[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.
YouTube- 750 Depth of Cut

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

[pete from TN]

Hey man, I had a couple questions for ya if you do not mind... I was watching your video you posted about the 3/4 roughing pass and I was wondering what coolant you are using there? I was also looking at your other videos that came up at the end of the movie and saw your trunnion table, how did that work out? Is it worth the trouble to build it and how difficult would you say it is to get your offsets correct to be able to machine on three sides of a part at one setup like that. It SEEMS very cool and it certainly looks cool but I gotta wonder about the complexity of setting up a machining operation on it. I suppose if you had a complex part you made a lot of and did all the necessary figuring for it, it would really come in handy but to build one just to have it I dunno... For the WOW factor it is sure to please tho.... And lastly, I was looking at the tooling plate that is now your table actually it seems and I was wondering what material you made it from and what was your thoughts on the bolt spacing and wether or not you put alignment pins in it anywhere for fixture location. Did you surface the table once you had it on there? What did you surface it with? Sorry for the million question post but I am seriously getting ready to add a tooling plate like that to my RF45 as I have been doing a lot of different products lately and they do not all fit on the vise adequately, it would be nice to be able to do away with the vise for a lot of it and just clamp directly to the table with custom fixtures for each parts run. This last part I made had three different setups due to it being made from aluminum angle and it became kinda tricky to be able to hold properly once material started disappearing. A dedicated fixture would make this much easier and a large tooling plate like that would make better use of the full travels of my machine. Also if you do not mind if you could give a good source for the material that would also help... Thanks again man for all the cool ideas, you are quite clever ya know... peace

Pete

[TXFred]

General note: I don't think that any of this discussion is in any way off topic. So keep it coming!

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.

Column Reinforcement: Check.
Recut dovetails and brass gibs gibs: Check.
Table reinforcement: Huh?

I've done two out of the three things that you think need to be done.

I don't see a difference between how much you can hog out on a roughing pass and how much you can cut accurately on a finishing pass. They are both functions of chip load multiplied by the machine's rigidity. Increase one, you increase the other.

And in any case, having done the above modifications, I'll Pepsi Challenge anyone else's X2 against mine to see who gets the best surface finish and accuracy. I can think of only two people who might beat me, Degreaser and Hoss.

Yes, that's a bold statement, but I believe that I can back it up.

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.

I think that you are confused about the function of the head spacer. The head spacer does not increase the mill's capacity. The head spacer gets the spindle back in the center of the Y travel after other modifications are made to increase the capacity.

And these capacity improvement are effective. Some of them are pretty epic cludges, but they work. Period.

If you increase your travels, it is very likely that you will need a spacer unless you happen to make equal changes in +Y and -Y.

[TXFred]

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.

True, but the assumption you're making is that the head is square to the Z axis when it is made. Given the quality issues we see, that's not a safe bet.

Milling it square is definitely the way to go, and surface grinding it would be even better. But shims may still be needed if the X2 parts are not made correctly. Thus my requirement that there be a way to shim the head.

Cheers,
Fred

[hoss2006]

Hey man, I had a couple questions for ya if you do not mind... I was watching your video you posted about the 3/4 roughing pass and I was wondering what coolant you are using there? I was also looking at your other videos that came up at the end of the movie and saw your trunnion table, how did that work out? Is it worth the trouble to build it and how difficult would you say it is to get your offsets correct to be able to machine on three sides of a part at one setup like that. It SEEMS very cool and it certainly looks cool but I gotta wonder about the complexity of setting up a machining operation on it. I suppose if you had a complex part you made a lot of and did all the necessary figuring for it, it would really come in handy but to build one just to have it I dunno... For the WOW factor it is sure to please tho.... And lastly, I was looking at the tooling plate that is now your table actually it seems and I was wondering what material you made it from and what was your thoughts on the bolt spacing and wether or not you put alignment pins in it anywhere for fixture location. Did you surface the table once you had it on there? What did you surface it with? Sorry for the million question post but I am seriously getting ready to add a tooling plate like that to my RF45 as I have been doing a lot of different products lately and they do not all fit on the vise adequately, it would be nice to be able to do away with the vise for a lot of it and just clamp directly to the table with custom fixtures for each parts run. This last part I made had three different setups due to it being made from aluminum angle and it became kinda tricky to be able to hold properly once material started disappearing. A dedicated fixture would make this much easier and a large tooling plate like that would make better use of the full travels of my machine. Also if you do not mind if you could give a good source for the material that would also help... Thanks again man for all the cool ideas, you are quite clever ya know... peace

Pete

Don't want to highjack freds thread so I'll move on after this but to answer your questions,
I used wd-40 in the old videos before i had flood.
The trunnion will be cool if i ever get back to it, could be good for production work but also 3d stuff.
The tooling plate was 3/4 7075 Aluminum Ebay find, after I mounted and braced it, I used the mill to surface itself with a 3 in. facemill, then machined all the mounting and pin holes.
No worries then that all were lined up with the axis'.
ssshapiro on Ebay sell mic6 tooling plate stock (they can cut to length)
Hoss

[pete from TN]

Sorry to hijack but just was wondering. YOu did have flood in that video tho that Is why I asked about the coolant you used. I gotta get me some of that mic 6 for the plate I guess, damn stuff is expensive tho as I need a piece that is like 12x40.... peace

Pete

[hoss2006]

Sorry to hijack but just was wondering. YOu did have flood in that video tho that Is why I asked about the coolant you used. I gotta get me some of that mic 6 for the plate I guess, damn stuff is expensive tho as I need a piece that is like 12x40.... peace

Pete

Ah, I use Syn-kool.
http://www.hossmachine.info/Shop_Info.html#msds
Hoss

[Dougal]

General note: I don't think that any of this discussion is in any way off topic. So keep it coming!

Excellent

Column Reinforcement: Check.
Recut dovetails and brass gibs gibs: Check.
Table reinforcement: Huh?

Table reinforcement being better support from the table right through to the base. Ultimately this means a wider table, wider gibs and a wider saddle. Basically a better load path from the gibs through to the column attachment. This isn't an obvious weak-point, simply that everything flexes and the longer the load path the more flex you get.

Climb milling makes the amount of flex my machine has painfully obvious, videos like Hoss' show conventional milling which holds the machine in more steady load. It's not every part that gives you the luxury of choosing your cut direction.

And in any case, having done the above modifications, I'll Pepsi Challenge anyone else's X2 against mine to see who gets the best surface finish and accuracy. I can think of only two people who might beat me, Degreaser and Hoss.

Have you got some videos of your machine in action? We're all making very different parts which is why our machines are modified in different ways.

I think that you are confused about the function of the head spacer. The head spacer does not increase the mill's capacity. The head spacer gets the spindle back in the center of the Y travel after other modifications are made to increase the capacity.

I understand the function perfectly well. I also understand the tradeoffs which are increased bending moment on the head, column and gib. This means more friction and more flex. Minimising the size of the spacer is important.
This can be done through gaining clearance towards the column (-Y) and keeping Y travel extensions down to keep machine rigidity.

Alternatively, how about making a new Z axis head mount which incorporates longer gibs? It will be more work but longer gibs will largely offset the increase in friction and bending moment that a simple spacer will cause in the Z axis.

[MrWild]

I gave X2#1 a .75" extension. I had some 6061 plate kicking around so I cut off a block with the circle saw and metal cutting blade. Then I C clamped it to the head base and drilled pass holes for the extended bolts using the existing bolt holes as a guide. To square up the head to the column, I tossed it on the Enco $25 surface plate with the HF $20 height gauge. After using a dowel in the dove tail ways to assure the ways were parallel to the column sides, I indicated off the spindle nose. Less than .0001 in 1.5 inches is close enough for me. I got lucky nd front to back in't need a shim. The column still needs ti be trammed though. I move slow.

Anyways, I disagree on the need to be able to get to the head bolts for tramming the head to the column. If you really need to get at them, drill two pass holes through the column up near the top for an allen wrench. You don't need four holes, just move the head up or down to get at the second set of bolts. To drill the pass hoes precisely, use the head base as a drill guide.