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  1. #1
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    BT30 or R8/TTS?

    Hi Folks

    Big decisions ahead for new Tormach buyers...BT30 or R8/TTS? And is retrofitting a BT30 spindle a good idea?

    Please post your thoughts in this thread.

    I start the ball rolling with this video:

    Cheers Cliff

    https://www.youtube.com/watch?v=m9rMbSLyAvM&t=46s

  2. #2
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    Re: BT30 or R8/TTS?

    Depends what you plan to do with it.... For an ATC, BT30 (or ANY real machine taper - BT/ISO/etc.) is preferable to R8. But, of course, your only choice for an off-the-shelf ATC is the Tormach one, which REQUIRES R8/TTS. For manual use, it doesn't make one bit of difference which you have, which one small exception - The Tormach PDB does not reliably retain TTS toolholders under maximum-effort cuts (MRR >= ~3.0). I dont know of Tormach has a version of their PDB that supports BT30, but if you plan to push the machine to its limits, and/or work with hard materials, AND use the Tormach PDB, I would get confirmation that the pullout problem does not exist with that combination. If you're not using a PDB, then, again, there is no reason to prefer one over the other. R8/TTS toolholders are generally cheaper, and more readily available, than BT30.

    So, to answer your question as to which is better, R8 or BT30: It depends...

    You absolutely can swap out the entire spindle cartridge to change from R8 to BT30. That has been an available option for many years, and it is a very simple swap.

    Regards,
    Ray L.

  3. #3
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    Re: BT30 or R8/TTS?

    I went R8/TTS. I'm wating for Tormach's BT30 support to mature.

  4. #4
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by SCzEngrgGroup View Post
    Depends what you plan to do with it.... For an ATC, BT30 (or ANY real machine taper - BT/ISO/etc.) is preferable to R8. But, of course, your only choice for an off-the-shelf ATC is the Tormach one, which REQUIRES R8/TTS. For manual use, it doesn't make one bit of difference which you have, which one small exception - The Tormach PDB does not reliably retain TTS toolholders under maximum-effort cuts (MRR >= ~3.0). I dont know of Tormach has a version of their PDB that supports BT30, but if you plan to push the machine to its limits, and/or work with hard materials, AND use the Tormach PDB, I would get confirmation that the pullout problem does not exist with that combination. If you're not using a PDB, then, again, there is no reason to prefer one over the other. R8/TTS toolholders are generally cheaper, and more readily available, than BT30.

    So, to answer your question as to which is better, R8 or BT30: It depends...

    You absolutely can swap out the entire spindle cartridge to change from R8 to BT30. That has been an available option for many years, and it is a very simple swap.

    Regards,
    Ray L.
    Some good points there Ray - Thanks, Cliff

  5. #5
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by burdickjp View Post
    I went R8/TTS. I'm wating for Tormach's BT30 support to mature.
    Hi - I am guessing you have got manual toolchanging? Cliff

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    Re: BT30 or R8/TTS?

    I must be missing something in this conversation. A taper system I thought has a pull-stud and locking dogs on side of holder. The pull stud eliminates holder pullout and the locking dogs on side ensure no rotary slip.
    On paper the taper system would have none of the problems a TTS system has for pullout or slip. Making the pdb system less of a clamp force and more of a lock force. As for pdb and tool changer, I don't see why Tormach would offer a new tool system without those options ready to go.

  7. #7
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by mountaindew View Post
    I must be missing something in this conversation. A taper system I thought has a pull-stud and locking dogs on side of holder. The pull stud eliminates holder pullout and the locking dogs on side ensure no rotary slip.
    On paper the taper system would have none of the problems a TTS system has for pullout or slip. Making the pdb system less of a clamp force and more of a lock force. As for pdb and tool changer, I don't see why Tormach would offer a new tool system without those options ready to go.
    The pull-stud keeps the taper loaded, typically with Belleville springs, exactly like TTS. Don't provide enough tension on the pull-stud, and the toolholder can pull down. Required tension is less than for TTS (~1300# for 30-taper). With manual use, and proper tightening of the drawbar, pull-out will not be an issue. If a PDB is used, and it provides enough tension, pull-out will not be an issue. The Tormach PDB CANNOT be used with BT30, for several reasons.

    Regards,
    Ray L.

  8. #8
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by keen View Post
    Hi - I am guessing you have got manual toolchanging? Cliff
    For the time being, yes, manual tool changing. I've got a 770M. It's my understanding that with the MX machines Tormach intends on doing an ATC with the BT30 spindle and that I would be able to upgrade to the BT30 spindle and the BT30 ATC when they become available. I'm not yet sold on BT30. I'm reserving judgement for when I can sit down with concrete costs for conversion including new tool holders and buying the available BT30 spindle for my manual mill as well.

  9. #9
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by burdickjp View Post
    For the time being, yes, manual tool changing. I've got a 770M. It's my understanding that with the MX machines Tormach intends on doing an ATC with the BT30 spindle and that I would be able to upgrade to the BT30 spindle and the BT30 ATC when they become available. I'm not yet sold on BT30. I'm reserving judgement for when I can sit down with concrete costs for conversion including new tool holders and buying the available BT30 spindle for my manual mill as well.
    I'm in the same boat. I've had an 1100/3 for four years and recently purchased two 1100/M's. I got one of the new machines with ATC and one without in case I wanted to upgrade to the BT30. However, when I sit down and see how much I have invested in tool holders I cringe at the thought of having to replace all of those. For the work I do, I've not had the TTS pullout issues (I also do PM on the collet system about every three months and replace the R8 once a year). The real selling point for me will be if they have the rigid tapping side dialed in. Otherwise, I'll just keep rocking with my TTS setup.

    Saw the 1100MX at FabTech yesterday. Was surprised that all their other machines were cutting away on actual products but the MX was just doing movements..... I think they are still a ways off on release.....
    The Body Armor Dude - Andrew

  10. #10
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by smokediver576 View Post
    I also do PM on the collet system about every three months and replace the R8 once a year
    I'm wonder how much lack of preventative maintenance or poor operating practice has to do with pullout problems.

  11. #11
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by burdickjp View Post
    I'm wonder how much lack of preventative maintenance or poor operating practice has to do with pullout problems.
    "+1 on poor operating practice" Its easy to get one to move. All you have to do is ignore tool stick-out, bad cutter, crappy fixture …… run some heavy cuts and before you know it chatter, noise, the dog runs out of the shop and the tool and or the part starts moving.

  12. #12
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    Re: BT30 or R8/TTS?

    Hi Ray. Your comment "The Tormach PDB CANNOT be used with BT30, for several reasons."

    I imagine that is because a pull stud PDB needs more travel to operate, and maybe a bit less force, so a redesign is needed. Please add any info you have on this eg more comp air consumption, design of cylinder, etc.

    Cliff

  13. #13
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by keen View Post
    Hi Ray. Your comment "The Tormach PDB CANNOT be used with BT30, for several reasons."

    I imagine that is because a pull stud PDB needs more travel to operate, and maybe a bit less force, so a redesign is needed. Please add any info you have on this eg more comp air consumption, design of cylinder, etc.

    Cliff
    Correct. The Tormach PDB, and Belleville stack, allows only about 0.05-0.075" of travel - barely enough to release a TTS toolholder. Pullstuds typically require something like 1/4" travel to release the pullstud, and that much travel requires a looooooong stack of Bellevilles - typically on the order of 100-150 of them. They need to be constrained, to prevent "whipping" when the spindle is spinning, so they are typically mounted inside the spindle, which means a MUCH larger thru-bore, and an internal step just above the gripper to retain the bottom end of the stack. The gripper requires a machined recess to house it, center it, and close it. So, unless the spindle is specifically designed to be used with a gripper, pull-studs, Belleville stack and a PDB, you won't be able to do it, without MAJOR re-machining of the spindle itself. I'd be surprised if the Tormach BT30 spindle has any of those features, since it appears to me it is intended to be used with a simple manual drawbar.

    BTW - Using an ATC with BT30 would also normally require spindle indexing, to align the toolholder to the drive dogs. However, with a 1.5HP spindle, the drive dogs are not, technically, required. With proper drawbar tension, the taper alone is enough to prevent the toolholder from slipping on the taper.

    Regards,
    Ray L.

  14. #14
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by SCzEngrgGroup View Post
    I'd be surprised if the Tormach BT30 spindle has any of those features, since it appears to me it is intended to be used with a simple manual drawbar.
    I believe the MX machines are getting a different BT30 spindle provisioned for a PDB and ATC.

  15. #15
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    Re: BT30 or R8/TTS?

    Thanks Ray - Good information. Current BT30 spindles and PDB will not suit.

    Yes I wondered if dogs and spindle indexing is really needed - this must be a tempting cost saving option...

    Do you have any thoughts on comp air with that much more travel, will a comp air source upgrade be also needed?

    Cliff

  16. #16
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    Re: BT30 or R8/TTS?

    Quote Originally Posted by keen View Post
    Thanks Ray - Good information. Current BT30 spindles and PDB will not suit.

    Yes I wondered if dogs and spindle indexing is really needed - this must be a tempting cost saving option...

    Do you have any thoughts on comp air with that much more travel, will a comp air source upgrade be also needed?

    Cliff
    With BT30 any compressor will do, and any combination of large and/or multi-state air cylinder, or mechanical linkage, or hydraulic intensifier can easily generate the force and travel required. TTS is the difficult one, since it requires MUCH higher drawbar tension for decent retention. Commercial VMCs typically use 40 or 50 taper spindles, which require as much as 3-4000 pounds of drawbar tension. They nearly all use hydraulic intensifiers.

    Regards,
    Ray L.

  17. #17
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    Re: BT30 or R8/TTS?

    Hi Folks

    Here is part 2.

    Cheers Cliff


    https://www.youtube.com/watch?v=ij-1Q8ayQtk&t=1181s

  18. #18
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    Re: BT30 or R8/TTS?

    Hi Folks

    This video, Part 3, includes an earthquake... is mainly discussing TTS, TTS accuracy, and how to get the best out of it. The final part 4 will be a wrap up of the series.

    Cheers Cliff

    https://www.youtube.com/watch?v=AlWTDUvF_ZI&t=330s

  19. #19
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    Re: BT30 or R8/TTS?

    Bt 30 with spindle orientation would sure be nice for using a boring bar so you can back away from the wall before retract and not score the wall of the part.

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    Re: BT30 or R8/TTS?

    Quote Originally Posted by AUSTINMACHINING View Post
    Bt 30 with spindle orientation would sure be nice for using a boring bar so you can back away from the wall before retract and not score the wall of the part.
    Thats an application for spindle orientation I had not thought of - Cheers Cliff

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