Here is a list of all the postings YouraT has made in our forums. Click on a thread name to jump to the thread.
|Thread: Correct boring with a steady - advice please :-)|
So - following the advice, I've turned the OD true with a centre on the end, and found around 0.4mm of out-of-round was present where the steady was set, which is the lion's share of the 0.6mm taper I'm seeing on the bore, and will of course depend on exactly how that interacts with the steady fingers.
With just that, and some care taken around swarf build up, I've got to <0.2mm taper on the bore, which is good enough for this purpose (It's a model light-saber handle I'm making with my son......).
Next will be working out how to hold two indicators as suggested by Pete for better setting of the initial and steadied locations of the stock, but I think that will need to be for when I next need to do something like this again - perhaps a new handle design in a couple of weeks...
On other comments - yes, that's a rather thinner and flexible boring bar than I'd like to use, but is the only one that was both long enough and would actually fit in the largest drilled hole I'm currently tooled up for (25/32" ). For reasons that escape me, I do have a larger bar, but it needs a 1" starter hole...
Thanks everyone, and many good pieces of advice to get my on the road to nice parallel bores !
Edited By YouraT on 14/04/2020 21:53:36
Thanks for the further input guys.
I'm returning the bar to the start by hand after moving it clear of the cut a little and then returning to the original position and putting further cut on for the next pass. The cut is done through the powered saddle - I do the last 2mm or so using the topslide as the Viceroy doesn't have a repeatable saddle travel clutch arrangement like the Boxford, just an 'anti catastrophe' dog clutch.
I'm going to:
I've not seen any tendency to walk out of the chuck, but I'll keep more of an eye on that too.
Likely tomorrow now, but might manage to start something tonight.
- a number of things to think about - I'll take a look at skimming the stock before setting up the steady (I have spare OD on the stock), and also at setting the steady up right up against the chuck initially, then moving it into position - both suggestions are eminently sensible.
'Not done it yet' - my terminology was perhaps a little vague - the boring bar stick out is only around 70mm - it's the aluminium bar stock that's ~150mm long.
Nick - I'm not sure I understand why cumulative spring might be the case here given the initial drilled hole (as large a drill as I have, but I'll give it a go.
Returning to a 'filed' project, I'm trying to bore a 60mm long hole in an aluminium bar using my lathe's power carriage feed, but I'm finding it's significantly tapered to the tune of around 0.6mm (in 25mm or so) over the 60mm length of the hole, with the end closest to the chuck being the smallest. The lathe is a Denford Viceroy 250, but I don't think that's particularly relevant for this question.
As the bar is around 150mm long, I've brought out my fixed steady to help keep things in place (see picture) but I wonder if my lack of experience in using it is causing the taper I'm seeing.
I've simply used the steady on the outside of the bar (which is perhaps not perfectly round....?) and gone from there - is there a technique/order of setup things up that I should be using in order to ensure everything is lined up properly to give me a non-tapered bore?
The boring bar is of course sticking out quite a long way, but I'm taking deliberately light cuts and in any case, the deflection forces on the bar should be the same at all points along the cut.
|Thread: dial matting|
I wasn't too hopeful of a reply, but thank you for your suggestion, which does make sense.
The problem I have with etching is the dimensions of the features - I think they would be too small if done chemically to look as they did on older clocks, but I'll try a few options and see.
Coming I realise *very* late to this thread, I'm reading Richard's description of the tool his friend made and I'm struggling with the phrase
Richard - if you're reading this - would you possibly explain perhaps differently so I have a chance of understanding, or maybe sketch something....?
|Thread: Warco A2F quill backlash - any pointers?|
So - I make the weight of the quill around 8kgs - my final question really is - should I "counterbalance" with as close to that as possible, or do I want to bias noticeably above that, at say 12kgs or more?
I'll work out the best way to apply that shortly - I'm in the middle of some stuff just now, and don't want to loose the mill for a period just yet....
Thanks for that - it does look a lot simpler to implement than the gas strut arrangement.
Something like one or two of these:
I'll take the machine apart again shortly to check the weight of the quill to work out what might fit - you don't perchance remember what the weight is (even approx...)?
Dave - no sadly - that would have been too simple - the quill resting on the table with the pinion removed goes up and down with the knee smoothly.
Bazyle - also unfortuneately not - actually remarkably clean in there! Cleaned and re-greased anyway though.
John - yes, the downfeed units make no sense - I also have a digital readout on the quill. I don't know if the depth stop is original or modified also (it's a 1mm pitch thread...) but it actually works reasonably well for my purposes - I get 0.03mm repeatability or so, according to the readout, in any case.
The quill rapid feed side of things is heavily modified with a whole new shaft, pinion (modified to 29 teeth), ball bearings at both ends and a new handle.
I've been able to adjust things to improve on the performance from the fine feed worm wheel, and I now only get unexpected movements of around 0.3mm, but I think with judicious use of the depth stop I should be able to live with that, and certainly not use the rapid feed for anything other than drilling (which feels lumpy, but will do). I might beef up the depth stop rapid movement arrangement though - I'm not sure they will last.
Long term a counterweight / gas strut and something like your arrangement based around the location of the depth stop seems very attractive - I'm a little limited in my ability to take the machine apart at the moment though...
Thanks guys - I'll take a look and report back.
At first sight though, it seems the feed and clamp mechanisms have been extensively modified by a previous owner, so they don't look much like the drawings I've found for this machine.
John - I notice in your CNC conversion album that you've used the external depth stop as the basis for the Z-Axis drive, rather than the original worm drive - was this for reasons of backlash in the worm arrangement and rack, or some other reason?
I have a Warco A2F milling machine, of 1999 vintage, so a later one without the feed gearbox (although it has an electrical power feed unit).
I have some problems with quill feed backlash, which come from I think three places:
- The rack/pinion combination that is attached to the quill rapid feed lever
The last two I think I can do something about - re-cut the keyway in the toothed collar so it's less sloppy on the key, and make an eccentric bush for the fine feed handwheel arbor so the meshing can be adjusted.
I'm less sure about the rack arrangement though - I think there's damage to the rack on the quill itself, as at times there's a sudden drop of ~1mm when downfeeding, especially at the top of the travel - I can't easily adjust the meshing on that, and have not been able to get rid of this problem without the feel of the feed becoming very lumpy, which suggests to be excessive depthing of the rack/pinion combination and thus rapid wear in use.
Has anyone any experience with these machines or the very similar ones out there and could make some suggestions? I think this problem has existed ever since I've had the machine, but it's only recently started to annoy me enough to do something about it....
|Thread: Strange clamps|
A more general purpose version would be something from the Reglus range.
I have one of these (not mine, but identical, and the pictures are better!):
Don't use it much, but invaluable when needed!
I'll bet the "setting screws" as you call them are hardened and have a range of different sized holes through them.
This looks very much like a cross-drilling jig - the cut outs on the bushes are for the retaining screw shown in your album.
|Thread: Machine moving recommendations.|
I have a couple of quotes now from Jackson Machinery and Matt Smith - not especially different from each other, and availability / dates is the most likely deciding factor.
The stackable plastic crates are a good idea - I do have a few I bought for my last move, but I didn't realise you could hire them too - I'll look into it.
LandyLift would be my first choice - Steve moved these machines for me when I moved some years ago, but he's unable to help on this occasion.
There are two lathes on underdrive cabinets - a Viceroy 250 and another of about the same general size and a Warco A2-F knee mill - range of ~400kgs to roughly 550kgs each.
Less confident somehow about hoisting them up onto a flat-bed by myself.....
I'm struggling to find someone to move my workshop machines from the Manchester to London areas (approx), and wondered if anyone had suggestions / recommendations for someone to do the work? Landylift (who moved me up here in the first place, and I would use again in a heartbeat) isn't able to help on this occasion, and a couple of quotes from large commercial machinery movers have been positively eye-watering...
I'm reluctant to put them on pallets and ship like that, as I've had a lathe fall-over in exactly that situation previously.
Any recommendations *very* gratefully received.
|Thread: Ferris Wheel Clock|
I've just downloaded all the files, and they are just fine (I used Firefox not IE...)
The magnetic clock articles are also there - many thanks!
I've tried using PDF (and .pdf) as a search term, and the only results I get are:
A search on 'Ferris' does however pull up a link to the page with the PDFs.
Did the Ferris clock DXFs ever make it into the wild, as it were....?
there are actually a number of things that don't add up on that page of the build instructions - some of the component values don't match - for example the parts list doesn't call up a 1k resistor, but it's in the build instructions (substituted for a 10k), etc.....
If I have some time over the next week, I'll draw something up properly, and try to resolve that and a couple of other little niggles I've noticed. Mind, I haven't actually got as far as building this yet, so especially when it comes to the time constants, I might get it wrong as they likely have mechanical dependencies....
|Thread: stuart pratt no 2 clock|
That's a shame - I understand of course the difficulties here, but I'm utterly fascinated by the escapement and the motion of the pendulum - do you (or anyone else for that matter) know if that was a new design thought up specially for that clock, or a copy/progression of something historical?
Thanks for that John and Maurice.
I have a couple of the relevant issues, and I'll have to get the others now!
A question more for David C. perhaps - I've also seen the no.3 clock video - the one with the whacky penduluum - is there any possibility of a drawing series or that one ?
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