Problem with Bridgeport backgear
 

Not really sure what model the mill is but from what I've read it is a
2J head.
The problem is the backgear won't engage. The mill seems to run fine in
high but won't switch back to neutral or low. I know I'll probably have
to disassemble to top part of the machine to find out why but I wanted
to ask if anyone has any info on this problem or advice for what parts
I need to remove to gain access to the backgear.

Thanks,

Steve

Problem with Bridgeport backgear
 

On 6 Mar 2006 07:20:50 -0800, wrote:

Not really sure what model the mill is but from what I've read it is a
2J head.
The problem is the backgear won't engage. The mill seems to run fine in
high but won't switch back to neutral or low. I know I'll probably have
to disassemble to top part of the machine to find out why but I wanted
to ask if anyone has any info on this problem or advice for what parts
I need to remove to gain access to the backgear.

Thanks,

Steve


Are you sure the release at the top of the head is working? They do
wear and the release lever will not drop the transfer gear down.

This is something you are likely going to have to disassemble the head
to find out. Should take you about an hour or so.

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3

Problem with Bridgeport backgear
 

wrote:

Not really sure what model the mill is but from what I've read it is a
2J head.
The problem is the backgear won't engage. The mill seems to run fine in
high but won't switch back to neutral or low. I know I'll probably have
to disassemble to top part of the machine to find out why but I wanted
to ask if anyone has any info on this problem or advice for what parts
I need to remove to gain access to the backgear.


What, exactly is the problem? Do you mean the handle can't be MOVED
to the low-range position, or the machine locks up the spindle when in the
low range? Either problem may come from the same area. The direct-drive
clutch is disengaged by pulling up on the driven (front) pulley assembly.
The whole pulley assembly in its bearing mount lifts up about 1/4". There
is a cast iron ring with two cam slots in it that fits around the bearing
assembly on the top of the housing. It has 2 1/4" pins that ride in the cam
slots. Rotating the ring lifts the bearing and the pulley. These pins are
a bit weak, and get chewed up until they can bind, shear off, or just get
really loose. You can unscrew them with a straight-blade screwdriver,
but don't take both out at the same time, or the pulley assembly will
drop to the bottom. Sometimes you need to rethread the holes in the
bearing mount to the next larger size and make new pins on a lathe.

Anyway, in either case, this area should always be inspected for wear and
damage.

If the handle moves part way, but won't go fully into low, then you
often need to
turn the spindle 10 - 20 degrees to put the spur gears into alignment.
Don't
change the hi-low setting while running, although you have to change the
vari-speed
pulley setting while it IS running.

Especially since you say you can't get it even into neutral, it sounds
like binding
in that cam ring. If the problem is the pins and cam, you don't have to
take
anything off to see it. Just do one pin at a time so you don't drop the
pulley.

Jon

Problem with Bridgeport backgear
 

replying to Jon Elson, Edke6bnl wrote:
great explanation I have two sets of stripped threads for the 1/4 in pins. I
will need to do what you say and tap them larger and make new pins. but for
now I just put a .025 shim under the ring and it slides better than ever. I
did find that to put the pins in I could put the rubberized arms of my channel
lock pliers under the pulley and lift up the assembly to align and reinstall
the pins

--
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Problem with Bridgeport backgear
 

replying to steve, Dale Daus wrote:
Series 1, wouldnt change high-neutral-low easily, they broke the lever,
replaced it, still didnt want to change, lever missing again, rod isnt
the same, they are only guessing because they dont know, mill had digital
read out,power feeds,they have broken all that, has other issues with the
table but usable, really need high-neutral-low working,Im a machinist
,Ive told them we need to at least to fix it because of feeds and speeds,no
manual on the mill,I need help to fix it in a timely manner,thats what
theyre concerned about,help please

--
for full context, visit https://www.polytechforum.com/metalw...ar-479655-.htm