CNC porting

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la360
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Re: CNC porting

Post by la360 » Tue Sep 04, 2012 6:36 am

I think most people are fairly ignorant as to how much CNC equipment and all the necessary tooling actually costs. No point cutting your own throat to get the work in, if it doesn't pay it's own way, you're not going to have the machine for long. I could imagine certain cylinder heads eating up a few days before you cut anything, don't give up your time for free!
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Re: CNC porting

Post by amc fan » Tue Sep 04, 2012 7:33 am

That is a great idea to use a Bridgeport Trutrace! You could use head you are copying as a template. My question would be: Does the spindle have enough stroke to do a big block chevy intake port? If I remember correctly the table moves X-Y only. you would do chambers and bowls, then flip head to do intake ports , then flip head again to do exhausts . Has anyone tried this? Even and established cnc shop could use it to do chambers on three heads at the same time and cut down run time on the 5 axis stuff!

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Re: CNC porting

Post by cboggs » Tue Sep 04, 2012 8:42 am

Rolling the cost into the cutting fees for multiple castings is something most anyone
will be glad to do, including myself. However, that has become as common empty promise
as the good old "I'll put your sticker on my car and get you tons of work"
Never pans out for the bank account.

Keep in mind, the digitizing time and the CAD / Computer time after the data is captured
can, and often does eat up as much or more time then actually cutting the parts!
If you're billing CnC machine time at $110 an hour or so, .. think of
the value of the time you spend on the computer side.

A simple way to handle this is with a contract, .. and as business men I'm sure we are
all using contracts. Digitizing is rolled into the cost of XX number of castings cut.
BUT, make it XX number by XX number of days or time or the digitizing fee is due.
Only problem I see with this is if this small amount of money is a problem I'd
assume paying anything in future will be a problem too.

Business is business, .. simple as that. If I have a customer that wants a major project like cutting
20 heads ( 10 sets ) and they want to roll the cost of digitizing rolled into an total cost for
the project. I'm glad to do that, however I don't start a project without a deposit, and I don't
start those types unless the 20 castings are on my floor.

The real benefit that I think some might miss here isn't just copying a bunch of ports.
Using the computer and CAD moves port / head design to an entirely new dimension.
The ability to measure and control size and shape so accurately is light years past
what a grinder and some molding rubber can do.
Once I have scanned data, I can now accurately measure radius's, bends, area, ..
and run it in either quick low level CFD or send it on to high res CFD.
I'm a fairly skilled hand porter, .. but I never would give up the control
I have over shape / design I do with CAD.

I do a large amount of consulting in my business, not just head and port design,
but also testing / development planning, team dynamics etc.
Again, I can't see doing it without the tools available in the computer.

Interesting discussion

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Re: CNC porting

Post by user-9274568 » Tue Sep 04, 2012 9:01 am

Personally, after buying out a head shop about a month ago. And getting ready to buy out another one this week. Most would do whatever they had do to make a machine payments and feed their family.

Myself, I never sacrifice the integrity of my work for a dollar. However I live by the theory that I can only value, what the market will allow. Big difference...

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Re: CNC porting

Post by cboggs » Tue Sep 04, 2012 9:07 am

markets should be influesnced by the business owners not the customers, ..

consumers always want cheaper and cheaper, .. look at the total mess it's driven
our country into. Used to be the most industrious nation in the world, ..
now we just buy cheap second rate junk from China, ..
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Re: CNC porting

Post by user-9274568 » Tue Sep 04, 2012 9:10 am

cboggs wrote:markets should be influesnced by the business owners not the customers, ..

consumers always want cheaper and cheaper, .. look at the total mess it's driven
our country into. Used to be the most industrious nation in the world, ..
now we just buy cheap second rate junk from China, ..

That will never happen. It's beyond fixable. Every major CEO proves this to us.

WE as a nation did this to our self. Our country was founded on cheap.

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Re: CNC porting

Post by cboggs » Tue Sep 04, 2012 9:15 am

* wrote:
cboggs wrote:markets should be influesnced by the business owners not the customers, ..

consumers always want cheaper and cheaper, .. look at the total mess it's driven
our country into. Used to be the most industrious nation in the world, ..
now we just buy cheap second rate junk from China, ..

That will never happen. It's beyond fixable. Every major CEO proves this to us.

WE as a nation did this to our self. Our country was founded on cheap.
Interesting, .. I set my own prices, .. and understand the cost and value, ..

it's a mind set, . ....

In the world market picture you have to understand that most of that is driven
by corporate PROFITS, .. not the final consumer pricing.
This is a big misconception.

While to final consumer cost of whatever might be lower as a result, ..
the move to offshore manufacturing is driven by profit margins
and federal tax costs, .. ..
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Re: CNC porting

Post by user-9274568 » Tue Sep 04, 2012 9:20 am

cboggs wrote:
* wrote:
cboggs wrote:markets should be influesnced by the business owners not the customers, ..

consumers always want cheaper and cheaper, .. look at the total mess it's driven
our country into. Used to be the most industrious nation in the world, ..
now we just buy cheap second rate junk from China, ..

That will never happen. It's beyond fixable. Every major CEO proves this to us.

WE as a nation did this to our self. Our country was founded on cheap.
Interesting, .. I set my own prices, .. and understand the cost and value, ..

it's a mind set, . ....

In the world market picture you have to understand that most of that is driven
by corporate PROFITS, .. not the final consumer pricing.
This is a big misconception.

While to final consumer cost of whatever might be lower as a result, ..
the move to offshore manufacturing is driven by profit margins
and federal tax costs, .. ..
Profit margins have been the driving force before we moved offshore. Slavery... Mexican labor... now China. Wal-Mart basically taught every small owner what they needed to do to survive. Perfect blueprint.

You can set your own prices, but the mentality of our nation was set a long time ago..

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Re: CNC porting

Post by kirkwoodken » Tue Sep 04, 2012 11:14 am

To the OP: shops typically used trunions to mount the work, turning as needed to get to the next work area, something done electrically with CNC. I proposed this idea to a MAJOR head porter in 1970. He said it wouldn't work as well as doing it by hand. It only took him 20-25 years to figure out that it could. I'm not saying the Tru-Trace is better than CNC, but in my opinion, it is more versatile when only a small number of parts needs to be REPLICATED from an existing part. Making a part from CAD/blueprint takes time that could be spent machining what you need from that old Bridgeport sitting idle in the rear of the shop.

Another point: The main reason CNC machines do such good work is they are NEW machines, not half destroyed by 75 years running like much of the equipment in American industry. I was once expected to hold "tenths" on a machine made in 1906, a 70 year old piece of crap. I ended up putting a "Tenths" indicator on the head slide and adjusting the depth with a lead hammer to meet expected "production".

In the early 70's, one of the big differences between American and Japanese government philosophies was: In America, machinery was allowed to be depreciated forever, so the purchase of new equipment was not encouraged. In Japan, depreciation was only allowed for seven years, encouraging the almost constant upgrading of manufacturing processes. At least that is what I was told.

Interestingly, neither of these two opposing systems has been successful in overcoming the effect of near slave labor wages in foreign countries.

Also, here is a link to a different way of doing business that some may find interesting. This isn't as much political as it is historical. I was friends with the Johnson family, hence my interest in this person. http://www.nationalinvestor.com/EJ%20story.htm
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Re: CNC porting

Post by cboggs » Tue Sep 04, 2012 12:04 pm

The Story of George F. Johnson

inspiring, . . .
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Re: CNC porting

Post by smeg » Tue Sep 04, 2012 7:58 pm

I have customers that think they should get a discount because they say that it is ok to use their port that I digitized on other heads.
But they dont realize that it is not quite that good or it is a funny shape or something out of the ordinary, that I wont use it anyway. But I feel you have to eat some of the digitizing time to keep their work.

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Re: CNC porting

Post by brad_m » Tue Sep 04, 2012 10:07 pm

For as long as we all keep giving in to the customer, we will be under charging for our time and knowledge.
I don't do any performance work for anyone but myself and friends.
I do own a mechanical repair/servicing shop.
I don't give in to the customer I set my pricing and if they don't like it, I will tell them to find some one else to do the work.

It's a long hard road to building a quality customer base, But it's starting to pay off. I would be easier if half the other places in the city weren't stuck in the 90s with their hourly rate and being to scared to lift the price.

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Re: CNC porting

Post by RAS » Tue Sep 04, 2012 11:06 pm

Perhaps in the future 3D printing will be another way to create custom parts. It's new technology but, the rate it's being developed is amazing. The new materials that can be used is a growing list that now seems endless. I'll bet we'll see intake manifolds that would otherwise never be built because of this technology. Among other things.

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Re: CNC porting

Post by kirkwoodken » Tue Sep 04, 2012 11:25 pm

OK, I have to ask because of ignorance: All the CNC machines are only doing one head at a time?
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Re: CNC porting

Post by smeg » Wed Sep 05, 2012 1:32 am

Yes,
Some have an advantage where they can digitize on a seperate machine while they are cutting on the cnc.
I was told not to go that way as it can/does induce errors from machine to machine.

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