Here is a list of all the postings Chris Parsons has made in our forums. Click on a thread name to jump to the thread.
|Thread: Using a radius cutter|
Thanks all - I thought there was some 'magic' formula that I didn't know about, but it seem to be a simple case of measuring things and working it out...
I see the ArcEuroTrade rounding cutters show the 'tip' diameter so perhaps this would be a good place to start - half the radius down minus the tip as Jason has said.
My diagram was wrong, the 'top' cutting edge is not stepped in so the side movement would be 5mm in I guess.
I'll so some experimentation of a bit of scrap aluminium
Having just got a nice new 5mm radius cutter, I am struggling a bit with it's geometry!
The diameter of the shank is 16mm, so I thought ok, centre line is 8mm and so centre of radius would be 4mm...so I set up for 4mm in from the edge of the work, touched off and then couldn't work out how much to drop!
The cutting edge does not extend to the centre axis - and there is a 'peg' in the centre so I guess I have to measure this and add 2.5mm to get to the distance on the Z axis?
Of course I can 'wing it' but wondered if there was some formula in the geometry I could use to get it set up accurately?
I have done a (very) rough line drawing to show the profile...
|Thread: What is this fourth (threaded) hole in the die stock holder ?|
I have this hole on some of mine too - never used it, only the top three but I thinks it's for dies that are not split - ie don't have a gap so they are held in two places?
If you have a screw in the centre in the split this stops the die rotating but when I was taught to use one I was told you could slacken this centre screw and tighten the outer screws to close the die up a bit to cut a deeper thread?
I never bother, just do all three up, never very tight and nothing has slipped so far (the force it trying to rotate the die in the holder and the screw in the split stops this?)
If I am wrong I am sure someone will correct me
|Thread: Help with Choosing a Milling Machine|
I also have an SX3 that I am very happy with - I have added a DRO I got from a company on FleaBay which I am also very happy with **LINK** and will convert this to CNC in due course. I got some plans from a US company and this looks to be achievable, you can see this at **LINK**
I liked the idea of still being able to use the mill manually - some conversions don't allow this.
I have also been talking to the chap who did the series about CNC for Beginners in MEW with a view of creating an open source software chain for driving the mill (I don't like spending money if I don't have to!)
You are welcome to get in touch if you want more details?
|Thread: Antique oil can|
Well, I have caved in and forked out 10 quid for the modern plastic equivalent with a brass spout...might be able to graft the new spout on, or dismantle it to see if I can reproduce the top half - or perhaps try and make one from the patent diagram but perhaps this will end up being another 'roundtoit' ...
Off to Tracy Tools lunchtime and the expression 'child in a sweetie shop' springs to mind...
Thank you Chris - and nuts, I had a feeling that the cap had something clever inside and it had been forcibly removed Think you are correct Ian, if only I had a diagram!
I can still make a plain cap (no hole) but perhaps will look around for another to see if I can swap the valve spout over, I'll have a look through the 'junk' boxes at the next few shows to see what turns up.
Would have been nice to have given it a new lease in life, I already have a few plastic dropper oil cans but it's not the same
What a knowledgeable and helpful lot you are!
I think the can I have IS plated brass - and I thought the 'artisan' poster was great I now have an idea of the original shape potentially
Not sure how the valve would work, if there is a hole in the cap closing it would not close the hole in the spout?? Must be something cunning inside...
That is of course if I can work out what the thread is, think it is 1/8 but I'll have to beg borrow (or buy!) some imperial thread gauges - thought it might be UNF/UNC but had not considered Whitworths (I am mostly metric)
I can see the material cost being 20p and the tooling 20 quid <g>
This has been a great help. thank you all
Thanks, this one is the same - the base is sprung like a diaphragm. If you are able to get a picture of the cap sometime this would be a great help?
Looks like something you would use on a sewing machine or similar
I could just bodge a plastic cap but thought it was worth making some effort...
Interesting - the only thing I can find on the web refers to Rolls Royce/Bentley - a precision oiler - but they all show an angled spout and mine is straight. It could be that old, I have had it since I was a boy.
I am now wondering if the 'valve' referred to is the missing cap, open a turn or so to allow the flow and close it to stop leaks?
I was given this oil can many years ago, and it was missing the cap?
I thought it might be nice to make a new one, preferably looking like the original if possible?
Anyone got one or can point me at an image anywhere? Not sure what the thread is, measures 0.1240 inches across
Although it is marked 'valve spout' the spout doesn't move, not sure if it is supposed to?
|Thread: Internal grooving tool?|
Need to cut an internal groove for an O ring in a 5/16 bore?
I am thinking about making a lathe tool by drilling across a round bar and grinding a square ended insert (with the appropriate relief) from an old drill bit held in by a couple of grub screws - any observations/comments anyone?
The groove needs to be 0.094" by 0.062" (2.3mm by 1.5mm)
I have an indexable internal threading tool but it was the square bottom and sides of the groove I was thinking about...
|Thread: BA, ME, Metric Coarse or Imperial : which taps and dies to buy ?|
I would also give a thumbs up for Tracy Tools (they are local to me which is also pretty convenient)
I started a year or so ago and decided to 'go metric' as this is what my lathe and mill were, but have bought many other odd (ME and BA mainly) taps and dies since as and when the need came up.
I originally went for a boxed set of metric taps and dies (2- 10mm) which got me going but would agree that they get blunt quickly and most of the commonly used sizes have been replaced by HSS ones from Tracy - but this does mean you have a convenient box to keep the various sizes in, which I am starting to find is a problem with the others - rummage through the drawer and the one you want is always the last one you pick up...
As someone has mentioned you can get HSS boxed sets but they are a few quid and you may end up with ones you never use
|Thread: BOTTLE ROCKET|
I had a go at this a while ago - even made a 'flight computer' to release a parachute at apogee (ok, after a time delay!)
Here are some links if it helps?
Good fun, but you get pretty wet if you are not careful <g>
My 'launcher' was a garden hose fitting with a bit of string to pull the ring down, but now I am into this model engineering lark I did briefly consider modifying a brass hose fitting to make something a bit more professional
|Thread: Emma Victoria - small drawing error|
I have now looked into the digital subscription details - and it appears that if I subscribe, and get (for instance) the first issue the series appears in - 4444 - I will only be able to continue to see this issue if I continue to renew my digital subscription every year??
I seem to remember reading something about this (the horror stories I mentioned) is this actually the case still?
I know you can keep the downloaded digital subscriptions but these start from the date you subscribe - it doesn't seem I can ask for them to start at issue 4444?
Blimey - didn't realise it was such a long series of articles, think the digital subscription idea is a good one, thanks
I'll have to check to make sure I can get a subscription that starts with the first one (I have read some of the horror stories about the MTM subscription policies...)
Been looking at the "Emma Victoria" as a first loco, and not being a ME subscriber I wonder how many back issues I would have to buy to get the complete series? Anyone know when the first one came out?
It looks like the 30 November 2012?
|Thread: MT2 for rotary table|
Ah - interesting, thanks
Don't have an angle grinder so would be cutting by hand - and ideally I would like to bore out the end to allow interchangeable inserts, I was twitching a bit at the thought of this, particularly if it's case hardened.
Do have some carbide tools though...
Thinking about making a stubby MT2 taper for aligning my rotary table (as shown in Howard Hall's book) and after trawling through the mire of messages about this am wondering whether it is better to buy a centre and cut it down (but it will be hardened?)
Howard suggested something 40mm (1.5 inches odd) long would be enough, what do people think? I can set the compound over and have a go but am wondering what other people do? Seems like it could be a pain (time consuming operation) for little reward
Guess the easy way out is to stick a centre in the RT and chuck, and line the points up but this seems a bit heath robinson (not very scientific)
Also doesn't allow the creation of workholding adaptors
I can find MT2 arbor blanks (used one for my slitting saw holder) but if I have to cut it down once again it's hardened?
|Thread: Rotary table inspiration....|
Thanks for the comments
John, your jig plate sounds interesting - think I can visualise it, grid and radial holes sound like an excellent idea, and perhaps not too hard to make, although 10 inches would be a bit big perhaps
Michael - no, it could be bigger but I need to be able to reach the locking clamps - although I could make longer levers, and I guess it doesn't have to be round
One issue I have had is sometimes the clamps tighten themselves up when cranking around and I sometimes remove them (depending on how annoying it gets)
Need to have a ponder methinks!
I have just found and ordered a 100mm chuck with 3 front mounting holes from RDG which should hopefully fit nicely - someone suggested this a while ago which is a good idea
Edited By Chris Parsons on 04/12/2013 11:11:02
Thought it was about time my new (well, new to me!) rotary table got some use...
I have a 4 inch table that, unusually it seems, has three not four T slots - which does make things a bit awkward when trying to clamp things down.
So I thought about making a face plate with some threaded holes that I can attach to the existing table (with countersunk screws) - but am thinking about the best layout of the holes, initial thinking was two rows at 90 degrees to each other aligned with the axis but now I am wondering whether two parallel rows at 90 degrees centred on the axis might be better? The idea being I could centre a bar along the axis and use the holes either side to clamp it down for instance?
Another thought is the size of the face plate - if I decide to fit a chuck I guess I would make a four inch plate and buy a three inch chuck to give me a flange to bolt it down, but could make the 'threaded hole' plate bigger? (would make it difficult to reach the locking clamps if it was too big)
Howard Hall has an excellent article on his website about making a centre plate with a set of spigots which I will make to fit the three slots but will still have the clamping down problem.
The RT also has a 2MT hole so Howards adaptor will help me with centering workpieces on the axis - by making a adaptor to turn the 2MT hole into a parallel one which he also suggests in the article.
Any ideas/observations would be gratefully received!
Edited By Chris Parsons on 04/12/2013 09:27:04
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