looking for a new host with more up to date ideas (and possibly cheaper rates). The 'quaint' display theme is quite attractive and wouldn't need to be changed much.
That is no help whatsoever. The "weight of the arm" is not the same as the force on the blade because of that massive / adjustable spring that partly holds it up. I read all that already. Can you tell me how I could get the information I wanted? I mentioned that I measured 10 to 20N on the handle but the range is greater than that in both directions. If I remove the spring, then I will get "the whole weight" acting on the blade. I don't think I'm being particularly thick about this when I say that the information is just not there.
But I now realise that it's only by looking at the resulting cut or time taken that I could tell if the spring should be wound in or out if indeed it makes much difference.
But hats off to Clarke on their fantastically good (cheap) workhorse. It cuts much straighter and truer than I could ever do by hand. The only snag is that at least two values of tip are needed and changing the blade is a bit like crocodile wrestling - so I will stay with a fine one and be prepared to wait ages to cut a thick aluminium bar.
i couldn’t find any figures on a prescribed maximum pressure (load?) on the Clarke manual. Mine’s the 41/2 inch version. I will avoid numbers here and look at results more.
What are “auto smilies”? There is nothing automatic in a proper forum. It’s important to make choices based on valid information.
I wouldn’t want TikTok; just some worthwhile improvements.
This reads like the old joke: "Everyone's out of step but our Joe".
I use a number of equally technical (if not more so) fora and the short hand is used to great effect yet not excessively so, There is nothing to say that the 'new fangled' ideas will be bad to use. What did you have in mind that makes these extras "an abomination"? No one is forced to use them.
Did you ever consider that some potentially valuable contributions don't reach this forum just because of its outdated procedures. Is it something to do with not wanting 'that sort of contributor'?
And "text based"? Mechanical systems are very much based on diagrams and other images (and formulae). This forum actually suppresses these things. Is that really a good thing? Is additional media a serious risk to the spirit and usefulness of this forum? Are your comments based on your experience of more up to data technical fora? Or do you just not like change? Perhaps we should correspond by postcard?
I have to say, the 'mechanics' of this forum are really well below average. When I've mentioned this before, people have leapt to its defence but in 2022, I can't believe this is the only forum they use. Is no one aware of just how convenient and productive the 'recent' innovations are. I find it so inconvenient, even just to quote from other posts; other fora have had a proper facility for at least ten years and, for some amazing reason, the shorthand facility to add likes and other comments to posts is deprecated . Also, why is there such hassle involed when I want to insert an image? I can't imagine that the ME members who want these things to stay the same would have refused to use advanced materials or tools in their machine shop as a matter of principle. Where's the difference.
The situation puts me in mind of a conversation I overheard, at a computer fair, between a man (well over forty) who was busy explaining to his wife that a computer mouse was a waste of time and that the cursor keys could do everything you could ever need to do.
Thanks for all the responses. Fortunately, the (second hand) saw seems to behave very well and gives a 'good' square cut. So far, two of the blades I have used have left a good finish but the newest blade seems to leave a more grooved finish. On occasions, the blade is thrown but increasing the tension always seems to sort that out. Some past threads on ME suggests that I may have to get into more than just tension eventually. Fun fun fun. ...
I have to say, I'm a bit disappointed that 'suck it and see' is as good as you guys can come up with but the sources I can find on the internet also seem to avoid committing themselves on the matter. I guess the feeds and speeds and angles are, in practice, a lot less rigid for the home operator than the books would suggest. The 'old guard' seem to talk in terms of the right sound and the shape of chips are the best indication for turning and milling and I am certainly 'getting there'.
I think I'll have to use my fishing scales to find the arm weights that I'm actually using but that seems to be a stage further than ME seems to use.
On the subject of lubrication, cutting aliuminium seems to be faster without lube because the swarf seems to clear better without clogging. Maybe the life of the saw is comprominsed if I stop lubing.
I have had a Clarke CBS45MD 4 1/2 inch band saw for a few years now and it is a fabulous tool in any ways. There is a screw to adjust the length of the support spring which varies the 'arm weight'. The handbook mentions the adjuster but I can find nowhere to tell me what weight I should be using. It's not so much the time taken for cutting but the length of life of blades that concerns me.
I know that hand sawing with a hacksaw can make a big difference in cutting rate, depending on hand pressure so there must be some optimum. I imagine I could get a clue if I was bright enough to translate what the "feeds and speeds" information about turning and milling offers but a simple rule of thumb would be nice to have.
Any ideas about sources of that info?
|Thread: High temperature plastics|
Mine is quite a bit older than that and keeps going well with very few replacement bits. There are a few quirky aspects of the design, of course; the flange between the boiler and the group head is, to my mind, 90 degrees wrong, to deal with the torque from the lever. The familiar bubbling from the gasket would not occur and the force on the bolts (and boiler) would be a lot less if the two bolts were over and under.
But the coffee is lovely and the ceremony of grinding, measuring, squeezing, steaming and pouring makes a great start to the day. It all fascinates the grandchildren, despite they fact that they are not too keen on the coffee taste and smell.
OTOH, my problem may not be to do with the insert material at all but the thin skirt of wood (which has split) and the clearance between metal and plug. Could the wood just be splitting due to a tight fit and a bit too much stress on a thin section of wood.
Perhaps a bit more wood and a bit less metal would give the wood an advantage? I must say, the wood (utile) does seem very brittle after getting that hot. There are wooden versions of the plastic on high end versions of my machine so it must be possible.
Thanks for the alternatives guys. As it will not be 'on show', I tihink I will try the lower cost delryn. It performs at up to 120C, apparently and that would be easily enough for the temperatures of the low pressure boiler.
I have a Pavoni Lever Espresso maker. A thing of beauty with chrome and S/S. The standard handles are hard black plastic and I am trying to change to prettier wood.
I am trying to replace the boiler filler plug and am experimenting with Utile on an aluminium base for strength. I have a problem with my first design because the wooden 'skirt' appears to have split due to stress and or temperature (higher than 100C, for the steaming). The split could be because my fit of the wooden skirt round the metal spigot is too tight to cope with the expansion of the metal. Making another wooden piece is a bit long winded if it's just going to crack because of excess temperature.
I want to try a plastic 'core' which will support a 2mm thread about 35mm diameter, with a wood cover.
I see plastic knobs, handles etc, on cooking equipment that can cope easily with the requirement but I can't find anything that would be machinable. PTFE took my eye but that would be far too expensive.
I'm sure some of you have experience of wood at high temperatures. What would you do?
|Thread: Single point tool profile for milling.|
I did wonder about of tram but the effect works in both directions so the tram can't be too bad. As Boadicea said when she drove her chariot in reverse "It cuts both ways". When only small parts are involved, you can avoid the back part of the rotation hitting the work piece - that always gives a better look and feel. But some things are just too big for that.
But my basic question is about symmetry or asymmetry for the cutter. The mention of 'buttons' suggests that the regular shape is not the best. But most of the world seems to be doing it the regular way. I have tried grinding the bottom of a tool to give a radius back up the other side but the HSS piece I had was sort so everything was tight up against the holder. I have some longer HSS square section now so I can experiment soon.
Steel on a mini mill is a bit of a big ask but I keep wanting to make useful stuff for lathe and mill and that calls of steel, mostly.
I have been hunting for definitive information about how to grind a fly cutter tool. The cutters I want to make are for a mini mill, which has more flex in it than a 'proper' mill, so things may be different.
The recommendation is to put a radius on the tip of the tool - like a lathe tool. That makes sense but then what happens to the tool when it's passing 'round the back'? The patterns we see of good finishes have that moiré pattern which has all lost equal contributions from cuts in both directions. That implies there must be something left for the tool to cut after the first pass.
Is this just because of the flexing of the machine?
Either way, I should have thought that the tool should not ideally look like a Lathe tool at all but it should have a profile that's an arc that's symmetrical fore and aft. All the arguments for a radius at the front should apply to the rear ofd the tool.
Are all the fly cutters that we see for sale actually not optimal? Is that 20 degree slope what we want, actually?
|Thread: getting MT3 tools to release from the taper on mill spindle|
So many ways of killing a cat.
Incidentally, I heard an opinion that thin paper on a morse taper could improve grip with less tension and make extraction easier.
Anyone else ever heard of that idea/
I thought I'd finish off the story with a successful solution to the sticky MT3 tapers. I made up a pair of opposing wedges to fit round the shaft, between spindle and tool. The combined angle is about 7 degrees . I made up a further U spacer to suit the particular gap with my RM25 collet holder. A gentle tap between two light hammers releases the taper every time with no trauma to any bearings - brilliant. Leaving the drawbar in place avoids the tool falling out
|Thread: Being nice to a vise|
Good idea Mick. Thanks for the loan of your brain!!!!
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