Re: DRO issue "HEDs in hand"
Thanks for the info, I think I'm going to give it a try. I feel that the resolution should be adaquate for the majority of the work that I do. Dan, how did you mount the strip? I was thinking about a fiberglass plane to support the strip. Hopefully this would lessen the effects of temperature on the system, but perhaps this isn't needed. I remember a website with pics of a linear encoder installation but I guess I didn't bookmark it. Does anyone have a URL showing this setup? Thanks again, Roger Linscheid --- In CAD_CAM_EDM_DRO@y..., "Dan Mauch" <dmauch@s...> wrote: I have used the linear 360 line encoder strips from USdigital with good results. I guess you have to ask your self this question. Can my machine really machine to .00069"? The reason I say this is many machines like mill drills and other imported machines suffer from a variety or
problems mainly caused by a lack or rigidity of the column and or
excessive play in the spindle assembly. If you machine is rigid then the USditial encoders used with the Kulaga/Mauch dro board should be
adequate. It should be equal or better than a rotary encoder driven by a rack or cable.
I have been following Usdigital's 500 line encoder development for the past three years. I have given up on them solving their problems with it. But that sure would have been nice.
Dan
-----Original Message-----
From: Ken Jenkins [mailto:kjenkins@b...]
Sent: Tuesday, October 29, 2002 11:59 AM
To: CAD_CAM_EDM_DRO@y...
Subject: [CAD_CAM_EDM_DRO] Re: DRO issue "HEDs in hand"
I posted a message a few days ago regarding the U.S. Digial Linear
strip options ... 360 is the highest and in my opinion not
high enough (360 x 4 = 1440 then 1 / 1440 = .00069 per increment.
I want something closer to .0005 which would need 500 lpi. U.S.
Digital in a recent email response did not sound very hopeful
re: a linear strip with 500 lpi res. So that leaves a rotary
encoder and wire arrangement. One would think you would want the
highest res possible ... 2048?
I have done several postings here in the past and recently ...
other than Bubba (who has been very helpful) no one seems to
have much information regarding what encoder works well with
the Camtronics board. Has anyone used the 360 US Digital strips
with the Camtronics board and got it to work and been satisfied
with the result? OR Has anyone used a rotary encoder with wire
loop arrangement with the Camtronics board and got it to work
and been satisfied with the results? Could you share your experience
here.
Also, you should be aware that just having a couple HEDS does not
help you unless they are matched to the particular encoder
you select. The HEDS unit and the encoders are selected together
and will not work if used with out matching them. There are linear
HEDS and rotary HEDS and within those two groups there are specific
ones for each resolution.
Ken
Message: 4
Date: Tue, 29 Oct 2002 01:26:52 -0000
From: "Roger Linscheid" <r.linscheid@a...>
Subject: DRO encoders- Rotary or Linear?
Hi, I am ready to begin adding a DRO to my G4003 lathe. What is the current thought on the best method to accomplish my goal?
IIRC, when I was looking into this before, the linear strips from
U.S. Digital were only available in 250 CPI and this was not
considered high enough to provide the necessary resolution. Using
rotary encoders meant the possibility of losing counts if the
drive cable slipped or stretched.
Now U.S. Digital has linear strips in 300 and 360 CPI. Will these
provide a resolution of 0.0005 or better?
I have a completed DRO board from Camtronics and several HEDS on
hand, so I just need to scrounge an old PC and start the
installation.
Thanks for any input!
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@y...
Subscribe: CAD_CAM_EDM_DRO-subscribe@y...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@y...
List owner: CAD_CAM_EDM_DRO-owner@y..., wanliker@a...
Moderator: jmelson@a... timg@k... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to
reach it if you have trouble.
I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
|
Re: VisualMill, which post for Mach1?
Roger,
You'll probably have to modify an existing post to suit your needs. I use the Flashcut post and have found that it is pretty generic and probably a pretty good starting point for Mach1. Once you select a post, at least you will be able to generate a G-Code file and then you can proof it to check for any anomolies within Mach1. Use the Post editor and save it to a new file name in the post folder and then make your changes. Of course, don't run the file with motor or spindle power on - until you have checked it very carefully then run the file with power on but cut air.
I have now received V4 but am still running V3.2 until I have time to install the new version - but looking at the new manual, it is pretty similar, just with several new and expanded features and probably some minor bug fixes.
Cheers, Peter
vrsculptor wrote:
toggle quoted message
Show quoted text
I'm finaly too that point. Which post are you using or if a modified one could you please mail me offline.
Roger
Addresses: FAQ: FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@... Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@... List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@... [Moderator] URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
|
Re: Has anyone built an SPC display for Digimatic scales?
Has anyone built a purpose-made box for displaying the output from this type
of caliper? I'd like to avoid using a computer if possible.
John
|
How do I 'make' a ballscrew antibacklash nut?
Hi all, I'm kind of a CNC newbie.
I've converted my Grizzly G1006 to CNC (Master5/Mach1 and Camtronics
4 axis servo), but the backlash and lead accuracy stink.
I understand I can get decent/cheap screws (.004/ft) from McMaster-
Carr, and use a pair of taper or angular contact bearings for the
drive end.
What I don't quite get is, how do you make a 'anti-backlash' nut
from two regular ball screw nuts? how do you connect them to the
mills existing mount (two screws)... I've read about using a spring
to pre-load, but I cant visualize how that works.
Also, doesn't anybody sell a reasonably priced screw with .100/rev
like a 'regular' mill screw?
Any advice?
Thanks,
Dave S.
|
Bob:
I built an X-Y Table once where chain-drive was used to connect the MOTOR to
the X-screws, and the #35 chain gave out the first month! Connect the motor
directly to the end of the screw, using a proper shaft-coupler that permits
SOME a-axial or antiparallel human-frailty.
|
Re: Ball/acme screw question
JJ wrote: One last (for now) question: Are acme screws their true diameter?
ie If I buy a 1/2" screw, do I plan on using 1/2" ID bearings?
My 1" acme leadscrews are 1" OD (ie 0.990 - 1.000" major pitch dia). As the minor dia varies (.7509"-.7800") you can use a .75" ID or smaller bearing. If you are looking at the 1/2" acme leadscrews, it is of course 1/2" OD and the minor dia varies( .3594"-.3800") so even a 3/8" id (.375") bearing is risky, so you'll probably need to go for an even smaller ID bearing! regards Doug Fortune <- Home of the 1KW BEaST power supply for Geckos .
|
VisualMill, which post for Mach1?
I'm finaly too that point. Which post are you using or if a modified
one could you please mail me offline.
Roger
|
I've checked my sent to email box and i don't see anything suspect.
I still getting emails with the virus on it some was email to me
with my own email adress.
is there any thing else to check on my computer just to make shure
its clean?
Fogassa.
|
Re: Ball/acme screw question
JJ,
You do not use the O.D. of the screw in the I.D. of the bearing. The
ends of the screw are machined or ground to the next standard size down, to
a snug fit in the bearing I.D.. My R & D in this kind of thing, is usually
done in the McMaster-Carr web site. www.mcmaster.com . They have bearings of
every size and shape available.
Marv Frankel
Los Angeles
toggle quoted message
Show quoted text
----- Original Message ----- From: "JJ" <jj5412@...> To: <CAD_CAM_EDM_DRO@...> Sent: Tuesday, October 29, 2002 4:23 PM Subject: RE: [CAD_CAM_EDM_DRO] Ball/acme screw question Thanks for all the info everyone!
One last (for now) question: Are acme screws their true diameter? Ie. If
I buy a 1/2" screw, do I plan on using 1/2" ID bearings?
Okay, one more: Does anyone make small mounting flanges for acme nuts? I
just can't see a 2.600" flange for a 3/8" rod.
Thanks again,
JJ
Be Kind, Be Careful, Be Yourself
-----Original Message-----
From: Marv Frankel [mailto:dcdziner@...]
Sent: Monday, October 28, 2002 11:11 PM
To: CAD_CAM_EDM_DRO@...
Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question
Brian,
Actually, I'm somewhat of an expert, and the reason
for a multi-lead
screw is this. You want a nut that will advance 1" in 4
revolutions, but if
the shaft is fairly small in diameter, the depth of the
thread, if you cut
it for a normal 4 threads/inch, would weaken the shaft considerably.
Instead, you cut it 4 threads/inch, but at the depth used for 8
threads/inch. You then have spaces between the threads in
which to cut an
additional lead at the 8 threads/inch depth. You then end up
with a screw
that appears to have 8 threads/inch, but the nut will advance 1" for 4
revolutions. The whole thing has to be done on a lathe, and sounds
complicated, but it really isn't. In the past, I've generated
screws with as
many as 4 leads. They looked like the threads were very fine,
but the nut
would fairly fly down the screw.
You just had a lesson in "Screwing 101".
Marv Frankel
Los Angeles
----- Original Message -----
From: "Brian" <ka1bbg@...>
To: <CAD_CAM_EDM_DRO@...>
Sent: Monday, October 28, 2002 2:41 PM
Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question
Hi, I am no expert but a few things to think about. Multiple lead acme
screws means you have several threads instead of one so they tend to last
longer and are stronger. Rolled acme thread has been going on for a long
time and the acme rods i bought the other day are nicely finnished and a
quick check says their ok on the length. a "v" thread begins to wear quickly
and once it gets sloppy it weakens as it wears out. an acme thread stays
rugged even as its wearing to a point. As for efficient i cant answer but
there are ground threads of all kinds out there some last for many years
even if they are "v" or acme or even buttress thread. Each has a best use.
Take a look at the size you want and then look at the different grades
available. 1/2-10 acme b2 is the cheapest because of so much use, if you
order a 15/16-16 thread custom made to your spec's then expect to pay
premium big bucks. Sometimes the nut and the retaining method(back to back
bearings or nuts) is the most important part. cul brian f.
----- Original Message -----
From: "JJ" <jj5412@...>
To: <cad_cam_edm_dro@...>
Sent: Monday, October 28, 2002 4:53 PM
Subject: [CAD_CAM_EDM_DRO] Ball/acme screw question
(Hoping this is on topic)
In my quest for constant upgrades to my CNC mill/router/pcb thing, I
have a couple of questions:
Why would you choose a multistart screw over a single start screw?
Are acme thread screws more efficient that generic threaded rod?
ADVthanksANCE,
JJ
Be Kind, Be Careful, Be Yourself
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@...,
wanliker@...
Moderator: jmelson@... timg@...
[Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru
Google.com to reach it
if
you have trouble.
I
consider this to be a
sister site to the CCED group, as many of the same members are there, for
OT
subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN
BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@...,
wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com
to reach it if
you have trouble.
I consider
this to be a
sister site to the CCED group, as many of the same members
are there, for OT
subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY
POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@...
[Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com
to reach it if you have trouble.
I consider this to be a
sister site to the CCED group, as many of the same members are there,
for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
I consider this to be a
sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
|
Re: Ball/acme screw question
In a message dated 10/28/2002 6:25:30 PM Central Standard Time, JanRwl@... writes: vices Duh... Make that "vises" ! ! !
|
Re: Ball/acme screw question
Thanks for all the info everyone!
One last (for now) question: Are acme screws their true diameter? Ie. If
I buy a 1/2" screw, do I plan on using 1/2" ID bearings?
Okay, one more: Does anyone make small mounting flanges for acme nuts? I
just can't see a 2.600" flange for a 3/8" rod.
Thanks again,
JJ
Be Kind, Be Careful, Be Yourself
toggle quoted message
Show quoted text
-----Original Message-----
From: Marv Frankel [mailto:dcdziner@...]
Sent: Monday, October 28, 2002 11:11 PM
To: CAD_CAM_EDM_DRO@...
Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question
Brian,
Actually, I'm somewhat of an expert, and the reason
for a multi-lead
screw is this. You want a nut that will advance 1" in 4
revolutions, but if
the shaft is fairly small in diameter, the depth of the
thread, if you cut
it for a normal 4 threads/inch, would weaken the shaft considerably.
Instead, you cut it 4 threads/inch, but at the depth used for 8
threads/inch. You then have spaces between the threads in
which to cut an
additional lead at the 8 threads/inch depth. You then end up
with a screw
that appears to have 8 threads/inch, but the nut will advance 1" for 4
revolutions. The whole thing has to be done on a lathe, and sounds
complicated, but it really isn't. In the past, I've generated
screws with as
many as 4 leads. They looked like the threads were very fine,
but the nut
would fairly fly down the screw.
You just had a lesson in "Screwing 101".
Marv Frankel
Los Angeles
----- Original Message -----
From: "Brian" <ka1bbg@...>
To: <CAD_CAM_EDM_DRO@...>
Sent: Monday, October 28, 2002 2:41 PM
Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question
Hi, I am no expert but a few things to think about. Multiple lead acme
screws means you have several threads instead of one so they tend to last
longer and are stronger. Rolled acme thread has been going on for a long
time and the acme rods i bought the other day are nicely finnished and a
quick check says their ok on the length. a "v" thread begins to wear quickly
and once it gets sloppy it weakens as it wears out. an acme thread stays
rugged even as its wearing to a point. As for efficient i cant answer but
there are ground threads of all kinds out there some last for many years
even if they are "v" or acme or even buttress thread. Each has a best use.
Take a look at the size you want and then look at the different grades
available. 1/2-10 acme b2 is the cheapest because of so much use, if you
order a 15/16-16 thread custom made to your spec's then expect to pay
premium big bucks. Sometimes the nut and the retaining method(back to back
bearings or nuts) is the most important part. cul brian f.
----- Original Message -----
From: "JJ" <jj5412@...>
To: <cad_cam_edm_dro@...>
Sent: Monday, October 28, 2002 4:53 PM
Subject: [CAD_CAM_EDM_DRO] Ball/acme screw question
(Hoping this is on topic)
In my quest for constant upgrades to my CNC mill/router/pcb thing, I
have a couple of questions:
Why would you choose a multistart screw over a single start screw?
Are acme thread screws more efficient that generic threaded rod?
ADVthanksANCE,
JJ
Be Kind, Be Careful, Be Yourself
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@...,
wanliker@...
Moderator: jmelson@... timg@...
[Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru
Google.com to reach it
if
you have trouble.
I
consider this to be a
sister site to the CCED group, as many of the same members are there, for
OT
subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN
BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@...,
wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com
to reach it if
you have trouble.
I consider
this to be a
sister site to the CCED group, as many of the same members
are there, for OT
subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY
POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@...
[Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com
to reach it if you have trouble.
I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill List Mom List Owner Your use of Yahoo! Groups is subject to
|
Re: DRO encoders- Rotary or Linear?
Instead of using a rack and pinion, would it be possible to use a rigid bar
(like 1" or 1.5" drill rod) and a rubber roller mounted to a rotary encoder?
With a solid bar, wipes could be used to clear the surface before the roller
passed over it, unlike the rack and pinion where clearing it would be a
difficult measure at best if something were to get in the teeth.
John
|
Re: Ball/acme screw question
Yo Torston; Is, "roundtooth", the type that looks sort of like a piece of rope? Bill On Tue Oct 29 12:19:34 2002, torsten98001, <torsten@...> wrote: --- In CAD_CAM_EDM_DRO@y..., "JJ" <jj5412@e...> wrote:
(Hoping this is on topic)
In my quest for constant upgrades to my CNC mill/router/pcb thing, I
have a couple of questions:
Why would you choose a multistart screw over a single start screw?
Are acme thread screws more efficient that generic threaded rod?
ADVthanksANCE,
JJ
Be Kind, Be Careful, Be Yourself multistart screws are usedfull in situations where the threadprofile
will be smaller then the pitch of the screw.
for example a 1. wide nut with a 1. pitch screw would allow only
1 thread to be engaged this makes for a low loadbearing on the screw.
multysthreading of this screw would add another thread of loadbearing
capabilitie for every thread added.
Add as many threads as there is room for them without overlaping.
the efficency of Different threadprofiles
depends on there intended use.
example:
Acme/ballscrew = in motion application
sawtooth = one directional loadbearing
roundtooth = in motion in contaminated environments
there are many more possibles for me to list but you
get the idee here.
different designs favor different operating conditions. -- ---------------------------------------------------------------------------- RKBA! Blessings On Thee, Oh Israel! 4-19! ----------------+----------+--------------------------+--------------------- An _EFFECTIVE_ | Insured | All matter is vibration. | Let he who hath no weapon in every | by COLT; | -- Max Plank | weapon sell his hand = Freedom | DIAL | In the beginning was the | garment and buy a on every side! | 1911-A1. | word. -- The Bible | sword.--Jesus Christ ----------------+----------+--------------------------+--------------------- Constitutional Government is dead, LONG LIVE THE CONSTITUTION!!!!! ----------------------------------------------------------------------------
|
Re: Ball/acme screw question
Yep, I'll take a 101 from anybody. some think of a nut by its length i
consider a nut by the amount of thread engaged. If i used a 4 lead screw and
put the same amount of thread engagement on one of 4 threads then the nut is
long but stronger..cul brian f.
toggle quoted message
Show quoted text
----- Original Message ----- From: "Marv Frankel" <dcdziner@...> To: <CAD_CAM_EDM_DRO@...> Sent: Monday, October 28, 2002 11:11 PM Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question Brian,
Actually, I'm somewhat of an expert, and the reason for a multi-lead screw is this. You want a nut that will advance 1" in 4 revolutions, but if the shaft is fairly small in diameter, the depth of the thread, if you cut
it for a normal 4 threads/inch, would weaken the shaft considerably.
Instead, you cut it 4 threads/inch, but at the depth used for 8
threads/inch. You then have spaces between the threads in which to cut an
additional lead at the 8 threads/inch depth. You then end up with a screw
that appears to have 8 threads/inch, but the nut will advance 1" for 4
revolutions. The whole thing has to be done on a lathe, and sounds
complicated, but it really isn't. In the past, I've generated screws with as many as 4 leads. They looked like the threads were very fine, but the nut
would fairly fly down the screw.
You just had a lesson in "Screwing 101".
Marv Frankel
Los Angeles
----- Original Message -----
From: "Brian" <ka1bbg@...>
To: <CAD_CAM_EDM_DRO@...>
Sent: Monday, October 28, 2002 2:41 PM
Subject: Re: [CAD_CAM_EDM_DRO] Ball/acme screw question
Hi, I am no expert but a few things to think about. Multiple lead acme
screws means you have several threads instead of one so they tend to last longer and are stronger. Rolled acme thread has been going on for a long
time and the acme rods i bought the other day are nicely finnished and a
quick check says their ok on the length. a "v" thread begins to wear quickly
and once it gets sloppy it weakens as it wears out. an acme thread stays
rugged even as its wearing to a point. As for efficient i cant answer
but there are ground threads of all kinds out there some last for many years
even if they are "v" or acme or even buttress thread. Each has a best
use. Take a look at the size you want and then look at the different grades
available. 1/2-10 acme b2 is the cheapest because of so much use, if you
order a 15/16-16 thread custom made to your spec's then expect to pay
premium big bucks. Sometimes the nut and the retaining method(back to
back bearings or nuts) is the most important part. cul brian f.
----- Original Message -----
From: "JJ" <jj5412@...>
To: <cad_cam_edm_dro@...>
Sent: Monday, October 28, 2002 4:53 PM
Subject: [CAD_CAM_EDM_DRO] Ball/acme screw question
(Hoping this is on topic)
In my quest for constant upgrades to my CNC mill/router/pcb thing, I
have a couple of questions:
Why would you choose a multistart screw over a single start screw?
Are acme thread screws more efficient that generic threaded rod?
ADVthanksANCE,
JJ
Be Kind, Be Careful, Be Yourself
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
I consider this to be
a sister site to the CCED group, as many of the same members are there,
for OT
subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING
THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it
if you have trouble.
I consider this to be a
sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
Addresses:
FAQ:
FILES:
Post Messages: CAD_CAM_EDM_DRO@...
Subscribe: CAD_CAM_EDM_DRO-subscribe@...
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@...
List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@...
Moderator: jmelson@... timg@... [Moderator]
URL to this group:
OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
I consider this to be a
sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.
NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill
List Mom
List Owner
Your use of Yahoo! Groups is subject to
|
Re: plasma cutter/machine torch
Dave, You might find an OK el cheapo plasma but the Hypertherm and Thermal Dynamic plasmas are the real deal. On the other hand some of the el chepos are real junk. So make sure the machine will do what you want. I personally have found that my Thermal Dynamics plasmas have all paid for them selves over and over again. That said, a hand torch can be used as a machine torch. All you need to do is make a simple clamp to hold the torch. I took a tube that fit into the machine torch holder and attached a clamp to it that clamped onto the hand torch. I made the clamp out of an aluminum block but Kee Klamps or other pipe clamps could be used. I also attached a rack to the side of the tube so the torched could be moved up and down manually. At the machine I wired in a switch on a pendant lead that is in parallel with the torch trigger. A relay could also be wired in parallel for computer control. In my book it is better to spend the bucks on a good plasma, even one that is bigger than what you think you need. A machine torch and or automatic standoff can be added later when the machine starts paying for itself. Jay david_margrave wrote: I have looked into various low-end plasma cutters in the 1,000-1,500
range, like hypertherm and thermal dynamics. The guy at the welding
store, when I told him of my interest in making a CNC plasma cutter
table, said that a machine torch (another $500) would be required. Snip... Are there any other alternatives to dropping $1,500-$2,000? How about
those cheap "chicago electric' or 'century' plasma cutters you see in
Harbor Freight for sub-$600 price tags?
Dave
|
plasma cutter/machine torch
I have looked into various low-end plasma cutters in the 1,000-1,500
range, like hypertherm and thermal dynamics. The guy at the welding
store, when I told him of my interest in making a CNC plasma cutter
table, said that a machine torch (another $500) would be required.
That seems a bit steep for the torch. The main difference between the
machine torch and the standard torch is the machine torch is straight
(cutter not at an angle to handle), has remote relay hookups, etc.,
and some provision for Z-feeding, like the ability to attach a rack
for a rack-and-pinion z-feed arrangement.
Are there any other alternatives to dropping $1,500-$2,000? How about
those cheap "chicago electric' or 'century' plasma cutters you see in
Harbor Freight for sub-$600 price tags?
Dave
|
Re: DRO issue "HEDs in hand"
I have used the linear 360 line encoder strips from USdigital with good
results. I guess you have to ask your self this question. Can my machine
really machine to .00069"? The reason I say this is many machines like
mill drills and other imported machines suffer from a variety or
problems mainly caused by a lack or rigidity of the column and or
excessive play in the spindle assembly. If you machine is rigid then the
USditial encoders used with the Kulaga/Mauch dro board should be
adequate. It should be equal or better than a rotary encoder driven by a
rack or cable.
I have been following Usdigital's 500 line encoder development for the
past three years. I have given up on them solving their problems with
it. But that sure would have been nice.
Dan
toggle quoted message
Show quoted text
-----Original Message----- From: Ken Jenkins [mailto:kjenkins@...] Sent: Tuesday, October 29, 2002 11:59 AM To: CAD_CAM_EDM_DRO@... Subject: [CAD_CAM_EDM_DRO] Re: DRO issue "HEDs in hand" I posted a message a few days ago regarding the U.S. Digial Linear strip options ... 360 is the highest and in my opinion not high enough (360 x 4 = 1440 then 1 / 1440 = .00069 per increment. I want something closer to .0005 which would need 500 lpi. U.S. Digital in a recent email response did not sound very hopeful re: a linear strip with 500 lpi res. So that leaves a rotary encoder and wire arrangement. One would think you would want the highest res possible ... 2048? I have done several postings here in the past and recently ... other than Bubba (who has been very helpful) no one seems to have much information regarding what encoder works well with the Camtronics board. Has anyone used the 360 US Digital strips with the Camtronics board and got it to work and been satisfied with the result? OR Has anyone used a rotary encoder with wire loop arrangement with the Camtronics board and got it to work and been satisfied with the results? Could you share your experience here. Also, you should be aware that just having a couple HEDS does not help you unless they are matched to the particular encoder you select. The HEDS unit and the encoders are selected together and will not work if used with out matching them. There are linear HEDS and rotary HEDS and within those two groups there are specific ones for each resolution. Ken Message: 4
Date: Tue, 29 Oct 2002 01:26:52 -0000
From: "Roger Linscheid" <r.linscheid@...>
Subject: DRO encoders- Rotary or Linear?
Hi, I am ready to begin adding a DRO to my G4003 lathe. What is the
current thought on the best method to accomplish my goal?
IIRC, when I was looking into this before, the linear strips from
U.S. Digital were only available in 250 CPI and this was not
considered high enough to provide the necessary resolution. Using
rotary encoders meant the possibility of losing counts if the drive
cable slipped or stretched.
Now U.S. Digital has linear strips in 300 and 360 CPI. Will these
provide a resolution of 0.0005 or better?
I have a completed DRO board from Camtronics and several HEDS on
hand, so I just need to scrounge an old PC and start the installation.
Thanks for any input! Addresses: FAQ: FILES: Post Messages: CAD_CAM_EDM_DRO@... Subscribe: CAD_CAM_EDM_DRO-subscribe@... Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@... List owner: CAD_CAM_EDM_DRO-owner@..., wanliker@... Moderator: jmelson@... timg@... [Moderator] URL to this group: OFF Topic POSTS: General Machining If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill List Mom List Owner Your use of Yahoo! Groups is subject to
|
Re: Ball/acme screw question
--- In CAD_CAM_EDM_DRO@y..., "JJ" <jj5412@e...> wrote: (Hoping this is on topic)
In my quest for constant upgrades to my CNC mill/router/pcb thing, I
have a couple of questions:
Why would you choose a multistart screw over a single start screw?
Are acme thread screws more efficient that generic threaded rod?
ADVthanksANCE,
JJ
Be Kind, Be Careful, Be Yourself multistart screws are usedfull in situations where the threadprofile will be smaller then the pitch of the screw. for example a 1. wide nut with a 1. pitch screw would allow only 1 thread to be engaged this makes for a low loadbearing on the screw. multysthreading of this screw would add another thread of loadbearing capabilitie for every thread added. Add as many threads as there is room for them without overlaping. the efficency of Different threadprofiles depends on there intended use. example: Acme/ballscrew = in motion application sawtooth = one directional loadbearing roundtooth = in motion in contaminated environments there are many more possibles for me to list but you get the idee here. different designs favor different operating conditions.
|
Thanks for the warning, now all further posts on this direct to me.
bill
|
Re: DRO issue "HEDs in hand"
I posted a message a few days ago regarding the U.S. Digial Linear
strip options ... 360 is the highest and in my opinion not
high enough (360 x 4 = 1440 then 1 / 1440 = .00069 per increment.
I want something closer to .0005 which would need 500 lpi. U.S.
Digital in a recent email response did not sound very hopeful
re: a linear strip with 500 lpi res. So that leaves a rotary
encoder and wire arrangement. One would think you would want the
highest res possible ... 2048?
I have done several postings here in the past and recently ...
other than Bubba (who has been very helpful) no one seems to
have much information regarding what encoder works well with
the Camtronics board. Has anyone used the 360 US Digital strips
with the Camtronics board and got it to work and been satisfied
with the result? OR Has anyone used a rotary encoder with wire
loop arrangement with the Camtronics board and got it to work
and been satisfied with the results? Could you share your experience
here.
Also, you should be aware that just having a couple HEDS does not
help you unless they are matched to the particular encoder
you select. The HEDS unit and the encoders are selected together
and will not work if used with out matching them. There are linear
HEDS and rotary HEDS and within those two groups there are specific
ones for each resolution.
Ken
toggle quoted message
Show quoted text
Message: 4
Date: Tue, 29 Oct 2002 01:26:52 -0000
From: "Roger Linscheid" <r.linscheid@...>
Subject: DRO encoders- Rotary or Linear?
Hi, I am ready to begin adding a DRO to my G4003 lathe. What is the
current thought on the best method to accomplish my goal?
IIRC, when I was looking into this before, the linear strips from
U.S. Digital were only available in 250 CPI and this was not
considered high enough to provide the necessary resolution. Using
rotary encoders meant the possibility of losing counts if the drive
cable slipped or stretched.
Now U.S. Digital has linear strips in 300 and 360 CPI. Will these
provide a resolution of 0.0005 or better?
I have a completed DRO board from Camtronics and several HEDS on
hand, so I just need to scrounge an old PC and start the installation.
Thanks for any input!
|
