Can the Sieg X2 Mill make T-Slots?

[MetalMuncher]

I can't seem to find the answer here by searching, so I thought I would ask if any of you using a typical mini-mill like my Homier Speedway model has ever milled T-Slots with it?

I made a tool plate table for the top of my 3" Grizzly rotary table. It is 6061 aluminum .800 thick and 6" in diameter. I would like to mill T-slots in it so I can mount work pieces using them. I have been using this mill for 9 years, have made lots of modifications, including a 3 axis DRO-350, and most recently the stiffening  bolster plate on the back of the column to make it much stronger. So I think the hardware is up to the task. But is the stock motor strong enough?

From what I have read, the typical way to do it is to mill a slot for the center of the T-Slot and then use a T-Slot cutter to make the "head" grooves, but this has to be done in a single pass. Seems like quite a cut to be making. However, since adding the stiffening plate, I found with a 3/8" end mill I can take 0.1" deep cuts in aluminum without worry. So perhaps this would be possible? But I also saw the 1" end mill I have stall the motor (I have the LMS belt drive conversion) when I tried to do a 0.050" deep pass across aluminum with it. I know the mill is rated at 1/2" end mill max, but I've done a lot of things on this mill that I would say go above and beyond its intended function.

I am not sure what size T slots I want to use, but making them the same dimensions as the mill table would allow me to use the hold down kit I have for it on the rotary table too. However, I have seen some smaller scale hold down kits, so if need be I could use smaller slots.

[John Rudd]

 Short answer is yes....
I have a mini mill and have made Tee slots using an appropriate cutter....
Just dont go trying to make something that the machine can't handle...

[MetalMuncher]

Short answer is yes....
I have a mini mill and have made Tee slots using an appropriate cutter....
Just dont go trying to make something that the machine can't handle...

So, short story answer is "yes, maybe no". 

Thanks. I ordered a cutter. I'll report back after I use it. For me, being completely self taught while using a professional textbook, websites, and forums as guidelines, over these 10 years with my mini-lathe and almost 10 with the mini-mill I have become accustomed to their sound in operation. They tell me when I try to push them toward what I believe is the limit of their capacity. But understand when I read some accounts of vibrations being so severe that parts and knobs fall off of some people's machines, I would never operate that way. The quieter the better when it comes to my tools. One of my favorite sounds is the quiet distant-sounding thump of using my R8 fly cutter, which always reminds me of a helicopter passing by at a distance.

With the 0.050" depth attempt I mentioned above that stalled the motor, thinking about it I realized that all the "chart" parameters for speeds and feeds on a 1" end mill would be an amplified load compared to a 1/2" or 3/8" end mill. I knew to reduce the speed in half. But this small motor lacks low end torque, so that contributed to the stall. Actually, it did cut OK for most of the pass along a 3" piece, but the stall came at the end when it was exiting. Much like how a drill bit will do the same thing at the bottom of a hole sometimes. Probably a variance in feed rate on the table's speed controller, as the forward force got lessened when the leading edge of the end mill broke through. I use the X axis power feed sold by MicroMark and LMS, and it's stability trails off at really slow speeds. Simple solution - take a lighter cut. At 0.030” it worked very smoothly. 

I will make this attempt at cutting T slots with the utmost caution, and practice on a scrap piece first. And I think it would be prudent not to try it while the tool plate disc I made is mounted on the 3 inch table, but instead clamp the disc on blocks to the mill table itself.

Thanks again for your reply.

[John Rudd]

One thing you need to remember is that if you go for a practise cut, the that's 'one life' less for the cutter.....

As for cutting speed, use tables as a guide and use the sound of the machine more....that is because they are just that, a guide...as you said from your own experience you know the sound of your  machines and know when they are labouring...
Cutting alloy....use plenty of coolant, paraffin is cheap enough and if it starts to smoke too much reduce the feed rate...
GL...

[chipenter]

I have an Sieg X1\micro mill and have cut t slots in cast iron , the cutter balences it self a cuts smoothly with a very slow feed ,

[MetalMuncher]

One thing you need to remember is that if you go for a practise cut, the that's 'one life' less for the cutter.....

As for cutting speed, use tables as a guide and use the sound of the machine more....that is because they are just that, a guide...as you said from your own experience you know the sound of your  machines and know when they are labouring...
Cutting alloy....use plenty of coolant, paraffin is cheap enough and if it starts to smoke too much reduce the feed rate...
GL...

Actually I did think about reducing the cutter life just this morning. So I guess I'll make it a short test, just to acclimate myself to how it works.

Paraffin......Interesting. I use it on my metal bandsaw. How do you apply it on a milling job? It does help the saw, and may be less messy than oils on the spinning tools. Do you just rub some on? For the saw I touch a block of it to the blade (very carefully) while it is cutting - using the opposite end from what I am holding of course.   But to rubs some on for a T-Slot job I am thinking cut a bit, reverse and withdraw the tool, add some paraffin, advance back into the cut and go some more. Then repeat. Like drilling aluminum on the lathe.

I'd like to start by milling the initial slots tonight. The T-Slot cutter comes tomorrow. It is a 1/2" cutter (I could not find 7/16" on Amazon). But I think it will still use the same T nuts as my mill table, no? So do I mill the slots the same width as the "slot tops" on the mill table? And I think I read somewhere while researching T slots that they did not mill the full depth with the end mill. They stayed up like .020" on the Z axis, so when they ran the T-Slot cutter it is actually cutting on all surfaces of the "T" as it goes across. Is that the right way to do it?

[ieezitin]

MUNCHER.

Milling with a T-Slotter in one pass to mill the head slot does not have to happen, it can be relieved of a 100% milling cut by raising the cutter from the bottom plane that’s been left by the slot cutter. Its using the same principle as milling with a dovetail cutter.

Instead of bottoming your slotter on the milled plane raise it up by .005, this will give bottom relief, you need to pay attention to the dimensions that you require and purchase a thinner slotter. The clearance in the slot head cut probably will allow for a standard slotter available.

All quality machined dovetails have a slight flat in the female slot for the very same reason of relief. Its remarkable the difference it makes.
Enjoy your project.

Anthony.

[MetalMuncher]

I have an Sieg X1\micro mill and have cut t slots in cast iron , the cutter balances it self a cuts smoothly with a very slow feed ,

OK, True Confessions time for me. I used the term "X2" in the title in a generic way. Actually, I do not know if my mill is an X1 or X2. How can I tell? It is a Homier Tools Speedway # 3947, which I know was made by Sieg. I bought it April 17, 2004. Sorry if I mis-stated something in its pedigree.

Thanks for the reply. Sounds like I'll be able to do this without a problem.

[Chuck in E. TN]

MetalMuncher,
I think the paraffin John Rudd is referring to is what we call kerosene, not canning wax. BTW, pics of X1 and X2 attached.
Chuck

[MetalMuncher]

MUNCHER.

Milling with a T-Slotter in one pass to mill the head slot does not have to happen, it can be relieved of a 100% milling cut by raising the cutter from the bottom plane that’s been left by the slot cutter. Its using the same principle as milling with a dovetail cutter.

Instead of bottoming your slotter on the milled plane raise it up by .005, this will give bottom relief, you need to pay attention to the dimensions that you require and purchase a thinner slotter. The clearance in the slot head cut probably will allow for a standard slotter available.

All quality machined dovetails have a slight flat in the female slot for the very same reason of relief. Its remarkable the difference it makes.
Enjoy your project.

Anthony.

Aha! I was thinking this might be so, because technically a T-Nut has no "bearing" (pun intended) on the bottom of the slot at all. Those in the bottom of the tables on our Sieg mills are not even very flat (which unfortunately contributes to cleaning difficulties). And for that same reason, I don't see why a bit of a taller dimension on the sides of the head of the "T" also would not hamper usage of the slot, would it?

When you mentioned getting a smaller cutter, I thought you might be heading toward cutting one side of the slot at a time. I know I have seen this done using a Gingery Shaper (I knew someone who did it) to cut the slots into its own table as it was being made. But, I have already ordered the cutter, so will try to make do with it when it arrives. Worst case scenario, I might have to make custom T nuts for this project if it ends up not working with those fitting the mill table, but there is no reason it can't use the same 3/8" bolts for the clamps.

Trying to select the right T-Slot cutter was confusing. Some sites, like Enco, just go by what size clamp bolt you want to use, then give the dimensions of the cutter. Others, like Grizzly, called it a 1/2" cutter but did not provide enough dimensional information to know for sure what size it makes. I ended up buying that one, via Amazon, so I could get it here before Monday. (Love Prime service!). As near as I can tell, the cutter for a 3/8 bolt, sold by Enco, and Grizzly's "1/2 inch" cutter yield the same, or very nearly the same, size slots as my mill table.

So, it appears I can mill the slots to the desired depth with an end mill, or even add 0.005 as suggested, (sounds good to me) and then finish them off with the cutter when it comes tomorrow.

Thanks!

[MetalMuncher]

MetalMuncher,
I think the paraffin John Rudd is referring to is what we call kerosene, not canning wax. BTW, pics of X1 and X2 attached.
Chuck

OK, even without clicking on the photos I can see I have the X2. Thanks. I 'thought' I did, but was never sure.

I've never heard kerosene referred to as paraffin before. But I know some of the good folks in places like the UK have different terms for things than we do. So would you mean like white kerosene, bought in a can for things like kerosene lamps or heaters, or #2 heating oil, which we use in our furnace? I do have a drain spigot under the heating oil tank, in case I want some of the # 2 for some reason.

I have some Tapmatic fluids I use, both made for aluminum and ferrous. I also have used Crisco in the past, but never really saw much advantage, aside from that it stays put with a brush when applied. I do a lot of non-ferrous machining dry, when I can. But I can see where an operation with this much cutting force will definitely be helped with lubricant.

Thanks!

[Chuck in E. TN]

By paraffin, they would mean heating oil or diesel fuel. I can translate most of the Queens English and some Ausie slang by virtue of 8 years (2 tours) in the UK with the USAF, and a TDY to RAAF Amberly in Australia, not to mention I married a Fens girl...
I have also used WD40, and lately Neutragena soap on aluminum. I think you probably have it covered with what you have.
I also have an X2, and feel it can cut T-Slots with no problem.
Chuck

[MetalMuncher]

OK, thanks for the info. I had to Google Fens, as I'd not heard of it. Never hurts to learn a bit of geography. ;)

I have a weakness for women with UK accents. Must be wonderful to be married to one. Was she a farm girl there? I do have the pleasure of being married to one of those, being farm grown myself.

Never thought about trying soap as a machining lubricant. Straight from the bottle, or diluted? Or was it bar soap?

[mattinker]

As a Brit, I can say that your diesel fuel is the same as our Diesel fuel. In my opinion, Paraffin is Kerosene, the level of crack that gives lamp oil or heating oil.

I was divorced from a Brit over thirty years ago! They can be charming like they can be the opposite!

Regards, Matthew

[Chuck in E. TN]

OK, thanks for the info. I had to Google Fens, as I'd not heard of it. Never hurts to learn a bit of geography. ;)

I have a weakness for women with UK accents. Must be wonderful to be married to one. Was she a farm girl there? I do have the pleasure of being married to one of those, being farm grown myself.

Never thought about trying soap as a machining lubricant. Straight from the bottle, or diluted? Or was it bar soap?

The wife was the daughter of a career RAF Sergant. The family was involved with farming, mostly flowers.
The soap is bar form. Bought it for the wife, she didn't like it. Saw somewhere on the forums it made a good machining lube for aluminum.
Chuck

[MetalMuncher]

So, I just read Wikipedia articles on paraffin and kerosene, and among other things mentioned here, I found that the word kerosene is based on the greek word keros, which means wax. They even mentioned using it as a cutting oil. And that kerosene is called paraffin in several parts of the world.

I found a cool way to visualize a milling job.  A 7/16 collet works very well on the body of  Sharpie marker. So with the marker spindle-mounted. I proceeded to follow the paths where I want the T-Slots to be cut, using my DRO for positioning. I got into some side jobs, so did not start milling the slots tonight. Once I get to see the cutter tomorrow, I can start working on the slots.

Thanks for all the advice!                                                                                 

[MetalMuncher]

The T-slot cutter finally arrived, so I did some measuring of it. Thought I'd share this because of my confusion on selecting a cutter. I mentioned above that Enco uses the size of the intended bolt in the T-Nut as the main description on its cutter sizes. The Homier X2 mill specs say it has "7/16 T-Slots". The dimension that matches that, when I measured the table slot dimensions, is the actual throat width, through which the bolt would pass from a T-Nut to hold whatever you have on the table. However, I could not find any T-Slot cutters on Amazon that were specified "7/16". So I ordered the Grizzly "1/2 Inch" model. I checked the Grizzly website to try to determine by what parameter they are measuring 1/2", but found nothing.

Well, the tube their cutter ships in is marked "for 1/2 inch Bolt". Followed by "Grizzly H5912 T-Slot Cutter 1/2-Inch". And the head space width dimension looks to be 0.968”. That is about 0.2" wider than the slots on the X2 table. It's throat width measures 0.505”, so it would not pass between the lands of the slots on the X2 table, which are approx. the 7/16 mentioned above. But milling an initial slot a little wider than 1/2" might allow me to use it on the rotary table tool plate project.

The head space depth looks to be 0.416". I'm not near the mill right now, so unsure of that dimension on its table slots. But I do know the entire depth of each slot below the table surface is 5/8". So if having only 0.250" of material thickness above the T-Nut for it to pull on is a sufficient amount, I could use this cutter to make slots that would accommodate my existing T-Nuts for the mill table, and still be OK within the 0.800" thickness of the plate I made. They would just be a bit wider than needed at the bottom, and also about 1/16 wider at the tops, compared to the mill table slots. Since a bit of wiggle room for indicating stock alignment on a mill job is often needed, I don't think it would be a problem. However, there is always the option of making new T-Nuts specifically for this table, and I could still use 3/8 bolts in them, allowing my current clamping kit to be used on it.

The bottom line seems to be that vendors refer to the clamping bolt diameter when they give a single fractional size for a T-Slot Cutter. Lesson learned. ;)

[MetalMuncher]

After measuring the mill table T-Slots, and seeing they have 0.312" throat depth between the slots, I realized if I did try doing the above with only 0.25" throat depth, the existing mill table's T-Nuts would be too tall, and would stick up above the table surface, so they would not work anyway. Due to the thickness of the material I am working with, I have decided to wait, and ordered a 3/8" T-Slot Cutter instead. Plus it will be less load on the mill to use it, compared to the larger 1/2" style cutter.

[ieezitin]

Muncher..

If the neck is to wide in diameter stick it in a 18volt drill and grind off the offending meat. I posted earlier to you and forgot to mention..... when you actually go to mill out your slots make double sure you clear the swarf behind the path the cutter is ploughing through, it will back-drag up chips and clog.

Happy slotting....      Anthony.

[MetalMuncher]

Muncher..

If the neck is to wide in diameter stick it in a 18volt drill and grind off the offending meat. I posted earlier to you and forgot to mention..... when you actually go to mill out your slots make double sure you clear the swarf behind the path the cutter is ploughing through, it will back-drag up chips and clog.

Happy slotting....      Anthony.

That would solve the neck issue, but still leave me the problem of the throat depth. I don't have enough material thickness to use the 1/2" slotter and make the material thickness around the neck be thick enough so my existing T-nuts would be usable below the table surface. I should have looked into T-Slotting parameters before I ordered the stock, and probably used 1" thick instead of 0.800 (for which my intended final dimension was 3/4" - but once I got it milled flat and parallel I still had 0.816", so decided to keep the thickness I had). I really had not thought about T-Slotting it when I planned this project. I had been thinking more along the lines of drilled and tapped holes more like a tooling plate. I only opted for T-Slots after it was milled flat.. So if I had to have the 1/2" T-Slots I would be in trouble here. The 3/8 slotter will arrive Monday.

Thanks for the tips! I would not have thought about the chips getting sucked back in. I'll see if I can rig my shop vac hose to ride along behind the stock and handle the chips.

Last night I added alignment grooves in inch increments from 1" thru 5". I used a 1/8" ball end mill held vertically at a depth of 0.013". Turned out nicely.

[MetalMuncher]

...

[MetalMuncher]

I've got the first T-Slot done. Things went very well.

[MetalMuncher]

All finished!

https://www.dropbox.com/s/pf7ptva9z3vrfj2/Rotary%20Table%20Plate.jpg

Thanks for the help, everyone!

[Chuck in E. TN]

Nice work! Great finish!
Chuck

[John Rudd]

Really smart....

Nice piece of work there, well done...   

[tom osselton]

Nice

[mattinker]

It's nice to see you answered your own question , with positive results!

Regards, Matthew.

[ieezitin]

well done brother... very nice looking piece of equipment you have ended up with...... enjoy it.

Anthony..

[MetalMuncher]

Thank you all for the kind replies! I'm very happy with how it turned out. I used intermittent applications of Tapmatic Natural cutting fluid and while doing the T-Slotting I retracted and vacuumed out the chips 3 or 4 times per slot. Very slow hand feed, running about 550-600 rpm. It sounds like it is working hard, but in fact the motor only got marginally warm. I decided to mill each slot, T-Slot it, then mill the next slot, so the machine (and I) got a break after the T-Slotting each time. The cutter still looks pretty much like new (I did not use it on any scrap, I just decided to go for it, because I had the rotab all set up.  But I did put blocks under the 6" table and clamp it down while slotting, just in case.

I've decided to buy a set of T-slot cam clamps (LMS' set similar to Mitee Bite) but they just arrived today, so have not tried them yet. Even with a 6" table, there's not a lot of room for traditional hold down clamps.

[stirling lad]

  muncher,
  you mentioned earlier that you were considering making T nuts to fit,, well when i recently got my mill I did'nt fancy the prices  of  the T nuts and they only came in packs of 2  or 6 or even 10 at best.. So I bought these wedge nuts and just sawed and filed them to size and they've been fine plus you can find then with lots of different threads...At a fiver for 20 it may be worth considering....just a thought....
....Mike...

http://www.ebay.co.uk/itm/M10-Standard-Wedge-Nuts-Pack-of-20-/160507677077?pt=UK

[MetalMuncher]

  muncher,
  you mentioned earlier that you were considering making T nuts to fit,, well when i recently got my mill I did'nt fancy the prices  of  the T nuts and they only came in packs of 2  or 6 or even 10 at best.. So I bought these wedge nuts and just sawed and filed them to size and they've been fine plus you can find then with lots of different threads...At a fiver for 20 it may be worth considering....just a thought....
....Mike...

http://www.ebay.co.uk/itm/M10-Standard-Wedge-Nuts-Pack-of-20-/160507677077?pt=UK

Nice affordable solution. I like those. I'll keep that in mind for future reference. Currently, I seem to have enough T nuts for whatever I need to do.

BTW, if anyone reading this opts for those LMS cam clamps similar to Mitee Bite, I found a solution last night to their stated restriction of only fitting the middle slot on a SIEG X2 mill table, IF it has a power feed mounted to the left end (so one can't simply remove the table end cap for access).

The problem is that their T nut is a little longer than standard size for these slots, because each has a pair of threaded holes in it so they can work correctly. This causes the need to lower one into the end of the mill table slots in the center, crossways, and then rotate it as you 'steer' it into the center slot (like driving a boat into a dock in a cramped harbor). But you can't steer it into one of the outer slots. The corners on the back end of the T nut jam against the table. So, with the help of a corner rounding bit for my mill, I put a 0.250" radius on the tail end corners of each nut. Now I can steer them into any slot.

I then got to use them fly cutting the face of a 4.5" aluminum disc I am making into a handwheel for the shaft I added to my mini lathe leadscrew. They held very well, using 2 on one side and 1 on the other, in use of all 3 slots.

[stirling lad]

muncher,,
I'd bet that once you get the leadscrew handwheel going the way you want it, you'll hardly use the other apron wheel except when you want to just move the whole carriage out of the way ... of all the little mods i've done to my mini lathe that one is by far the best,,,oops sorry,,, i'm away off topic...

...Mike...

[MetalMuncher]

Well, being that the topic, the question of whether making T slots on the X 2, is very resolved, I promise not to call the Topic Cops on you. lol

I will say that when it comes to hand cranking, if I don't absolutely have to, I'll go for power feed most of the time. I honestly don't like the CCW rotation on the new handwheel needed to advance the lathe saddle, so may someday add some gearing to reverse the handwheel so it goes CW. Just makes more sense to me.

When I figure out how I would want to do it, I may add power to the leadscrew, and I have similar inclinations on my Y axis mill crank. I've even entertained the notion of a power feed on my rotary table. But that would see very little use, for sure. The Y axis on the mill needs it the most. That gets tiresome. Had they exposed the column end of the Y axis screw I might have figured out a way by now. But adding it on the handhweel end would kind of be in the way.

I did encounter something last night on the lathe that could be mentioned in regard to why the X2 is able to mill the T slots without much difficulty. Even though it is a lot of cutting on both sides and top of the T slot cutter, it is not all that big in diameter. I was truing up an aluminum round of 4.5" diameter on the lathe. That is the largest project diameter I've mounted on it. Really only do-able because I added over an inch of crossslide travel recently.

Out at that diameter, getting the right combination of speed and depth of feed was tricky. Trying to go too fast caused chatter, and trying to go what would normally have been a simple to cut 0.010" depth also caused chatter and a tendency to stall the lathe, due to the low speed, flex in the QC tool post hanging out that far, and lack of slow speed torque on this lathe's stock motor. I had to limit passes to about 0.003" to get a smooth finish, even with a brand new indexable cutter mounted, and frequent removal of built up edge. Apparently the surface speed at that diameter even at the lathe's lowest effective speed creates too much loading force to go any deeper.

So it seems to me that even though a T slot cutter seems to be moving a lot of metal, it works a lot better than even a single point tool, WHEN that tool is way out on a large diameter driven by a similar motor. Interesting.