[jflongo]

Hello:
I'm designing a couple fixture plates larger than the PCNC 1100 XY travel (18"x9.5") specifications but would like to do a clean up pass around the perimeter as one of the operations to square up the fixture. Is there a preferred method for machining a piece of stock larger than the XY travel specs?

I have an idea to install a pair of locator pins in each quadrant of the fixture, then clamp a piece of 0.5" thick sacrificial aluminum plate to the table and insert two steel bushings with the same spacing as the locating pins. Then run my operations in each quadrant of the fixture plate. Is this a good method or is there a better way to solve this problem?

Thanks and my apologies if this topic has been discussed before.
Regards

Joe Longo
Iowa City, IA

[SCzEngrgGroup]

Why clamp anything to the table? Align pins in the fixture to the T-slots. They should, in theory, be perfectly parallel to the X axis. Then either use a T-nut to make a stop for the X axis position, or just re-zero the X axis each time you re-position the plate.

Regards,
Ray L.

[mioduz]

FYI you can adjust your limit switches and gain about an inch of travel typically. My fixtures are the same size and I can clean off all the sides with a 3/8 end mill.

Sent from my SM-G900V using Tapatalk

[jflongo]

Ray, thanks for your response. I like your idea of aligning fixture pins to T-slots. I thought a sacrificial plate under the fixture plate would be in order since i'm drilling and drilling/tapping through the fixture plate...and i want to avoid drilling into the table.
Regards
Joe

[jflongo]

Thanks for your input mioduz. Good to know that the limit switches are adjustable.
Regards
Joe

[jflongo]

Thanks for your input mioduz. Good to know that the limit switches are adjustable.
Regards
Joe

[Hirudin]

Are the T-slots on Tormach machines suppose to be parallel to the X-axis travel? I seem to recall a couple people saying there is *one* slot that is ground parallel with the X-axis. I would not trust the other slots. Though not a Tormach, the slots on my Torus Pro table are not even close to being accurate; I'm pretty sure a couple of them deviate by a whole mm (~40 thousandths).

Regarding squaring the sides, for the front and back I would face it with it sticking up vertically. Depending on the thickness of the stock, the type and diameter of the tool, and cutting depth/width, you may need to reinforce the stock material in some way (very tall jaws, thick pieces of metal sandwiching the stock, etc.). Once the front and back are finished and parallel I'd clamp it down in a vise (horizontally) and finish the two remaining sides, one at a time, with the side of an end mill.

By "face it with it sticking up vertically" I mean face it using a technique similar to that discussed in this video starting at 16:59.
MIT TechTV – Machine Shop 5

[Don Clement]

Are the T-slots on Tormach machines suppose to be parallel to the X-axis travel? I seem to recall a couple people saying there is *one* slot that is ground parallel with the X-axis. I would not trust the other slots. Though not a Tormach, the slots on my Torus Pro table are not even close to being accurate; I'm pretty sure a couple of them deviate by a whole mm (~40 thousandths).

I have never seen a Novocain, however the center T-slot on my Tormach is parallel with the X-axis within "tenths" (0.0001"). I use this accuracy of the center T-slot on my Tormach PCNC 1100 with Kurt T-slot keys to mount fixtures and my Kurt vise without need for a dialing-in using a TDI. BTW Not an expectation but from actual experience in using my Tormach.

Don C.

[SCzEngrgGroup]

Are the T-slots on Tormach machines suppose to be parallel to the X-axis travel? I seem to recall a couple people saying there is *one* slot that is ground parallel with the X-axis. I would not trust the other slots. Though not a Tormach, the slots on my Torus Pro table are not even close to being accurate; I'm pretty sure a couple of them deviate by a whole mm (~40 thousandths).[/url]

I don't know that I've ever seen any machine where the slots are actually ground - just milled. But it should be done on the same fixture where the dovetails are cut/ground. The ones on my Pro are straight, and I use them for alignment all the time. I would expect the Tormach to be the same.

Regards,
Ray L.

[mountaindew]

I have never seen a Novocain, however the center T-slot on my Tormach is parallel with the X-axis within "tenths" (0.0001"). I use this accuracy of the center T-slot on my Tormach PCNC 1100 with Kurt T-slot keys to mount fixtures and my Kurt vise without need for a dialing-in using a TDI. BTW Not an expectation but from actual experience in using my Tormach.

Don C.

As Don advised me over a year ago and is also detailed in the tormach manual the center t-slot is precision aligned and made for quick vise alignment using vise t-slot keys.
This feature is very nice for changing setups and not needing to worry about vise alignment much! just set and go!.
Well designed features like this on tormach makes the machine so nice to use . I have no idea if other mills have this, all I can say is if they don't I would not even consider buying one.

md

[CadRhino]

Maybe your machine is a little different than mine but I do not get perfect alignment with vise keys in my Tormach vises so I don't use them. They are close but not close enough for my haimer to accept.

As Don advised me over a year ago and is also detailed in the tormach manual the center t-slot is precision aligned and made for quick vise alignment using vise t-slot keys.
This feature is very nice for changing setups and not needing to worry about vise alignment much! just set and go!.
Well designed features like this on tormach makes the machine so nice to use . I have no idea if other mills have this, all I can say is if they don't I would not even consider buying one.

md

[Don Clement]

Maybe your machine is a little different than mine but I do not get perfect alignment with vise keys in my Tormach vises so I don't use them. They are close but not close enough for my haimer to accept.

Check for burrs or dings in the center slot.On my series I Tormach 1100 the precision made center slot is very well aligned to the x-axis. I use an Interapid TDI to periodically check my Kurt vise with vise keys and other fixtures with vise keys and have found excellent alignment with the X-axis to vise and fixtures. e.g. the 6" fixed jaw on the Kurt vise deviates less than 0.0001" As md said:" just just set and go!". A trick I use when mounting the vise and fixtures is to push the vise or fixture forward so the T-slot keys make good contact the center T-slot

Don C.

[SCzEngrgGroup]

Maybe your machine is a little different than mine but I do not get perfect alignment with vise keys in my Tormach vises so I don't use them. They are close but not close enough for my haimer to accept.

But is it the slot or the vise that is off? IME, the keys on vises, even on high-end vises like my Glacern, are rarely truly precisely aligned, and need to be fine-tuned for best alignment. The slots, even on many low-end machines, are generally pretty well-aligned.

Regards,
Ray L.

[Don Clement]

But is it the slot or the vise that is off? IME, the keys on vises, even on high-end vises like my Glacern, are rarely truly precisely aligned, and need to be fine-tuned for best alignment. The slots, even on many low-end machines, are generally pretty well-aligned.

BUMP Didn't have to fine-tune my Tormach or Kurt vise to get excellent repeatable alignment with the Tormach precision made center T-slot. I built the base plate on fixtures using Kurt vise keys but even these have stayed aligned for over 5 years negating the need for constant alignment using the precision made T-slot on my Tormach. BTW I do clean the Tormach mill table, center T-slot, Kurt vise, fixture mounting plates and all T-slot keys when mounting and dismounting with WD40. I also run my hand along the mating surfaces to check for dirt, burrs,or contamination before mounting vises, fixtures, or RT on the Tormach mill table.

Don C.

Don C.

[nitewatchman]

But is it the slot or the vise that is off? IME, the keys on vises, even on high-end vises like my Glacern, are rarely truly precisely aligned, and need to be fine-tuned for best alignment. The slots, even on many low-end machines, are generally pretty well-aligned.

Regards,
Ray L.

The slots tend to be well aligned because of the method most manufacturers us to final machine the tables.

The center slot in the table is usually machined first using a slotting type milling cutter which produces and straight accurate slot. The table is then turned upside down on the way grinder and fixtured to the center slot. This produces ways that are very true to the slot.

For me the accuracy problems are usually in the keys or in the slop between the width of the keys and the width of the slot. As Don said you must also do your part and keep the table and slot "stoned" to remove debris, corrosion and burrs.

[CadRhino]

That is good to hear Don
I will give them another chance but the key to slot fit is so tight with my setup that there is absolutely no adjustment or wiggle room (which is good is the were perfectly parallel with the X).
Since I have 2machinist vises to alignI kind of gave up.

Check for burrs or dings in the center slot.On my series I Tormach 1100 the precision made center slot is very well aligned to the x-axis. I use an Interapid TDI to periodically check my Kurt vise with vise keys and other fixtures with vise keys and have found excellent alignment with the X-axis to vise and fixtures. e.g. the 6" fixed jaw on the Kurt vise deviates less than 0.0001" As md said:" just just set and go!". A trick I use when mounting the vise and fixtures is to push the vise or fixture forward so the T-slot keys make good contact the center T-slot

Don C.

[LeeWay]

Why can't you machine the slot a little truer? You only need to do one side. That would loosen it up a little and give the needed adjustment. I know on some mills, the spindle it too high to reach the table with anything but a very long expensive tool. I already use tools though that would reach my table and hone the slot. My slots are smaller than typical size, so my Vise inserts are too large. Thankfully the vise never comes off the table.

[ErnieD]

Hi,

Just throwing this out here; when I got my Tormach vise the slot in the bottom of the vise was not true to the vise jaws. So I took a piece of stock that would fit snugly in the center tee slot, turned the vise upside down, clamped it to the stock in the tee slot ( which puts the vise jaws in alignment with the center tee slot) , clamped the vise down and re milled the slot in the vise, then made a set of step keys and milled the step in the keys while bolted to the vise. Everything is in alignment.

Ernie

[mountaindew]

Hi,

Just throwing this out here; when I got my Tormach vise the slot in the bottom of the vise was not true to the vise jaws. So I took a piece of stock that would fit snugly in the center tee slot, turned the vise upside down, clamped it to the stock in the tee slot ( which puts the vise jaws in alignment with the center tee slot) , clamped the vise down and re milled the slot in the vise, then made a set of step keys and milled the step in the keys while bolted to the vise. Everything is in alignment.

Ernie

I wondered about this also! And if this could be part of cadrhino's problem.
I disassemble my tormach 5" vise every couple months to clean and wondered the 1st time if it was going to align with precision when reassembled. I found no problems using precision ground jaws, I did notice some variance using monster soft jaws, still not enough to get excited about but figured I better keep an eye on those. Also I noticed there are a couple spots on my table the vise aligns with more precision "about 2" off center" then say right in center of table!
just observations I made this last year and things I look for when doing setups.
md

[popspipes]

On my 6" vise, the keys didnt fit the table so I machined the back side of them off to fit the table slots plus a few thousandths so that it coud be moved slightly, then align it with an indicator in the spindle using a piece of known true bar stock in the vise.

I rarely ever remove the vise as I do mainly small parts and alignment is critical for my fixtures etc.The front edge of the keys after machining were pretty close though, within a couple of tenths.