# Jet 15 mill



## RMO (Apr 17, 2011)

I have an opportunity to pick up an old Jet mill. Model 15 built in 1986. Fully manual, 2hp 3 phase motor, round column and a quite large head/pulley system to drive this spindle. The wheel handles that move the table have been bumped and the hard plastic is broken off in some places so they will need to be replaced eventually, but nothing looks bent. I noticed that in one direction the handle turned a full 10 thousands before it engages and moves the table and a full 20 thousands in the other. (Backlash?) Once engages it seems to move smoothly in both directions. The table looks good.

I thought this might be a good machine to learn on as I have not done any milling on my own yet and want something to use to get my feet week. They want a $1000 for it, but that seems kind of high. (I have hints that they would take $800) Is that reasonable? Can the play (backlash) on the mill table be corrected or improved? Would this be a good machine to learn on? I do have a freq drive that I can use to power it so I am not worried about the 3 phase power. I appriciate any advice.


----------



## Tin Falcon (Apr 17, 2011)

Some general info. Jets are usualy top of the line imports that vintage is likely Taiwan rather tan mainland china. 
All the imports come from the same factories . but the imports have there own qc and inspectors. Jet will tell you they get first dibs and pick the best of every run for to jet the white paint. so quality should be near the top for imports. 

If you are concerned about the availability of spares I would call jet and ask do not assume either way. And ask how long the spares will be available. they could be in stock today and slated for recycling next month do not know. 
All in all sounds like a nice solid machine you should be able to work out much of the backlash with thrust bearings etc or maybe just adjustment. 10 -20 thou backlash is not really that bad and unless you are trying to etch-a- sketch a contour it should not be a real problem for you. 
Tin


----------



## RonGinger (Apr 17, 2011)

If it really has that much backlash it must be pretty badly worn. It sounds like you dont have a lot of experience with mills, can you get a friend that has more experience go along to look at it?

I am not a fan of a round column mill- to many setup issues. 

Id keep looking, even $800 would not seem a good deal on this on.


----------



## Swede (Apr 17, 2011)

I agree with Ron. Even if cherry, $800 is way too much for a round-column mill. If I had the space, I might drop $300 and use it as a drill press or small boring machine, with the head trammed and kept that way.

The latest Chinese mills have gotten a lot better, and the larger machines seem to exhibit better fit and finish than the smaller "mill drills." Look for a square column, as much Z-axis space as possible, and if there's any chance at all, take your time, pool your $$, and find a nice clean knee-mill.

My favorite compromise mill (space and size) are the 8" X 36" "baby" bridgeport clones.  They are like a 3/4 scale B'port with most of the functionality of the larger machines, just more compact. Grizzly offers one, but the price might be too high. Used, they are out there. I've seen guys pick up chromed-way bridgeports with R-8 spindles for less than $1,000. With the shift for shops to CNC, there's a lot of good manual machines out there.

Good luck.


----------



## RMO (Apr 17, 2011)

Thanks all for the comments. I will keep my eye on the machine for a while. I have purchased equipment here before and the longer it sits in stock, the lower the price becomes as they are very space constrained and will often take a very low bid on something that has not moved just to make room for other stuff that comes in.  I am in no hurry as I plenty of projects already. Besides that I still have a lathe to put into shape.


----------



## awJCKDup (Apr 17, 2011)

RMO, here's my two cents worth. I have been at this for almost 2 years now, using a dove tail (or square column) bench top mill drill. I did CNC it, and it has been adequate so far, but I do end up moving the head up or down a lot, depending on what operation or tool is being used. Raising the head on a round column is difficult to do without losing your zero setpoint, not impossible but definitely harder. I would not settle for less than a square column, but if I had it to do over I would get a knee mill, more useful in my opinion - especially for us starting out.

John


----------



## Omnimill (Apr 18, 2011)

Using an old Mill with lots of backlash is no fun. I thought long and hard before buying my small Knee Mill and am so glad I did. Round column machines probably have their place but not as a main machine if you can afford anything better.

Vic.


----------



## RMO (Apr 18, 2011)

I think I get the message, thanks again. Not much available in the used mill category in southeast idaho so it is easy to "want" the first that comes along. If the price drops significantly, I will consider it, but only until I can get something better. Again thanks.

Mike


----------



## 44-henry (Apr 24, 2011)

I have a Jet 15 and it is a decent machine. I paid about $200 for mine four years ago. Mine is also much older as it has a 1/2 hp motor on it. Since I don't have the space for a Bridgeport this works well for me. The backlash can be dealt with by the addition of a DRO. Moving the head is a bit of a pain, but you quickly get used to it and its not a really big deal to me anymore. Though I think you could get a better deal, $800 is about what they would sell for in my part of the country unless you got really lucky, just not enough used machinery in these parts to keep the price down.


----------



## RMO (Jun 22, 2011)

Been awhile, but while I was looking at other projects the price dropped on the Jet mill/drill, (It is actually a Jet 16, rather than a 15). I was in talking with them and threw out an offer of $250. After a couple days consideration they called back and said come get your mill!!. (It had been at the sale location for six months) It came with a fairly sturdy table and a drill chuck and the manual. The table top is very clean with no cuts, gouges or scratches and while it still has the backlash issues, it appears to be mostly adjustment. We will see when I get a chance to go over it. Two of the three handles are broken, apparently this happened when the unit was moved to the sale location. The unit was used infrequently by the physics lab at the local college. My first mill and I have a little left over to buy some tooling.  Sorry the pic of the table is a but unfocused.


----------



## Rayanth (Jun 23, 2011)

RMO  said:
			
		

> I think I get the message, thanks again. Not much available in the used mill category in southeast idaho so it is easy to "want" the first that comes along. If the price drops significantly, I will consider it, but only until I can get something better. Again thanks.
> 
> Mike



Mike, don't want to derail your thread, but what part of SE Idaho? I'm originally from Idaho Falls, myself 

- Ryan


----------



## metalmad (Jun 23, 2011)

Good pick up Mike
Pete


----------



## Omnimill (Jun 23, 2011)

Looks like a nice machine for the money Mike. Spend a little time setting it up and maybe some new bits like leadscrew nuts and you can start making some chips on it! Do a search as well, there are plenty of tips around on getting the best from Mill Drills on the net.

Vic.


----------



## RMO (Jun 24, 2011)

Thanks I will look into the leadscrew nuts when I go through it,

Ryan, I am in Rexburg, about 25 miles from Idaho Falls If you are still in the area, let me know I am always willing to learn.

Mike


----------



## Rayanth (Jun 24, 2011)

RMO  said:
			
		

> Thanks I will look into the leadscrew nuts when I go through it,
> 
> Ryan, I am in Rexburg, about 25 miles from Idaho Falls If you are still in the area, let me know I am always willing to learn.
> 
> Mike



I'm not in the area any more, I'm now in the greater Seattle area. Just nice to hear of people from Idaho. Few are willing to admit they're from the state ;D

- Ryan


----------



## pete (Jun 24, 2011)

You've got a much larger mill than I started with and at a way better price. There's some work arounds for the round coloum problem on this and various other forums. .020 thou backlash is pretty good even for a brand new lower end machine and especialy so if those nuts have never been adjusted. If it were me I'd pull the X,Y table movements apart as it's a pretty simple job. I'd doubt that machine was properly cleaned up from brand new. You'll need to partially disassemble it anyway to adjust the nuts so you may as well strip it down the rest of the way. If you do this you'll find the movements will be far smoother and easier to get decent accuracy. While it's apart roll the leadscrews on a flat surface to see if they've been bent during that handwheel damage. New blank leadscrews aren't too tough or all that expensive to find if they have been bent. Handwheels can be bought thru companys like MSC industrial. Check your bearing hangers that support the leadscrews to see if they've been bent too. It's probably not a good idea to remove the leadscrew nuts from the machine as they've been or should have been carefully aligned to the table movements at the factory. Just use something like a spray can of electrical contact cleaner or carb cleaner to blast all the congealed oil and crud out of them.

Pete


----------



## RMO (Jun 24, 2011)

Thanks again for the advice and comments. 
Today I went to visit the physics department at the college which originally had the machine and found the other half (the drive half) of a power feed for the table. I was wondering why I had some of the parts and the manual for the power feed and what happened to the rest. I will go back next week as the person in charge was not there. Hopefully I can pick up the rest of the parts for the powerfeed as it was a add on for the Jet 16 and I don't think it will fit on the Smithy they just installed to replace the mill. I am told there were some space constraints and the 3 in 1 gave them more real estate. Who knows maybe I can talk them out of the large Jet rotary table and 3 axis tilting mill vise that are probably too large for the smithy as well.  (I can dream can't I?)


----------



## pete (Jun 25, 2011)

The power feed if you can get all the parts and it works would be a huge bonus. Same for the R/T. The 3 axis vise? Depending on what you build maybe not all that usefull. You can only take light cuts with them due to rigidity and your setting it by eye against a stamped scale. For single angles a cheap $50 sine bar and a $100 set of round spacer blocks will give you accuracy within a few .0001 of a true angle over that 5" length of the sine bar. The accesories for a mill never seem to end, I originaly spent 5 grand for the mill I now own and have spent over twice that on accesories alone and that doesn't include any cutting tools. Buy a cheap 20 pc set of 2 flute and 4 flute end mills to start with. After you get a bit more experience then start buying top quality ones like Niagra or OSG brands. There really is no comparison between the cheap stuff and the quality ones. Make or buy a flycutter. A real good 115 pc set of fractional,letter and numbered drill bits and ONLY use those for tap or clearance drills. IMO high quality, long lasting and sharp tooling is a requirement and not optional. All high speed steel and carbide tooling are not equal, With cutting tools you do get exactly what your willing to spend. It took me a lot of years to understand that I couldn't afford cheap cutting tools.

Pete


----------



## metalmad (Jun 25, 2011)

RMO
if u dont ask u dont get 
see what they say


----------



## RMO (Jun 25, 2011)

Pete, you were correct, the original grease had never been cleaned out of the table. A couple of hours of fun later the table moves very smoothly. There are no wear marks that I can see anywhere. I don't think this has had much use. 

I would like some advice on how to adjust the leadscrew nuts. I see there is a cap screw between the two sections of the nuts that when tightened would pull the two sections of the nut closer together. How do you tell when you have got it right? I played with one, but could not seem to get it to reduce the backlash and I don't want to crank on it too hard. I can imagine what might happen.

Thanks

Mike


----------



## Tin Falcon (Jun 25, 2011)

I think folks get confused with backlash issues. there are two sources of backlash. wear on the nut is one but more important is play in the lead screw mounting . take care of this first this usualy where most of the backlash comes from. the nut adjustment should be minor. 
Tin


----------



## RMO (Jun 25, 2011)

I think I was one of the confused ones. If I understand you correctly Tin, this means that I need to do something to take up the slop between the thrust bearing and the mount. I did notice that there was some play there, but did not see any adjustment. Just the housing, the thrust bearing and a sleeve/handle mount that was held in place by a roll pin. Would you mind pointing me in a good direction to learn more about how best to correct this?

Thanks


----------



## Omnimill (Jun 26, 2011)

Tin's right on the mounting, you need to make sure everything else is tight first. Not sure how the adjustment works on your leadscew nut even though I've seen pictures of it : But maybe you're turning the bolt the wrong way? Some leadscew nuts are in two parts with a strong spring between them to keep the two half's apart.

Vic.


----------



## Tin Falcon (Jun 26, 2011)

I am not familiar with your mill but it seems there should be some way of adjusting the thrust collar. the first place to looks is Your manual. These should be available on line. if you do not have one. there may or may not be instructions for adjusting out end play. but an IPB (Illustrated Parts Breakdown ) should give you a good idea. beyond that an internet search may help you have a fairly popular hobby machine that has been around for a while I would think someone has gone before and written , blogged or otherwise documented a procedure or fix. it may even require changing or adding a thrust collar. 
Hope this helps.
Tin


----------



## pete (Jun 26, 2011)

Mike,
A lucky semi-educated guess on my part about your mill never having been properly cleaned. Most people who aren't paying for the equipment rarely take the time to look after it. You got lucky too with the lack of wear on your machine. I'd highly recommend a proper way oil for lubrication. It does make a difference. Automotive high detergent motor oils are NOT compatible and especially so with those bronze leadscrew nuts. 

The advise and people not willing to comment about the proper procedure to adjust your leadscrew nuts is 100%, Unless you've had one of these machines it's too easy to be wrong. Someone here or on another forum will know for certain. Even with a properly adjusted machine you'll still have a certain amount of backlash but there's nothing wrong with trying to reduce it to a minimum. I own a 3/4 sized Taiwan built Bridgeport clone mill and even brand new it had .004 of backlash. Just be careful not to adjust your machine too tight or you'll accelerate the wear by a large factor.

When I bought my mill I was forced to pull it apart to get it into my shop. That worked in my favour as it allowed me to see the need to clean out all that preservative dragon fat? grease. I'd highly recommend doing the same for anyone else and for any size mill from the smallest benchtop mill to full sized ones. Too many people get in a rush to try the machine out. I also pull my machines table off about once a year to verify that the one shot lube system is working at all the points and also clean off the minor amount of metal particles due to wear. IMO that can only help to slow the wear down. Machine tools are like any mechanical equipment, They do require a certain amount of preventative maintenance.

Pete


----------



## RMO (Jun 27, 2011)

This just in! They are going to give me the power feed for the mill. The rotab and other items will go on sale in the next month so I might be able to get those as well. In any case, thanks again for all the help. Hopefully I will be able to start making chips soon.

Mike


----------

