jet's CNC kit installation
Ok, I still don't have a full kit (no Z servo, missing a few other things), but taking into account having to send Z-parts in to be re-machined, I think I have enough to get started.
If you built a kit recently, is there anything you regret not doing while you had the machine apart?
For example:
- while I have the head off I'm going to take it down, inspect all the bearings, clean out casting sand, and tap some holes for an hour meter on the motor and maybe even do a VFD/belt drive conversion if I have the extra $$$. What else should I do while I have the head apart?
- Is the one-shot oiler conversion worth it or is it just a nice feature for shops running 24/7?
wish me luck!
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I am at the same spot you are except I have completed the VFD and belt drive upgrade. I also replaced the spindle bearings like cruiser mentioned in a previous post. When I tore the gearbox open I found a sludge inside, made up of casting sand and oil. Also, most all bearings where damaged by this.
i would definitely get a one shot oiler. but not the cheapy lever operated one, get the automatic one. it will save you from runing your ways and ballscrews dry. also one thing i did was to build shims to go under the ball nut mounts to center the screws into the respective openings. also you may have to cut the axis for the ball nut open in the base casting so the y axis can move further. you paid for it might as well have as much travel as you can. always loctite all your screws in place and definitely use red loctite. it seems scary at first but i had to disassemble some stuff to loctite it after the fact, because some screws would vibrate loose when cutting. even with 2 axes you have alot of work ahead of you. good luck and take your time.
Having never worked with either -- I'm a manual mill sorta guy -- can you explain the difference or point me to a good example of an automatic one?Originally Posted by Runner4404spd
the one shot oiler whether manual or automatic does the same thing. it provides lube to the ways and screws. on a manual machine a manual oiler is fine since you pump it once or twice before you start machining and the few travels you make with the axes and over the screws is lubricated. when you run a cnc, the mill may make a lot of back and forth moves in a very short period of time. all this motion pushes the oil out from between the ways, sometimes you may remember to hit the oiler but if you walk away and let it run ideally you would want someone or something to relubricate you ways and screws. thats what the auto oiler does. its got a small motor attached to the pump so it can put out a shot oil once every 15 minutes or so.
Ok, that makes sense. On the 3D printers we only have to occasionally lube some carriers and slides (like wipers on a lathe or mill bed), didn't think about how much lubrication the ways and screws would need on CNC.
Thanks, this is exactly the sort of "of course you'd do X modification while you're in there" advice I'm looking for.
update: no progress!
SWMBO broke her foot so I've spent the past couple of weeks driving/shopping/cleaning/etc in all my copious free time.
On the upside, turns out a buddy of mine close by has a mill that I can use for drilling/tapping and cutting the channels for the one shot.
It don't take much of a mill for that. I have a friend that has a small HF mill and we did mine on it. It was just slow going. The rest I did on my drill press, breaking a few bits in those deep holes. Came to the point I don't like the gold colored drill bits very much. A black oxide seems to be more forgiving.
Bob
My original plan involved careful use of a die grinder and a straight edge to cut the grooves, so the mill is a step up!
It don't take much of a mill for that. I have a friend that has a small HF mill and we did mine on it. It was just slow going. The rest I did on my drill press, breaking a few bits in those deep holes. Came to the point I don't like the gold colored drill bits very much. A black oxide seems to be more forgiving.
Bob
FINALLY got started today, after clearing out a bunch of simple welding/fab projects for friends. Got the mill head (mostly) disassembled and off for cleaning/inspection. Now on to the column then the x/y tables.
I also scrounged what I need for a automagic one-shot lube system on eBay after doing a little research.
Crossing my fingers for the next week and a half.
Head and motor is off, x table is *almost* off. I am completely clueless on how to move it the final 8" or so without the screw. I have shoved as hard as I can, tapped with a deadblow hammer, and no real movement. It's supported on the far end, so I can't image it's purely friction as it was moving fine up until the acme screw bottomed out.
Off to dig through the archives, but would appreciate a pointer if anyone is reading...
Pull the screw supports off of both ends of the table and remove the gib. Leave the screw in the nut for now. Then just lift or slide it off. Be careful cause it's very heavy. I'm a 90 lb weakling and did mine. Didn't like it, but did it. Just have a place to set it down pre-determined before you get it hoisted off the saddle. Hope I'm remembering correctly!
Bob
AHA. I just loosened the gib screw, I didn't remove the gib entirely.
Like I said, it must be obvious. :-)
Seems like a few of us are installing CNC kits. I took my mill apart to move it into the basement many months ago. Then I got layed up from an accident, now I am getting around better and have started to install mine.
I did all the recommended mods to the cast iron. Removed the cross tie on the column (more Z travel), extended the opening in the base (more Y travel in combination with table extention), and bored the hole in the base (to facilitate ball screw installation). That latter is a must do in my oppinion.
I have completed the mechanicals on the Y. One hard learned lesson is to make sure the pulley is screwed down very tightly. I failed to do this the first time around, and after preloading the ball screw there was backlash caused by the ball screw moving forward and back as the pulley started to turn. Had not noticed this on initial install because there was not enough load on the nut. Lets just say Red Locktite on that long a thread is a bear to get undone. Took a long time to preheat with my heat gone.
You will find reference to a 1/8 inch sim under the y mount done by some people. I did this too. It makes the ball screw center perfectly in the hole in the front of the base.
Chris
I went out and bought a good quality strap wrench to use on the pulley and used two or three vise grips on the ball screw and managed to really tighten up the pulleys. Only used the blue Locktite, but once tight, it pretty much stays that way.
Bob
Yeah, those are on my list, as is possibly filling the base with some sort of granite/epoxy mix.
I'm not sure I've seen this, can you elaborate?
Sure, the height of the ball screw (relative to the base of the mill) is set by the mount on the saddle. As delivered by IH, the mount will locate the ball screw "high" in the hole in the front of the base. Placing a 1/8 inch shim under the mount will locate the ball screw dead center in the hole. If you have the 3 inch extender this is particularly important as the ball screw nut comes all the way out to the hole.
I discovered (by accident) that the saddle could come out so far (as I was testing travel, by hand) that the front wiper (snap on) got lodged in the hole and pulled off the ball screw nut on retraction. I will set my limit to prevent this in practice. I will also put a tie wrap on the ball screw as a fail safe.
Also of interest, if you have the Y extention you will likely not have to cut the ball screw. I think IH makes the Y screw to length for the extention. Without it you have to cut the ball screw.
Another tip is when installing the ball screw nut, put the first nut on the shaft and then rotate the second nut (still on the cardboard) so that the it can be placed as close to the first nut as possible (you will have to rotate the locking collar too). But keep both circulating tube in the same position relative to each other. Doing this will give you maximum range when you preload the ball screw. As delivered to me, the two nuts were far apart and the locking collar went way up on the threads during preload.
I had to use a chain pipe wrench to get the pulley off (pulley was wrapped with a leather strap to prevent damage). I used less loctite on the reinstallation. I did not use the wrench to reinstall but I did press the shaft forward (from the far end) and used by leather strap to get a real tight set on it. Now it is rock solid
Let me disclaim that I am learning as I go. I read as much as I could about what others have done and began my process from there.
Chris
Thanks, I think I get it. I don't remember ordering an "extension", but I bought my mill a couple of years ago so maybe it was included?
Because IH still hasn't sent me any instructions I'm working from an older set of instructions provided by someone who did this awhile back. The pictures are a little different but I am figuring it out.
One question for anyone who's done it recently: Does the guard that locks under the y-table with little pins get re-installed? Mine isn't wide enough to fit around the ball screw mount (see photo below), but a few minutes with a grinder and I could fix that.
I didn't re-install mine, but covered the ways and ball screw with a sheet metal cover attached to the front of the Y saddle. It slides back and forth with the saddle and extends out to cover the Y axis spacer and part of the motor brackets when the saddle is back towards the column. Here's a pic.
Bob
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