# Possible first v-mill?



## HEPHAESTUS

Hello everyone.  New to the forum, not new to machines in general.  I would say that I am still an amateur though.  I have owned a lathe for many years and taken college courses on vertical mills.  I've been in the market for a mill for years, never have found the right deal.  I've got a few projects that have been adding up over the years that I'd like a mill for and I feel like it's time.  My biggest issue is just my location, there's nothing around here.  So many of the deals  I find are a risk / rewards assessment that includes travel time.

Anyway, I've found this beat up old Jet mill.  Several handles are either missing or broken.  I think I can repair those easily enough.  But the overall condition of the machine is a little worrisome just from the pics.  That being said, I know sometimes things can get beat up just from sitting there and a fresh coat of paint is all they need.  The dealer knows nothing about it, hasn't even powered it up.  No model number on it, he says.  Just wondering if anyone has any insight on it?  The price is right (Under $1000) and it's about 5 hours away, which is about average for everything it seems.  (Again, my location just sucks for anything having to do with automotive / machines / mechanical stuff.  No one around here works on things so everywhere that would support such an activity is far away.  There is no industry here.)  I know it's probably 3-phase, I can deal with that.


----------



## machPete99

Need to look at the condition of the ways, can't see them in your pictures.
If they are rusty or grooved I would pass.


----------



## HEPHAESTUS

machPete99 said:


> Need to look at the condition of the ways, can't see them in your pictures.
> If they are rusty or grooved I would pass.



Yeah, I know, thanks.  I'm not sure what the dealer's issue is.  He has been very difficult to get info out of.  I know he's elderly.  It seems like he may have mobility issues and he's not good with electronic communication.  I've asked him for pics of the ways.  It's taken him a few days to get a pic when I asked for them.  And when he sends them he sends them one at a time and gets frustrated when I ask for more.  We'll see ...

Does anyone have any idea what model this might be?  I've asked Jet and they can't seem to identify it yet.  I've looked at every manual available on their website, for both current and obsolete models, and this doesn't match any of them perfectly.  It seems to have features from several that I see but not completely identical to any.  The speeds are variable from 80-3800 and the table size is either 9x42 or 10x50.  (Again, dealer has measured twice for me and come up with both those measurements, doesn't seem willing to measure again.)


----------



## HEPHAESTUS

He just verified the table dimension.  It's 10x50.  You would think he would snap some pics while he's in front of the machine but nope.


----------



## Aaron_W

At less than $1000 in an area you describe as machinery sparse it sounds to me like it is worth a drive to take a look at it. Take your significant other and make a weekend out of it, then if it isn't worthwhile you still have a nice weekend. If it is worth getting, pay the man and make a plan to get it home. 

It sounds like the seller is technology challenged rather than being evasive. Being patient and putting in some extra effort may pay off. Going to look at it should tell you if it is just some broken knobs or junk.


----------



## HEPHAESTUS

Yes, definitely technologically challenged, not evasive.


----------



## markba633csi

The biggest concern for me would be the vari-speed head.  It may be broken or very worn and you may not be able to source parts for it even though Jet is still in business.  You do have a lathe though so that may help if you need to make a part.  Hard to tell.  If you can't run it and test it out I would pass, personally.  Long table machines can be problematic and not work smoothly at the ends of travel.  I would stick with a short table like a 32" or 36". I'm not saying don't buy it, but I smell some issues with it, be skeptical
-Mark


----------



## HEPHAESTUS

markba633csi said:


> The biggest concern for me would be the vari-speed head.  It may be broken or very worn and you may not be able to source parts for it even though Jet is still in business.  You do have a lathe though so that may help if you need to make a part.  Hard to tell.  If you can't run it and test it out I would pass, personally.  Long table machines can be problematic and not work smoothly at the ends of travel.  I would stick with a short table like a 32" or 36". I'm not saying don't buy it, but I smell some issues with it, be skeptical
> -Mark



That's probably a good point about the head.  It appears not to matter anymore though.  I guess the seller got tired of getting actual information about what he was selling and stopped responding.

Now I'm onto a step pulley Bridgeport clone that appears to be in great condition with tons of tooling and a phase converter for $2500 - $3000.  The name cast into the base is Kodiak, which I've never heard of and can't find any info on.  But every bit and piece of it looks like all the other Bridgeport clones I've ever seen.  Anyone know anything about Kodiaks?


----------



## markba633csi

There's probably a hundred "brand" names for the clone machines.  Fortunately some of the parts interchange .  Phase converter or rotary phase converter?  What is "tons of tooling"?  A decent vice and collet set would be good, at the minimum.  A DRO is nice if it is functional and not too old. Add a dividing head and then you're really talking
-Mark


----------



## HEPHAESTUS

markba633csi said:


> There's probably a hundred "brand" names for the clone machines.  Fortunately most share many of the parts.  Phase converter or rotary phase converter?  What is "tons of tooling"?  A good vice and collet set is would be good, at the minimum.
> -Mark



I know there's a million brand names, but when I've happened upon them Google has enlightened me on all but Kodiak.  Literally zero results for Kodiak.

Vice, collect set, some end mills.  I think it's just a VFD, but it doesn't matter much because I have a 7hp rotary that I run my lathe on that I could just pull power off of for this.  Here's pics, I would be getting everything in the pics:




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/117303604_3217048675057343_2257625457223517175_n.jpg?_nc_cat=108&_nc_sid=b96e70&_nc_ohc=KOdYDxREjH0AX-j08tL&_nc_ht=scontent-atl3-2.xx&oh=fa099c1c039e3ed369d3dfbf8dfb9abd&oe=5F58975D
		




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/116600816_1111275459266019_9149348940405087970_n.jpg?_nc_cat=107&_nc_sid=b96e70&_nc_ohc=Q7ZUNkhT-oIAX_W7PD1&_nc_ht=scontent-atl3-2.xx&oh=2c123431bc90a52167028feb228b331e&oe=5F59C290
		




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/117444606_1201433043572415_5715091339299974924_n.jpg?_nc_cat=102&_nc_sid=b96e70&_nc_ohc=yNQH1xcdaFUAX8vUIne&_nc_ht=scontent-atl3-2.xx&oh=a5148dcd5c3af2d9e5a672dd4ebfdefc&oe=5F58C741
		




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/116639245_1037207070030178_3200795039673367340_n.jpg?_nc_cat=101&_nc_sid=b96e70&_nc_ohc=O0YjnDbdsJAAX95l18j&_nc_ht=scontent-atl3-2.xx&oh=7715d736ad8c3b3600d3a1d57e0eade2&oe=5F5BBE55
		




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/117079716_947070839144559_625994655758675648_n.jpg?_nc_cat=101&_nc_sid=b96e70&_nc_ohc=doqorM0buUgAX8vXPoA&_nc_ht=scontent-atl3-2.xx&oh=48e12b1c74528cc23d7bdce67c8ba66f&oe=5F5BF32F
		




			https://scontent-atl3-2.xx.fbcdn.net/v/t1.15752-9/107093913_733735337196715_8706270525186475740_n.jpg?_nc_cat=111&_nc_sid=b96e70&_nc_ohc=L8tkbPunagwAX-5bOuS&_nc_ht=scontent-atl3-2.xx&oh=dd10f649fa597066547c1ca03d6f0d68&oe=5F58EC4A
		


I also have a video of it running that is not shareable.

He's stuck at $3000 for it all.  That's more than I wanted to spend but maybe the tooling makes it worth it?


----------



## markba633csi

Probably more than I would pay, but then I'm a real penny-pincher.  Could be a good deal though.  I'm in a semi-machine desert here as well. I sometimes wish I lived in the Northeast for the great selection of machines


----------



## HEPHAESTUS

He changed his mind, didn't want to include the vise like we originally discussed, but didn't want to lower price.  Told him I would pass.  The search continues ...


----------



## HEPHAESTUS

I found one today.



			https://i.ebayimg.com/images/g/u~8AAOSwGihfOhTH/s-l1600.jpg
		




			https://i.ebayimg.com/images/g/XaMAAOSwccdfOhTZ/s-l1600.jpg
		




			https://i.ebayimg.com/images/g/guYAAOSwbyFfOhTg/s-l1600.jpg
		




			https://i.ebayimg.com/images/g/5PUAAOSw7BdfOhT1/s-l1600.jpg
		


It was 1.5 hours from home, the first even remotely that close that I've seen in years within my price range.  The ways seem like they're in decent shape.  The DRO and power feed both work.  There's a lot of backlash on both x and y but I can deal with that.  Came with all the end mills you see and some others as well as the massive vise.  I'm not ecstatic about the brand name but given the alternatives I've been watching for years was not something I could turn down.

Blew a rear tire out on the way to get it and the other rear tire has a 5" bubble that developed on the way home.  Got to love factory Firestones.  That was probably one of the sketchiest rides home I've ever had.  That top-heavy mill standing up in the bed of my truck for an hour and a half on I-10 running on a spare tire with the other tire shaking more and more violently the further I went.  LOL.


----------



## Mitch Alsup

HEPHAESTUS said:


> Blew a rear tire out on the way to get it and the other rear tire has a 5" bubble that developed on the way home.  Got to love factory Firestones.  That was probably one of the sketchiest rides home I've ever had.  That top-heavy mill standing up in the bed of my truck for an hour and a half on I-10 running on a spare tire with the other tire shaking more and more violently the further I went.  LOL.



a) did you put the tire pressure up to side-wall rated pressure? (around 50 PSI)

b) how fast had you been averaging in the 10 minutes before it went bang?


----------



## HEPHAESTUS

Mitch Alsup said:


> a) did you put the tire pressure up to side-wall rated pressure? (around 50 PSI)
> 
> b) how fast had you been averaging in the 10 minutes before it went bang?



It's a 3/4-ton truck with load range E tires.  Sidewall psi is 80 and I keep it there because I only use the truck for towing.  But last time I was towing my RV I felt the vibration start toward the end of the trip.  I suspect this was the inevitable conclusion of that.  The tongue weight of my 5th wheel is well within the payload capacity of the truck and tires so who knows why they blew.  The first one blew when I was empty doing 80mph on I-10 heading to get the mill and the second one after I had unloaded the mill and was on my way home.  (I felt it going so I only did 65mph home.)  So I'm just glad neither went with either the mill in the bed or the RV hooked up.  Definitely the sketchiest trip home I've ever had.


----------



## pontiac428

The thicker the ply, the harder they fail.


----------



## HEPHAESTUS

pontiac428 said:


> The thicker the ply, the harder they fail.



Haha.  I think I would approach that from about 100yds with a rifle.


----------



## pontiac428

Yeah, just aim for the split ring!


----------



## HEPHAESTUS

Thoughts on VFD vs rotary?  Basically, I hate listening to my rotary run.  Are bearing concerns with VFD unfounded?  Seems like many use them ...


----------



## pontiac428

VFDs are really popular here.  They are affordable.  I don't think there's any cause for bearing wear, especially since you can soft-on/soft-of with the push of a button on a VFD.  If you can isolate the power mains for the motor you are driving, VFD would do the job well.

I like the rotary in my shop.  A rotary is a 3-phase power source you just plug the machine into and go.  If I want to run another 3-phase machine, swap plugs and go.  My reason for going rotary is not wanting to cut apart the beautiful and complex wiring job inside my mill's panel box.  I get to keep my ever-important 2-speed motor so my machine runs the full range as intended.  You could work around that, but it is a workaround.  I don't want workarounds.  So I get the most straightforward use of my machines, and whoever gets them next (outta my cold, dead fingers) won't have to figure out what I did to the machine.

You could really go either way, but you already have a rotary setup.  I'm sure others will have equally convincing ideas in favor of VFDs, probably forming the majority.  A lot of VFD installs have been done by the members of this board.


----------



## HEPHAESTUS

VFDs are scientifically proven to cause motor bearing damage over time.  It's one of those things that is so negligible that it is nearly inconsequential I think.  You can read more about it here:






						How Do VFDs Cause Bearing Damage? | The AEGIS Blog
					

How variable frequency drives cause electrical bearing damage, explained as simply but accurately as possible.




					est-aegis.info


----------



## DavidR8

HEPHAESTUS said:


> VFDs are scientifically proven to cause motor bearing damage over time.  It's one of those things that is so negligible that it is nearly inconsequential I think.  You can read more about it here:
> 
> 
> 
> 
> 
> 
> How Do VFDs Cause Bearing Damage? | The AEGIS Blog
> 
> 
> How variable frequency drives cause electrical bearing damage, explained as simply but accurately as possible.
> 
> 
> 
> 
> est-aegis.info


Interesting. From the article it sounds like the HF currents in 100hp and above are the bearing killers.


----------



## pontiac428

Fascinating.  I expected to see a jagged waveform, but I'd think that would be damped by rotating mass.  As far as induced current goes, wow, never imagined bearings would ablate from electrical discharge due to the VFD.  I can imagine this was discovered the hard way and at the worst time.

How to quantify the risk to your equipment is the hard part.  Still, wow.


----------



## Mitch Alsup

HEPHAESTUS said:


> VFDs are scientifically proven to cause motor bearing damage over time.  It's one of those things that is so negligible that it is nearly inconsequential I think.  You can read more about it here:
> 
> 
> 
> 
> 
> 
> How Do VFDs Cause Bearing Damage? | The AEGIS Blog
> 
> 
> How variable frequency drives cause electrical bearing damage, explained as simply but accurately as possible.
> 
> 
> 
> 
> est-aegis.info



I wonder if you could put a little commutator onto the output shaft and capture the currents away from the bearings?


----------



## HEPHAESTUS

Mitch Alsup said:


> I wonder if you could put a little commutator onto the output shaft and capture the currents away from the bearings?



It talks about things that can be done to save the bearings in the next article / tiny link at the bottom:









						Best Practices for Bearing Protection
					

Electric motors driven by VFDs are vulnerable to electrical bearing damage. Here's how to protect their bearings.




					est-aegis.info


----------



## HEPHAESTUS

I cleaned it up a bit and got it moved into it's new home yesterday.  I love owning a forklift.  Best money I've ever spent.  There used to be an industrial washing machine concreted to the ground there so I had to bust some concrete out to get back to a flat surface.  Hopefully wire it up tomorrow.


----------



## jlesser27

HEPHAESTUS said:


> It talks about things that can be done to save the bearings in the next article / tiny link at the bottom:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Best Practices for Bearing Protection
> 
> 
> Electric motors driven by VFDs are vulnerable to electrical bearing damage. Here's how to protect their bearings.
> 
> 
> 
> 
> est-aegis.info



We see VFD caused bearing failures all the time. In fact we are installing (6) Aegis split core shaft grounding rings next week at a state building in Oakland. Highly recommend you install the shaft grounding ring on a converted VFD system. They are really easy to install, typically (3) 6/32 taps into the motor housing and some loctite and away you go. 


Sent from my iPhone using Tapatalk


----------



## kb58

I don't disagree that this may be happening, but I suspect that the problem takes a long time to show up. That is, it's probably a big deal for industrial users, but what about us who use our small stuff a couple hours a week. In other words, if it fails after 5000 hours of use, that's not a concern. Just trying to get a read on the scope. I mean, if you wait long enough, the sun will expand and will ruin our machinery, too...


----------



## GunsOfNavarone

I'm guessing you could talk him down a bit if this is his asking price. That would be a fun project, I'd just be worried about the ways/wear.


----------



## jlesser27

kb58 said:


> I don't disagree that this may be happening, but I suspect that the problem takes a long time to show up. That is, it's probably a big deal for industrial users, but what about us who use our small stuff a couple hours a week. In other words, if it fails after 5000 hours of use, that's not a concern. Just trying to get a read on the scope. I mean, if you wait long enough, the sun will expand and will ruin our machinery, too...



The problem can happen quickly we have seen failures within a few hundred hours on machines that have motors that are older and converted to VFD. The shaft grounding rings for most of the motors we deal with are only about $125 so it really is cheap insurance. What happens is the small eddie currents find their way out through the bearing and shaft. When this happens you get micro arcing/potting between the balls in the bearings and race. Now depending on how all the stars align this can take a while but depending on wire length, output current, harmonics it can happen quickly. 


Sent from my iPhone using Tapatalk


----------



## HEPHAESTUS

Today I got it cleaned up, powered up, and trammed in.  I also cleaned up the massive 8" vise that came with it.  My back is hating me for lifting that thing.  Everything seems to work great except two small issues:

1.  No elevation crank.  It is a 30mm, 7-toothed crank and I can't seem to find any on eBay except for one that won't arrive from China until Oct.  Maybe someone here has a lead on one?  For now I'm going to try to 3d-print a Crank Yanker and if I can't eventually find something I guess I'll machine my own.

2.  The quill auto-feed works if I hold the engagement handle in, but it does not stay in on it's own.  My best guess is that there's a retaining ball / spring somewhere in there that is either worn or missing?  Any ideas there?  I'm looking in my manual but the resolution of those parts is so crappy it's hard to tell anything.


----------



## HEPHAESTUS

3d printed crank yanker worked better than even I thought it would.  Will report back on how long it lasts.


----------



## Mitch Alsup

You might just want to machine out that part in some kind of steel while the printed version is in working order. Then swap it in permanently.


----------



## HEPHAESTUS

Mitch Alsup said:


> You might just want to machine out that part in some kind of steel while the printed version is in working order. Then swap it in permanently.



The steel crank from China shipped yesterday.  So I just need to make it until it gets here.  It says it will be a month but it's never actually that long.

That piece was doing good until I tried to put aa power tool on it.  LOL.  I'm going to print it again with a collar around the cogs this time.

I fixed the quill auto feed today.  It was just gunked up.

Drill some holes for the first time with the mill, too.  Having fun.


----------



## HEPHAESTUS

Version 2.0.


----------



## HEPHAESTUS

Mitch Alsup said:


> You might just want to machine out that part in some kind of steel while the printed version is in working order. Then swap it in permanently.



I would like to eventually make it out of steel.  I don't have an indexing table though.  How would I do it without that?


----------



## pontiac428

HEPHAESTUS said:


> I would like to eventually make it out of steel.  I don't have an indexing table though.  How would I do it without that?



The best low-cost way would be to use a hexagon collet block in your mill vise.  Very accurate, very affordable.


----------



## HEPHAESTUS

pontiac428 said:


> The best low-cost way would be to use a hexagon collet block in your mill vise.  Very accurate, very affordable.



You're suggesting that as a way to hold the piece I think?  But that's not my main issue.  My issue is how to mill the grooves from 7 equally-spaced angles.  360 / 7 = 51.42857142857143 degrees of rotation for each cut.  Easy on an indexing table but how would it be done without?


----------



## HEPHAESTUS

Actually, now that I think about it, it wouldn't be 7 angles.  It would be 7 PAIRS of angles, one cut to cut each side of each cog / tooth.


----------



## pontiac428

Aaahhhhh, you said 7 tooth crank... yeah, division by 7 takes a different approach.  You can do the geometric layout with a compass and scribe using dividing techniques known since antiquity, and using a mill vise, v-block, and square you could mill the form "good enough" for a crank handle, yes?  If you have the Karl Moltrecht books, the chapter on dividing is excellent.


----------



## HEPHAESTUS

pontiac428 said:


> Aaahhhhh, you said 7 tooth crank... yeah, division by 7 takes a different approach.  You can do the geometric layout with a compass and scribe using dividing techniques known since antiquity, and using a mill vise, v-block, and square you could mill the form "good enough" for a crank handle, yes?  If you have the Karl Moltrecht books, the chapter on dividing is excellent.



Maybe using Solidworks is cheating, maybe it won't work?  But here's my tentative plan:

I will 3d-print the blue 7-sided collet and vise block in these pics.  Then I will center on the part ID.  Using a 1/4" end mill I'll offset my center by 1/8" along one axis.  Then I will run the mill all the way through both sides of the round part.  This will cut one edge of one tooth and the opposite edge of the opposing tooth.  The rectangles imposed on the round part in the one pic will be my cuts.  By rotating my block I'll just run the cut along the same axis again all the way through.  After repeating this 7 times I should have all 14 cuts done accurately.  I'll probably rubber cement the piece into the collet so that it doesn't rotate on accident when I am rotating the collet / it isn't in the vise.  Anyone see any issues with this idea?

I'll probably also print a 6-sided collet so that I can flip it over and cut a hex on the other side for the socket.


----------



## HEPHAESTUS

Does anyone happen to know the name of the Chinese company that makes these for Enco?  I knew it at one point but have forgotten it.  It is two Chinese words ...


----------

