[MUDSUX]

....Lets says the head is 250 pounds, so in just its natural state it is forcing at least 250 pounds down on the column

If you acheieve perfect balance one would then think that relieves that 250 pounds that is normally forcing down on the column

So I would guess that instead of the natural 250 pounds the head puts on the column you are then putting 500 pounds on the column since the head is now being fully supported in opposite direction, instead of the 750 pounds of the whole machine.

OMG I just had a college flashback!

[pete from TN]

I agree with your reasoning and I can see why you or anyone would think that. Let me explain why I would not lift an RF45 that way. The whole head on this machine is supported vertically by a small cast iron mount that literally on most of these machines is held to the Z axis slide with a single medium sized socket head capscrew. On my particular machine when I bought it that screw was loose and the nut was not really fully locked down to the back of the Z axis slide. Lets assume( and it is a fairly safe assumption) that the pecker heads that assembled this machine in China were smokin' some ganja that day and they failed to adequately tighten this screw down. Then you are looking at the only thing actually supporting the weight of this machine and all of it 750 some odd pounds is the friction of the gib locks assuming you tightened them. If they were to slip your mill and all of it's weight and mass is gonna come crashing down onto your feet or worse your head/hands. Here is another scenario, EVEN IF they were not peckerheads and they were sober and not smokin' the wacky weed that day they assembled your mill the aforementioned cast iron nut mount has been known to crack under load on several of these machines including my own recently. This would result in the same scenario described above where the only thing supporting the mill again is the friction of the gib locks. SO in a nutshell I would NEVER lift my mill using the head only. It is just too dangerous in my opinion. Now having said that if and when you do a CNC conversion on your machine or any RF45 mill I will now HIGHLY recommend machining a NEW ballnut mount from SOLID STEEL.... Also when you do the Z axis Mod inspired by Aaron Moss of IH make the bushing a NICE tight fit and get rid of the crappy metric Socket head capscrew and replace it with a MUCH larger US made grade 8 SHCS. It might also not be a bad idea to make the mount accept two screws one down the center of the head like IH and another atop it. Arizona video on here posted some nice pics of his nut mount and while I agree that it needs to be MUCH beefier I personally would not put it at the top of the Z slide simply for the fact that when it is in the center of the Z slide you can use as much of the available travel in your column as possible. I recently made a new mount that is TONS beefier and heavier duty than the Cast bit that broke on me. That mounting point gets a huge amount of stress applied to it with that head running up and down at rapid speed all the time and just to stave off a future crack or problem I recommend making a beefier and better mount from steel in the first place. The millhead is REALLY heavy and it just plain does a number on parts and even ballscrews and nuts have been killed by it on some mills. Especially if you are one that likes to crank down on the gib adjustments.

SO as I said there is no offense intended or implied here, I just would hate to read that someone got hurt or just plain destroyed their milling machine on what would have been a wonderful happy day getting and installing their shiny new milling machine. Peace

Pete

[MUDSUX]

Hey Pete,

What is this z axis mod you mention? I can't seem to find it.

[pete from TN]

A picture is worth a thousand words, even from me!! peace

CNCCookbook: Z-axis Mods for IH Mill

Pete

[pete from TN]

That first set of pictures depicts Bob doing a great job of threading the original cast iron mount for the ballnut. What I am suggesting is that this mount is inadequate and as I said several people have had this mount fail on them and get cracked or worse. I am suggesting to make an entirely new mount from Solid steel and drill and tap it for the ballnut. On mine I made the Z axis mod bushing very snug and I actually made it longer than just flush with the back and let it protrude out the back of the z slide maybe 3/8". Then I machined the face of the new ballnut mount with a round recess in the face where it hits the Z axis slide to accept this bushings face/shoulder. This makes the bushing and the ballnut mount one solid piece and you are not just relying on the SHCS itself to hold the head up. Again I also made the bushing larger to accept a larger SHCS and threaded the new ballnut mount deeper to accept a longer larger screw. I also decided to use a fine thread on the screw because I feel it makes for a stronger joint and also makes it easier to torque it down nice and tight. Then I just assembled everything together with loctite and after I got it together yesterday I was pleased to find I have near zero backlash. This is what I would call an essential mod and makes for a much more rigid setup that should hopefully remain so for a very long time.. Peace

Pete

[MUDSUX]

A picture is worth a thousand words, even from me!! peace

CNCCookbook: Z-axis Mods for IH Mill

Pete

Thanks. I don't think I can do that just yet. I don't have a lathe yet.

[pete from TN]

Tell you what, If you intend to do this mod, I would be willing to machine you a bushing for your mill if you send me a hunka steel and some dimensions of what your size is gonna need to be. I think this is an essential mod even if you never intend to go cnc just for the pure strength and proper mounting of the millhead. I forgot to mention I took a few snapshots of my completed assembly before I stuck it back inside the mills carcass... Here ya go...

In the pictures you can see my steel IH inspired bushing the new steel bodied mount, the brass bush I built to accept the bellville washers for my zero backlash double ballnut setup and the screw you see there goes thru the bellville washer housing to keep the ballnut from unscrewing yet allow the ballnut and bellville stack to expand and contract over the slight irregularities of the ballscrew and also for thermal expansion.... The large SHCS goes into the bushing hole there and threads into the block at the face and goes into it like two inches or so...


peace

Pete

[pete from TN]

Almost forgot, the ballnut mount is also drilled and tapped 1/8 npt for the one shot oiler brass fitting and the ballnut mount is threaded from underneath 1 1/8- 18 to accept the ballnut and then it is crossdrilled and tapped for a setscrew to lock the ballnut to keep it from unscrewing itself. This is pretty important because I have had my X axis ballscrew unscrew itself this way before when I forgot to tighten that setscrew down. Now I install the ballnut, install the setscrew with loctite red and tighten the crap out of it.... That cross hole in the middle of the body just happened to be there in the piece of scrap I made this thing from but it does not intersect anything but the SHCS threaded hole which is fine... Also note that the new mount is also both wider and taller where it contacts the back of the Z slide to aid in leverage when it lifts the head. THe factory mount face is MUCH narrower and not as tall. This setup is rock solid and should outlast the machine easily. The fact that the IH bush goes into the face nice and snug and goes into it like 3/8 inch makes them basically one piece of steel once you torque the SHCS down.. peace

Pete

[MUDSUX]

Thanks for the generous offer Pete! It will be awhile before I get to that phase but I will keep you in mind. That looks very nice!

[pete from TN]

No problem man.... just lemme know what you want to do and when... good luck and peace

Pete

[MUDSUX]

Ok so I emailed Matt about hooking up the coolant pump but got nothing. I have 3 wire coming from the mill. I am guessing a ground and 2 hot. The problem is I don't know which terminal on the pump to connect them to. Can anyone help? Thanks!

[thedave]

Mine came in today, and I have it on the stand. I will hook up the pump tomorrow and post some images. I noticed the wiring diagram is molded into the inside of the plastic cover.

Some setup notes:

I has to adjust the pin that lines up the slot in the R8 collets to stop them from spinning. I had to unscrew the round plate at the bottom of the quill. There are double set screws, so you have to remove the outer one to adjust the inside one.

I got the x axis power feed installed, real easy to do, and it will be a worthwhile investment

Can someone measure the length of the draw bar on theirs for me? Mine works fine for the drill chuck, but it is an inch too long with the collets. I tried 4 different collets, and even removed the drawbar to make sure it was threading into the collet all of the way. I have the lower top nut run the the bottom of the threads.

[MUDSUX]

Mine came in today, and I have it on the stand. I will hook up the pump tomorrow and post some images. I noticed the wiring diagram is molded into the inside of the plastic cover.

Some setup notes:

I has to adjust the pin that lines up the slot in the R8 collets to stop them from spinning. I had to unscrew the round plate at the bottom of the quill. There are double set screws, so you have to remove the outer one to adjust the inside one.

I got the x axis power feed installed, real easy to do, and it will be a worthwhile investment

Can someone measure the length of the draw bar on theirs for me? Mine works fine for the drill chuck, but it is an inch too long with the collets. I tried 4 different collets, and even removed the drawbar to make sure it was threading into the collet all of the way. I have the lower top nut run the the bottom of the threads.

Yeah I saw the diagram too but I have no idea what it means. Please let me know how you set up the pump.

The set screw in my spindle was TOO long and stuck out too far in the spindle and wouldn't let my collets seat correctly. I had to unscrew the bottom plate also but I had to back the screw out by just a hair to clear the collets.

My drawbar measures 19 inches end to end, including the top nut. It bottoms out on the collet with about an inch left on top and I have to use the bottom nut to tighten it.

[rwskinner]

First, what voltage is the pump 220/110. Next, what color are the wires. My eyes are not good enough to tell from those photos.

[pete from TN]

As far as the collet pin goes.... I removed mine years ago and have never had a problem. It makes installing toolholders much easier and really if the taper is ground right and you torque down the drawbar properly you should never have a collet or toolholder spin in the bore. I recommend getting yourself one of these cheap small pneumatic impact wrenches to quickly tighten and loosen your drawbar unless you wanna go real fancy and build a nice high pressure pneumatic power drawbar first. I am planning on a nice pneumatic drawbar A la Tormach's design but until I do I am using a handheld impact wrench and doing it manually. It is pretty quick and works well despite the noise.

If your drawbar is too long and you are absolutely sure your collets/toolholders are seating in the spindle properly and you can still not tighten them down I suggest DO NOT CUT THE DRAWBAR DOWN... Instead machine yourself a nice bushing for the top of the spindle that has a lip or cup for centering the top of the drawbar in the spindle. I made a little one from steel on my lathe and it makes the whole bit spin a lot more concentric whereas before sometimes when I tightened the drawbar it would be kinda out of round and I got tired of watching it spin unconconcentric atop the spindle like that. Mine is only around 3/8 inch thick and has an internal ring that fits inside the top of the spindle bore nice and snug and the hole for the drawbar that goes thru is much snugger than the spindle bore..... This is something you should check out on your mill and make your bush to it's dimensions and the excess length of the drawbar.. Good luck and peace

Pete

[The_Tuner]

I agree Pete ... a small bushing with a lip would be great for these, the uncentered spinning drawbar is getting on my nerves ... my drawbar is also a little over 19 inches as well, however using the other nut draws it up fine, not ideal but it works, I didnt have any trouble with the pin other than when I first tried a collet it was very sticky, I noticed up inside toward the top inside the collar was really cruddy so I really cleaned it well inside, they slide up well now.

[MUDSUX]

First, what voltage is the pump 220/110. Next, what color are the wires. My eyes are not good enough to tell from those photos.

Sorry, 220v. The 3 wires coming from the mill is:

1. yellow with a green strip
2. black
3. black

The three wires on the pump is:

1. gray with a red strip--tagged Z2--connected to Z2 post
2. gray with a green strip-tagged U2--connected to V1U2 post
3. yellow--tagged U1--connected to U1 post
4. Z1W1 post empty
5. Ground post empty

[thedave]

Ok, Got the pump hooked up and working.

Ground go to the center connection with the lines next to it

the other 2 wires go to U1, and Z2. They also have and extra nut and washers. Does not matter which, Motor is 220v

I think I have everything working. The only outstanding issue is the drill chuck. It has .006 runout. I swapped it with the chuck from my X2 mill and now I am at .0003 If I am reading it correct. Runout with a 1/2" mill in a collet is .00025.

[thedave]

Additional Observations.

While the vise seems of decent quality, I will get a pair of Kurt style vices. The solid handle is a pain.

Power Feed on the X was well worth it. It is a lot of cranking to get the table back and forth.

The Z hand crank is not long for this shop, I'll have to look for some cheap solutions.

I am going to see if the quick tool changer Hoss came up with can be adapted to this machine. It looks like a possibility.

[rwskinner]

You got that right on the Z cranking, that is already old and I barely started!!!

Mine has a rack type system in it and it sure will wear you out. Since it will be awhile before I cnc mine I ended up with Power Feed on the X, and I need to do something about that Z.

Since I'll eventually end up CNC, I may just go ahead and convert the Z to ballscrew immediately and build all my mounts, then just stick a DC motor on top for now. Later I can stick a servo on there.

I was looking at DRO's earlier and I had to catch myself. Like the SX3, I added everything to it, then CNC'd it and everything was pulled off and sitting in boxes!!