What's new
What's new

What is a Jig Borer used for ?

  • Thread starter Admin5
  • Start date
  • Replies 78
  • Views 145,939

Greg White

Titanium
Joined
Jan 22, 2007
Location
Pinckney Mi.
Yep

Never ran a Zip nor a Moore,plenty of DeVliegs.
I would like to weigh in on G&Ls,so sweet,especially the era when they were making their own controllers.
Good story going on here folks.
Respect
gw
 

Mikey D

Aluminum
Joined
Jan 4, 2006
Location
Good Ol Sunny Arizona
Boring with a torque plate

...boring small (motorcycle) cylinders on a Moore Jig Borer (and also a lathe). I've recently accomplished that by way of fabricating a combination torque plate and jig with which to hold a Harley Evolution Cylinder upside down. The plates are torqued per HD specifications...

(Jim's V-Twin).

Jim,

I'm glad to see someone else using a torque plate on motorcycle cylinders! the last time I took apart my CR500 I found shadows around the head bolt areas. (and chatter marks from the bone head who I paid to bore and assemble it the first time! GRRRR!!!). I made up a torque plate on my trusty, not so dusty, south bend 9" and gave it to a trusted friend with an engine shop to bore.

This cylinder has lasted way longer and runs with more power than ever before. I really don't want to soon but am looking foward to seeing the cylinder the next time i need a new bullet.

First Pict is the torque plate and the shadow fromt the head stud.

Second Pict are the chatter marks. This guy tried to tell me that the piston rings must have made those marks!
 

Attachments

  • torque plate - 1.jpg
    torque plate - 1.jpg
    29.5 KB · Views: 3,022
  • torque plate - 2.jpg
    torque plate - 2.jpg
    46.6 KB · Views: 5,038

Jim's V-Twin

Plastic
Joined
Feb 7, 2007
Location
Mississippi
Mikey D.
Understand your consternation. I've been into a number of engines where things were done improperly . . . didn't show up right away, but obviously would over time.
In regard to spindle travel, which was commented on, the Moore Head is so rigid that you can retract the spindle and lower the head and begin recutting without being able to tell where you left off. The first time I did it I reasoned that there probably would be a slightly detectable imperfection that would be taken out by final honing, but it was a non-issue. As for the fellow who performs to bore on a lathe, whatever works for him. I just don't think you can jig a jug up on a lathe as quickly and as accurately as you can on a Moore #2. The table feeds and heads, with pre-loaded bearings, are so precision you're just not going to get the same accuracy.
BTW, I just completely rebuilt an 80" Evo for a fellow with a '98 H-D Night Train. The pinion shaft runout way exceeded factory specs, so the crank had to be re-trued. Since it was already torn down he had me go back with .005" oversize Screamin Eagle high compression pistons. Runs great.
Happy Machining to all.
Jim
 

donie

Diamond
Joined
May 17, 2003
Location
Walla Walla Wine and Wild Turkey
The Jigborer now considered obsolete in industry, is a great machine for bike crankcase work.
I used Bridgeport for many years, the Moore is just plain more accurate and easier to use.
One little thing I like is, the spindle housing can be quickly retracted for gaging a bore, and then returned without losing true.
The Bridgeport, its either moving the table or lowering the knee, "not good".
If the Moore is in good shape, the spindle will be true to the table, regardless of quill extension and spindle housing location.
The table locking devises on the Moore, do not deflect the table, not so on the Bridgeport.
I modded the #2 for the finer quill feed of the #3 machine, .00075".
I did this by removing the Spindle speed indicator generator, and placing a compound pulley in its place, and using two belts to drive the quill feed box.
I installed a digital tach, with its sender reading a thin steel disk glued to the spindle drive pulley.
Many ways to go about HD cylinders. My main objective is, to have the cylinder base true to the bore.
 

bishop265

Plastic
Joined
Jul 4, 2010
Location
baltimore Maryland
Linley jig locking lever

Does anyone know which direction, UP or DOWN? The locking lever on the left hand side of the head of a Linley boring jig needs to go to unlock it? -thanks
 

MauriceG

Plastic
Joined
Sep 14, 2004
Location
Northern Utah
Moore wrote a wonderful book about Jig Boring, Grinding, and Measurement that brilliantly explains the problem and its solution. In the days before DRO's you had to mark-up work, transfer the work to the tool, orient it correctly, perform some operation, and then measure the result. Errors of transcription would build up and it was exceptionally hard to do things accurate to a tenth or better. The lack of precision in lead screws led to a lot of work with machinist buttons, gage blocks, scribers, etc. By making "perfect" lead screws, Moore made the machine as good as the measuring tool (Moore lead screws were designed to be as accurate as gage blocks). One might say that Jig Borers were the precursor to CNC machines and coordinate measuring machines. Moore's claim to history was to add a decimal point to the accuracy of machine work - this feat was an extraordinary one and makes a great story - I recommend Moore's book to anyone curious about the history of machine tools.

The book is called:

Holes, Contours, and Surfaces

Subtitled:
Located, Machined, Ground, and Inspected by Precision Methods

By Richard F. Moore and Frederick C. Victory

Published by the Moore Special Tool Company, 1955
I would love to add that book to my library. I have "Foundations of Mechanical Accuracy" by Wayne R. Moore c.1970 also published by the Moore Special Tool Co. It was reprinted in 1989 and is a wonderful history of the subject.
Maurice
 

cballen

Plastic
Joined
Dec 22, 2005
Location
Sandia Park NM
Hi folks,
This discussion brings back memories from my apprenticeship days(1974).
In my 3rd year I was able to run a SIp,Dixi, and P+W jig bores.
Great machines. The Dixi and Sip were in a temp and humidity controlled room (very comfortable in the summer in the DC Area).
The P+W had these magnetic scales that were really cool, very accurate.
There was a small trash can next to the Dixi. A long aluminum chip from the drill I was using fell in to the trash can. It just so happened that the
other end of the chip cane to rest against the 120v outlet. Presto! Fire! It was a small one,I was able to put out right away but after that no more trash cans next to the machine. I'd love to get one but I haven't used one since.
Thanks jimK for the trip down memory lane.
Carl
 

hitandmiss

Titanium
Joined
Jul 31, 2010
Location
Rochester, NY USA
As of the last 5 years or so, well equiped SIP's and Moore's are bringing scrap metal prices, less than really tired and stripped Bridgeports. The last one I saw, the buyer bought it for $100 and took the .0001" sony scales and left the mint machine! How sad.

Bill
 

43monarch

Aluminum
Joined
Sep 1, 2008
Location
pacific northwest
To help answer the question of what do you use a Jig borer for.My use for the 1 1/2 Moore I have is to build fixtures to hold heads for other machining operations.Today I am working on a fixture for holding a KJ Henderson intake manifold to machine the intake valve pockets,seats and guide holes on the bridgeport.The accuracy required for the placement of the holes requires it so that repeatability is a possibility.I guess there is always an upside to the scrapping out of America,sad but it does create opportunities.I,ll post some pics this evening of this project.
 

sticks

Cast Iron
Joined
Jun 20, 2012
Location
Mid-Michigan, USA
We had a 6" G&L (IIRC) in our tool room that was tight for its age but seldom used. Older guys who hobbed gears & did other tough walk-ins wouldn't touch our cheesy two Tree 325s or the 425 CNCs and preferred the jig-bore's easier setup/precision for locating. Worst day of my career might have been hearing I missed the auction when the plant was liquidated some time after I retired. Missed out on the 4 Cinci #2 tool grinders I'd had to myself 10 yrs or so for production tool work, tho' the backup I'd bought earlier is ok. Worst of all, I heard the jig-bore didn't sell & was scrapped. (aaack!) DRO locating/pattern software on my Grizzly manual is pretty cool, but holding a whole thou' is a matter of sheer luck any day ... :-/
 

[email protected]

Stainless
Joined
Mar 18, 2001
Location
Gaston, Oregon USA
Wow, a real blast from the past- I was the first to post a reply to this one in 2002. At that time I had a #3 Moore, and maybe by then a Kearney and Trecker Autometric. Fast forward 11 years, and still
virtually every day I'm operating some sort of jig bore. The Moores size limitations quickly became apparent as I was making larger and larger machines, so now I use three large Sip jig bores as well as Devlieg Jigmils.
I also regularly use a Bridgeport mill. I marvel at how effortlessly I can move the rather gigantic table on the Sip 7A in ten thousanths increments. I can SPLIT a tenth as easily on that machine, as I can machine to the the thousanths
on the Bridgeport. With FOUR FEET of daylight under the spindle, with the head in its upper position, the problems of boring deep holes in tall castings are a thing of the past.

It's an absolute joy to use some of the finest machines ever made. Its taken a long time, but with the full set of tilting rotary tables and a full assortment of tooling, these machines ARE pretty efficient. But this year I stepped up and bought
a CNC vertical machining center, which is built just like a Sip. Two columns, the spindle housing travels on a rail, gigantic table. It will be interesting in a year to see which ones I gravitate to the most.
 








 
Top