[Runner4404spd]

does anyone have the IH mill extensions on their machine? i am finding that i need about an extra 1.75-2.00 inches of space between the column and the spindle to really take advantage of the extra travel. has anyone made a plate to sandwich between the head and the gib plate?

[Cruiser]

I understand that the new 12" has some more reach but i don't know for sure. I thought of the what if's involved for the 10" and come up with two major points. One is you would have to take the load off of the gib such as I did. Second, Is you would need to take machine apart to design it and then put it back together to produce parts, Hense it would be better suited for a team effort of sorts ! One to breakdown and design and others to machine and ship. Personally I talked myself out of doing it for myself as my reach is well useable. And I'd prefer getting more use out of table length than anything else. But then again the table travel is suficient for most jobs. I understand your just north of me in washington right ? I suppose we could work something out if there were a call for such an item then ! >>>>>>>>>>>>>>>>>

[Runner4404spd]

no i'm just north of detroit. really designing up the spacer would force taking the head off, not really a big deal its only 3 screws. then a plate would need to be designed and made. then sandwiched in between the head and the plate. my big worry is that the extended reach would add extra stress on the gibbs. since it alot of mass hanging an extra two inches away from the intended mounting point.

[Cruiser]

Two inches sounds like a lot to add on and i would only add enough to average the Y into center. The added leverage would increase the load on the Z Gib's, and I would deem it necessary to rail the Z to some extent like I did, which was a lot of work. The router arrangement I used could only allow a small bite with 1/4" end mill and somewhat less than perfect, but The rails assembly in use works perfectly ! It could easily handle much more load now. I don't have any Y extensions, nor do i believe in traveling off the Gib's for added work area. Mine does have near an inch extension to Y but it's travel is close to flush at base end. What ever you decide to do I'm curious as to what you find in your travels, and will offer support any way I can. Good Luck Runner !

[Runner4404spd]

i have the 2" y axis mod on my mill. i now have a travel of about 13.5" but the when i add the chip pan to my table, (i'm not doing a full enclosure) i want more useable space. i will try and post some pics of the whole setup. basically i added two inches forward on the y so it makes sense that i need to add two inches to space the head further away from the column. at worst i was figuring i would need to add some sort of counter weight system to the head assembly. i don't think that i need to add the linear rails. if i was to go that far i might as well add them to the x and y axis as well.

[Cruiser]

Adding two inches will also subtract from what you have on the opposite side of your Y axis ! And adding springs or struts or whatever else will not add to the rigidity of the column or do anything else but help the servo or stepper pull the head back up. My servo as supplied by IH pulls the head up with enough authority that It would handle a much heavier box, but the Gib/dovetail on my machine anyway, needed help ! My box is much lighter now and with the rails is solid as Gibraltar ! The X and Y don't need any help as they are not fighting gravity to control the weight, so they are quite solid. In that light i found your statement in regards to the rails a bit strange !
I would still only average in to the center of the table when figuring the amount of extension so travel was equal rather than going the full amount. I guess that the splash pan you intend then is the factor involved that really makes the difference on your decision and I don't have any idea what that is so. Good Luck and may the force be with you !

[Runner4404spd]

basically what i found when moving the table in the y direction...when moved all the way forward, the cutter is about 2" behind the table. my splash pan is designed to extend about .5" beyond the back of the table. attached is why i'm asking the question, its a pictorial of the mill with the y at its farthest forward point. now maybe alot of guys don't have the 2" mill mod, but i think with even the 1" mod you would want a 1" spacer.

[acondit]

basically what i found when moving the table in the y direction...when moved all the way forward, the cutter is about 2" behind the table. my splash pan is designed to extend about .5" beyond the back of the table. attached is why i'm asking the question, its a pictorial of the mill with the y at its farthest forward point. now maybe alot of guys don't have the 2" mill mod, but i think with even the 1" mod you would want a 1" spacer.

It seems to me that you ideally want the center of your spindle to be at the center of the work envelope (wherever that turns out to be).

Alan

[Cruiser]

Looks like ya got that part figured out pretty good. So the next part of the equation is how to handle the stress load on the dove tails of the column. I don't think the springs will cut the mustard but you already know that and since you know what i gotta say i'll cut the chase and just say
"Hope it all works out well for you there Runner !"

[JeepJake]

Runner,

an alternate to placing a spacer between the slide and the head would be to mount roller rails directly onto the way surface of the column and the linear bearings could be mounted to the z-axis slide. (this may require machinging the z-axis slide to get rid fo the dovetail if the thickness of the bearing does not put the slide completely outside of the dovetail) this will add the thickness of the linear bearing to the y-axis, and at the same time take care of that pesky z-axis stick-slip. Put a weight compensation device onto the z-axis, and you may have a near zero backlash system.

If you use the idea, you are required to post pics If I get that far, I will do the same.

JeepJake
Bend, Oregon

[Cruiser]

Jeep, As you may know I put rails on my column. There is NO WAY I'd recommend putting them on the slide faces as they are highly functional as is and would open up a nightmare that the best of engineers would cringe with the thought of dealing with it. If he used side rails and then the spacer it would take care of both aspects of what he has to deal with and believe me when I say it was quite the task to install my rails and end up with such a success as I did. I was seriously sweating it till It was all done !

[JeepJake]

sounds just like the set of challenges I'm up for!!!! (J/K)

For the purpose of my own education, is the most difficult issue of placing the linear rails on a face like that, "just" the alignment of the rails and bearings.

I agree that would be a significant challenge, however I was assuming that the already flat, parallel, and square surfaces provided by the dovetail ways would provide a wonderful reference to start from.

Thanks for the info.

Jake

[BobWarfield]

Linear rails are not neccesarily straight out of the box. They're intended to be installed against a small shoulder of some sort. So, you should machine that shoulder into the surface you plan to mount them to, as well as arrange a fastening system that will keep them hard against the shoulder.

You may also have a clearance issue with the travelling blocks and the existing dovetail that may require you to machine some of it off if you mount there.

So, yes, you have a precision surface to start from, but it needs a fair amount of work to prepare it properly.

If you're really intent on a head spacer, why not make one and measure the nod you're getting and how well it works. Making a spacer is not that hard and you'll know soon enough whether its a good thing by itself or whether even more engineering is needed.

Cheers,

BW

[JeepJake]

Thanks for the info on the rails Bob, the comment I made was really just a passing concept that i had not researched extensively, for the benifit of Runner who mentioned he was thinking about an extension. I am happy with the envelope for now, but Runner is right, a bit more could be made useful with a small extension. it does however beg the question, how often do you have a part that will require all that...I guess it only takes one

From cruisers post, relevant to this thread....

I don't know which rails you have in mind but most the ones I have seen will handle only one or two dimensions of force. If you loose dove tails, and raise off face then you will have three full dimensions of force to control with a very heavy gear box. That Is why I mounted mine on side of column and only use it to pull weight of gear box up against slide and the other forces are controlled by dove tails and slide face ! The rail I chose is a hell for stout construction and holds the weight admirably but that is all it is good at. In order to do what you want then you would need to apply force to all facets of the rail and then wonder how you mount it to face or mount it and wonder how you control the different forces in play ! I hope this makes sense to you, it is difficult to put into words. Oh, and if it is only mounted by the ends then what happens in the middle. You go ahead and design and build this kluge and I'll be the first and loudest to say " Son of a * He did it !"

I am certainly not an expert on rails, I assumed that they could handle load in all directions tangential to the axis of the rail. i guess I had better do some more homework on that... I wonder if Gene has an extra column and z-slide laying about.....

If a rail was capable of handling these forces, it would certainly be an interesting project, but I've got enough of those right now....or do I?

Runner-- if you are truely interested, and willing to tackle, I would love to do some ground work, engineering, and research to see it happen, it sure would be neat. However I don't know if it would be superior to what Cruiser has done, it seems that is a pretty slick setup for supporting the Z, and as Bob had mentioned, a spacer would certainly be a "less effort" solution.

Cheers
Jake

[Cruiser]

Jeep, I just checked on it and yes Gene will sell you a brand new column for $2400 ! And He'll gladly throw in the rest of the mill for free !

[Runner4404spd]

the spacer only does one thing and that is to move the spindle to the center of the travel. what cruiser has done is try to take some of the load off the ways. ultimately i think what he has done is over kill, i think it came out great, but overkill none the less. i would try and rig a counterweight system on the mill before i retrofitted the linear guides. but again neither of these address the issue of the cutter not being in the center of the y travel. thats what the spacer would do if sandwiched in between the head and the z axis slide.

[SCzEngrgGroup]

the spacer only does one thing and that is to move the spindle to the center of the travel. what cruiser has done is try to take some of the load off the ways. ultimately i think what he has done is over kill, i think it came out great, but overkill none the less. i would try and rig a counterweight system on the mill before i retrofitted the linear guides. but again neither of these address the issue of the cutter not being in the center of the y travel. thats what the spacer would do if sandwiched in between the head and the z axis slide.

I don't think you WANT the spindle in the middle of the Y travel. Here's why: Yesterday, I had to make some parts that are 18" long and 13-1/4" wide. My mill (a BP clone) has 34" of X travel - no problem there. It has 14-1/2" of Y travel - big problem there. The spindle *was* located in the exact center of the Y travel. But, if I positioned the piece centered on the table, or, for that matter, hanging more than 1/2" off the back of the table, the piece would hit the base before the table was all the way back, restricting the Y travel. But, with the piece positioned as far back as it could be without restricting Y travel, the spindle was still several inches short of reaching far enough forward to do the front-most part of the work. Fortunately, on a knee mill, there is a simple solution - loosen the ram, and move the head forward. I moved it forward enough (5-6") so that with the table as far forward as it could go, the spindle was about 1/2" behind the rear edge of the table, so i can now *use* the entire 14-1/2" of Y travel on a single part, albeit with the part cantilevered off the front of the table. I intend to leave it there from now on. Without the ram, I would've been unable to do those parts without doing them in two passes, and flipping them over in-between.

Regards,
Ray L.

[Cruiser]

Runner, Your sorta correct other than overkill ! For the dove on the column of the old 10" like I have, If you were to grab the column with thumb in bottom of dove and finger wraping around to inside, you would feel that there is a thin section mayb 1/4" at thinnest point which allows the dove to flex under the tension of the gib. Now It don't matter the way that I have it.
BUTT ! I just got back from Evan VanH's home and I had the chance to do the same thing to the new 12" column and OH MY GOD ! It is seriously beefy, with the addition of iron inside this area ! I mean to say that what we have experienced with ours is by no means any part of the game or pertanent to the new casting. Also the grinding of the slide, doves, and gibs is BEAUTYFULL ! Along with the improved wireing plan and a few secret weapons (swarn to secrecy) This new machine is totally AWSOME I was very truely impresed to a high degree. I stay firm on one note here, Do not try to convince anyone to integrate or add anything because you will only be disrupting the systems integrety. If ours was to the extent of todays machine we would have nothing to talk about except for maybe the dogs hangnails or the dream fishing trips ! anybody wanna buy my old iron ?
Just kiddin there, but I almost forgot. I just finished fine tuneing and also found out one fine point that was not in my info then i set the debounce to 160 and left to visit evan, when i got back and after dinner it sat total 8+hrs without an error or hichup at all ! I am now happy and ready to go back to work on this bugger !

[Runner4404spd]

Ray,

right now my spindle is 1.75" behind the table when the table is all the way forward. i would need to move the head 1.75" to line up with the rear of the table to achieve what you've done with your ram.

cruiser,

i have a 12z machine that i've cnc'd so i don't plan on using the linear rails i think that its stiff enough. if i had the 10z i might consider doing what you did.

[pete from TN]

I am overall more than happy with the machining envelope on my Lathemaster mill as it is pretty large especially for a benchtype mill. I have however thought about ways to make it even better especially in the Y travel area. MY thoughts did not go to the head mounting altho that seems like it is doable. Rather I was thinking about a way to machine a column spacer block that would go between the base and the column. This block would be machined in the one pattern exactly as the column bolt pattern is and then another set of holes that would be studded to accept the column would be made to both fit the bolt pattern of the bottom of the column as well as have a recess machined in it's face to accept the column. Then the plate would be torqued down onto the base with the four bolts that came on the machine and the column would be installed over the studs that protrude from the top of this spacer plate to accept the column. Then tram and torque appropriately. If this spacer were to be made of the right material and machined flat it should allow you to move the entire column back maybe an inch or an inch and a half and also raise it slightly. This is something I have considered a lot but I have yet to try it. Any ideas guys....peace