Input on 3/4 diameter tool in R8 Collet

[Bill_Barschdorf]

Hi guys, I have a large diameter reamer for my airsoft AR-15 project upper receiver, I will use for the bore. The tool has a 3” long x 3/4 shank end, the rest of the shaft is 7/8 diameter, and then a 1 1/32 cutting end. I will use the tool directly in the R8 collet per Roy’s input on the fourm. Thanks, Roy! To make the tool usable, I need to cut about 1” off the 3/4 end so it’s a bit shorter and so it will seat up to the bottom of the R8 collet. This is also necisary for tool and part clearance I need for this tool to work for my set up in the Micro Arc.

My question is, once I cut the 3/4 shaft end will it be necessary to install and use one of the 3/4 shank collars Tormach sells? or Could I just use a standard set screw shaft collar? Or will the 7/8 diameter edge of the tool itself be enough, its a 1/16 step. Hopefully, my question is clear. What im unsure about is if the tool needs to seat against the spindle nose itself WITH a collar or if the 1/16 edge seating on the bottom side of the R8 collet is just as good?

The picture showing the underside of the spindle nose shows the maximum amount the tool will go inside the R8 collet.

BTW: machine is a 1100M with ATC.

Hi guys, I have a large diameter reamer for my airsoft AR-15 project upper receiver I will use for the bore. The tool has a 3” long x 3/4 shank end, the rest of the shaft is 7/8 diameter, and then a 1 1/32 cutting end. I will use the tool directly in the R8 collet. I need to cut about 1” off the 3/4 end so it’s a bit shorter so it will seat up to the bottom nose of the R8 collet and give me the tool and part clearance I need for this tool to work for my set up in the Micro Arc.

My question is, once I cut it will it be necessary to install and use one of the 3/4 shank collets you guys sell? or Could I use a standard set screw shaft collar? Or will the 7/8 diameter edge be enough? Hopefully my question is clear. What im unsure about is if the tool needs to seat against the spindle nose or is that 7/8 edge seating on the bottom side of the R8 collet is ok.

BTW: machine is a 1100M with ATC.

Thanks

Do I need this

https://tormach.com/tts-collar-32432.html

OR can I use a standard shaft collar? I think this is fine and even better because it has the set screw and I can mount on the 7/8 shaft diamter and that is better for me and my set up clearances.

[Ian_Vivero]

The collar only serves as a locating feature for repeatable tool lenghts, so it’s arguably not needed at all, unless you are planning to run a bunch of parts and don’t want to have to check tool length for each one.

If you do need repeatable tool lengths, the TTS collar is needed as it has clearance built in to prevent it from contacting the R8 collet. It’s actually the edge of the collar contacting the spindle nose that provides the repeatable reference. Contact with the R8 could lead to inconsistencies.

[Bill_Barschdorf]

Gotcha, Thanks for the confirmation. Im going to go with the 7/8 set screw collar, IF I did go with the TTS collar, this would make the tool longer, and I’d have to turn it down to gain more shaft. The set screw collar is 1 1/2 so compatible with the spindle nose.

Thanks

[Ian_Vivero]

Just be sure you counterbore the side that will be in contact with the spindle, otherwise it’s more likely to hit the R8 collet and not seat the tool properly.

[Davie]

For the record. You don’t have to have a collar of you can get repeatable placement with that shoulder.

[Ian_Vivero]

I have (clearly) been under the impression that the design intent of the TTS system was to locate the tool against the spindle rather than allow the R8 collet face to have a potentially inconsistent impact on tool length. I don’t want to continue spreading false info so could you confirm that or let me know if I’m mistaken?

[Roy]

That’s the idea, but I think Davie meant if the shoulder allows for repeatable placement OP should be ok especially since this is a long reamer and precise length is unlikely to be critical.

[Bill_Barschdorf]

Good Point, thanks

[Bill_Barschdorf]

Well noted thanks Davie.

[Davie]

You’re not wrong here. The contact of the flange against the spindle nose improves repeatability, but for a one off tool that is being hands loaded the operator will seat the tool.