Here is a list of all the postings blowlamp has made in our forums. Click on a thread name to jump to the thread.
|Thread: Suggestions please Vol2|
Remembering my school days - and just for a lark really, here's a variation of the idea
Having drawn it, I reaslised it might be useful to make a couple of the Gun Sights (in yellow) adjustable for height, to aid calibration.
I haven't seen the size of the bearing, but I've just got this nagging feeling that if it's got enough friction to self-damp to some degree, then it will more than likely stop in a position that isn't guaranteed to be consistanly level.
If you want to guard against your successors' lack of mechanical sympathy, then rather than a needle point suspension, why not radius the tip ever-so-slightly, so that along with a suitable cup, it would make a tiny ball joint that would be robust enough to stand the odd bit of carelessness?
The only potential pitfall I can see now is with the choice of bearing - as pointed out by Les.
All the care in setting up might amount to nothing if it is at all sticky in operation.
It may be that a compass needle type arrangement would be appropriate for minimum stiction?
Another go at this.
1/ Sit the completed unit on the milling machine table.
2/ With a pointer/probe mouted in a drill chuck, position the table and lower the quill, or raise the knee until said probe just touches a suitable reference point on one of the arms and note the reading.
3/ Repeat this operation several times, by spinning each arm into position, to get a good average reading of level for repeat accuracy.
4/ Make suitable adjustments as you go.
I think this method is almost immune to outside influences such as an unlevel machine table etc.
If I understand the problem correctly, then provided all the arms are at an accurate 90 deg to one another, you could attach a weight to one of them (à la plumb bob), and let it find it's own level.
Edited By blowlamp on 05/04/2011 18:22:33
|Thread: Suggestions please.|
Here's a link to an article on Toolmakers Buttons http://www.neme-s.org/Model_Engineer_Files/3147-Ways%20with%20Toolmakers%20Buttons.pdf
Has anyone contacted The National Physical Laboratory yet, to see if they can help?
|If you have a rotary table and milling machine, you could make a simple jig from MDF or plastic etc with a couple of 29 deg slots to hold the cutter and present it to the grinding wheel in a predictable manner.|
It would be easy to regrind the tool if you need to as well.
|Thread: Acceptable runout|
Quit while you're ahead - it'll just distort all the hard work you've put in for very little practical benefit.
And you shouldn't be smoking cigarettes at your lathe - a cigar would be much more the order of celebration for a job well done.
I think most people would class ~ 0.0015 mm, or 60 millionths of an inch radial deviation from centre as a success.
Merely leaning on the cross slide while checking for runout will show far greater movement than this.
He's got this place buzzin' !!
Taking your example of there being only 1 correct way to turn a Morse taper.
Surely the correct way would be to use a Taper Turning Attachment.
This is my preferred method, given that if more than 1 item needs to be made, then repeatability of the taper angle can not be guaranteed between centres, simply because each blank will vary in length and so will the depth of it's centres.
Personally, I find the 'test bar' method of resetting the tailstock to be unreliable for close accuracy and find that a test cut on some scrap to be a much better way of returning to a parallel setting.
Welcome aboard, Donald!
|Thread: Boxford cross slide dial grub screws|
I'm not at my machine at the moment, but I think it should have either a couple of brass slugs or ball bearings in there.
|Thread: The boat that Guy built|
Could it be any worse?
I'm not trying to speak on behalf of Graham, but I think he was highlighting just how much he despises Mrs Thatcher's actions during the 80's, by comparing his feelings against yours.
If that's the case then it's perhaps an example of where a suitable Emoticon could have been used to good effect.
It's just my view, but I hope that it makes some sense.
|For those that remember them, some of the BBC's Horizon and Channel 4's Equinox documentaries made for excellent viewing.|
There also seems to be a belief with many of the programme makers that if we're not singing, dancing, or laughing, then we can't be having fun or enjoying ourselves.
I've also noticed the 'fear' of the producers of anyone having a meaty chat about things mechanical as it's always done in a jokey way, as if it's too painful for the viewer otherwise.
It is interesting to see how they're trying to remind the population of our manufacturing past and I wonder if those in charge are hinting at what we should be doing now, with programmes like this, along with the very interesting documentory Britain At Work, which is presented quite nicely by Kirsty Young. After all, now it's so expensive to buy a degree, many school leavers may need to go back into manufacturing whatever we can.
|Thread: Mystery Tools|
It's hard to tell for sure, but the last pic looks like it could be a Spade Drill.
|Thread: Trouble posting to forum!|
I'm using Windows 7 along with Internet Explorer 9 (release candidate) and am really quite pleased with the combination.
I'm not a 'fan boy' of Microsoft, but I appreciate the free lifetime support and updates of their operating systems, as well as their other totally free stuff, such as Security Essentials, which is a virus/spyware protection application and I'm finding it to be as effective as anything else available, without slowing the system.
I started a thread about what I consider to be the deficiencies of this site with regard to things like attachments of files and pictures etc.
Edited By blowlamp on 23/02/2011 00:14:18
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