Help quoting drilling holes?

InspireCNC · Jul 19, 2021

Hi, i have a chance to win a job and i want to quote efficiently. I dont have any experience quoting for just drilling holes so im wondering what you guys would charge or what you think. What i think may work are these numbers below, let me know if im too high or low. These are mild steel acme nuts that need the minor diametor drilled. I will be doing this on a CNC. Thank you for your input.

1 - 5 NUT GR LC HEX ACME R/H/T (1" thick)
units- 1600
minor diameter- 0.86"

$1.65 per hole

1/2 - 10 NUT GR LC HEX ACME R/H/T (1/2" thick)
units- 1480
minor diameter- 0.421"

$0.55 per hole.

2 - 4 FLANGE NUT GR BRONZE ACME R/H/T (2" thick)
units-25
minor diameter 1.781"

$6.25 per hole

memphisjed · Jul 19, 2021

I get the big hole costs more because that is in a none optimal speed unless you have a seriously stout machine, but why discrepancy in the other two holes? Time to drill a hole is very similar, and positioning time is the same. Material handling is at least 2x what you think it should be time wise. Is that 1000 holes per part or 1000 holes on 1000 parts?

Bobw · Jul 19, 2021

I love these threads.

Some are going to say WAY!!!! too cheap.. Some are going to say WAY!!!! too much.

Of course part of that depends on the customer.

I also wouldn't drill, I'd drop an endmill down the center, interpolate and
be done. Less burrs that way, and they'll look better. Drills are very very
unhappy going down holes that are anywhere close to their size, and they aren't
the happiest things with interrupted cuts. Insert drill is a different story, but
I wouldn't want to run them one at a time in a lathe.

So I have no clue what GR LC is. But I'm going to guess just run of the mill
steel acme nuts. Not case hardened or anything.

Also guessing plus or minus 10 on the tolerance.

The 1".. I think you're high. This isn't rocket science here. Soft
jaws and interpolate. If it was 200 or 300 I'd think you are good,
but 1600 I think you are high, not intoxicated, but the price will land
you un-competetive.

Really good customer, and I had idle machine time, or needed something to
keep the help busy, or I was sick of diddle fucking with castings. 35 cents.

Good customer. 50 cents.

Pain in the ass customer. 75cents to $1.50 depending on how I felt that day.

Same for the smaller ones. .55 cents isn't bad.

The big ones.. Again.. Depending on the customer and the tolerance, I'd say you
are in the ball park, maybe even a bit low.

I think you are just high on the 1".. If you interpolate with a 1/2" endmill, they
are going to take the same amount of time as the 1/2" with a 1/4" endmill. But they
are bigger, and they are going to be a little harder to move around in qty, so the 1"
should be a little higher.

InspireCNC · Jul 19, 2021

memphisjed said:
I get the big hole costs more because that is in a none optimal speed unless you have a seriously stout machine, but why discrepancy in the other two holes? Time to drill a hole is very similar, and positioning time is the same. Material handling is at least 2x what you think it should be time wise. Is that 1000 holes per part or 1000 holes on 1000 parts?

its 1 hole for 1 part. 1000 holes on 1000 parts. Youre probably right on the discrepancy. what would you charge?

memphisjed · Jul 19, 2021

I would have to manually run a radial drill on the big holes, but a hole is one dollar minimum. Figure your handling time, from opening box of stock to taping box of finished parts up, multiply by 1.5 and that should be ball park. Add a at least a full minute for the 1.8 holes (machine time is a driving factor on this part only).
Agree that there is customer and day of the moon calendar taxes or rebates to your price on a job like that.
Bidding is a guessing 50/50 game. You either get the job or don’t; if you get the job you either make money or loose money - you never “break even”. 50/50

InspireCNC · Jul 19, 2021

Bobw said:
I love these threads.

Some are going to say WAY!!!! too cheap.. Some are going to say WAY!!!! too much.

Of course part of that depends on the customer.

I also wouldn't drill, I'd drop an endmill down the center, interpolate and
be done. Less burrs that way, and they'll look better. Drills are very very
unhappy going down holes that are anywhere close to their size, and they aren't
the happiest things with interrupted cuts. Insert drill is a different story, but
I wouldn't want to run them one at a time in a lathe.

So I have no clue what GR LC is. But I'm going to guess just run of the mill
steel acme nuts. Not case hardened or anything.

Also guessing plus or minus 10 on the tolerance.

The 1".. I think you're high. This isn't rocket science here. Soft
jaws and interpolate. If it was 200 or 300 I'd think you are good,
but 1600 I think you are high, not intoxicated, but the price will land
you un-competetive.

Really good customer, and I had idle machine time, or needed something to
keep the help busy, or I was sick of diddle fucking with castings. 35 cents.

Good customer. 50 cents.

Pain in the ass customer. 75cents to $1.50 depending on how I felt that day.

Same for the smaller ones. .55 cents isn't bad.

The big ones.. Again.. Depending on the customer and the tolerance, I'd say you
are in the ball park, maybe even a bit low.

I think you are just high on the 1".. If you interpolate with a 1/2" endmill, they
are going to take the same amount of time as the 1/2" with a 1/4" endmill. But they
are bigger, and they are going to be a little harder to move around in qty, so the 1"
should be a little higher.

Looking at it again the 1" does seem high. Im probably going to bump up the price for the 2" hole aswell. I initially thought to do a spiral down and finishing pass with an end mill for the holes, but drilling seems to be faster, but now that you mention issues with drilling to exact diameter, im probably going to go with the endmill(im more comfortable making holes with endmills anyway). Anyhow thanks for you input, hopefully i get the job.

Bobw · Jul 19, 2021

InspireCNC said:
Looking at it again the 1" does seem high. Im probably going to bump up the price for the 2" hole aswell. I initially thought to do a spiral down and finishing pass with an end mill for the holes, but drilling seems to be faster, but now that you mention issues with drilling to exact diameter, im probably going to go with the endmill(im more comfortable making holes with endmills anyway). Anyhow thanks for you input, hopefully i get the job.

The minor on the 1" is .800.. You're only taking out .030 a side, no need to spiral.
Unless this a CNC knee mill. One shot and done, drop her in the middle, spin her
around, and pull her out. 10-15 seconds at worst.. even on a Fadal.

Here's a handy little cheat, if you are running centerline. Take the difference
of the endmill RADIUS and finish hole RADIUS. Then multiply by .414. Make your
lead in line that length, and your lead in radius that radius, and 135 degrees,
and it will drop you dead nuts on center every time.

Bobw · Jul 19, 2021

Another thought here.

Are the nuts cast? or are they made from bar stock.

I'm going to guess that at least the 2" is made from a big
cast mess.

One of my customers, on occasion needs 2"-12 nuts that go on
the end of a big stupid shaft that I get to key and turn..

The first one I did, he gave me a nut to check the thread with, and
I found out that the thread in the nut only had a very very loose
relationship with the hex, and even a worse relationship with the faces.

They wouldn't clamp for shit. One side of the face was touching, and the
other side would have a giant gap, up to .060". So now when I'm
turning the threads on the shaft, I just jam up 2 nuts and face them
so the thread and face are at least moderately perpendicular.

If the nuts are all golly wompers like that, it could really bite you in
the ass.

Booze Daily · Jul 19, 2021

I’ve modified purchased hardware.
Lost my ass. Every. Single. Time.

Bobw · Jul 19, 2021

Booze Daily said:
I’ve modified purchased hardware.
Lost my ass. Every. Single. Time.

I've lost it on a few also. But I've also made some pretty good money.

I HATE doing safety wire holes, unless its a straight through shot, or at the least
just 2 holes. Drilling them every other point is a pain in the ass.. EVERY point is
a bitch.

Turning down set screws to some stupid little point.

I've made good money shortening up short screws to some stupid un-obtainable
really short length.

The best one, and I've done it multiple times.. Part of some repair kit. The best
I can figure, this part was used to hold back some brushes in a motor for assembly..

You've all done it. paper clips.. or any other piece of wire you can get your hands on.

This one actually had a specific part number for sewing pins to be obtained from
JC Penny. And then chopped to length. They were some form of copper and coated with
nickel. I did the entire job with a pair of nail clippers, and then just hit the end
real quick on a de-burr wheel. GRAVY!$!$!$!$!$!!!!$$$$

Had one years ago, little 10-32 SS screws, about an inch long that needed to be necked
from just under the head for about 3/4", about 2000 of 'em. Sent a part timer home with
a 7X14 Harbor Freight mini lathe. He did 'em piece work. We made money, he made really
good money, and he got to work while drinking beers with his buddies. He just set the lathe
on his coffee table in front of the TV and sat on the couch.

Once in a while, you get a print for a modify, and its just easier to make it from scratch.
Well.... Not from scratch, I don't want to be mixing up a little molybdenum, a little copper,
some iron, a bit of carbon and then cooking it... But from bar stock.

Mike RzMachine · Jul 19, 2021

I'd cut a few test parts on your time, customer supplied nuts and see what the burr situation looks like as barbter mentioned. Specifying datums sounds picky but I've come across off the shelf acme nuts with horrendous runout and the thread was at an angle. If you hold the hex, your bore will likely be spot on to the hex but may not line up with the thread itself so check if that matters to the customer. The abrasive plastic bristle bottle brush in a drill press may be the ticket for cleaning up a slight burr. Be sure to cover your deburring and cleaning/counting/packaging time.

For this oddball stuff, I'd price it based on the cost of other work you could do in the same time. Not sure if you are full time or do this on the side. I always get a job I look forward to immediately after agreeing to something like this.

Good luck
Mike

Mtndew · Jul 20, 2021

After realizing who you are, I deleted my advice.
Dooshbags like you don't deserve our help.

AJ H · Jul 20, 2021

"Pay someone to teach me? No thanks. cnc machining is simple stuff. Figuring out specific hardware to use and learning the machines programing just takes time to figure out."

Over a year later and you haven't even got drilling a hole mastered? You're right this shit sure is easy.

TeachMePlease · Jul 20, 2021

AJ H said:
"Pay someone to teach me? No thanks. cnc machining is simple stuff. Figuring out specific hardware to use and learning the machines programing just takes time to figure out."

Over a year later and you haven't even got drilling a hole mastered? You're right this shit sure is easy.

I'd forgotten who this guy is.

Before anyone wastes too much time trying to help him, I suggest you go back and read this old thread of his:

Big time noob needs help with Fadal EMC.

pb1 · Jul 20, 2021

Bobw said:
I've lost it on a few also. But I've also made some pretty good money.

I HATE doing safety wire holes, unless its a straight through shot, or at the least
just 2 holes. Drilling them every other point is a pain in the ass.. EVERY point is
a bitch.

I loved wire holes. ~Ø.060 diameter took 60s a hole on a slow older EDM drill, or 30s a hole on a faster machine.

AARONT · Jul 20, 2021

"Fortunately for me this is easy stuff, for most it's not."

"its been pretty easy to figure out so far. Im sure you struggle because youre weak and mediocre."

"Sorry but this work doesnt take a smart person to do, thats why shops hire non educated operators and high schools are teaching teenagers to be machinist as an elective, LOL. Its easy"

GTFOH. I've seen my fair share of arrogant pricks crash machines. You deserve zero help and a trashed spindle.

boosted · Jul 20, 2021

AJ H said:
Over a year later and you haven't even got drilling a hole mastered? You're right this shit sure is easy.

Good catch. Sorta wish we could have talked him into quoting about 4x cheaper - since it's so much easier for him than anybody on here who would be quoting.

michiganbuck · Jul 20, 2021

My brother worked at GM as some kind of buyer for a time. He said they books that gave a good estimate on just about every kind of machining operation.

I had access to tons of tooling data at the big shop, yes I should have recorded a lot of it.

Help quoting drilling holes?

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