Possible to make a qctp "indexing?

[lakeside53]

Mine is fast - maybe 2.5-3 seconds per change (1 second out, 1 in, 1/2 to 1 for fumble).

Much of it is simple practicality - a lot more money and work to put a QC tool holder on a typical BP type mill than to add a power drawbar. I have many tools in holder also - pre-indexed, but more often than not is just as easy to just use collets and zero Z each time

[Mcgyver]

but when you mention QC toolholder for a manual mill spindle, most folks on here say they have no use for one, and proceed to tell you how fast their powered draw bar is..
Next thing we care gonna hear is that someone on here can change their QC lathe toolfaster than you can change to next tool on a turret lathe.. ....

collets not so much so, but with drill chucks, endmill holders etc, that is synonymous with a lathes QCTP - you can swap tools back and forth and they'll be in the same position.

However unless its production (in which case I use automatic tool changer) I don't see much advantage to the tool returning to the same position. When doing multiple parts I usually swap the work out. I would like to make a power drawbar though, that part gets old.

[J Tiers]

It seems that the multifix is no big advantage. To actually move the tool, you have to unclamp, pull out the holder, find the position (among many) that you actually want, replace the tollholder, and re-clamp.

For indexing, unclamp, turn the toolholder, reclamp.

As for the advantage, ot starts with simple things like doing a chamfer. Those are often at standard angles like 45 deg, which are commonly part of the indexing system. And, they are typically not large, so are practical to do with the side of the cutter. Unclamp, turn to position, reclamp, touch off for the chamfer, unclamp, turn holder back, reclamp.

Even for the Multifix, let alone changing tools for the Aloris, there are many more actions ("Therbligs" for you time and motion folks) taking more time. For the Aloris tool change, you unclamp, remove the holder, find a place, transport and set it down, find the holder you want, pick it up, transport it, put it on the post, and reclamp. It is FAR faster than replacing the actual tool tool in the post, but involves a lot more actions that unclamping, turning, and reclamping, which requires no extra selecting, along with zero in the way of "transport" actions.

If you know your sequence of tools, it seems likely that indexing the toolpost to the next tool, or position, is faster than all that is involved with replacing the holder even with a QCTP.

[pinstripe]

If you know your sequence of tools, it seems likely that indexing the toolpost to the next tool, or position, is faster than all that is involved with replacing the holder even with a QCTP.

Sure. If you can get by with four tools AND you can get those tools loaded at the same time AND the unused tools don't get in the way. This was probably common in a production environment when each lathe was only used for a small number of operations.

I like the gang tooling idea shown earlier. That could definitely save some time on a production run in a home environment.

[754]

Hmmmm must have missed gang tooling.. post # or poster?

[pinstripe]

Bented mentioned it in post #30. https://bbs.homeshopmachinist.net/fo...52#post1885452

I think he had a photo of two drill bits in an aluminium block at one point. Maybe in another thread?

[metalmagpie]

My suggestion would be to acquire an old Enco 4-way toolpost and then take it apart and modify its components to suit. You might for instance decide to remove your compound and mount the 4-way toolpost base directly to your cross-slide and mount your toolpost to it. That way you could have 12 indexable positions. You'd need to replace the lever on top of the 4-way and its shaft (whose functions are to pull the 4-way toolpost down into one of the 12 positions and lock it there) with the nut and shaft from your QCTP, but it should be easy.

metalmagpie

[754]

If the parts that you sell require six or more tools per part it will be difficult with a 4-way short of gang tooling, you simply can not set more then 6 or so tools without some getting in the way unless the parts are small.
This tool post could probably hold another 4 tools, however if the tail stock is in use or the part is much longer all bets are off.

https://www.youtube.com/watch?v=2o08V-7iKJc

The way they are working , is a lot like a rear turret functioned, some of it is and some is not.
gang tooling really saved crime and setup , will show a piece later that I did.
to answer Bented, 4 or 5 tools will cover many parts, if I need more then it would be second op time..
sometimes I set a tool , run all parts .. then repeat for other ops.. lots of part switching. .. whatever it takes..

[Bented]

Bented mentioned it in post #30. https://bbs.homeshopmachinist.net/fo...52#post1885452

I think he had a photo of two drill bits in an aluminium block at one point. Maybe in another thread?

I often make gang tool blocks to save tool changes. Spot drill, drill then ream with tools held in the chuck and make that position X .000, then drill and tap the set screw holes whilst still in the tool holder. Indicate one side so that if removed one can at least get them straight in the Z axis again.

I NEVER purposely rotate the tool post in a CNC lathe, it is pointless and changes the origin of all of the set tools.

Such lathes have no compound because any tool can do chamfers through programming so there is no need to rotate the tool post or use the compound, want a taper then program a taper. G Code also gives the option of an Approach Angle when threading much like using a compound.


End mill and boring bar.
This one, here unfinished, holds 6 tools on the other side.

[challenger]

I have the original 4 way tool holder that came with the lathe. I could not get comfortable with it. Shimming lathe tools just seemed odd to me.
How does on put 6 tools in a 4 way tool post anyway?
Fwiw my plan, after completing many other projects is to make a block for the qctp and run the lathe without the compound. I can always just plop it back on if I need to turn a short taper or do threading.
Thanks

[Bented]

I have the original 4 way tool holder that came with the lathe. I could not get comfortable with it. Shimming lathe tools just seemed odd to me.
How does on put 6 tools in a 4 way tool post anyway?

This only works for small parts otherwise some of the tools not being used will hit the part.


Just started these parts today, 360 brass



They take 5 tools, 175 parts = 700 tool changes, the last tool is also the first tool for the next part.

[Bented]

Tools

[Randy]

For years I used a home-brew 4-way indexing tool post inspired by the old Royal 4-way. When I finally got around to making my QCTP I included 15° indexing. I found that, while indexing is pretty essential to a 4-way post, it's not so important with a QC. But I like it, and would be reluctant to give it up. Adding an indexing feature to an existing QCTP could be an interesting, challenging project, but perhaps of marginal utility. BTW I haven't done a critical analysis of repeatability for my unit, because in use I'm plenty satisfied.

[754]

The video posted on here regarding putting index holes in an AXA toolpost. There is a problem it appears , the body has too much clearance to the shaft, so i believe repeatability will suffer. His mount is same as my 4 way.
S ome ask how you get good repeatability with a 4 way. I posted a pic to show why mine stays tight and won't wiggle, the pin is snug to.

[Paul Alciatore]

Great! Another 30+ minute YouTube video where we watch each and every chip coming off the mill. And NO introduction where he shows what he is building and how it works; well, he did do a bit on that but he should have shown the finished product there, up front. Some math, a lot on the initial set up and into the "...and here is this chip, and here is that chip, and here is another beautiful chip...". Reminds me of Jackie's tour of the White House. And of course, the excessively loud music at the open: at lease he kept that short.

I did skip to the end in hopes he would finally show the completed indexing post there and he did. I made a comment about the use of a detent ball in an earlier post and he shows the slop in the angular positioning there. It is horrible and he even admits this, in a slightly different choice of words of course. If you move that tool post from one detent to another, you will completely lose your numbers and will have to start from scratch. I said it before and I will say it again; I do not think an indexing tool post made with a detent ball is a usable device. Yes, you can quickly get to an approximate position, but you lose one of the great features of the whole idea of a QC tool post; the positional accuracy when you re-mount a tool. That is the second greatest advantage of using a QC tool post. The first advantage, of course, is the time saved when making a tool change.

Food for thought...

https://www.youtube.com/watch?v=t90uCe2u_k8