[SomeWhatLost]

I may have a little bracket I need to make soon that is fairly simple, and I could do it fairly easy without a 4th axis, just mill, rotate 90 and and re reference and mill some more, rotate 90 and and re reference and mill some more, etc...
and while that is very doable, two things keep jumping into my mind:

1. it seems like it may be a bunch easier with a 4th axis...
2. and it seems like a perfect excuse to get a 4th axis (ie I just need one now )

so I was looking at Tormach's offerings (ie I want easy plug and play... I don't want to cobble anything together...), so what are the pro's and con's of the 8in vs 6in? is there any particular reason to go with one over the other?
I was thinking of going with the 6" just because that is all I need right now, and I was kind of thinking I like my back (I am guessing the 6" is lighter/easier to get on the table)
but is that being a bit short sighted? it looks like there are more cool accessories for the 8"?

what about the tilt? how does that work? how do you tell sprut7 that it is tilted?


actually, how to you sprut with the 4th axis in the first place?

[SpruTormaCam]

I have the 8" and it is heavy. I use plywood on the bed during mounting/un-mounting. One issue with the 8" is the ATC clearance with long tools, ie drills. I've considered trimming the top as shown on this forum but I keep thinking about selling it and getting the tilting version (which takes care of the ATC clearance issue) and was worried it would affect the resale value. Of course then I'd have to spring for a gantry crane....

As far as SprutCam and the 4th axis, it actually works quite well (well, as well as SC works for anything... which is great if you know how to make it work).
I had a project where I made a bracket to hold the whole 4th axis at a 45 degree angle (see photo) and SprutCam handled it no problem. I set up the SprutCam as a 5-axis milling machine (B,C) and then set the B axis as 45 degrees. I have the "all post" version of SC but I'd think Tormach would include the post that handles the tilting 4th in the standard Tormach version.

Oh!, just remembered, Eric did a new video for SC8 which shows setting up the tilting 4th in the simulation function. Actually a very cool tutorial, makes me want to upgrade to SC8.
SprutCam 8 - Tormach PCNC 1100 Machine Definitions - YouTube

Mark...

[rlockwood]

Consider what the larger platter does to tool extension and tool holder interference with a 1" diameter part on centerline.. among other things

[shred]

The 8" is a lot heavier. Good and bad there (see: Rigidity & ATC clearance), but with a chuck on it unless you lift heavy things for fun, you'll be wanting a crane or lift-cart or similar power tools to move it on and off the table. Without a chuck mounted it's more manageable but less convenient.

[MooreLei]

Ok, I am looking to buy a 4th axis for my Tormach as well. I want to buy a used one that has been modified for maximum clearence for the ATC. I assume I can get a 6" or an 8" correct? I realize Tormach recommends the tilting 4th axis but I am not convinced I need it. What do you think? Any suggestions on where I can find someone ready to upgrade their 4th axis?

[wwendorf]

I may have a solution for you! Yes, this is a bit of a shameless plug, but, I had the same issue as I needed to use my 4th axis with the ATC.

My solution was to develop the 4th axis relocation kit. Currently it is only for the 6" table because I haven't gotten my hands on a 8" table yet in order to modify my kit to work with it, but, that being said, please take a look at my stepper relocation kit on my website.

Mandala Rose Works - 4th Axis Stepper Relocation Kit for Tormach 6 inch rotary table

I just couldn't justify machining away the top of my 4th axis, so I designed and created the stepper relocation kit. The nice thing about it is that you do not need to change ANY software settings. Just install the kit, mount the 4th axis on the right side of the table, and start doing 4th axis machining. I have used the kit for many hours with no problems or issues, and with perfect repeatability, hence why I am now posting this as ready for sale.

Wade

[shred]

I may have a solution for you! Yes, this is a bit of a shameless plug, but, I had the same issue as I needed to use my 4th axis with the ATC.

My solution was to develop the 4th axis relocation kit. Currently it is only for the 6" table because I haven't gotten my hands on a 8" table yet in order to modify my kit to work with it, but, that being said, please take a look at my stepper relocation kit on my website.

Wade

Cool, I've been waiting for somebody to do this (even thought about designing it myself for a while). Need a beta tester for the 8"?

[LRF]

I have been a life lonnnnnng buddy of Wade's and he won't even sell me one at cost. (defintion "life long" since fall 2012) LOL

I saw the 6" version the other night while at the user group meeting. Nicely done! Worth ever penny. Solves all kinds of issues and I mean all kinds. I have not yet used my 4th but as soon as I do I will purchase Wade's solution. You could figure out how to do it yourself but why???? Wade already did.

[menzzer37]

Not to threadjack, but while on this topic, how are you guys clamping the 4th down to maximize table space? I keep mine at the far left edge, but need to get a clamp on the rear size for rigidity. Any ideas?

[wwendorf]

I use step clamps from a clamp kit like this:
Clamping Kits & Components | Step Block & Clamping Kits | JET® 52-pc Clamping Kit w/ Tray for 1/2" T-slot | B231047 - GlobalIndustrial.com

I just angle one so that the t-nut just locks onto the t-slot 1 slot over from center, if that makes any sense whatsoever.

I've attached a pic below.

Wade

[Don Clement]

I was just using my Tormach 8"RT for drilling and tapping three 10-32 holes in an 1-1/16" diameter part held in a 5C collet shown in the photo below. The 8" RT is heavy so I built a shelf at the same height as the mill table to store the RT and Kurt D688 vise. When changing between the 8" RT and 6" Kurt vise I only need to slightly lift either the RT or Vise and turn around to place the items on the shelf. No bending needed. The second photo shows clamp down using the smallest TECO clamps with T-nuts. Could even slant the clamps as mentioned earlier and gain more room. I didn't bother with SprutCAM for simple indexing, just wrote some G-code. I always approach from the same direction when indexing the RT to eliminate backlash in the worm. Does SprutCAM do this?

Don

[Scott_M]

When I have to squeak out every last inch I put a bar in the end trough and set my step block on that. good for another inch.



Scott

[MooreLei]

Scott, that is a great idea for gaining more clamp space. All I need to do now is find someone who is willing to sell me their 4th axis! I also like Wade's modification to mount the stepper behind the rotary table.

[menzzer37]

Scott, Genius! Just what I was looking for! Thanks!

[Scott_M]

Thanks guys

Just a word of caution. Your t-slot nut will be very near the end, don't go gorilla on it. I use 1 in the back and snug it down and 2 in the front that I put a little more pressure on.

Scott

[SomeWhatLost]

just a quick update... I ended up getting the 8" non-tilt, all hooked up, and it seems to work just fine...

sprut on the other hand is really pissing me off...

every thing is fine... for a while... then all of a sudden, it starts complaining about the faces not being sewn..
they were sewn just a minute ago, why does it believe they have somehow magically become un-sewn? the model hasn't change, it hasn't even been touched... I just added a waterline op, did the reset all to build from scratch, and somehow it came un-sewn?!!?!?
and now apparently it wont re-sew...
it claims it sew'ed just fine...

stupid sprut (chair)

[tbaker2500]

It's amazing how similar us Sprut users sound…
Just make sure not to save AFTER Sprut starts crashing. I've had it corrupt my file many times.
I did learn that it keeps the previous version with a different extension. Very needed.