RE: JET JVM-626

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

Moderators: Harold_V, GlennW

Post Reply
Mike Warner
Posts: 3
Joined: Sun Apr 15, 2018 8:42 am

RE: JET JVM-626

Post by Mike Warner » Sun Apr 29, 2018 3:54 pm

Does anybody know where I may be able to purchase a manual for a 1980 JET JVM-626 vertical bench mill. I’ve been online the last week or so and have found nothing. JET Corp. was no help.
One other thing, I’m looking for a print or design of a 4”-6” riser for this mill. Can anyone help me out.

Regards,
Mike Warner; Monroe,Mi.

pete
Posts: 1451
Joined: Tue Feb 10, 2009 6:04 am

Re: RE: JET JVM-626

Post by pete » Sun Apr 29, 2018 4:48 pm

I can't help you with a specific manual but the Grizzly website should have a manual for there current version that should be close enough Mike. Jet just like Grizzly doesn't manufacture any machine tools, they have them painted and tagged with there logos. For example my 3/4 sized Bridgeport clone was built in Taiwan by Bemato. It's manual clearly shows pictures of Bemato and Jet mills that were the same size. So at that time Bemato was building at least one version of the smaller Jet turret mills. A few differences between them but the basic parts were the same. 38 years is a long time in the machine tool world and with all the different Asian manufacturers and suppliers it's doubtful Jet would even have records about who exactly made your mill.

I believe a guy on Youtube with the user name of Doubleboost installed a riser to his version of your mill. It might be worth checking his older videos. There not complex to make since heavy wall pipe with welded on upper and lower flanges to match what you already have are about all that's needed along with longer bolts. The riser does need to be accurately faced off so it's parallel. With the ratio between the riser faces out to the spindle centerline even a .001" difference in being out of square will show a large change in tram to the table. Since the head is much like the standard Bridgeport where it can be rotated for larger work then an accurate riser is required so no changes show up in whatever position the heads moved to. Depends on the size of lathe you have, if it's large enough then facing off those welded flanges with it turning between centers might be the best method unless you've got easy access to a surface grinder. Any time you add a riser there's going to be trade offs in the machines performance. Easier for chatter to develope and a bit less rigidity in the head should be expected. It's my understanding that these mills do suffer a bit on the total Z axis amount that's available so it's understandable your looking to increase that.

Mike Warner
Posts: 3
Joined: Sun Apr 15, 2018 8:42 am

Re: RE: JET JVM-626

Post by Mike Warner » Mon Apr 30, 2018 9:04 am

Thanks for the information Pete. I’ll look at the Grizzly website later on this evening and see what they have to offer. I bought this mill from a guy who bought it at a public auction at the Lionel Train Co. in Chesterfield, Mi. after the company went out of business. The mill has a few dings here and there on the painted surface but overall it is in almost pristine condition. I plan on doing a “up-grade” to the mill by adding a manual pump oiler and a small digital readout system on the x,y and z axis's if there is a decent and reputable one out there.
I understand what your saying concerning the parallism on the flange ends of the riser and don’t think that will be much of a major problem. A good friend of mine that owns a large tool and die shop allows me to come in on the weekends to use any of his machines that are idle when I have a small job to do. As far as the chatter is concerned, I may have a slight solution for that. I have a quart of rubber bed liner repair that I use to coat all the battery trays on the tractors that I restore. I plan to brush several coats of this liquid rubber. Don’t know for sure if it will work but I got a gut feeling it will

pete
Posts: 1451
Joined: Tue Feb 10, 2009 6:04 am

Re: RE: JET JVM-626

Post by pete » Mon Apr 30, 2018 3:42 pm

Well chatter under cutting conditions is caused by many factors. Harmonics being only one of them. Painting the inside of the riser with bed liner may or may not help but it can't hurt. I'm going by what I've read about those installing risers on Bridgeport machines and having to reduce feed rates and depths of cut a bit to make up for the machine being a little less rigid. If you normaly only run less than maximum feeds and depths you may not really notice it very much.

The self contained bar type dro's much like the digital calipers have seem to have a bit of a reliability problem by some. Today there's some fairly decent 2 and 3 axis dros around that use the more standard glass or magnetic scales and encoders. Mill vices, cutting tools and dro's are where your return on investment really pays off if you can possibly afford a bit better dro system. Even the built in half function, bolt circle, tool offsets alone just make things much easier.

Rigidity is everything with machine tools to get the best results. With a knee mill like yours it makes a difference when not drilling or boring to keep the spindle up all the way and locked then use the knee for Z axis moves. There is a noticable difference between both methods.

Russ Hanscom
Posts: 1437
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: RE: JET JVM-626

Post by Russ Hanscom » Mon Apr 30, 2018 8:42 pm

When we made risers for a mill, we added a number of reinforcing ribs inside the riser, not uniformly spaced. Made it a lot stiffer and not subject to any one frequency.

Mike Warner
Posts: 3
Joined: Sun Apr 15, 2018 8:42 am

Re: RE: JET JVM-626

Post by Mike Warner » Tue May 01, 2018 7:16 am

Thanks Russ ......That makes a lot of sense. The only reason I want to add a riser is so that I can set up a boring head if needed. If the mill had another 3”-4” of knee travel I would not even consider making a riser.

Russ Hanscom
Posts: 1437
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: RE: JET JVM-626

Post by Russ Hanscom » Tue May 01, 2018 3:46 pm

I found a riser block essential - always trying to get a big part into too short a space. My riser is 12" long and 16" dia - on a Gorton 1-22. For small parts I have a rectangular block that goes under the vise, and I have a riser block for me too!

wally318
Posts: 91
Joined: Sun Jun 05, 2011 1:06 am
Location: Kelowna, British Columbia

Re: RE: JET JVM-626

Post by wally318 » Wed May 02, 2018 9:08 pm

Hi Mike.
There is a specific 6 x 26 Yahoo group.
They would be your best bet.
And someone there probably has a Jet 6 x 26
from whom you might get an actual manual or copy of.

Post Reply