[native34]

Can anybody tell me if the holders in this video would work?
Http://www.youtube.com/watch?v=0JMMf-gOV4w

[SCzEngrgGroup]

You do realize that (absolutely horrible quality) video is 5 years old....

[native34]

Yeah i'm not interested in purchasing them. I'm just looking to convert my R8 spindle to Quick change with pull stud and was more interested to find out if the fact that half the R8 holder was missing, would be effective or would it cause issues. If not then I have to look at converting to some other type of spindle that allows pull stud. I had the Tormach tooling system but had problems with the tooling backing out under load causing Z repeatability issues among others.

[SCzEngrgGroup]

If you had problems with the toolholder pulling out, then your drawbar tension was inadequate. Period, end of story. Don't blame TTS. TTS is MORE than able to handle anything any benchtop machine can throw at it, IF the drawbar tension is adequate. Just yesterday was making some parts, using a 1/2" 2-flute HSS endmill. I was running 1.2" Depth, 0.05" stepover, at 80 IPM, WITH TTS, and had zero pull-out. I manufacture power drawbars for TTS, and I have never once had pull-out - My 1.5HP spindle will stall before the toolholder will move even a thou.

Regards,
Ray L.

[dracozny]

TTS backing out: I would suspect to be either spindle taper wear or lack of spring strength on the drawbar.

As far as the video:
The problem I see with this guy's invention is the lack of spline in the shortened collet. I just see it as a place to create friction and wear on the spindle when under load. Based on operation in the video it appears he is just using a impact driver to quickly screw and unscrew the collet from the drawbar. (Chance of cross threading?)

[rs4race]

I just got TTS er32 tool holders and have had problems with them pulling out using 3/8 endmills trying to do a finishing pass. The only thing I can think of is maybe the ID of the tormach collet being too big. I measure 0.762 for the tormach, and 0.752 with a standard r8 collet. I'm just waiting to hear back from tormach if this is my issue or not. I made sure the ID of the collet was clean, toolholder was clean, and drawbar with anti seize/grease. The same operation was done with the endmill directly in 3/8 R8 collet with no problems, and I didnt have any problems running smaller endmills in the TTS toolholders.

Maybe something like the ID could be an issue? Maybe the drawbar needs to be torqued better? I'm still using the 10mm wrench that came with the mill, havent had problems with anything else slipping in the collet.

[R.M.S.]

I just got TTS er32 tool holders and have had problems with them pulling out using 3/8 endmills trying to do a finishing pass. The only thing I can think of is maybe the ID of the tormach collet being too big. I measure 0.762 for the tormach, and 0.752 with a standard r8 collet. I'm just waiting to hear back from tormach if this is my issue or not. I made sure the ID of the collet was clean, toolholder was clean, and drawbar with anti seize/grease. The same operation was done with the endmill directly in 3/8 R8 collet with no problems, and I didnt have any problems running smaller endmills in the TTS toolholders.

Maybe something like the ID could be an issue? Maybe the drawbar needs to be torqued better? I'm still using the 10mm wrench that came with the mill, havent had problems with anything else slipping in the collet.

What machine . What size pneumatic cylinder , how many disc spring washers and what order are they stacked in. A picture is worth a 1000 words.
Did you set tension to the collet correctly.
I use TTS STYLE tools. I had a part fly out of my chuck once doing a profile .5 deep dont remember the ipm but it was fast. Never had pull out. I also run like 32 or 3500 lbs or pressure.
And again we use Chinese machines. Expect inferior QC. Maybe your spindle isnt grabbing like it should. I would blue it or the collet to see contact the spindle is providing to the collet. Then maybe blue a tool holder to the collet. That me though.
Theres a plausible reason ya just have to find it.

[rs4race]

I received an email back from Tormach's support and it sounds like the ID of my collet was out of spec. They said they were going to personally check a replacement was 0.752 before they send it and to make sure to let them know if I had any more problems. I don't know what the clamping range of a collet is, or what the spec is, I actually couldn't find it. 0.752 makes sense, 0.762 sounds really loose to me. Do any of you with Tormach TTS collet have a second to measure yours?

I am using with a G0704 with the stock drawbar. It looks like even a grade 2 7/16 bolt will produce 4000lb of force if torqued to 30 lb ft. I haven't used a TQ wrench but I'm sure I'm somewhere close to there. This could be a good experiment, I will have to break out the torque wrench.

[SCzEngrgGroup]

I received an email back from Tormach's support and it sounds like the ID of my collet was out of spec. They said they were going to personally check a replacement was 0.752 before they send it and to make sure to let them know if I had any more problems. I don't know what the clamping range of a collet is, or what the spec is, I actually couldn't find it. 0.752 makes sense, 0.762 sounds really loose to me. Do any of you with Tormach TTS collet have a second to measure yours?

I am using with a G0704 with the stock drawbar. It looks like even a grade 2 7/16 bolt will produce 4000lb of force if torqued to 30 lb ft. I haven't used a TQ wrench but I'm sure I'm somewhere close to there. This could be a good experiment, I will have to break out the torque wrench.

The measured dimension of an expandable collet is absolutely meaningless, since you have no way of knowing how much it is expanded or compressed when you measure it. What IS important is that you get good contact over most/all of the tool shank when the drawbar is properly tightened. This can be determined ONLY by "blueing" the tool colet, putting in the toolholder, and tightening the fdawbar, then releasing it and carefully removing the toolholder, ideally by spreading the collet so it does not contact the shank as you remove it. If the shank does not have an even coat of blueing on it, you have a problem.

Getting maximum retention on TTS requires a GOOD collet, and over 3000 pounds of drawbar tension, which equates to 25-30 ft-lbs of torque on the drawbar. If all is right, it doesn't even matter much if the tool shank has coolant on it - it will still hold on ANY cut any machine under 2-3HP machine can handle.

Regards,
Ray L.

[109jb]

Yeah i'm not interested in purchasing them. I'm just looking to convert my R8 spindle to Quick change with pull stud and was more interested to find out if the fact that half the R8 holder was missing, would be effective or would it cause issues. If not then I have to look at converting to some other type of spindle that allows pull stud. I had the Tormach tooling system but had problems with the tooling backing out under load causing Z repeatability issues among others.

Back to the actual question, look at the following video of Dave Decaussin's (one of the FADAL founders as I recall) mill. He uses a similar shortened R8 taper and pull stud, although he also has drive keys. Look at the 7:00 minute mark in the video. I would say that it works just fine.

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

[Larken]

Yeah i'm not interested in purchasing them. I'm just looking to convert my R8 spindle to Quick change with pull stud and was more interested to find out if the fact that half the R8 holder was missing, would be effective or would it cause issues. If not then I have to look at converting to some other type of spindle that allows pull stud. I had the Tormach tooling system but had problems with the tooling backing out under load causing Z repeatability issues among others.

Hey native34, i tried to send you a PM but your mailbox is full up.

[native34]

Larken i cleaned out my inbox if you want to resend the message