x2 tramming

[krymis]

I have my x2 all torn down and ready to do what is needed to make it a good operating machine.  Where should i start with putting it back together?  I have a craftsman roll around tool box from sears to mount it on.  I welded allthread and long nuts to the 4 corners of the tool cart to level it anywhere in the shop. I have the base laid on the cart for mounting but wondered if a filling with epoxy and sand mix would help it?  any help will be appreciated.   

[spuddevans]

Hi there Krymis, I have my own X2 broken down in pieces as well, and have just done the 1st stage of tramming. I made brief reference to it in my post about my CNC X2 conversion. I've just gone out and taken a few pics and will upload them and make up a post about what I did and then I'll re-post here with the link.

Just give me a few mins to gather my scattered thoughts,



Tim

[spuddevans]

Just posted it Here


Tim

[krymis]

i am going to start tramming the head to the column tonight.  I am planning to remove the controls and electronics box away from the mill.  I will also be removing the motor and Z axis ballscrew and cnc mount.  I will see how good i can get that before i move on to any other tramming. 

[krymis]

so i decided to take the tram a little further and add a treadmill motor and controller to the mill.  I will also be using the hoss belt drive.  I harvested the motor, choke, control board, circuit breaker, and POT from my wife's treadmill.  
The parts are common place if you type in the right stuff on steal-bay..
motor is a B4CPM-089T (2hp 130v 5950 17A)
choke is a YBI-601-Q
it uses a 10k POT
and motor controller is a MC-60
all parts priced on steal-bay was under 100.00
i have videos of the motor testing and such from my cell phone.  sorry for the crappy video.  Also have a 1/2"x12" rod in the spindle and starting the tram process on the spindle.  Once i get it in tram i am going to make a few brackets to help fine tram the x axis...y axis is just using some expensive shims aka tin foil.

pic of the control layout
http://www.youtube.com/watch?v=JFAWb6WfLWE
http://www.youtube.com/watch?v=iSqz4HvF-6c
http://www.youtube.com/watch?v=IaqCPydEfuw

[krymis]

guys,

i got a real problem.  I am pulling out my hair.  I am using Rollie Dad's method.  I have a pc of 1/2 CRS in a 1/2" collet.  It is not a precision shaft by any means but i was told you did not need it with this method.  I got the rod in the collet and tightened and ready.  I set up my DTI on the column to measure the up and down deviation.  The rod holding the DTI is as about as parallel as i can get it while allowing me to adjust the DTI.  I set the DTI and rotated the spindle to find the max and min at the collet end.  I then reset the DTI to 0 on the midpoint.  Then i move the carriage to the top of the column.  

At this point i already have a -.002 reading one the DTI telling me that the rod drops that much.  Then I rotate the spindle and come up with a min of -.004 and a max reading of .0015.  So what do i do with the numbers... do i add the -.002 reading to the min since it drops that far to begin with?  
http://www.youtube.com/watch?v=AbpiPwVdM60

[kwackers]

Krymis,

Rollies dad's method relies on the bar being the same diameter at the measuring points (you've checked this right?)

When you zero the DTI at the first point you're simply setting zero at the 'average' movement. When you move to the other end what you're looking for is the average between the two values.
In this case (-0.004 + 0.0015) / 2 = -0.00125.
This suggests that you've moved (towards your DTI??) by -1.25 thou.

The fact that the DTI changes as you slide along doesn't matter. As a thought experiment, imagine doing it with a bar that has a 1 inch bend in it. At the first point the bend hasn't happened yet so your two measurements are zero.
The bar starts bent away at the other end so that when you slide your DTI towards it, it reads -1.000", but when you rotate the bar it bends 1" towards you so your average becomes (-1 + 1) / 2 = 0.
However if the bar has shifted 1 thou away then the first measurement will be -1.001 and the second 0.999 which gives (-1.001 + 0.999) / 2 = -0.001 - which is your 1 thou error.

Hope this makes sense.

[krymis]

kwacker,

so that means i need a shim at the bottom of the spindle head to lift the bar right?  If so is it telling me that I need to put a .00125 shim in or do i need to half the value to get the shim? 

[kwackers]

The value of the shim isn't so simple...

The error is the amount the bar diverges between the first measuring point and the second.
Imagine that the first point is 10" away from the 'pivot' point on the head (the point it rotates around when you shim it).
Imagine that the second is 11" away, so you've got 1.25 thou error per inch, but you're ten inches away so this represents a magnification - i.e. the amount to shift the head is a large amount.

The other factor is how far away from the pivot point the shim is. The nearer the larger the effect, the further the smaller.

If you've got a scientific calculator, a reasonable grasp of sine's, cosine's and triangles you can work it out. What you may prefer to do is stick a shim in, remeasure and then best guess...

[krymis]

got you.  thank you for the explanation. Rollie dad's is not that hard once it is explained like that.  I think a lot of people make it harder than need be.  And it would not be so bad if there were some better notes on it and less people saying oh it can't work because of this and that.

I am taking the measurements at the max and min of my travels so after i get it dialed in it should be good because the work should always be in the travels correct?   

[kwackers]

The error will always be linear (unless your head shimmies from side to side as it slides down - which thinking about might be worth doing it with a 'tight' Z axis just to make sure).

The only reason to make the measurements as far apart as possible is to magnify the results. Because it is a linear error once you fix it it'll be valid over the entire range.

I know what you mean about the explanations though, it's a fairly simple thing but to read some of the online explanations you'd think it was rocket science. I had to read one of the explanations several times before it suddenly clicked!

[krymis]

welp it took me these few minutes to get the up and down under .0005" deviation. now time for the x axis.  

Scratch the above still got a deviation. 

[krymis]

so i now have checked this 3 times and get the collet to 0 out.  I then move tot eh end of the rod and get -.0035 down and .002 up so my math  ([(-.0035+.002)/2]) i come up with -.00075.  Does my math look correct and I think this is good for this little thing or do you guys think i need more tweaking?

[kwackers]

Looks good to me. Over that length (same as the video?) the error sounds pretty good (to me).
I wouldn't like to say what an acceptable error is, my mill has a tilting head and tbh I tram it quickly with a dial gauge against the table - probably to no better than a thou or so.
Obviously having a fixed head I guess there's more point to spending a bit of time with yours.

[krymis]

so i got the x set up and according to my math i am -.00025 with 2 different readings.  I think this is good enough. 

[krymis]

so i got a little more on the tramming tools done.  I used some steel angle to make the column tilt mod.  I got the x axis dialed in less than 0.0005.  I am putting y axis adjuster screws in the same way sonny harrison did.  I should have that done today. 

[krymis]

so i figured out that i had to much slope in my holder holding the DTI to the spindle.  So the key was to break out a Starrett DI set up and the x axis is now within .001.  I am now working on the y axis again.  then all should be good and i can make all the little widgets to make tramming a lot easier.  I finally feel like i am getting some where with this machine.  I have had 4 of these and have never had this much trouble and questioned my methods like this.  I now have the 8x6x.5" steel plate on the haas minmill to make the backplate. 

[Bogstandard]

Once you have your mill up and running again, maybe you could consider making a tramming tool.

http://madmodder.net/index.php?topic=822.0


Bogs

[Brass_Machine]

Once you have your mill up and running again, maybe you could consider making a tramming tool.

http://madmodder.net/index.php?topic=822.0


Bogs

Bogs is right...

Once my mill is back in tram, I am going to make one.

Eric

[krymis]

sorry for the not posting up guys...my father in law passed this past weekend so i have been taking care of some of the estate things and such.  So today i am hoping to get the tram all finished up and make some parts. 

[krymis]

so you ever have one of those AHA moments?  Well i just did and realized that all the different ways people are measuring the tram all measure out the same.  Dumb maybe but at least i have not thrown this machine. 

[John Rudd]

Who's have thought that such simple machine could cause so much aggro....

[krymis]

i definitely aggree.  This is the first one where i have had this much aggravation.  I have had a few of these and none where this bad or a PITA like this.  I am just waiting on a new pc of steel for the back plate as the first one was used for another more pressing project.  I will have it by next week hopefully.  Then all the extra gadgets to tram this easily will be on and ready.   

[krymis]

well i got the braces done for helping to tram and stabilize.  




i also got a plate of glass and a starret indicator to help with tramming.  hopefully i will have this whole machine tramming taken care of tonight.  

[Brass_Machine]

Very good!

Have you thought about filling the column with an epoxy/sand/gravel mix to help stiffen and dampen the mill?

Eric