# TTS - Should I Do It?



## MontanaAardvark (Sep 24, 2017)

Back in April, once I got my G0704 CNC conversion finished, I posted a thread about ideas for ease of use.  Several of us got into a discussion about the TTS.  I ended up putting that on the back burner as a couple of summer vacation trips were coming and it seemed like there was no rush to get a TTS running.  I got my Z-axis touch plate working (also part of that discussion), built a couple of tooling plates (ditto), spent entirely too much time on my GB-22 (single shot .22 pistol that never did work right) and now that the trip to see the eclipse is over, started playing with thoughts of the TTS again.  

One of the things I had concluded about the TTS is that it really only improves the speed with which you change tools.  I can very easily convince myself that since I'm not trying to make money from my shop, that speed doesn't matter.  Why do I say this?  Every tool I put in my spindle has the same center.  Once I define where (0,0) is , the only thing left to zero is Z, and that's the easiest thing to zero - especially with my touch plate.  Even without the touch plate, bumping Z down .001 at a time until I touch a feeler gage or the top of the work, is easy with my hand controller.  So the TTS saves me the time of finding zero for all tools, since I can put every tool in a tool table in Mach3 with its length offset.  That figures to be a minute per tool change, but let's say it's five minutes.  So what?  

What else does the TTS buy me?  

The TTS is based around a special 3/4" R8 collet that is ground flat across its top.  Little Machine Shop has a description and picture here.   In that original post, Spumco had posted a link to eBay seller cncmachinetool as a source of parts that interchange with some TTS parts.  I went there and found some 3/4 R8 collets, so I thought I'd get one and see if I could cut or grind it flat so that it looked like the TTS "master".  This is what I got.  It's already ground flat:



I haven't put this in my spindle yet and tried to make any measurements of TIR, or even make sure it fits, but I really don't doubt that.  It seems just like the 3/4" collet that I got in a set when I bought the Grizz, except for being ground flat and not slightly domed toward the center.  I did try one of my 3/4 tools in it and the opening seems just right.  

It looks like it would work as a TTS collet to me, but I don't have one to compare to.  Does anyone with experience have any input on this? 

This is probably too rambling, but I'm a hobby guy and it just seems like it adds a lot of expense and complication, all of which serves only to get projects done a little faster.   Am I missing something?


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## DAT510 (Sep 24, 2017)

At my previous job we had the TTS system.  The only difference with the TTS collet was it sit flush or slightly below the face of the spindle.  This was so the TTS tool holders could index of the face of the spindle, giving a repeatable surface to index the tooling to.  

The TTS tooling also had a "cupped washer" to insure the tool holders indexed off the spindle surface and not the face of the collet.









So if this collet sits flush or slightly recessed on your machine, I would think you should be good to go.


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## MontanaAardvark (Sep 24, 2017)

DAT510 said:


> At my previous job we had the TTS system.  The only difference with the TTS collet was it sit flush or slightly below the face of the spindle.  This was so the TTS tool holders could index of the face of the spindle, giving a repeatable surface to index the tooling to.
> 
> The TTS tooling also had a "cupped washer" to insure the tool holders indexed off the spindle surface and not the face of the collet.
> 
> ...



Thanks!  That's very helpful.  

With a 3/4" end mill in there, the bottom of the collet sticks out of the spindle a LONG way.  About .075.  With nothing in the collet, it closes enough to retract all the way into the spindle and be recessed.  

Too bad.  I don't think the R8 collet fits in my lathe chuck.


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## DAT510 (Sep 24, 2017)

Maybe someone with the TTS system can measure the depth of the "cup", which would tell you if .075" stick out would fit?  Unfortunately I no longer have access to the system I used. Or I'd do it.


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## jbolt (Sep 24, 2017)

DAT510 said:


> Maybe someone with the TTS system can measure the depth of the "cup", which would tell you if .075" stick out would fit?  Unfortunately I no longer have access to the system I used. Or I'd do it.



All TTS holders measure .080" at the recess. With the recess I can use the TTS holders in my HD drill press with a standard R8 collet. 

I like the TTS system a lot when combined with a pneumatic draw bar. Works best with a power draw bar. I have to be careful when I use them in my drill press (manual draw bar) to not loosen the collet too much or the tool holder will drop out.

On my mill I have a 3-stack 4" pneumatic cylinder/ Belleville washer system which is barely enough to keep most end mills from pulling out under heavy cuts. A 4-stack would be perfect. 

Here is a pic of the tools I am using for a part I am making. I could have used a few more 1/4" drill chucks and ER-20 holders. Once setup and the tool tables entered its a breeze to run the part. I would go nuts having to use a touch plate on the mill. I use a touch plate on my router but I don't use nearly as many tools on that machine and there is no coolant to deal with.


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## RJSakowski (Sep 24, 2017)

I think TTS is one of the best things since sliced bread.  I have been using it for almost six years.  

I initially bought the system with my Tormach 770 but a soon bought a second 3/4" R8 collet and ground the face flat so I could use the TTS system on my mill/drill as well.  The one difference between the Tormach R8 collet and others is that it has a second keyway.  Presumably, this was done for balancing purposes since the PCNC770 is capable of 10K rpm.  The amount of grind is not critical as long as the TTS tool holders contact the spindle face first.  My mill/drill spindle face had no runout so I was good to go.  If there is runout, Tormach has a white paper which describes truing the face.

Aside from the convenience of rapid tool change, I like the improved accuracy and the ability to set up tooling away from the mill.  I use a digital dial indicator to set my machine z axis reference and zero my height gage to the indicator.  I can then replace a tool and measure its height to determine my tool offset.

 Another big advantage is the ability to conveniently run multiple parts without the need for multi-part fixturing. I can run the full tool sequence  on a part, pull it and replace it with another piece of stock,  and run the machining again.


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## benster (Sep 24, 2017)

I'm a big fan of it, especially for multi tool jobs. I keep my most commonly used tools as numbers 1 thru 6 and it makes program writing faster and less error prone since I don't have to make sure Linux CNC has the right tool numbers set each time.

Sent from my Nexus 5X using Tapatalk


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## MontanaAardvark (Sep 24, 2017)

jbolt said:


> All TTS holders measure .080" at the recess. With the recess I can use the TTS holders in my HD drill press with a standard R8 collet.



That makes it sound like the collets I have would work.  The amount the collet was sticking out was closer to .072 which would be fine with a .080 recess.  The animation from Tormach makes it look like the face of the collet is unimportant and what really matters is where that cupped washer, as DAT510 described it, contacts the spindle around the perimeter of the collet.  


It seems like something like the way you're set up is the way to go, Jay.  Not a tool holder sitting ready for every cutter in the tool box, but the 8 or 10 most used, including a few common drill bits and maybe a couple of center drills.  Maybe the exact tools in the holders change a little depending on the exact job being done.  

Because of my CNC Sherline, most of my cutters are standardized on 3/8" shanks, regardless of what the cutter is.  I have 1/8" and 1/2" cutters with a 3/8 shank.


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## MontanaAardvark (Sep 24, 2017)

?? Not sure how, but the very last sentence I had there went away.  The thing about the 3/8 shank tools being standard was followed by.  I could get tool holders and a handful of 3/8" collets


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## jbolt (Sep 24, 2017)

I generally use the TTS set screw tool holders for tools with Weldon flats and the ER collet holders for carbide tools or tools with larger than 1/2" shank. I'm finding you can't have enough drill chucks. I have (4) 1/4", (2) 3/8") and (2) 1/2" and I plan on getting two more of each. Same for the Er-20 collet holders. 

I don't use the keyless chucks as they don't grip as tight as a keyed chuck.

I have about a dozen tools that are permanently setup.


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## spumco (Sep 25, 2017)

MontanaAardvark said:


> What else does the TTS buy me?



Told you you'd get a better response than in a PM!

Here's my take on it...

I'm a clutz, and new at this thing - both CNC and machining in general.  I want to make stuff, not fiddle with the machine, and I also need to minimize the frequency with which I bugger something up. Every time I changed tools I had to re-set zero, introducing an opportunity to hose it up.  I even made a touch-probe arrangement (two plates) that works with an auto-zero macro.  Worked OK-ish, but chips would trigger the probe, it wasn't THAT accurate, and it was slow as hell coming all the way down from G53 Z0 to the table surface... every. single. tool change.  The macro is superb (UCCNC 2017 screen set), but piles of chips and flood coolant were my nemesis.

Having driven end mills in to both of my vises in the first couple of months after I got this thing going, I quickly decided that the TTS system with a PDB was the ticket.  Tightening the drawbar by hand got old about the second time I did it.

1. Tool changes are very, very fast.  Step on the foot switch, swap tools, let off, cycle start.  I'd be faster than most ATC's if I didn't sit there waiting for a minute so the juice drains off everything.
2. Everything is repeatable to the limits of my ability to measure and the machine's capability.
3. Runout is superb, once I faced the spindle nose dead flat.  Used a carbide lathe tool in the vise and took about 0.005" off the face with no collet in it.  I think runout is more a function of your bearings, spindle taper, and collet quality than the TTS system in general.  
3. Using a surface plate, a homemade collar/riser, and a height gauge I can set up my tools off the machine.  I didn't want a tool height dingus - as beautiful as the one you made is - on the table.  Frees up setup space and one less 'single-use' item to buy.
4. I bought a set of 10 ER-16 collets and 5 ER-32 collets as I mentioned a while ago.  I don't plan on having 100 of the things around - just those loaded with the tools I use most.  Jbolt is right - you can't have enough drill chucks, but LMS has a good deal on the TTS/Jacobs + chuck combos.
5. I also made 10 TTS-compatible set-screw holders for a couple bucks each for the small stuff (1/8"-1/4").  Easy to do using ground 41L30 3/4" stock for the shank and some 1-1/2" stock for the flange.  If I felt like carving one out of solid stock, I could have up to 1/2" set screw holders - but it bothers me turning 1-1/2" stock down to 3/4".
6. If I break a tool mid-job, I can install a new tool in the same or new holder very quickly off the machine using the height gauge.  Back in business, no fiddling with new off-sets mid-program.
7. Part Z0 is set using a blank TTS tool I made with a nice radius tip set to #96 in my table.  Once I'm ready to run, having found X/Y, I change to tool 96 and drop it down to the table until a ground pin just squeaks underneath the dummy tool.  Set Z to the pin OD and insert the first tool of the job.  If I'm feeling anxious (usually), I'll cycle through the tools and double-check the off-sets.  Everything has been within 1 or 2 tenths no matter how often I change tools.
8. Once I get a probe, it'll be mounted in a TTS holder with an appropriate off-set and then I can really go to town.  One touch X/Y/Z zeroing and all tools set up ready to rock.

Is it perfect?  Of course not.  There are valid concerns with pull-out, but those can be overcome in a few ways.  Since I was building my own air over hydraulic PDB, I just upped the drawbar torque over Tormach's recommended torque and designed the PDB to have more grunt.  No pull-out so far, even with chattering end mills and fly cutters.  In addition, Tormach's white paper on TTS pull-out is also very useful - but honestly the same thing can happen with a standard R8 collet.

As usual, I've rambled on a bit.  If you've got specific questions fire away.

-S


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## Boswell (Sep 25, 2017)

spumco said:


> Told you you'd get a better response than in a PM!
> 
> Here's my take on it...
> 
> ...



I don't use a TTS or any type of automatic tool changer. I would like to point out that there are two separate arguments for an Automatic tool Change system (TTS or otherwise).  
First is speed gained from not having to re-zero the Z each time you change.  I want to point out that this is only a function of the tool holder and not of the automatic release. It seems that you can get this value with little or no fabrication or changes to your mill, just buy the parts.
Second is the speed gained from having an automatic release/change system. This in itself has nothing to do with Z axis repeat-ability and is just a labor saving device. While many have added this to their mills it does seem like a "Project". 

Personally, while I have considered both, I still change tools with a wrench on the draw bar and I use a little z-Setter with an LED in it to set the z on each tool change.  Tool changes take between 60-120 seconds. If I were making money, I would probably invest in some additional time savings so I could re-coop the 120 seconds per tool change. As for preventing mistakes, I  have made a few due to errors during tool changes, but keeping my head in the game is part of the job/hobby and after much "practice" it does not happen very often.

Have fun with what ever you decide to do.


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## Groundhog (Sep 25, 2017)

I have some tools set up with the TTS system and it work good. Even better is a touch plate that measures each tool when a tool change is reached. A lot less expensive and for my hobby needs doesn't add hardly any time.
I use a probe for finding my work zeros and offsets. I have been using MachStdMill screens (a system really) overlay for Mach3 for a long time. It has screens and routines for all sorts of probing and tool length touch plates.


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## spumco (Sep 25, 2017)

Boswell said:


> I would like to point out that there are two separate arguments for an Automatic tool Change system (TTS or otherwise).



Both points are _entirely_ valid.  TTS makes things convenient and faster, but there's no fundamental improvement in the machine's ability to hold to a desired Z-height.  

I also like not having to change collets in addition to the tool during a tool change.  That  - to me - was messy and frustrating since I was using a dab of never-seize on the collet taper.  Everyone's tolerance for this is different.

Yes, the PDB was a bit of a project.  Not terrible, however, and not expensive - perhaps 3 weekends worth of time to CAD & fabricate.  Maybe $200 in parts and materials including the air cylinder and valves.  If you go with a 3-stage cylinder typical of standard PDB's, the cost goes up unless you score an Ebay deal.  I viewed this project as a learning experience - even if I got it wrong I wasn't out big bucks in materials.

For about $500 (PDB and TTS holders), I reduced the likelihood of a user-induced Z-height crash, and sped up tool changes dramatically.  TTS is not necessary - but it's _nice._

I used to own junky cars with no power windows or other goo-gaws.  Now that I have something with working A/C, heated seats, and a few other nice options I'm never going back.


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## MontanaAardvark (Sep 25, 2017)

spumco said:


> Yes, the PDB was a bit of a project.  Not terrible, however, and not expensive - perhaps 3 weekends worth of time to CAD & fabricate.  Maybe $200 in parts and materials including the air cylinder and valves.  If you go with a 3-stage cylinder typical of standard PDB's, the cost goes up unless you score an Ebay deal.  I viewed this project as a learning experience - even if I got it wrong I wasn't out big bucks in materials.



The only thing about the stock draw bar that annoys me is the square nut head on my Grizzly.  I think it's possible to get a long bolt with a hex head.  If not, I could make a replacement bolt.  After that, I'd leave the cordless drill there with a nut driver bit on it and a couple of button pushes changes the tool.  

There are a few designs that I've seen for a manually activated draw bar, but I think getting the tension balanced just right must be tricky.


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## jbolt (Sep 25, 2017)

spumco said:


> Told you you'd get a better response than in a PM!
> 
> Here's my take on it...
> 
> ...



I'd like to hear more about your air over hydraulic PDB?


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## spumco (Sep 25, 2017)

MontanaAardvark said:


> I think it's possible to get a long bolt with a hex head.



Make a new one.  Gr-9 (or 8)  7/16-20 all-thread from Crackmaster Carr, add a heavy hex nut & bearing washer and make a bushing with a couple 'thou clearance to center it in the spindle.  Polish the top of the bushing and washer bottom.  Pin or weld the nut to the all-thread - done.  7/16-20 Gr-9 is good up to about 40ft-lbs or so, which is double the recommended torque in the TTS white paper.



jbolt said:


> I'd like to hear more about your air over hydraulic PDB?



Short version - I shamelessly copied the concept from the manual lever drawbar spotted on the Tormach forum (CNCZone).  

I was about to go on about the design, but I'll start a new thread so we can stick with the TTS theme here.

-S


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## MontanaAardvark (Sep 26, 2017)

I've got to say I think you guys have convinced me I really don't want to switch over to the TTS, probably without intending to.  I think I'm with Boswell.  



Boswell said:


> Personally, while I have considered both, I still change tools with a wrench on the draw bar and I use a little z-Setter with an LED in it to set the z on each tool change. Tool changes take between 60-120 seconds. If I were making money, I would probably invest in some additional time savings so I could re-coop the 120 seconds per tool change. As for preventing mistakes, I have made a few due to errors during tool changes, but keeping my head in the game is part of the job/hobby and after much "practice" it does not happen very often.



I could see getting a few dedicated End Mill holders for my highest use cutters and leaving them ready, but the TTS system seems like it's going to cost me more than I want to spend for the convenience.   I ran the numbers on the Little Machine shop site, so I'm sure I could cut those costs some, but LMS tells me an ER-16-9 collet is $9.66 (based on being one of a set of six different sizes), and the TTS ER collet holder is $34.75.  That's $44.41 to hold *one* tool.  It looks like with China.com sources, I can get those down to about half that price.  I figure I'm looking at easily $250 to $300.


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## jbolt (Sep 26, 2017)

Well that's the thing about CNC. Are you making one part or several of the same part? On a one-off part doing manual tool changes there may not be much different from a time savings aspect when you consider tool setup and entering tools into the tool table. On multiple parts with multiple tools it pays off in time savings. For hobby work its really a personal preference. For me adding the pneumatic draw bar and TTS system has been part of the journey and learning experience.


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## RJSakowski (Sep 26, 2017)

One additional benefit of the TTS system is that it is usually not required to tap the drawbar to release the TTS tool holder.  The nature of the beast drawing the tool holder to the spindle face creates enough of a preload to disengage the tool holder when the drawbar tension is released.


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## MontanaAardvark (Sep 26, 2017)

jbolt said:


> Well that's the thing about CNC. Are you making one part or several of the same part? On a one-off part doing manual tool changes there may not be much different from a time savings aspect when you consider tool setup and entering tools into the tool table. On multiple parts with multiple tools it pays off in time savings. For hobby work its really a personal preference. For me adding the pneumatic draw bar and TTS system has been part of the journey and learning experience.



So far, I've never made the same thing twice.  That could be changing, but it's not like I can't decide to add the TTS later.  

I think that for my purposes, there are better uses of funds.  I'll be starting a thread about one of those either later tonight or in the morning.


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## spumco (Sep 26, 2017)

Consider making a few 3/4" shank set screw holders with TTS features.  As I said, they're cheap to make, and if you don't already have a couple of reamers you will probably need them later  - maybe for dowel pins.  I don't think a tiny bit of runout or vibration is a big concern if you've got a max spindle RPM <6k.  We aren't running 1/16" carbide end mills at 24k here.  At least I'm not...

Once you have a few, you can play with the TTS system for $50 in materials and zero modifications to your machine.  At the very least, you'll be running the same 3/4" collet for those holders, so it's easy to switch things out.

In the future, if you like it, you can shop for new tooling like insert mills or fly cutters that already have 3/4" shanks and just add a flange to them with some epoxy and maybe a C-clip.  You're still at zero machine mods and no 'specialized' accessories.

I should mention that if you don't have a lathe, you can do a TTS holder by mill-turning the stock and in the mill spindle.  Yet another thing I need to learn more about.


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