The X2 head spacer design thread

[TXFred]

One of the most popular improvements to the X2 is to modify it to increase the Y axis travel. Often this involves moving the column back or extending the ways forward. In both cases, a spacer is needed to put the mill's spindle back in the center of the Y axis' range of movement. After all, it does no good to have 6" of Y travel if the spindle can only reach the first 2"

I was surprised to find that there are no good spacer designs out there. So I want to come up with a design to share with the forum.

Here are the design constraints:

1. The design must allow access to the head mounting bolts without removing the head from the column. This will allow the head to be shimmed and adjusted parallel to the Z axis.

2. Any modifications to the X2 head components must be achievable using hand tools and a power drill only.

3. Must be able to be produced on the X2 mill.

4. The design must be easily altered to different lengths. 1" to 5" is an acceptable range.

5. The design will not articulate the head. There's already a design for an articulating head spacer available.



I will be starting the design in Inventor and will post details as I develop the design. I would like to hear feedback from others on here about the design.

Cheers,
Fred

[cyclestart]

There's already a design for an articulating head spacer available.

Gotta link ? Is it the Hoss design ? TIA.

Good luck with the project.

[TXFred]

Yeah, I was referring to Hoss's design. It's good for what it is, but it's really big and you need a lot of Y travel to get any use out of it.

I'm after something smaller and less complex.

[Dougal]

1-5" seems like a very large range, any spacer will introduce a lot of extra flex and chatter into the column, the bigger the spacer the more flex you will introduce.

I'm curious as to what size table would need such a large spacer and what would be the point on such a low powered mill?
I see scope in the column mounting to gain an inch of clearance in that direction just through a redesign. An inch of clearance can give you two inches more travel while remaining centred.
There is a huge stiffness benefits if this works out, personally I think the resulting 6" of Y travel is plenty for a mill this size.

[TXFred]

5" is definitely the outside edge of the envelope. I cannot see many people needing that big of a spacer, but why artificially limit the design?

In the case of my mill, I need 2.4" to get back on center after my column move. I moved my column back as far as possible. In addition to large Y travels, I have some extra space between the table and the column when at minimum Y. This leaves room for sheet metal chip guards, and also gives extra space for my vise. Before, it was possible for the vise contact the column. Now that's no longer an issue.

I've got a pretty simple design on the boards now. It's one piece, so it will be heavy. But it should do the job.

Fred

[Dougal]

So what's your total Y travel now?
I see issues running out of table width. I'm even thinking my planned mods for 6" total of y travel will be little use as my table is only 90mm wide so fixing parts that big becomes an issue.

[Johann ohnesorg]

Dougal,
think tooling plate.

Fred, just a few thoughts:

1. The design must allow access to the head mounting bolts without removing the head from the column. This will allow the head to be shimmed and adjusted parallel to the Z axis.
Mill it square and level, that´s far more solid than cardboard spacers. Or Dykem and file it until it fits with the whole surface to the spindle housing.

2. Any modifications to the X2 head components must be achievable using hand tools and a power drill only.
A replacement housing costs close to nothing and would leave you with a working machine under any circumstance. Never modify a mill without a second mill on hand. Hard learned experience from the past . The 0,001-0,004" of error on the spindle housing can be dealt with handtools, it is a pretty small area that must be filed, maybe 4-6 square inches. And it´s only cast iron, files like a breeze.

Cheers,
Johann

[Dougal]

Dougal,
think tooling plate.

Cheers,
Johann

Yes that can give you the table area, but you lose Z travel, still have small jibs underneath and you need to space the column back even further to clear the larger plate.

Opinions will vary, but mine is that beyond the simple travel mods you end up turning a small very usable mill into a medium size flexy mill that has a new set of issues and isn't really capable of jobs that it's new size would suggest are possible.

So coming back to the spacer, doesn't anything past 2" start getting silly?

[Johann ohnesorg]

Fred, please excuse the OT in your thread.

Hy Dougal,
it depends a lot what you do on this machine. If one is into light alloys or engineering plastics or maybe electronics it may be sufficient to enhance table travel, take out z-axis slop and fit a tooling plate.
If the lost height from the tooling plate is an issue then one can rest assured he bought a mill at least one size too small. Most people have a make do attitude towards this small beasts, main topic is to get things done even if it takes a little longer.
But I agree with you, it is of no use to buy a small mill and modify the heck out of it just to find out that a modified small mill is still nothing but a small mill and now is as expensive as the next higher class of machines was in the first place without all the extra work involved. It looks different the moment you upgrade to a bigger mill and now you have the mini mill sitting idle on your bench with a load of tools that fit both machines. Longer Y-travel, a few steppers and Mach III instantly pop up before the inner eye, just reminds me why I came here.

Cheers,
Johann

[hoss2006]

Yes that can give you the table area, but you lose Z travel, still have small jibs underneath and you need to space the column back even further to clear the larger plate.

Opinions will vary, but mine is that beyond the simple travel mods you end up turning a small very usable mill into a medium size flexy mill that has a new set of issues and isn't really capable of jobs that it's new size would suggest are possible.

So coming back to the spacer, doesn't anything past 2" start getting silly?

I've heard these claims before and debunked them all. Maybe sit back and watch some videos of what an extended mill CAN do.
[nomedia="http://www.youtube.com/watch?v=C3jl6cbhWqs&feature=player_embedded"]YouTube- 750 Depth of Cut[/nomedia]

If your X2 can cut more aggressively, I'd like to see it. It's been 3 years and I've never
seen it outdone, even by X3's.
http://www.hossmachine.info/Videos5.html
It cost less than $1k to get to 18 x 12 x 10 on the X2.
Would I do it again today? heck no, I'd get a G0704.
Wasn't an option 3 years ago. The mill is still going strong, used it last night for milling the G0704 saddle.
Hoss

[Dougal]

I've heard these claims before and debunked them all. Maybe sit back and watch some videos of what an extended mill CAN do.


If your X2 can cut more aggressively, I'd like to see it. It's been 3 years and I've never
seen it outdone, even by X3's.
http://www.hossmachine.info/Videos5.html
It cost less than $1k to get to 18 x 12 x 10 on the X2.
Would I do it again today? heck no, I'd get a G0704.
Wasn't an option 3 years ago. The mill is still going strong, used it last night for milling the G0704 saddle.
Hoss

I use my mill to also cut and drill steel and stainless steel. I'm not talking about how much you can hog out with a roughing pass, more how much you can realisticly cut and still be close to the dimensions you want.
For example cutting steel I am not limited by motor power or stepper speed, I'm limited by the rigidity of the frame. To speed up cutting that I would need a big reinforcement of the table, column (already reinforced) and rework all the gibs.

I can see the need for people who want big travel and a big table without needing much stiffness. But for those people isn't a rgantry type machine more suitable?
I can also see the value in fitting a larger table with larger gibs etc to the X2 for some light cutting applications. But at that point you're more building a new mill with an X2 head than actually modifying a stock X2.

I bought my X2 because it was small enough to be portable but big enough to do some of the jobs I wanted it for.
Long term like Hoss etc I plan to convert a bigger machine, the difference is I plan to keep my X2 as a small portable CNC mill and maximise it's function as one, rather than turn it into a large mill without the capacity of a large mill.

[hoss2006]

I use my mill to also cut and drill steel and stainless steel. I'm not talking about how much you can hog out with a roughing pass, more how much you can realisticly cut and still be close to the dimensions you want.

Then keep watching all the many other videos, it cuts anything a stock X2 can cut, as accurate as any X2 can cut.
Increasing the travels doesn't suddenly give it kneemill capabilities, it didn't gain 2000 lbs of mass.
It lets it cut X2 rates on much bigger parts without the need for multiple setups.
That's why people work to increase the travels on these mills.
The work envelope is too small.
If someone needs cut at higher rates, then they need to step up in overall mill size.
If X2 rates suit someone, then there's nothing wrong with getting more
travel capacity out of the mill they already own even to the extreme.
Hoss