Question 1:
Is there any way to remove scratches from a ground surface finish (the
surface is flat) and have it match the existing ground finish without
regrinding the entire surface?
Question 2:
What media compound(s)works best in a tumbler to put a high shine on
steel parts that have rusted and been treated with phosphoric acid
(all rust removed, part now has a blackened dull finish)?
Jon Banquer
San Diego, CA
On Sat, 9 May 2009 16:17:58 -0700 (PDT), jon_banquer
If the pitting isn't too deep try walnut shells and maybe add a light
polishing compound, rouge or tripoli. Would prefer to use vibratory
bowl but tumbler may work.
If pitting is deep it may be best to use a medium to rough abrasive to
cut through the pitting and create an even (rough) finish all around,
then change to a mild abrasive and for the final load walnut shells
possibly with a polishing compound to bring it to a "high shine".
--
Tom
http://tinyurl.com/5okkgz
ScotchBrite pads and a DA orbital sander. That will give a
crosshatched pattern. Start course and finish fine. After the deep
scratches are out finish in your tumbler or tape some sandpaper down to
your surface plate and do like Vinny suggested.
They are small parts that won't really fit or take to a DA or random
orbital sander.
Question 1 and Question 2 weren't related and that is why I made them
two separate questions. I guess I could have gone the extra step and
tried to be even clearer and said Question 1 and Question 2 weren't
related.
The parts in Question 1 won't work on a DA or random orbital sander
and don't have deep scratches... they were rusted, I treated them with
phosphoric acid and they are now dull and black. The part in Question
2 would take a DA or random orbital and does have deep scratches.
I'm going to try what Vinny said, as he seems to have plenty of real
world mold making experience with this problem.
I'm sorry you once again confused beyond belief (to me) what I posted
as you often do. Inspire of this I often get useful information from
what you post (talon grips, etc.) so I wouldn’t want to discourage you
from posting helpful information that I can use despite the FACT that
you often get most of what I post very badly wrong and others get it
right. I no longer have the interest in correcting the mountain of
misinformation you post and haven't for some time.
Jon Banquer
San Diego, CA
Jon:
I was just giving some options to remove scratches. We did it all the
time. If my suggestions help - then great. If they're not usable for
whatever reason for your current project - then just file them away in
your memory banks for possible future use.
You can always get a cheapie Harbor Freight glass beader to clean rust
and discoloration off parts.
If sometimes my answers are a little too far "out of the box" for you,
then just ignore them. They are just suggestions, not mandates.
Bob, I hope you are starting to catch on that he is Only trolling for
an argument.
According to one source, 1 out of 25 people are totally devoid of any
concience.
They are sociopaths, and cannot be reached through their "concience"
since they have none, and cannot comprehend the concept of one,
either.
Jon has never demonstrated any empathy for another human being.
I do apploud your unending attempts to reach him, but I don't beleive
it will work.
HN:
You know, I think you may be right. With his recent spate of comments
(measuring to 1/2 a millionth), and apprentice questions (how to get
scratches out of parts - what's the different between round and square
boring heads - or why you'd have to measure a rigid angle chamfer tool
at more than one dept rather than trig. it out - or not knowing that
thread gauges can be sent out to be checked & calibrated - etc. etc.) -
these are all questions that should have been answered in the first
year of machining.
Soooo it appears that the questions are just trolls like you suggest,
or someone seriously hasn't been paying attention for the decade and a
half they've been in a shop(s).
On Sat, 9 May 2009 19:36:02 -0700 (PDT), jon_banquer
Well you did say "tumbler" which usually refers to rotary barrel
tumbler. http://www.mcmaster.com/#about-barrel-tumblers/=1t3shj
NOW! that you added "Vibratory"
If the pitting isn't too deep try walnut shells and maybe add a light
polishing compound, rouge or tripoli.
If pitting is deep it may be best to start with a medium to rough
abrasive to cut through the pitting and create an even (rough) finish
all around, then change to a mild abrasive and for the final load
walnut shells possibly with a polishing compound to bring it to your
required "high shine".
----------------
FYI:
Centrifugal Barrel is a great way to go, amazing machines. We used it
and got near mirror finishes on machined parts as well as raw castings
and forgings.
http://www.mikro1.com/equipment/tipton_hs.pdf
Tom
Get a sheet of sand paper and put it on a surface plate and rub the part on
it the direction of the grinder marks. Rip off a corner of the paper and rub
the spot across the scratch a few times the direction of the grinding marks.
Then rub the whole part on the flat piece of sand paper on the surface plate
the same direction again. Go back and forth until its hidden.
Start with 600 paper, and change to a coarser or finer sheet as needed to
match the grind.
Just takes a minute to hide deep scratches on a fine grind.
If it's a soft steel or aluminum, take it slow and easy. If its hardened,
give it hell.
When I repair a mold, I do that to all the parts real quick, turning it into
a brand new mold. Some say it's cheating, but I feel it's part of the
grinding process.
Plus it makes the surface less prone to scratching.
Sometimes it's best to use a "used" piece of sandpaper. Just make sure you
wipe off the back of the sandpaper on your pant leg before putting it on the
surface plate, a small piece of dirt will cause a new scratch.
On May 10, 3:36 am, snipped-for-privacy@cin.net wrote:
Very helpful background information as well as the logic to dealing
with this problem.
I prefer jet fuel... kerosene. Is there a reason I have to use mineral
spirits?
If you wish to describe this specific process in detail such as how
many times you have to change grits of diamond polish, exactly what
kind of tool is used (I have an Engis (sp?) catalog around somewhere)
I'll read your post with the care that I read this one.
It's unfortunate in your push of Cimatron that you won't provide the
kind of specifics and attention to detail (for drilling holes) that
you have shown you can provide in this post. You criticize Cimatron
horrible marketing (rightly so) but yet you are guilty of exactly the
same kind of thing when it comes to describing Cimatron. There are
still a few people left in this world that are interested in the
important specifics rather than broad sweeping generalities such as
are most often posted about Siemens NX by Bill Triffet. There is
something very seriously wrong when I learn more on 3 minutes of a
sales presentation of NX than I have from many, many years of reading
posts on UG / NX from Bill Triffet.
Jon Banquer
San Diego, CA
On May 10, 7:39 pm, snipped-for-privacy@cin.net wrote:
Like anything else it's a learned skill.
You don't have to film it.
What I do is sit in front of the software and take notes every step of
the way as I do what I want to write about. Here is a specific example
of me doing that:
http://jonbanquer.wordpress.com/the-mastercam-handbooks /
What I'm asking you to do is put a bunch of points on the screen at
the *same Z level* and then describe step by step how you would drill
these holes to *different diameters and different Z depths* in
Cimatron. What does the software present you with? How are different Z
depths entered? What does Cimatron present you with for an interface
while doing this?
I don't think it's that hard but I do think it requires a little time
and effort on your part for something that doesn't come naturally to
you.
Jon Banquer
San Diego, CA
Hmmm....... guess I'm still learning, but then again we never stop
learning till the alternative happens
I do like that Masterscam guys demo training video to peddle his
stuff. I don't have access to ver 9.?? so the engraving stuff I
could'nt use. Thats all I'd use it 4. I'm sure I could do better than
that & be funnier on top of it with Cimatron adding little digs to all
the other softwares I've used & seen used by guys falling on their
face or jumping thru hoops to do what Cimatron can do with a few
clicks. That'd piss allot of people off. Its either that or I've been
told I should write a book on my lifes follies? Any thoughts? Who'd
buy it? Hell I can even get right of some damn Holdzems fer nothin!<g>
IIRC ( its coming back now) Cimatron can use points at the same Z
level, It would require the user to create those points. - more leg
work creating points- not a big deal, just an unecessry step. The way
I prefer to drill is by selecting the 3D point- not point per say, but
circle center point, at the bottom of the hole. That gives the correct
depth automagicly!
Natutally that point should be checked before hand to insure Mr solid
model guy designed it correctly in his software. If is a "2D piece of
paper cad file" drawing you'r stuck with the flat point(circle center)
at top & you would manually enter the drill depth. You see there are
so many variables as to what type of file your working with,
determining how to proceed in Cimatron by selecting circle centers,
line end points, physcal points, surface edge ect. Every job could be
different, unless your getting the cad data from the same source all
the time.
Once a depth is determined, either by 3D circle selection ( automatic)
or manual input & physical point selection. The depth is modal as a
global variable, just select the rest of the same type holes. If there
are allot, I usually change the feature colors of all same type holes
to the same color - a little leg work, but a snap to do in Cimatron.
It keeps things eaiser to pick & straight in my head. ie: mask select
all blue circles (1in deep) mask select all green circles (2"deep) &
so on.
Once all the selections have been made, 1 toolpath is created for each
group of same holes.
I copy those toolpaths as many times as needed for center drill,
drill, tap ream, c-bore ect.
tools & depths are changed manually but no reselecting of points are
needed. There are some choices for optimization as far a path taken
from hole to hole. I usually select the points in the order I want the
machine to go.
What does Cimatron present you with for an interface
Very..............Hmmm........... I've been told archaic( by Pro-e
guys). IT13 is not icon driven.
buy buy all you windows pretty icon guys.
The new version of Cimatron "Elete" is icon driven. I have not used
it.
Like I said a video would be kwel. Think anyone would buy it? even if
I thow in some Holdzems?<g>
On May 11, 6:27 pm, snipped-for-privacy@cin.net wrote:
Or, you could just use Mastercam and let it select all of the correct
drill and tap sizes and depths, along with the correct countersink
depths all automatically.
On May 12, 11:36 am, snipped-for-privacy@aol.com wrote:
Interesting. I just clicked it and it opened right up.
Must have been because I copied it from the address bar instead of the
"URL" box on youtube. Here's the correct one:
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