Author Topic: Another new project... a QCTP (Quick Change Toolpost)  (Read 91133 times)

Offline AdeV

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Re: Another new project...
« Reply #50 on: September 12, 2010, 01:43:05 PM »
Well, another couple of steps complete, and it's just that little bit nearer to being done   :thumbup:

First job today was to make the second piston. No action photos, I'm afraid, you've seen it all before I'm sure. At least I got all my radii right today  :lol:

Now, before I go any further, I owe an apology to a fellow MadModder - I don't know who unfortunately, because I can't find the post in question  websterz - because a few posts back, I pooh-poohed the idea of using a retaining pin, drilled up from the base of the QCTP which I saw in his thread. Well, I hereby eat humble pie & apologise - because all my grand ideas of tapers and/or flanges went out of the window, and I've ended up with, yes, a pin going into a slot in the bottom of the piston:



The hole is drilled 3.5mm, and partially tapped M4 for a grub screw. The slot in the bottom of each piston is 3mm (I lunched one of my 3mm cutters too, oops). If you're really sharp-eyed, you might spot the cock-up in this picture... The "grub screw" is just a cheap-ass M4 bolt with the head cut off, and a screwdriver slot cut in with a hacksaw.

I didn't have any 3.Xmm material, the smallest stock dia I've got is about 5/8". Rather than waste 95% of that, I ended up using a section of the handle of a deep fat fryer basket (the basket will appear later). My chuck won't handle anything smaller than about 5/8", so I put the ER32 collet chuck in the 4J & dialled it in to within a thou or two. Popped the stainless (?) bar in, with about an inch & a half stuck out, and proceeded to make some cuts. This is all new to me, I've never lathed anything this small before.... so I bent the first one trying too big a cut (& then trying to rescue it, didn't work); I was more circumspect after that:



And so.... it was time for the moment of truth.... with all machining operations on the main body now complete, it was time to try to black it. Earlier this week, I handed 85 of our queen's heads over to Caswell Europe, who in turn sent me a bunch of chemicals:



They didn't send any coffee though, I had to make that myself.  :lol:

And....




...that's it for now! I've run out of time & have to go out.... the rest of this update will be along later this evening. Sorry about that!
« Last Edit: September 12, 2010, 08:35:53 PM by AdeV »
Cheers!
Ade.
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Offline raynerd

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Re: Another new project...
« Reply #51 on: September 12, 2010, 02:45:02 PM »
Wow - 85 squid is a good bit of brass...look forward to seeing the results. It looks amazing so far!

Offline AdeV

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Re: Another new project...
« Reply #52 on: September 12, 2010, 05:35:20 PM »
And back... sorry about leaving y'all in the lurch there, but, duty dinner called  ::)

Chris - I thought long & hard about the stuff I bought; price wise, it is the most chemicals I could get for less than 100. It should last me for months, and that's even if I gratuitously blacken stuff I make. The solution is good for 4m2 apparently; I don't know how much I used today, but if it's 0.1m2 I'd be amazed.

So, having poured/diluted the chemicals - as applicable - into the 4 plastic buckets, and having pre-washed the block in fairy liquid as recommended (in the absence of a hot degreasing solution), it was time for the 4-tank-shuffle... First, degreaser:



Then conditioner, then the cold-ox stuff itself:



As you can see, it started to blacken immediately. Telling when it was done proved difficult; in fact, I over did it a bit & it started making "soot"; the trouble was, the soot rubbed off & it looked grey underneath... Visions of failure swam before my eyes.... leaving it in a bit longer just made it worse, so in the end I gave up & followed the rest of the instructions, rinsing the soot off under the tap. Then, into the sealer oil:



Handy thing, that basket... it came from one of the deep fat fryers I bought to make machinable wax (remember that stuff?)... I left it 1 hour that way up, then turned it over & left it another hour and it STILL wasn't dry (the instructions said 45 mins to 1hr - that must be for small stuff), so I cleaned it up with a paper towel...

So, how does it look? Well, I put it all together, and...:



Eee, just like a bought one  :D

In normal use, the piston should stick out this far (RH piston):



If I make a shabby tool holder, it will come out this far:



Let's face it, that's just an excuse for more pictures. So..... got the base to make, and the central pin that holds it all down & locks it in position. And then some toolholders, and it'll be ready.... Onto the home stretch now, I feel :)
Cheers!
Ade.
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Offline Powder Keg

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Re: Another new project...
« Reply #53 on: September 12, 2010, 05:40:18 PM »
Looks great!!! I've been thinking about their nickle plating setups.
Wesley P
A Gismo ??? If it has a flywheel or spins and is made with small parts. I'll take one! If it makes noise, moves, or requires frequent oiling and dusting it's a better deal yet. It's especially right if its shiny and bright; but if it's dirty and dull it wont mater at all...

Offline Bernd

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Re: Another new project...
« Reply #54 on: September 12, 2010, 09:03:29 PM »
That looks to nice to be covered in swarf or even to put on the lathe and get scratched.  :D

Bernd
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Offline AdeV

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Re: Another new project...
« Reply #55 on: September 13, 2010, 05:44:16 PM »
Work had me working late tonight, so shop time was curtailed  :( I made a start on the base, however....

Since my vice doesn't seem to be well dialled in, I got rid & worked straight on the table today. First up, line the base up as best as possible (it's already been hacksawed to size):



Then trim the two accessible edges; jiggle the clamps about a bit (i.e. add an extra clamp, move the other two around, one at a time):



It's now square to within a thousandth. Take that, cheap chinese vice!

I then had to disassemble the top of the lathe to get the old toolpost off, to find out what spacing the mounting points are... 3" for the record. So, drilled & tapped two holes in the base to mount it. I also centre-drilled the middle of the base, as it will need a threaded hole cutting in it (size TBA), not to mention relieving (on both sides! - the underside because there's a ring sticking up where the old toolbase sat, and on the topside I need to leave a circular upstanding piece for the new toolpost to ride on...

Anyway, just for laughs, I decided to take a "preview" shot, of it sitting on the lathe:



Hmm, it looks a bit high.... Ah, that's because it is:



Centre height is about 0.450" below the bottom of the piston  :( I plan to relieve the base a bit, so that will claw me back about 0.200" of height, and I could (in theory) skim about 0.400" off the bottom of the block; but for now I think I'll just leave it & see how it pans out. If I have to do something about the height, I may also make an entire new cross-slide, as mine is badly worn...
Cheers!
Ade.
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Offline AdeV

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Re: Another new project...
« Reply #56 on: September 14, 2010, 05:17:01 PM »
A touch more progress today...

First - after putting the lathe back together... - mount the base plate in the chuck, centering on the hole I made yesterday, pin the piece onto some parallels for straightness, then drill to 8.5mm, before power-tapping M10 at 60rpm:



These HSS spiral point taps really do work very well...

Now, cut a relief for the circular thingy that will be left on the cross-slide (the current toolpost uses it as a guide, but the hole in my t/p is too big for it). This was a proper arse-puckering procedure... last time I did this I wrecked a parting off tool, destroyed the piece I was cutting, and quite possibly damaged the chuck too... so, lots of very slow feeding, take it down to 0.100"; then another 1/2 width cut just to make sure. The following photo is posed - no way was I going to take a photo while it was all spinning:



Then, turn the piece over & mount on some bigger parallels. I originally took the parallels out after I set it all up, but the first interrupted cuts pushed the piece very slightly off-line, so I had to leave the parallels in & squish it all tight with the live centre - I bet that did its bearings the power of good... not:



The idea here is to cut away about 0.100" again, leaving the central section for the toolpost to ride on. It took a while, I had to keep the speed & feed rates right down, it was interrupted cuts almost all of the way. Anyway, after 0.100" was done, I did a touch of filing on the lathe, and some more off the lathe. It's not finished yet, so no more photos.


There's another problem too: Look at the last photo in the previous post, and you'll notice a touch of discolouration on the black top. Today, it was worse:



Aargh! RUST! Damnit!

That block has sat, naked, in the workshop for weeks on end, with nary a smidgeon of rust on it. 2 days after I blacken it, it looks like THAT! Curses!

I can only assume I didn't let it sit in the water-displacing oil for long enough, and/or a bit too much water soaked into the steel (yeah, you might think it was waterproof, but it's not: Just play an oxy-acetylene flame over some steel & watch the water dive out of it). So, I baked it at 90 degrees in the toaster oven for a couple of hours, then soaked it in WD40. If it still looks OK in a couple of days I'll call it done; if not, it's out with the sandpaper, and I'll have to re-black it. Grumble.

Next task: The central pin which clamps the toolpost down to the base & also acts as a retainer for the offset-cam. So, I cut some stock off my 2" bar of EN1A-Pb (leaded steel), and curse it if it wasn't too short. Grumble grumble mutter grumble. So I cut a longer piece off, I'll make that bit tomorrow now.
Cheers!
Ade.
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Offline raynerd

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Re: Another new project...
« Reply #57 on: September 14, 2010, 06:52:50 PM »
Looking mighty cool AdeV - nice one!

Offline Brass_Machine

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Re: Another new project...
« Reply #58 on: September 15, 2010, 12:41:06 PM »



Eee, just like a bought one  :D


Ade, That came out fantastic. Now... could you do a write up on the finishing (blackening) process??

Eric
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Offline AdeV

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Re: Another new project...
« Reply #59 on: September 15, 2010, 01:45:10 PM »
Hi Eric - I did cover the process briefly in the post you quoted that picture from; but sure, I could put together a proper "full explanation" type post together if you like.

I may have to re-black the toolpost anyway... after the rust incident, I baked it for a while then slapped lots of WD40 on it; that seems to have done the trick (for now), but some of my other experiments involved fine wet&dry, so I've actually scraped some of the black off one side.... We shall see.

Anyway, it's time to hit the workshop for a couple of hours, be nice to get this one finished off...
Cheers!
Ade.
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Offline Divided he ad

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Re: Another new project...
« Reply #60 on: September 15, 2010, 04:43:04 PM »
Looking mighty good Ade  :thumbup:


Aluminium bronze!!! Tough stuff indeed  :jaw: I've got a few lengths of 1'2" hex that Bogs got for me from the scrappy (not as expensive as yours) only made a torch from it so far, looks great when polished up but machining it wasn't fun!


I like your experiments into the blackening. Never had the resources or the room for such.... One day  ::)  Hope it all works out after handing over the hard earned for it?




One of these days I'll get over there again to visit and see all this stuff first hand eh?



Hope today went well?







Ralph.
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Offline DeereGuy

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Re: Another new project...
« Reply #61 on: September 15, 2010, 07:13:34 PM »
Nice work!

Offline AdeV

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Re: Another new project...
« Reply #62 on: September 15, 2010, 08:07:11 PM »
Thanks Ralph & Bob - much appreciated. Ralph, I could use you popping over, I haven't the patience to polish it properly!  :lol:

Anyway, tonight, I did a bit more. I needed to work on the central pin, that locks the tool holder to the base, whilst still allowing the cam portion to rotate. It also acts as a retainer to prevent the cam from being lifted out, should you be perverse enough to try such a thing... Anyway, I chucked up a 6" piece of 2" leaded steel, and got busy with the rough cuts:



The retaining ring diameter was 1.75"; having reached that, I cut the main section (1.5"), then the bottom section (1"):



The retaining ring is, as you can see, cut right up to the chuck. Annoyingly, and stupidly, I hadn't left myself a long enough section on the end to reach all the way through the toolpost & into the base. So a bit of lateral(ish) thinking required... I drilled & tapped the base for some M10 stud:



Then, using two bolts tightened against each other, I wound the stud in as far as it would go. Before I finish this off completely, I'll probably take the stud out again & loctite it back in, just to be sure it stays there forever. But tonight was all about making sure everything would fit together OK.

So - having inserted the stud, I moved the piece away from the chuck by 1/2", and parted it off, finishing off with a hacksaw. And so, finally..... all the major parts are finished, hooray!



And when it's all put together:



 :beer:

Obviously, we're not quite there yet - I still have to do something with the top of the post. I had thought, drill & tap it for M10 or M12, and loctite in a cap screw, which could then be used to tighten or loosen it. Or I could make another handle thing, rather like the original plans suggested. I've yet to decide... However, what I will try and do, is finish the top off with some brass, just to give it some contrast with the stainless steel. As to how it performs; well, once I'd done a bit of file work, I can now clamp it right down hard on the base, and still turn the cam lock with only a little binding (I reckon some valve lapping paste & elbow grease will cure that).

Oh go on then, if you insist, one more photo.... An "exploded diagram":




Some final thoughts (for tonight): It would seem that my "rescue" of the rusting situation has worked. Basically, I stuck it in a toaster oven at 90o for a while, then whipped it out & drenched it in WD40. And that's pretty much it; the rust has disappeared, and the black surface remains - except where I'd rubbed it off with sandpaper  :doh:

I will probably blacken it again at some point, but I'll see how it holds up in use before I do.

The next job, then, is to make a holder, so I can try it out...
Cheers!
Ade.
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Offline AdeV

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Re: Another new project...
« Reply #63 on: September 16, 2010, 04:23:47 PM »
Onwards!

More or less from the moment I parted off the centre pin, I wasn't happy. Feelings of unhappiness persisted through the night & into the morning... e.g. how was I going to tighten it down? Visions of drilling/tapping for a cap bolt swum around. Nah, ugly. Same with welding a bolt to the top, ugly. I can't cut hex holes, haven't got the technology.

Luckily, our next door neighbour here at the shed is a tame racing driver welder (Top Gear fans may make their own Stig jokes up now). So I cleaned the ends of the pin & the stump, and added a "fillet" (the chamfer on both parts):



Then my tame welder simply glued them back together:



Next, some quality time on the lathe, slowly trimming, tapering, parting off the excess, drilling & tapping for M10, and - some time later:



That's better! If you imagine the lathe ways coming towards you, perpendicular to the visible piston, that's where the top handle will be in relation to the tool block. It's a doddle to just back it off 1/2 turn, swivel the toolpost to whatever angle you need it, then scraunch it back down again, job done  :thumbup: The only issue is, when it's really ground down hard, the cam binds up. I think it's because of the various centering/wobble issues I've had while turning, mean that the bottom of the central pin is actually a smidge off centre; and when wound down, it's being pushed into the cam spindle, locking it up too. It's not pushing down at the top, of that I am certain. All I need, then, is to find some valve grinding paste (Can I find any? Can I buggery. Halfrauds don't seem to sell it any more either.) & lap the cam in to the pin (or vice versa, it really doesn't matter which one takes the wear) so it turns a bit more freely. I don't mind if it's a bit stiff to turn, that should help prevent any liklihood of the thing undoing itself in the middle of a vital cut...
Cheers!
Ade.
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Offline Bluechip

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Re: Another new project...
« Reply #64 on: September 16, 2010, 05:16:41 PM »
Chemico Grinding & Lapping paste ..... got some from here last year .. then found the local car bits shop sold it ... bugger   :doh:

http://www.frost.co.uk/chemico-lapping-and-grinding-paste.asp

EDIT  It seems yer need to click the pic. Didn't buy 72 tins ... just the one ..

Dave BC
« Last Edit: September 16, 2010, 05:20:00 PM by Bluechip »
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Offline AdeV

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #65 on: September 17, 2010, 05:33:57 PM »
It's finished!*

*for certain values of "finished"

Bit of a marathon session today; the first task was to figure out why the cam spindle was locking up when the central pin is tightened down. I figured it was probably due to the lack of concentricity (is that even a word?) between parts, and probably as the screw thread was tightening up, it was pulling the bottom of the pin out of centre. On that hunch, I whipped a few more thou off the bore of the cam unit (that being the easiest part to hold in the chuck while still cutting the bits I needed to cut). It took a couple of goes, but now the cam operates perfectly in "the zone" in which it's needed.

So, next job, a slight modification to t'underside... X marks the spot, approximately:



Milled 1/4" to within a smidge of the top of the base. Milled with a 6mm ball-end mill (the only type I have) just a smidge (that's an official SI unit, you know) into the base as well, then finally drilled 7mm & tapped M8 for a few turns:




No prizes for guessing what happens next:



Yep, there's a ball bearing stuck in there, with the tiniest fragment of a spring, all held in with an M8 bolt (in turn reinforced with Loctite), which was then cut off & filed flat. And that there is my "zero" position; the theory is, when the QCTP is set straight along the ways, the ball will drop into the dimple, so I don't need to think about it to return it to straight, it just goes straight in.

In practice, I think the 6mm ball end mill was a bit too close to the 1/4" ball; so it locates OK, but there's quite a large amount of lateral movement with the ball in the hole. Shame, but never mind, it gets pretty close. If it annoys me too much, I'll just do it again somewhere else (and make a much smaller indent in the bottom of the tool holder.


So, finally, we get to the end of this project; here's the QCTP successfully mounted on the lathe, no fettling required.:



I'm pretty chuffed, even if I do say so myself. I have managed to wear/scratch the black surface off in a few places, just with general mishandling and - of course - the rust incident... so I may black it up again in the near future. And, of course, I have the proper handles to make, but they'll just be some 1/2" bar with an M10 thread on the end. The balls will have to wait until I've made a ball turner... but, of course, I now have a dandy base on which to mount any new stuff, like a ball turner. It only takes 10 seconds to whip the QCTP off, another 15 minutes to locate the bl**dy ball turner (or whatever tool is going on instead) from the deepest recesses of the workshop which have never been seen by human eyes (how does stuff end up there?), and another 10 seconds to pop it on & fix it down. MUCH better than all that messing with hold-down bolts, shims, etc. Goodbye 4-way toolpost, you won't be missed (not much, anyway).


I'd like to thank everyone who's commented on this project along the way. :nrocks:  Your comments have been inspiring, and have kept me at it more than once. Thanks in particular Lew for introducing me to a metal even more expensive than having a wife (weight-for-weight), although it did make a fine pair of pistons (the metal, the metal....).

Hopefully, once Bogs has straightened my chuck jaws, I'll be able to make a staight one next time  :lol:

























But.... wait...... what's this?






















Down in the deepest darkest recesses of the workshop......




A toolholder is calved!

Yes, of COURSE this isn't the end of this project! There will be no actual end, 'cos I'll be making toolholders for the rest of my life. I'll do a bit of a photo writeup of the 1st one (the one that's even now being weaned in the basement), after that, no more...

Until tomorrow, then....  :D
Cheers!
Ade.
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Location: Wallasey, Merseyside. A long way from anywhere.
Occasionally: Zhengzhou, China. An even longer way from anywhere...

Offline Ned Ludd

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #66 on: September 17, 2010, 09:20:39 PM »
Nice job there and soo much cheaper than buying lots of toolholders.

Re. your 6mm ball, the dimple should be made by the next size smaller ball ended mill. For 6mm ball a 5mm mill is used, this allows the ball to sit on the periphery of the dimple and not fill it completely. If it fills it you just don't get a clean and positive location (too much of a cam action). I found this out the hard way after making a batch of indexable drilling jigs for woodturners.
Oh well, you live and learn (hopefully)
Ned
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Offline ibuildstuff4u

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #67 on: September 17, 2010, 10:59:30 PM »
Easy fix,  all you need is bigger balls!


Offline Divided he ad

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #68 on: September 18, 2010, 03:29:47 PM »
Looking good Ade  :clap:



I'd have thought a smaller dimple too...

My old tool post had a one way affair on it. A spring loaded pin with a smoothed taper on one side (allowing the tool post to be turned to the left) and a flat filed across the back side, so the post could not be turned back to the right once in position.... Not bad but could get annoying if you turned it too far and had to do the full revolution again!
Just another way of doing it.


Tool holders ehh? Hope you're planning to make them in batches?  Could prove tedious?  I'm sure you'll have fun with the first few anyway  :dremel:  :thumbup:





Keep us posted on the rest of the build.... Including the ball turner  :whip:   :)





Ralph.
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Offline Ned Ludd

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #69 on: September 19, 2010, 09:10:52 AM »
My dear chap, if I had bigger balls that would make me a Politician on the make. :)
Ned
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Offline krv3000

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #70 on: September 20, 2010, 06:44:35 AM »
HI thats brill  :)

Offline ksor

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #71 on: September 20, 2010, 02:36:16 PM »
-->AdeV
Ohhh that's a very nice peace of work you have done here ! :clap: :clap: :clap:

Especialy I like the black finishing of the main block - I have found a description of how to do it on the net and I will try use it on my small vice:



BUT

I don't want to do all the filing work to remove the "circle-pattern" on the surface - there must be another method to prepare the surface before doing the ecthing !

The surface on my vice is very smooth and very soft and you can NOT feel the "circles", you can only see them - if I start filing or sanding ....  :bang: ohh, I think the surface will be rough and not so smooth and soft as it is now !

On the other side, I think the circles will been visible "under" the black finishing.

How should I prepare the surface then ?
Best regards
KSor, Denmark
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Offline AdeV

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #72 on: September 20, 2010, 03:50:22 PM »
Thanks guys, all praise gratefully received, all hints greedily taken...

Ned - you're right, and as soon as I felt how it worked I was cursing like a good 'un. I'd hoped that using the 6mm ball mill (closest I have to 1/4" - the ball size - and very slightly smaller) would be OK, but as you state, it needs a slightly smaller cut on the tool block so it rests on the rim. Duly noted for next time.

Ralph - my previous toolholder had a one-way mechanism in it (although it could occasionally be defeated, allowing a 90 degree backward turn), an extraordinarily complicated affair full of little springs, pawls, ratchets, levers.... if it had a bit more brass in it it'd almost be a steampunk mechanism... Of course, I only found out about the fancy stuff when I took it apart (trying to figure out how it came off the cross-slide), and the springenwerk went everywhere. Fortunately, I found it all, and - by absolute blind luck - managed to put it all back together again with no bits left over. A miracle!

Bob - thanks fella :)

Ksor - Don't worry about filing the surface. Yes, it looks horrible as you just get started, but as soon as the machine marks start to disappear, the surface takes on a really silky texture. The key things - in my brief experience - are:

 - Use a fine toothed file (not a klunky coarse one)
 - Keep the pressure as even as possible across the file
 - Slow & easy does it
 - Clean the file up every few strokes; I found just wiping it on my "shop coat" did the trick most of the time, but a soft wire brush was occasionally needed to clear a stubborn chip out. Remember - whenever you've got chips stuck in the blade, they drag & make lines in the surface which, inevitably, require another 30 mins of filing to remove...

Once you've done filing, you'll be amazed at how much better the finish is, even than the one you have now. And yes, I've had finishes like yours (which I usually decide is good enough) which you simply can't feel the marks.

Incidentally... I've always stopped after the filing stage (or after 1 stage of wet&dry paper (120 grit); there's nothing to stop you doing exactly the same draw technique using ever higher grits, until about 800 or 1000; then move onto polish, and you'll eventually have a true mirror finish - Ralph (Divided he ad) will point you towards polishing techniques, I'm sure).

The blacking BTW will work just fine with the finish you have there, but you will still be able to see the machining marks. I can still see every little scratch & ding on the toolpost, whether it occurred before or after the blacking...

Ah - to answer your actual question, yes there is one other way to remove the maching marks; a very very very light surface grind on a proper surface grinder, with a fine grit wheel, would leave you again with a silky smooth finish; if you then wanted to go further & get a mirror polish, you're into the polishing mops, brasso, etc.
Cheers!
Ade.
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Location: Wallasey, Merseyside. A long way from anywhere.
Occasionally: Zhengzhou, China. An even longer way from anywhere...

Offline AdeV

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #73 on: September 20, 2010, 04:11:56 PM »
Right, now on with the show, such as it is...

Apologies for the delay - Sunday morning was spent standing in a muddy field somewhere near Stoke-on-Trent, collecting a rusty water pump which wants some machining work, and also riding a genuine coal-fired steam powered narrow gauge railway - it was their grand official opening. Naturally, it rained continuously. Good old British weather.

The afternoon was mostly spent bothering Bogs, breaking his grit wheels and generally getting under his feet. I think I'm right in saying a good time was had by all :) Well, once the palpitations caused by the broken grit wheel & flying lathe chuck jaw had subsided

The evening was spent "finishing" the toolholder, trying out the newly ground square chuck jaws, and pottering.... And most of tonight was spent fitting a new quill spring to the Bridgeport (the 1st replacement having broken when I got frustrated with a recalcitrant woodruff key & smacked it with a hammer. It didn't like that...) Of course, the Olde Screw Shoppe didn't have any #10-24 screws in stock, but they did have a die, so I made my own.

So.. the toolholder... Well, you saw the lump of steel. I soon had it squared off in the mill, and the dovetail slot roughed out:



After cutting the dovetails, a quick test fit:



Next up, mill out the toolslot:



Final operations (no pix of these, sorry): Mill a slot off the top so the bolts I had would reach (only had 25mm bolts...) Drill 4 holes to hold the tool in place, and another hole to work the height adjust. I didn't leave quite enough material to contain the whole thread, so I drilled/tapped it deep & used some stud to hold a home-made "washer" (also drilled & tapped). The result of all this bodgery is as follows:





And here it is on the lathe (had to skim nearly 0.010" off the piston before the tool would drop over it):



And - taken yesterday when it had the boring bar mounted in it - taking it's first ever cut!:




Subsequent toolholders will be a bit "fatter" (2" rather than 1.5"), and I'll hopefully find a shorter piece of metal, so I don't have to cut an inch off it every time...
Cheers!
Ade.
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Location: Wallasey, Merseyside. A long way from anywhere.
Occasionally: Zhengzhou, China. An even longer way from anywhere...

Offline Bogstandard

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Re: Another new project... a QCTP (Quick Change Toolpost)
« Reply #74 on: September 20, 2010, 08:39:23 PM »
Ade,

I meant to show you the adjusting bits I made for my tool holders when you called yesterday.

Instead of making a washer to go under the nut, just get a length of bar the same diameter as your 'washer', knurl the outside for a few inches (50 to 75mm), then drill and tap the same thread as you are using. Part them off to about 3mm thick whenever you want a new length adjuster. Once it is screwed onto the thread for exact height, your nut is then used to lock it into position.

Like shown in the last few pics of this post.

http://madmodder.net/index.php?topic=2323.msg24924#msg24924


John
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Location - Crewe, Cheshire

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