[naspc]

Hi everyone I am new to this, cnc that is. Sorry if I don't know the lingo or processes. I am interested in getting a piece done by cnc. I am interested in a single piece made out of acrylic plastic, the dimesion are approx. 18" x 14" x .7". Thank you for your time. I have attached some jpegs of what I have in mind.

[naspc]

can anyone point me in the right direction?

[RdHawg]

I can't exactly figure out what it is your drawing is showing. Is this all one piece, or two seperate ones.
What kind of corner radius can be tolerated in the internal corners.
What type of finish are you hoping to achieve.
What kind of tolerances are you looking for?
It looks as if you've done a dandy job of modeling it, Can you upload a step file of the part?
How thin does it get in the center section? From what I can see this could be a very pricy project as the center section is very large thin and prone to extreme chatter (Read imploding on itself) if not handled very delicately - translate to, high risk part. Maybe a removable center section that only requies thru holes with no pockets would be a better design.

[kevinjia]

Dear naspc ,

We can do this projects.China Mold Sourcing co.,Ltd will give you "really chinese price"for mold making.and may you send your updated drawings to my email.and we will quote as soon as possible.


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Shenzhen City, Guangdong Province China.
Email: [email protected]
Website: www.chinamoldsourcing.com
Manager:Mr. Bruce Jay

[RdHawg]

Or- you could send it to china! But please contact me first I'm sure we could work something out! grrrr this grates me wrong(nuts) (chair) (flame2)

[cnckid]

Yea, me too RdHawg. I want to say something, but I'm lost for words at the moment.

[Helix60]

I am interested in getting a piece done by cnc.

Looks to me like he's looking for a one off part. Doubtful anyone would send it to china just for one part. But you never know...... And quite Frankly Yes the above adds peturb me also...... To be very polite....

Regards,
Heli

[naspc]

you got that right ain't going the china route!

[dahui]

Not to add oil to a fire, but this situation intrigues me. What is the difference between farming out the job to china as opposed to farming out to some guy from outside of your zip code? In either case you are "taking business away from local companies." Even small towns have machine shops. Obviously this brings up the us/them comparison...but again does it matter if "them" is a guy from china or just a guy in a different state...if they are taking work away from you? If you are talking about keeping the US economy "strong" then boycott Wall Mart...but enough politics...or is that economics?

As far as the part. Can you say what it's for? That would help people understand what you need since you haven't shown a complete set of specs. Looks like a mount for an LCD screen to me. Keep in mind that machining will make the acrylic "frosty" where the tool cuts. If you need it totally transparent that will require a lot of polishing after the machining.

A part that requires "square" inside corners is not suited to machining since you have to use a round tool to cut with.

The other thing about CNC is one part is very time consuming. You have to generate the program, figure out how to hold the work, maybe have to hold it more than once, run a test part, adjust if it's not right etc. A good way to guesstimate is at a shop rate of $50 bucks an hour (this is cheap). Say it takes five hours to program, build work holding fixtures, run, debug, re-run. You are up to 250 bucks for one part. Say you want another one...might only take 15 minutes. Good luck and nice drawing. What software is that?

[turmite]

Even small towns have machine shops.

That's not necessarily true, and even if true for most small towns, you can't get a part made when you need it! At least that has been my experience.

Guys let's also not forget that whether we like it or not the Zone is a global community. As far as I know Paul does not have restrictions on who can bid on a job or who can't.

Mike

ps I just let two rfq here on the zone......one to a shop on the West Coast and the other to a shop in the MidWest! I couldn't get anyone local to make them, at least at a price I could afford.

[RdHawg]

If you are talking about keeping the US economy "strong" then boycott Wall Mart...

I'd like to - I find it hard to believe that most americans feel they can pay dirt for everything at Wally-world and then expect to continue making 60k+ at work - who is buying their product? Eventually this has got to come around.
This man could by all rights send his part to China and maybe get it done for less then I can do it. But hopefully he'll at least let some of us quote it and choose to get it done here in the states. While he may not be giving the $ to a close neighbor at least he's given another American a job and meaningful employment.
If I don't at least try to make a stand for keeping work here in the US what shall I tell my kid when he can't find a job to earn a living wage?

[dahui]

Yep I agree, demanding goods at next to nothing prices does not go along with the high wages to produce the very same goods. The hole that has been dug here in the US is pretty deep for sure. I'd say that it's the average american consumer who has pushed jobs out of the country, not that other countries are stealing american jobs.

For example on this part. Say some american shop quotes 250 plush shipping for one part. I think that would be pretty cheap based on the drawing. Say the fellow from china quotes 200 DDP (Delivery Duty Paid). Okay so the china option is cheaper...for the individual buying the parts, but not for the economy in general. This can be applied on a larger scale. I'm all for keeping jobs in the US, especially manufacturing...and customer service but that's another issue! I'm also for paying a higher price for something that's made domestically AND to a higher quality standard. I'm also for high wages.

In this industry people always say that US made tooling is toooooo expensive and they go buy import stuff, at the same time talking about how US jobs are going overseas. What does 2+2 equal?

So, it looks like us consumers will have to change their attitude of over entitlement, the right to have it all and ignore reality and consequences. In a practical sense, you might do well to enroll your kids in Chinese classes so they have the opportunity and advantage to choose and shape their destiny and country and not just struggle to live with the mess that short sighted domestic and foreign policy has left us with. Might as well thow in arabic too. You can bet that's what's going on over there. I'm not trying to be rude or anything of the sort, it's just that, as was pointed out, we are living in a global economy, not just a US one, and the US will have to adapt in order to survive. I think, as a country, it's time to start working with what we have and not just complaning about what we don't. So, now the question is...who gets the job!

[naspc]

wow, i just wanted a electronic casing! didn't expect this to turn political! its ok, I am glad that people have points of views different then mine, as long as its kept civil. for me i really don't care who does it or where its done. i would prefer it local, but i can't find anyone around here. if rdhawg didn't reply i would have probably went to china! i like local because at least i can go there and explain and maybe learn something. there is also turn around time/shipping.

@dahui
yes and no its for a lcd monitor. I am actually a designing a lcd monitor that you can draw on. almost like a wacom cintq. i know the finish won't be polished. the inside corners might be a concern but relief cuts (drill holes) will be fine. i was expecting it to be around that price, someone quoted me something similar. I appreciate your input, any more would definetly be appreciated.

[mctoxey]

That looks like a Sketchup Drawing to me. Love that application. Google now owns it and there's a free version online!
http://www.sketchup.com/

[naspc]

Actually It Is, Its Cool

[dahui]

Hi,

Wow, that sounds very cool and I don't mean to hijack your thread with political discussion. As someone "in the business" I find it an interesting topic.

So does that mean you are going to repurpose a tablet PC screen or something? That would be great! Sign me up for one. I have a regular wacom tablet that is great, and a tablet PC...if only I could hook up my tablet screen...to my PC! Guess you are ahead of me on that one. Actually, my toshiba is about ready for a trip to the dump (since I could only get about ten bucks from selling it) but if you have something else in mind...Makes me wish I had a CNC machine to cut this thing out for you.

Another primary issue that comes to mind is if the part you are requesting is for "proof of concept" or if it's supposed to be a finished model/product. The difference being hack it out or make it pretty.

I'm not that familiar with machining acrylic but I'd say that if you can tolerate a 1/16 (.o625) radius at the corners that shouldn't be too hard...smaller might be. Again, you'd want advice from someone who machines acrylic. It tends to melt and I don't know if it's brittle or cuts freely.

Things like little slots (perhaps for the wiring/buttons/leds?) would have to have a radius equal to the tool radius as well. You can always use a smaller cutting tool, but that makes it harder to cut since the tool begins to bend.

Is this a one off? You might consider simplifying the geometries on the inside if you can or using multiple layers and gluing them together. There are some pretty high tech acrylic adhesive that will cure fully transparent. Waterjet might be an option if you can cut multiple sheets and then bond them together...or if you don't need all the height changes on the inside.

[naspc]

its cool.
i am looking for a proof of concept/ finished product. but i understand it might that a couple of tries to get right.

and as for signing you up for one, you are on top of the list!

[jpwatkins]

Cool idea for a standalone unit. I concur with the idea of multiple plates, just use a safety plexi insert for anything clear you need. No need to buff and whatnot.

Cutting plastics and laminating them isnt exactly a cnc job though. All you need is afew hours of quality time with a variable speed router/dremel etc.. It works out quite well. For the price of a sheet of plexi ($6) I made a whole set of esoteric gears (cynasaural, yeah weird) in an afternoon. For many plastics just keep the revs high, its more melting than cutting but it doesn't burn the finish as much and the melted product flakes off leaving a clean optical surface.

But for production.. injection molding is the way to go, which is relatively easy to do with some of the softer plastics. The molds are definitely a cnc job ofcourse.

[metal_god]

naspc....I have 1" acrylic sheet in inventory...send cad model. I don't post quotes on an open forum especialy with people who deliver via Junk.

Finish is not an issue on thin wall thickness with us. We have a regular run of machined fron solid acrylic housings that have a wall thickness of .016" over 60% of the perifery of the part which has to be crystal clear.

[SORCHEROR]

thats right,anyone can go to china to have tooling made,50% down,the other 50% before delivery of your mold,you do get parts off the mold,but
they will do anything to get a good part off it,doesnt mean it can run production at a reasonble rate,ive seen it time after time,and dont be surprised if a year later they are selling your product after copying it,seen that too,people usually dont send one offs to china,ive had many customers go to china with molds and ive even replaced some of the molds already
nothing is standard and nothing is interchangable,i tell all my customers to go to china if they want cheaper price,i wont work for rice!!!