Adding a "home position" locator to vertical mill with tiltable head.

[Brian Rupnow]

My new Craftex mill has a nice feature, in that the head with motor and spindle will tilt up to 90 degrees in either direction and lock there for machining on an angle, This is all well and good, but I don't see any provision made for restoring it to its vertical "home" position. I could drill a hole through the rotatable part of the carriage into the portion of carriage that doesn't rotate, but then again, that would have no adjustability, and I have learned through bitter experience to never add anything to a machine that doesn't have some adjustability. Has anyone addressed this issue, and if so, how???---Brian

 

[Mcgyver]

Brian, you tram the head square with an indicator - indicator in spindle sticking out on arm, get zero deviation in 4 directions. even on big mills its amazing how the cutting for will take it out of tram so its not a bad exercise to go through every now and again

 

[Powder keg]

When I was going to school to learn to be a Machinist. The instructors would knock the heads out of tram daily You'd be surprised how good you get at tramming them back in after a while. It's a good skill to know anyway.

Wes

 

[shred]

You can also make a nano-tram like thing (a flat plate that attaches to the spindle sort of like a faceplate on a lathe-- run it down to the table and tighten the spindle). Not as good, but ok for quick and not very precise setups.

 

[Tin Falcon]

Brian:
Sounds like you need to learn the mill 101 skill of trammig the head.There are several gadgets out there to make the job easier. Like the easy tram or the spindle square witch mounts a pair of indicators to the spindle.
if you use just one indicator an inspection mirror comes in handy.
Also I would not assume the mill head was square as shipped. likely only eye ball close.If you need further help let us know
Tin

 

[Loose nut]

Get a slice of pipe that fits your table, maximum Y axis table width, and machine it parallel (the sides must be parallel or it won't work).

Place it on your table and just run an indicator around it, a Coax type works best if you have one but isn't necessary.

You will quickly see any error without having to worry about the indicator tip fouling the tee slots etc.

 

[sparky961]

One of my first posts here included my own experience with tramming...

http://www.homemodelenginemachinist.com/index.php?topic=2229.0

Plenty of pictures there.

-Sparky

 

[macona]

Once you have the head trammed real well you can find a spot and drill and install a taper pin with a retracting nut on it. You will need taper reamers as well.

http://www.mcmaster.com/param/dsc/dsc.aspx?dscIds=47379&term=Threaded+Taper+Pins

 

[jack404]

G'day all on my x2 clone i put a ball bearing and spring into a drilled and tapped hole and a threaded collar to hold the BB in place but allowing it to protude almost 2mm.

i drilled a small hole in the base plate and when i bring it to "home" position the BB clicks in dead on the 90 deg every time, i plan to do this with 30 and 45 deg as well but its a job to pull it all apart to do but when i do so i'll take pic's and show here but its spot on every time and only a couple hours work ( after 6 hours dissasembly and reassebly)

cheers

jack

 

[rake60]

Brian tramming the mill is an easy function but don't expect to get it right
on the first attempt.

I use an indicator with a mag base set on the spindle such as this:

When that indicator reads the same at 90 degree intervals the head is set
dead nuts straight to the table. First time an end mill or cutter grabs you do
it again.

Rick

 

[wareagle]

Tramming is really no different than any other locating procedure... When one is new to the task, it is challenging and even daunting at times. But with some practice, it becomes easy. Tramming the head once you get proficient will only take a few minutes of time.

When I was brand new to machining (I have since graduated to new ;D), just squaring the vise was a huge ordeal. Now, it is just a simple procedure that takes a couple of minutes to perform. Same thing with locating a center or an edge. Used to be a nerve racking experience, but now it is just another procedure. Practice makes a huge difference!

 

[Cedge]

W.E.....
Truer words were seldom spoken. I too used to dread tramming, edge finding, centering and it took forever to square the vise. Now it's all just part of the routine. The first milling cut I see that isn't making a nice clean matching set of cross hatched swirls brings out the tramming tools. Everything simply cuts so much better when it's all dead on.

I use the Nano-tram here and it definitely makes it less painful to get things sorted out. Had I known then what I know now, I'd have made the little beggar instead of paying the, IMO, too high price they get for them. It's just a "T" shaped turning sized to fit the mill spindle and a flat surface to rest on the mill table.

Nothing at all to making one. I've checked the results with a DTI and glass plate and it will get you within less than half a thou with a bit of practice. It will also quickly show you where and how much you might need to shim the column.

I contemplated adding a bracket with an adjustable stop screw and locking nut to my X2 but never got around to it. That big honking nut on the back of the X2 is the devil's spawn when trying to get it tight and still retain the tram you've just made.

Steve

 

[small.planes]

Quick tip for squaring a Vice:
Get a long piece of straight bar, needs to hang each side of the vice by a reasonable amount (must be straight, but round or square makes no difference), clamp it in the vice so its level and then eyeball the bar and the T slots / edge of the table. I can plonk my vice to within 1 thou / 6 inches in a few seconds, close enough for most things. ;D
Old printers are a good source of straight precision ground bar. (I use a 3 foot piece of CRS as it happens, but my mill table is 49" long...)

Dave

 

[gunboatbay]

I noticed in Cedge's post, the comments about problems tightening "That big honking nut on the back of the X2...". On one of the other forums, there was a long going discussion about problems with the head movement on the X2 mill during operation. Most of the conjecture was relating to problems with the column flexing because of its smaller size and various solutions given. One of the members took a little more scientific approach to the problem and one of his findings related to the large conical washer under the "big honking nut" that comes on most X2 mills. I've attached the article for the education of X2 owners on this forum.

View attachment column flex.doc

 

[ksouers]

GBB,
Thanks. That's great info for us X2 owners. I've noticed a lot of flex and developed the habit of taking a couple finish passes to reduce any springing tendencies of the column/head contraption. I've also encountered, and complained about, the difficulty of tramming the X2 and keeping it trammed. It doesn't help that using the machine puts it out of tram in a short time. No matter how much care I take tramming, as soon as that "BHN" gets turned the whole thing gets thrown out of kilter. I've taken to a progressive approach: snug up the nut a little, check and adjust as necessary, repeat until the nut is tight. I also use a little "Kentucky Windage" before tightening down the BHN. If you're lucky you'll only be out a couple tenths. Sometimes I get real lucky and it's dead nuts, but it won't stay there.

This information should hopefully go a long way to help alleviate those issues.

 

[CrewCab]

And thank you from me also .............. I suspect I will be having "discussions" with the BHN and associated parts in the near future

CC

 

[LatheDude]

Hi everyone,

Here's one solution to increasing the rigidity of the X2 column base--> http://www.harrisson.biz/backplate/rigid.htm

It looks like a good solution, but, I haven't tried it.

 

[Hilmar]

Hi
On Tramming the Mini Mill, first I set the best square I have on the table. Indicator put in spindle. Run Indicator up and down the square to see if the column is square to the table. This I do in X direction. After this is done then I go for the rotating part of tramming to the table. The reason for this is as the head rotates in the X direction as it is bolted to the column. You have the column, and then comes a spacer or transmission and then the head itself. Head bolts to transmission.
This in course bolts to the column.
If you do not follow this you may tram the mill only at one height position of the head at the column.
Hilmar

PA: on spell check, when I go to it the second time, a blank window shows so no spell check. Is it me or the Site?
Hilmar