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? This is the fine-adjuster to LMS 4700 Mill. Have somebody made a lock for this? ? My adjuster is moving (turning) when I am milling, and before I am doing something stupid, I want an advice from you. ? Best regards Johannes ?
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I bagged that whole rack-pinion thing for something a bit more robust:
Actually my wife wanted it changed. She used it when we first got it, said it sucks, and suggested the stepper I did, or something like this:
I can send the 3D model of that if you'd like...Uses off the shelf gears from Boston Gear. Uses the same CNC Fusion ball screw.
I've been using the stepper/Arduino thing for years and really like it. I can get accurate depths that hold.
As to the stock mini mill setup, everyone states you should lock the gibs, or tighten them up. Also you can check your rack-pinion mesh and shim the rack to make it a bit more tight.
I didn't like any of those suggestions. A rack-pinion is great for a drill press; not so much for a mill, at least in my opinion...
//
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On 7/25/2017 10:12 AM, 'Johannes' johannes@... [7x12minilathe] wrote:
l.JPG?dl=0
This is the fine-adjuster to LMS 4700 Mill.
Have somebody made a lock for this?
My adjuster is moving (turning) when I am milling, and before I am doing
something stupid, I want an advice from you.
Best regards
Johannes
|
I see you have the 4700 micro - a bit different than the mini that I posted a link to.
Not sure how you'd fix the slop in that...
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Show quoted text
On 7/25/2017 10:12 AM, 'Johannes' johannes@... [7x12minilathe] wrote:
l.JPG?dl=0
This is the fine-adjuster to LMS 4700 Mill.
Have somebody made a lock for this?
My adjuster is moving (turning) when I am milling, and before I am doing
something stupid, I want an advice from you.
Best regards
Johannes
|
Johannes,
The Z axis fine-adjustment mechanism is one of the more poorly-designed components of these machines.? It is a sloppy worm drive that engages a sloppy castle nut system which drives a sloppy rack and pinion.? Sloppy cubed = VERY sloppy :).
The end result is the so-called head drop problem where the head will suddenly drop during a milling operation.? The vibration encourages the head to seek equilibrium, with sometimes bad results.
Solutions include an improved head lift -- replacing the torsion spring with an air spring (your machine probably already has the air spring), and ALWAYS lock the z axis before you start milling.? Putting a DRO on the z axis can be helpful here because the z axis often moves a little when it is locked (mine moves about .001" down).
If your fine-adjust knob is moving even when the z axis is locked it's probably not affecting the actual z axis position, just messing up your positional accuracy.? This is where a DRO or DI attachment shows its real worth.? They are independent of the crappy z axis drive system.
I would have just suggested you visit the GrizHFMinimill group but many folks in this group belong to that one, too.? However, it would be the one to get input on how owners have tried to address various parts of the z axis problem.
Mark
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Does it move when you have the Z axis lock lever on the left side
of the column locked down??? Unless you are really using this in
the "drill press" mode, that should be locked after the cutter
depth is set.
Does the cutter move, or does just the knob move??
On the X-2, the knob will move within the slack zone, and it is
important to take up the slack before unlocking the Z axis.?
However, with the Z axis locked, the tool itself does not move.
I dont like the sloppiness of the X-2, so I work with an
indicator on the Z axis to measure/set depth.
Warren L
On 7/25/2017 10:12 AM, 'Johannes'
johannes@... [7x12minilathe] wrote:
toggle quoted message
Show quoted text
?
?
This is the
fine-adjuster to LMS 4700 Mill.
Have somebody
made a lock for this?
?
My adjuster is
moving (turning) when I am milling, and before I am
doing something stupid, I want an advice from you.
?
Best regards
Johannes
?
|
The GrizHFMinimill group has been dormant for some time. I think most posting has been done here. ---In 7x12minilathe@..., <mark.kimball2@...> wrote <SNIP> I would have just suggested you visit the GrizHFMinimill group but many folks in this group belong to that one, too.? However, it would be the one to get input on how owners have tried to address various parts of the z axis problem.
Mark
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WAM there is a recessed M8 socket screw bolt that locks quill in position on the other side of the headstock. I have added a lever to mine so I do not need to find the M8 allen key, see:
Mike
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That's a great idea.
You always have cool stuff for these Sieg things... your site should to be required reading for anyone with any of these mill/lathes...
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On 7/25/2017 2:18 PM, mikey.cox@... [7x12minilathe] wrote: WAM there is a recessed M8 socket screw bolt that locks quill in position on the other side of the headstock. I have added a lever to mine so I do not need to find the M8 allen key, see:
Mike
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Hello Johannas,
?
I'm not familiar with the 4700 mill, but from the photo of it
on the LMS website, there is a column/gib locking lever on the left hand side of
the column. Locking this down should lock the head from moving. Any movement
from vibration of the fine adjust wheel while milling should not matter, and
will not move the milling head.
?
All unused table and head travel
should be locked down prior to milling.
Michael - California, USA
Micro-Mark MicroLux 7x16
LMS 3990 Hi-Torque Mill with power
feed
?
This is the fine-adjuster to LMS 4700
Mill.
Have somebody made a lock for
this?
My adjuster is moving (turning) when I am
milling, and before I am doing something stupid, I want an advice from
you.
Best regards
Johannes
|
Hi and thanks for response. Here is how the fine adjuster looks inside: https://www.dropbox.com/s/s2tx6cgt0j8wm7s/adjuster.jpg?dl=0 ? My thoughts was to look the axel from underneath, it have most of the steel to make a hole for a screw. But may maybe I can fix the problem from the other side as Mikes workshop suggest. http://mikesworkshop.weebly.com/mill-quill-lock-lever.html ? I will think about all suggestions for some days and I will come back when I have done the job. ? /johannes
|
Disregard my comment, I was unaware that the 4700 has a
spindle that moves up and down, unlike the other mini mills where the entire
head moves up and down.
Mike from mikesworkshop has the correct
solution.
toggle quoted message
Show quoted text
?
Hello Johannas,
?
I'm not familiar with the 4700 mill, but from the photo of it
on the LMS website, there is a column/gib locking lever on the left hand side of
the column. Locking this down should lock the head from moving. Any movement
from vibration of the fine adjust wheel while milling should not matter, and
will not move the milling head.
?
All unused table and head travel
should be locked down prior to milling.
Michael - California, USA
Micro-Mark MicroLux 7x16
LMS 3990 Hi-Torque Mill with power
feed
?
This is the fine-adjuster to LMS 4700
Mill.
Have somebody made a lock for
this?
My adjuster is moving (turning) when I am
milling, and before I am doing something stupid, I want an advice from
you.
Best regards
Johannes
|
How does the side mounted ball screw work? ? I'd be worried about the torque trying to turn the milling head.
The design I like better places the screw on center line and almost touching the existing rack.? The head's weight is basically hung off the stationary screw.? The screw does not turn.? A motor is used to rotate the nut.? I think the overall design is simpler.
People are getting better than .001" with this kind of setup.
Searching around I find a photo of this design here.? It lifts from the center of mass.? Disadvantage is you need a full height ceiling but likely a non-issue for most.
Allthat said.? I have a simple DRO mounted to the z-axis and it is accurate to .001 and reads to .0005 if I use the gib lock if there is any depth movement it does the DRO is not detecting it so I amuse not movement over .0005" ?and this is with a stock mill, I'm not done with the CNC conversion.
On Tue, Jul 25, 2017 at 8:01 AM, WAM ajawam2@... [7x12minilathe] <7x12minilathe@...> wrote: I bagged that whole rack-pinion thing for something a bit more robust:
Actually my wife wanted it changed. She used it when we first got it,
said it sucks, and suggested the stepper I did, or something like this:
I can send the 3D model of that if you'd like...Uses off the shelf gears
from Boston Gear. Uses the same CNC Fusion ball screw.
I've been using the stepper/Arduino thing for years and really like it.
I can get accurate depths that hold.
As to the stock mini mill setup, everyone states you should lock the
gibs, or tighten them up. Also you can check your rack-pinion mesh and
shim the rack to make it a bit more tight.
I didn't like any of those suggestions. A rack-pinion is great for a
drill press; not so much for a mill, at least in my opinion...
//
On 7/25/2017 10:12 AM, 'Johannes' johannes@... [7x12minilathe] wrote:
>
> l.JPG?dl=0
>
>
>
> This is the fine-adjuster to LMS 4700 Mill.
>
> Have somebody made a lock for this?
>
>
>
> My adjuster is moving (turning) when I am milling, and before I am doing
> something stupid, I want an advice from you.
>
>
>
> Best regards
>
> Johannes
>
>
>
>
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Chris Albertson
Redondo Beach, California
|
Works silly well - better than I would have imagined. With the Arduino/Anaheim Automation stepper/driver combo I can step down less than a mil using microstepping - what the toggle switches set - see the vids on that page -
Solid as all hell too.... I can ramp into a cut and it stays at the depth I want. With large cutters it's the typical "small mill - big cutter" vibe (you can see a bit of it on the DRO that reads down to 0.0002 [DRO PRO mag thing]) but it just plows thru - even on mild steel.
Even with the extended solid column -
I did the 2" solid column mod and sent the pics to LMS - they now sell a 2" riser block like what I made.
The thing is just solid... well, as solid as a little mill can be. And I use it a lot for my day job, doing silly I should never even try on a mill that size.
toggle quoted message
Show quoted text
On 7/25/2017 5:42 PM, Chris Albertson albertson.chris@... [7x12minilathe] wrote: How does the side mounted ball screw work? I'd be worried about the
torque trying to turn the milling head.
The design I like better places the screw on center line and almost
touching the existing rack. The head's weight is basically hung off the
stationary screw. The screw does not turn. A motor is used to rotate the
nut. I think the overall design is simpler.
People are getting better than .001" with this kind of setup.
Searching around I find a photo of this design here. It lifts from the
center of mass. Disadvantage is you need a full height ceiling but likely
a non-issue for most.
hossmachine.info/images....JPG
<(Medium).JPG>
Allthat said. I have a simple DRO mounted to the z-axis and it is accurate
to .001 and reads to .0005 if I use the gib lock if there is any depth
movement it does the DRO is not detecting it so I amuse not movement over
.0005" and this is with a stock mill, I'm not done with the CNC conversion.
On Tue, Jul 25, 2017 at 8:01 AM, WAM ajawam2@... [7x12minilathe] <
7x12minilathe@...> wrote:
I bagged that whole rack-pinion thing for something a bit more robust:
Actually my wife wanted it changed. She used it when we first got it,
said it sucks, and suggested the stepper I did, or something like this:
I can send the 3D model of that if you'd like...Uses off the shelf gears
from Boston Gear. Uses the same CNC Fusion ball screw.
I've been using the stepper/Arduino thing for years and really like it.
I can get accurate depths that hold.
As to the stock mini mill setup, everyone states you should lock the
gibs, or tighten them up. Also you can check your rack-pinion mesh and
shim the rack to make it a bit more tight.
I didn't like any of those suggestions. A rack-pinion is great for a
drill press; not so much for a mill, at least in my opinion...
//
On 7/25/2017 10:12 AM, 'Johannes' johannes@... [7x12minilathe]
wrote:
20adjuster%20LMS%204700%20Mil
l.JPG?dl=0
This is the fine-adjuster to LMS 4700 Mill.
Have somebody made a lock for this?
My adjuster is moving (turning) when I am milling, and before I am doing
something stupid, I want an advice from you.
Best regards
Johannes
------------------------------------
------------------------------------
------------------------------------
Yahoo Groups Links
|
? Set the height by raising the head, not by lowering it. This removes a lot of backlash in the fine feed. Same principal as raising a saw blade to exact height on a cabinet saw. Also if you are using an end mill holder, make sure the cutter is pulled down to the top of the cutters flat portion. This prevents the cutter from being pulled down into the work. mike Sent from for Windows 10 ?
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Johannes
Warren LeMay