Gang tooled Lathe Must have Features?

Ok so here i am in the final parts of the gang tooled lathe build, literally got one more ball screw nut bracket to make and fundamentally mechanically im like 95% of the way there. Electrics im rapidly figuring out just what im doing but i have it covered.

Question is, what features if you have a choice do you want - need? Currently i have something like 16" of cross slide travel to load up with tooling, average part size is going to be say sub 2" diameter, but a varied range of bits, though all perfect gang tooled lathe parts. Im thinking with 2" parts i need tooling on circa 1 1/2" centres minimum to allow for some clearance. Straight shank ER collet chucks are dirt cheap, hence its probably what im going to go for in a simple tooling block, will make it easy if i get the longest ones i can to grip any typical, drill, tap or small boring bars i envision using whilst using there length to keep the gauge line reasonably constant? I currently have a mass of ER32 collets, but only a odd few ER25's, am kinda thinking i probably should be giving a lot more thought to ER16's or ER20's though? they would have enough capacity for most of the planned needs. But having so many ER32's im kinda wondering if i should stagger it er32-er 16-er32 etc, like this i can get tight centre distances - more tools in a given space whilst having a lot of options. equally 32mm bore holes spaced with smaller ones would open up a very wide range of boring bar options down the road. Would also make it effortless to have adaptor sleeves to use any of my existing and extensive 1" shank turret lathe tools.

Full threading, CSS and rigid tapping are going to be there, have all of those covered. Also am planning a proper MPG style hand wheel set-up. Is a tool probe a must? Or just a pain on a lathe like this, i know some people love em others hate em on turret lathes. Theres plenty of IO capacity for a range of coolant options too or pretty much any thing else i need control over, got a good 40+IO free and can easily add a lot lot more!

Currently there’s no plans for a C axis - live tooling, the parts im looking at doing whilst benefiting from this , just vary too much, as im kinda hoping 90%+ of the time to have this thing setup and just run any part with out changing too much tooling. Its going to be faster to just chuck them onto the mill than it is mess with masses of set-up time! Realistically this time next year im envisioning 100+ different parts programmed but probably only doing runs in the 10-50 of range of any given part every few months. Its about freeing me up and passing the work onto something automated + being able to machine very complex curvy parts. Its really not so much about being-able to drop finished parts in seconds, more about having a easier life! hence current thoughts are that anything much over 1/4" ID is going to simply be bored out, most parts threaded will be single pointed etc, all processes that let me avoid spending a hour or so swapping drills, taps etc. Equally quality taps in the thread pitch i need are bloody expensive, will be far cheaper to just thread em all single point style, even at the expense of some time (all 26tpi BSCY though so common pitch :-)

Any thoughts welcome!

A good parts catcher, nothing annoys me more than good parts getting ruined on the drop off, or worse still flying in to chuck jaws etc etc.

Have you thought about having interchangeable cross slide ''sub plates'' pre set with alternative batches of tools - think (say) just 4 bolts, and that's a set of tools changed and zeroed in.

What control are you using?

I could see something like this Dorian tool bar system. However, I would be tempted to use two tool posts as one has been known to turn; two posts are also much more ridgid.

Gang Tool Lathes Boost Outuput

Tom

Limy Sami said:

Have you thought about having interchangeable cross slide ''sub plates'' pre set with alternative batches of tools - think (say) just 4 bolts, and that's a set of tools changed and zeroed in.

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Sami types faster. Or sleeps less.

I'd ask much the same question.

Why not use but two 'master' positions, but spaced so each could have a salvaged/new pre-tooled Hardinge 6, 8, 12, dual-tool-per-slot turret plate swapped on or off like changing the magazines of a Lewis gun?

JM2CW

Bill

TDegenhart said:

I could see something like this Dorian tool bar system. However, I would be tempted to use two tool posts as one has been known to turn; two posts are also much more ridgid.

Gang Tool Lathes Boost Outuput

Tom

Click to expand...

Yeah have seen that, problems cost and costs of adding multiple set-ups. That said the basic idea has merits. What i have considered is having a parting set-up the far side, then having a stop, spot drill and maybe a std pilot drill size as one tool block, then having a separate removable tool block containing every thing else that’s job specific. tool blocks look like im simply going to have a bunch - pattern of dowel holes and M8 tapped mounting holes. Like this things will peg for approx location and then bolt for security, im sure anything i can make alignment wise will need off set tweaks at swap over, so rather than getting all silly and elaborate, seams best to stick with KISS, and just get things located within a few thou and then tweak the offsets as needed thats really easy to do control wise too.

Parting wise sami, yeah, its gotta be addressed, currently the chuck centre line to cross slide top is a good 5 1/2" Am kinda planning on having the parting tool sit on a gantry like structure, upside down, rear tool post style, part catcher in the middle of the gantry. Some of the little brass and nylon bits this will be doing have a really bad habit of launching every were, (could probably complete a order or 2 of em if i cleaned out behind the current lathe!) like this the part could be cut off more or less in a tunnel and drop down - be deflected down out of the way nice and safely. For the time being this will have a 3 jaw 6" chuck, so part pulling - self feeding is off the menu for a while but the spindle does have provision for a draw bar + the controls got the capabilities of having it added. Just at this point, i need her working, not racking up ever more cost - complexity. Theres a 500 of parts order on the radar for october, it takes me a week to turn em by hand, hence i really want this working by then no fail!

Hardinge tooling is not as readily available over here, simple as that, hence tying it to some odd std of tooling i can not easily get seams silly, far easier to stick with say, 32mm 25mm and 20mm mounting holes! Can get tooling to fit thoes in the 6 for £100 range which is more or less cheaper than i can buy collet nuts and steel to make my own holders! Equally i don't want the complexities of turrets, just don't need them for what this is doing and slinging the extra weight of a turrets drive around will slow things down even more. This is not about having a big powerful industrial work horse, this whole projects about a cheap cnc lathe that makes the parts i need as simply as possible. whilst fitting into my very very limited shop space + working on my limited power supply. Trust me, if i had the power and space there would be a twin turret with sub spindle at work now. As is i need a gang tooled lathe for production, but the option of stripping it off to make up some large circa 10" diamiter contoured short rollers for in house future tooling needs, ergo this will do both!

Control wise, its Linux CNC. Will be programmed off line through my current cam so none of that’s really a issue right now. Controls will not be in the PC though, i now have a MESA 7I76e card which will handle real time events very very nicely! Currently its running the largest steppers i can get, in time it will probably get switched to servos, but again funds and such dictate a cheap get it running and upgrade later approach. All control - interface parts will use industry std stuff so i can get spares fast and easy with no OEM crap or obsolescence issues. All electrics will be IP67 enclosed, theres ample spare capacity in all cable chains for future upgrades too, oh yeah this is not some alu extrusion build of ebay either, currently we are just over - approaching the 400Kg mark with over 1/4 ton of steel 1" flat making up the key bed part :-) can't wait to find out if i over engineered it enough to get rigidity numbers to were i think they are or not? Goal was to be as or more rigid a lathe than my current 11" harrison, machine bed wise im easily at double the material mass. The beds wider (11" wide rail centre line) and all the preloaded linear rails are lovely and slop free :-) but nothing shows or destroys the ideas of rigidity like sticking a boring bar in a deep hole so time will tell on that! But its fair to say im very very hopefull.

adama said:

..in time it will probably get switched to servos...

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Going slightly off topic, but check out Adtech on ebay. I have a few of their ac servos and drives and they're nice gear for the money, integrate easily with the Mesa hardware.

The guy selling them on ebay is their UK agent, based in Wales. He can supply anything from their range rather than the small selection he has on ebay.

I believe adtech offers a control as well.

Yeah adtech do offer a control, but for the £800 they want for it i don't see what you gain over the PC option. There control like any other controls digital logic running code, weather its on pc based components or something else what do you gain? Equally your tying your self into one supplier again something i do my best to avoid. Linux cnc is undergoing constant development - enhancement, Mach's chasing its heals too so there’s another option that in reality could be up and running in under a hour. I know both well and both are dead easy to set-up. If i had the money, right now yeah i would be seriously toying with going for a large servo for the spindle drive, like this a C axis - live tool work would be a easy option down the line.

As to there servos, yes and no, i should be able to close loop the steppers i have with just the addition of some encoders if i wanted to go that way and then have similar capabilities as to there servo's. Alternatively i can fit glass scales and have real position feed back. Realistically though, its a gang tooled lathe, not a 50ft gantry router, if im moving 2" between tools low down torque like a stepper makes should be better than the high speed of a servo, yeah the servo moves faster on long stretches, but with 5mm pitch screws, its more a question of how fast i can accelerate and de-accelerate over 10 revolutions! If it works out as im hoping then all out rapid speed won't be such a issue, its simply not like a VMC thats gotta haul that z axis up and down for every tool change. But yeah its still a interesting thought. I have purposely built it such that alternative Nema 34 steppers - servos are a screw in job, others would require some work mounting wise, but theres purposely masses of space around each stepper to leave thoes options open.

Hi Adama:
You commented that you intend to run this lathe with a conventional 3 jaw chuck.
You need to be very aware of your tool positions when you run a big chuck on a gang chucker.
You eat up a LOT of X axis space for each tool getting tool #2 to clear the chuck while tool #1 is cutting.
That's one of the reasons gang chuckers mostly use collets.

I have about 12" of X axis travel on my SNK Prodigy.
It can be a real fight getting 6 tools on that slide and having everything clear.
Sometimes I have to swap tool positions to get long ones like drills to clear, and that's with a 5C collet noes that's been turned down to be only about 2.5" diameter.

So by the time you have a spot drill, a drill and a tap on your slide, you've used up more than half the X axis travel, so you've got nothing left for all the other tools you need.

What that means for your plan to make tool blocks that are ganged, is that you give up flexibility.
I went that route in the beginning and it was hopeless.
So I made very compact individual toolholders that can be mounted very close together and crucially, can be taken off the slide WITHOUT having to disturb any other tool.
This is super important when you're working with a gang chucker...it's a royal pain in the ass to have to strip off and relocate every tool because of tool blocks or tee nuts that you cannot unbolt and lift out individually.
You'll often have to mount tools out of order and accept long rapid moves between tools just to get everything on the slide and clearing the chuck...if you can't swap them around easily you'll be cursing a lot.

For the same reason, I don't bolt anything down until I've jogged every tool past the stock that's sticking the correct amount out of the chuck and checked the clearance.
Before they're bolted down and touched off, it's easy and fast to give them a nudge or swap them around if you need to.
After they're touched off it's a PITA.

I've drifted off topic a bit, I know, but I thought it'd be worthwhile to point this stuff out before you start building tooling.
Cheers

Marcus
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Marcus, nahh thats exactly the thoughts i want to hear. Im far more interested in others problems going this route than i am even there fixes! Knowing what causes grief makes it so much easier to avoid altogether.

Yeah the second i watched the first youtube of a tormach being tooled up, thoes 2 long T slots and i instantly saw were your coming from, I won't be haveing t slots but a grid of holes and studs, may not be as adaptable, but it will allow for far more swap around with out issue. Due to the height of my centre line, i am planning a very reinforced gantry like spacer block set-up. Its going to be circa 4 1/2" tall, it is relativity easy to make this so whilst it bolts - pins solid to the lathe, the tool blocks are on simple slots - keys above to give me movement as needed. With simple nuts underneath i can access to make removal - reinstall easy and not mess with anything else.

Chuck - tool clearance is a problem, no denying it. That said, nearly everything i want this to make will have a good mixture of ID and OD work, then parted off. Everything so far im looking for this to do would naturally all want to be machined outside the chuck jaws. IE no in the chuck jaws swing working should be required right now. I have modelled up a few tool block arrangements in CAD. Seams like if i have long collet holders for drills - taps ie ID tooling i should be able to have - set it up as a common gauge line arrangement in the mill world (ie everything has nearly the same Z offset) Like this so far on the bits i want it to make the clearance issues not too bad and equally im not having to pull back to far to do tool changes.

Right now a chucks a cheap way of getting it working and also keeps my spindle ID clear, i have 45mm and will be using that a fair bit, a collet set large enough to do thats costly, the collet chuck even more, draw tube looks like i would lose 5mm minimum hence down to 40mm or less and thats starting to be a issue for some of the parts. Right now most bits are lowish qty 10-25-50 tops normally, on more than a few of those sticking say a 1 1/4" nylon rod out 2" will easily let me drop off a good half dozen bits. hence whilst still being something i have to do, is really not to much of a issue, due to the size of my shop, its impossible to be more than a dozen foot steps away! If my typical run was in the hundreds, it would be diffrent, but today, low qty and a manual chuck + keep the spindle bore as large as possible make most sense.

Problem seams to be when i come to OD work. Unlike id which only needs the radius of the part clear either side of it, OD work needs the dia of the work clear on the side of the tool, real world, that means a good 3" of my x travels lost for every od tool i want to use. Assuming im using a 1" wide boring bar for OD work. Use a bigger bar and ever more space is gone. Yep i can get this free if i have one od tool on the far side of the x axis. A lot of people at least on you tube and pictures i can find seam to have a OD turning tool on the far side of there setup, parting tool the other then id tools in the middle.

The more i consider it the more i conclude, its the OD tooling thats the biggest issue, simply because they need a material dia clear in x in front of them! With My nominal 2" part, that gobbles space fast, that said, think i can win some back by making it such that each gap has one up and one down tool IE a conventional VCMT insert tool with a upside down threading bar facing it say for OD threading work. Same in front of my upside down rear parting tool, the 50mm clearance it needs in-front of it could again have a additional OD working tool right side up, maybe a finishing tool spot?

ID wise, a spot, drill, tap, boring bar, small solid carbide ID threading bar. would let me do all the ID work i need to do. If i can pull of circa tool diameter + 1" clearance that should all be fittable in just under 8 inches of my 16" travel.

Swapping drills - taps between the different parts is not such a issue, with a common gauge length its easy to just slide them in - out to the length needed. Its messing with od tools - moving blocks of tools and having to readjust a load of diameters i want to really avoid.

Yes the above means im probably going to be jumping back an forwards - doing more moves a part than the optimum tool layout, hence losing time, but the reality is on a run of 10 - 25 parts, gaining 10 seconds of rapid time is going to easily be saved in minimal set-ups part to part.

Im still also toying with having a conventional wedge tool post for the od tool nearest the operator. Would be easy to match it up so its identical height as my manual lathe, like this i easily have the option of changing tools in - out manual to get a ever wider range of things done. Yeah it ties me to the lathe, but it might well be the simplest fastest approach for some of the odd ball stuff i do. Or dare i even think it some kinda turret for the OD tools. That said, right now, OD work only needs OD turn with something like a VCMT, grove tool, threading and part off.

Gang Tool Lathe Prodigy GT-27 - YouTube

^ is the kinda video im bassing most of my ideas off, my problem is the parts im doing are a lot bigger, would love one of thoes, for the smaller bits just dread to think what they are over here though :-( Key thing is being able to make large as in circa 10" dia contoured roller like parts about 5-8" long max on the same machine once in a while for a future product line i have had on the cards for a while. Yeah every tool will get stripped off to make them, but realistically i probably need to only ever turn 100 different versions of them in this life time. Would love to just farm thoes out, but have had so much issues with farmed out things here i avoid it at all costs now.

What a timely topic!

I just bought a gang tooled 1994 Takamaz miniturn from an auction, and it's probably coming to my shop next week. It doesn't have any tooling with it, so i'll have to make the tooling blocks myself and i'm looking for ideas as well.

It's a machine with 5C? powered collet chuck and around 200mm X and Z travels. Seems like i'm turning a lot of tiny parts for customers, so it's an welcomed addition to the shop. I've got a lathe with 6" hydraulic chuck already, so i'll probably keep this one only for collet work. Might get some 2" 5C soft collet chucks for holding the odd and bigger diameter stuff.

Oh, and due to the auction being middle of the holiday season, i got a bargain. 1100€ for a functional Fanuc controlled lathe isn't too bad...

I'll get some pictures when the machine arrives and i begin making the tooling blocks.

€1100 lol thats what £1k got more than that in parts several times over so far! Can't imagine how small a stuff you must be doing to fit it in 200mm of gang tool travel! One things for sure, your not going to want to use ER32' collets!

..That's probably why it's called "Miniturn"
I just bought a few more 0.8mm boring bars and a digital microscope as well as a 0.3-1.0mm gage pin set for turning and inspecting some of the parts i make, so i'm talking about tiny parts

If i'll use the 5c collets, then the maximum bar capacity would be 30mm, which is enough for all the parts i intend to make on this machine out of bar. 200mm divided by 30mm equates to six tools. Not plenty, but should be enough for most parts. Most of the complex stuff is smaller, so if i mount tools 20mm centers, it would equal to ten tools. (might be doable on ER11 collet chucks which have a 16mm OD on the mini-nut which fits to a face-spanner) For boring, i usually use Sandvik XS series tools, which have a 16mm diameter holder.

I'm thinking of a layout with heavier OD turning tool on the one end of the X travel and a parting tool at the other end. In betveen of those would be places for ER11 collet chucks and max. 16mm ID tools with 30mm centers or tighter (for smaller parts with lots of tools)

http://www.cottandco.com/media/lot/Lot-7---03-17.JPG
^ This is probably the original set-up on the machine. I think the Z adjustment of the tools is great, because if the tools are set up close to the same Z offset, they don't have to clear the collet chuck but only the workpiece.

If i have to turn bigger stuff on the machine, i could always fit the Rapid Ba-size QCTP of my engine lathe on the tool slide... Wouldn't be good for production, but could work in an emergency.

Ps: Do you have a build thread of your machine somewhere, or even some pictures? It would be fascinating to see your work this far! Years ago i started building a small CNC lathe myself as well, but didn't finish it as i began buying industrial grade machines to make the parts...

No i don't have a build thread, contemplated it, but not really a member of any forum were its ok to post something like that. Around here, talking about a gang tooled lathes fine, making one is kinda border line too hobby based on this place. Equally the builds very on - off around other paying work,some weeks i get a lot done, then like the last week i just order parts. Currently the lathes not even in the shop but else were so i have space to get around it to work on it. This weeks and the next has too many deadlines so it looks like littles going to be done this month :-( Have been building it for over 2 years, but in total probably have less than a months working hours in it.

Its kinda loosely based on the hass tool room lathes more so than being a specific gang lathe, just the gang bits how its going to be earning its real keep - 95% of its work load. I have been passing up way too much work that involves simple curved part turning.

If you have cad draw up the tool layout, best advice i can give you od tools, if you alternate one up one down you can have 2 tools working the part in the same gap! Am planning od work positions at both ends of my travel, far side upside down parting tool, then a right ways up finishing tool opposite that gap. Front will be the main turning tool, with probaly a upside down threading bar the other side of its gap, middle will be full of the id working tools. Will post some simple cad to this thread when i have drawn up the rest of the tools i plan on using.

Would also for parts that small just make up my own blocks, simply drilled on the lathe, then use grub screws side lock style. Should be easy and cheap to do + you should be able to fit a couple or more tools in your 30mm centre distance. Have been looking at thoes xs tools and others of similar ilk for a while, am thinking there going to be the way to go for my smaller boring needs too. Then jump to the good old faithfull CCMT06 insert boring bars.

..The Takamaz Miniturn has landed on my shop floor!

It's indeed a tiny machine for making tiny parts. Despite it's size, it's heavily built. At 1080kgs, it's twice as heavy as a Haas OL-1, which is a comparable machine. It's got boxway slides, no linear ballslides on this one!

It came with the original tooling system, which seems to use the travel in a horribly inefficient way. I've got to improve it... Might take several months, i'm buried in all kinds of projects, and i'm not in a hurry to get this machine making parts. I'm going to steam clean the whole machine, do a complete overhaul and tool it up for precision work. I've got bigger machines for heavier parts, so i'll dedicate this one for tiny parts which fit in a 5C collet.

@ adama
This machine is certainly imported from UK, it's got "Yuasa Warwick machinery ltd" stickers on it as well as few UK electrical sockets..

Highly recommend a simply brake mechanism to hold the spindle still. You can then use NSK air spindles in holding blocks to do both off center as well as operations perpendicular to the main spindle axis.

I have a few pics of this in this thread:

http://www.practicalmachinist.com/vb/cnc-machining/almost-done-my-kia-lathe-refresh-240767/

Nami said:

Highly recommend a simply brake mechanism to hold the spindle still. You can then use NSK air spindles in holding blocks to do both off center as well as operations perpendicular to the main spindle axis.

I have a few pics of this in this thread:

http://www.practicalmachinist.com/vb/cnc-machining/almost-done-my-kia-lathe-refresh-240767/

Click to expand...

Excellent idea!

Many of my parts have milled flats, grooves or holes on the face, rarely needing more than one live tool. I'd consider some kind of (manual) indexing mechanism for the spindle as well. Most of the parts are made in runs under 50pcs, so indexing manually wouldn't be a problem.

What kind of RPM/torque do those NSK airspindles have? How big are they? There's lots of space on the T-slot table of my machine despite the small X travel. So if i mount spindle at the end of X travel, it should fit easily even if it was somewhat big.