Here is a list of all the postings Martin W has made in our forums. Click on a thread name to jump to the thread.
Thread: Sandown Model Engineer Exhibition 2009 |
12/12/2009 13:27:20 |
Hi All
Went yesterday, Friday, it was a great show and much better than I had expected. It was a great day out and like Martin L spent far too much money having ordered a new mill from Warco coupled with other more minor purchases. Even my good lady enjoyed it, well she must have done to let me spend the money!!
Overall I rate it as one of the best this year with plenty to see and areas well laid out.
Thanks to the organisers.
Cheers
Martin W Edited By Martin W on 12/12/2009 13:28:08 |
Thread: Plastic abrasive sheet |
10/12/2009 17:11:08 |
Ray
Again probably not the answer but 3M do a product they call Microfinishing Film Sheets. As far as I can see these product either come with a backing material for fitting to powered tools or in sheets. I have tried to copy their description from the 3M data sheets.
Cheers
Martin
3M™ Microfinishing Film, 266L PSA Sheets
Micron graded aluminum oxide resin bonded to a 3 mil polyester film backing. Open coat abrasive surface is coated with a dry lubricant to resist loading. Sold as discs & sheets with pressure sensitive adhesive (psa) backing.
3M™ Microfinishing Film, 268L PSA Sheets
Micron graded aluminum oxide resin bonded to a 3 mil polyester film backing. Sold as discs & sheets with pressure sensitive adhesive (psa) backing. Use wet or dry for finishing a wide assortment of workpieces.
Edited By Katy Purvis on 01/06/2015 12:19:52 |
Thread: Why do I do it?! |
08/12/2009 18:59:29 |
Hi All
I bet the designer of the Tacoma Narrows bridge wished he had the benefits of computer simulation available at the time. Now that's what I call a proper c**k up. But seriously the advent of CAD has been a mixed blessing. It is often assumed that if it can be drawn it can be made!!
Tony with regard to your remarks regarding disasters and the words being proffered by the interviewees there is another classic when some person is expounding some new pet theory or another and they use well worn phrases like 'Based on the well established ------' or 'Known parameters----' . At this stage one looks forward to see where the cliff is they are going to walk over as a result of a question from a perceptive member of the audience!!!
![]() Cheers
Martin |
Thread: Washers |
08/12/2009 18:32:25 |
Hi Frank
Depends what you want the washer for.
Plain Washers, generally are used to protect the parts being bolted together and can allow a certain amount of movement between the parts. They also to some extent tend to spread the load and can take up small irregularities of the surfaces being joined, i.e. they can bend/deform when things are tightened. As KWIL says it gives a certain amount of protection to the paintwork/surface finish of the parts under the nut or bolt head.
Crinkle Washers are frequently used in areas where there might be some vibration and also they protect the parts being bolted together. They are a halfway house between plain and spring washers. They are normally thinner than plain washers but have a wavy profile that is compressed and the screw is tightened.
Spring Washers, these are used when there is likely to be a fair amount of vibration and are used to stop the nut/bolt unscrewing under these conditions. They actually dig into the surface of the material and the nut/screw and effectively form a sort of ratchet at the spring ends. As the name implies they are spring shape and often hardened to some degree.
Star Washers, these tend to be used where there are high levels of vibration and by their design are very aggressive in so much as they are frequently hardened and the many points dig into the parts being joined to form a multi-point ratchet. The surface of the material that has been screwed together under a star washer is normally pretty well chewed up or marked.
I know this is very basic but I hope it goes a little way to answering your question. I know that there are more qualified/experienced members of these forums that will be able to give you a better answer with a more detailed description as to where, when and why.
Cheers
Martin Edited By Martin W on 08/12/2009 18:35:47 |
Thread: Loctite on shafts |
07/12/2009 22:56:17 |
Mike
Looked at the data sheet again and should you decide to give it a second try with Loctite 648 you can delay the setting time by cooling the parts to be joined. The graph indicates that at 22C the bond reaches 5% of full strength in 5 minutes whereas at 5C the bond reaches 5% of full strength after 1 hour, these figures are for steel/steel joints and the time taken to reach 100% bond strength of other metals/finishes vary. These figures are based on a 0.05mm gap.
Looks like the way to go would be cool, assemble, adjust and then warm.
Cheers
Martin |
Thread: Sandown Model Engineer Exhibition 2009 |
07/12/2009 18:45:09 |
Me too with a bit of luck, a following wind and, of course, permission from her indoors. ![]() |
Thread: Loctite on shafts |
07/12/2009 18:38:02 |
Hi Mike
Just been on the Loctite site re 648 retaining compound. The data sheet says heat parts to about 250C then dissemble when hot. Then if required clean by soaking in Loctite solvent and use a wire brush to remove any residue, presumably a brass brush would do and it shouldn't mark the steel.
This compound is not a cyanoacrylate based material but a Urethane Methacrylate based product. Even so its probably best not to take a chance by breathing the fumes giving of during heating.
Hope this helps and good luck.
Martin |
Thread: Plastic abrasive sheet |
04/12/2009 00:13:46 |
Ray
I don't think this is the answer you are looking for but Crocus Paper was a very fine polishing grade abrasive but as expected on a paper backing rather than plastic but hey it was blue.
Cheers
Martin |
Thread: Milling collet arbor jammed in milling machine |
21/11/2009 02:05:09 |
Hi Chris & Meyrick.
I realise that this is a bit late it the thread but I have fairly strong feelings regarding the regulations regarding health and safety versus common sense that we are being subjected to these days.
I'm afraid that I'm with you regarding taking the odd and calculated risk. Hell's teeth we wouldn't dare cross a road or drive if we weren't prepared to take a risk. As far as I am concerned HSSW is good but there are limits to how much 'Safety' needs to scrutinised. Any aged adult, I am in that category at 65+, has lived without HSSW or regulations long enough to judge risk against damned stupidity. Yes I have four fingers on each hand plus thumbs to match, two eyes physically intact as well as the expected quota or arms (needed to support aforesaid fingers/hands) and legs but does that mean I haven't taken the odd risk or ten of course it doesn't!!!!!!! Assess the risk take the obvious precautions and go for it and yes I haven't got a mill yet so a pillar drill complete with chuck, three jaw of course, is used as a substitute mill with light cuts and acceptance that a job could be completely screwed up. Would I recommend this to a friend or beginner of course not!
What do they say 'Variety is the spice of life' and a little excitement never hurt
![]() Please keep the advice coming.
Best regards
Martin
Not Irresponsible but inventive when needs arise.
Without this the human race would still be cracking their nuts with stones and how would health and safety regulate this, perhaps with rubber stones, Oh s**t then they might bounce out of control and hurt someone so lets starve to death because it's safer. ![]() Edited By Martin W on 21/11/2009 02:14:32 |
Thread: Leaky Safety Valves. |
21/11/2009 01:20:53 |
Chris
Given the tool some thought but it won't fit on my lathe !!!!!!!!!!!
![]() Best regards
Martin |
Thread: O-ring coming off pulley when motor power is cut |
12/11/2009 14:05:26 |
Martin
As an ex air whisker and thrasher I was thankful on more than one occasion that the free wheel unit was there. It was for me a very necessary part of the gear train especially when the engine stops unexpectedly!! At least there is a chance of an auto-rotation of sorts. Never tried to auto-rotate deliberately though as was not to that skill level.
Got two airframes hanging from the ceiling but haven't flown for years. Last rebuild found me digging the gyro out of the ground after a cyclic servo failure!!
Still that's not for this thread. Take care and have lots of soft landings, any landing you can fly after is a good landing!
Cheers
Martin W |
Thread: Metric vs Imperial - Practical or Traditional? |
11/11/2009 22:16:36 |
Ian
Just keep the curmudgeonly hat on cause its makes good reading and raises a smile.
Cheers
Martin |
11/11/2009 12:00:39 |
Hi All
I think what this extensive thread shows that we are all capable of handling numbers and measurements whatever their origin but the real problem is CHANGE. As a species it seems that we humans love what we get accustomed to, even if we dislike it at the time, and resist changes to that system.
In the computer world there are/were several ways of expressing numbers, binary, octal and hexadecimal just to mention three, oops here come the thirds again, but there was little argument about using them as they were, relatively speaking, new standards and in them days people were used to them all.
I reckon variety is the spice of life and this thread has surely shown that, so not sure which is best then press the conversion button on your vernier/calculator and use the easiest for you. What the hell it's only how far two points are apart physically.
Cheers
Martin |
Thread: O-ring coming off pulley when motor power is cut |
10/11/2009 23:09:49 |
Hi
You could use a speed controller, the same sort of thing as used in model railways or model cars, then you can control the rate of speed up/ down and the viewing speed well. Or it may be possible to slacken the belt slightly so that its braking action is moderated but again it may just fall off under braking loads. This of course will in time wear the drive band out.
I think that the first suggestion is preferable as this limits the stresses put on the system to an acceptable level and should preserve the mechanism. Anyhow it could be fun varying the speed of the action from Charlie Chaplin film style to slow motion.
Cheers
Martin |
Thread: Turning Eccentics in Three Jaw Chick |
09/11/2009 18:28:33 |
Is there any value in using a face plate. Fix a sacrificial plate to the surface and turn this surface until true then fix your eccentric to the plate lining up the hole centre using a wobbler then drill/turn to required dimension.
I think I have seen this in articles but as a relative novice I am open to correction as my recall may not be too brilliant
![]() Cheers
Martin |
Thread: Which boring bar to get. |
09/11/2009 14:35:53 |
Depending on how much you want to spend on tool holding it might be worth looking at the RDG site. They do Dixon type quick change tool holder for Myford style lathes and for about £65. For that you get the tool post, two standard tool holders to about 12mm, a boring bar holder and a parting blade holder with parting blade. This takes away the need for packing pieces used on a standard holder and allows quick changes between favourite/most commonly used tools. Height setting is dead easy and the quick change is a boon because once the height is set for a tool it repeats exactly until you change it.
I adapted my lathe to take one of these and haven't looked back since. Parting off steel bars of over 1 ins is easy and trouble free as are the normal turning tasks. I think that the extra mass/weight it give to the tool assembly helps to damp down any vibration/chatter.
Hope this helps
Martin |
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