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Chroming 3D printed plastic

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I was asked by a friend to print some badge's for the valve covers of his new ride. I have already sent one set down to ChromeTech that got rejected for porosity and roughness. They were just a straight WSF (sintered nylon) print with no sealing or polishing. I now have the new revised parts in hand that are polished alumide. Alumide is also a laser sintered nylon, however, it has aluminum in suspension to better handle heat. Alumide's heat capability is roughly twice that of WSF.

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The one in back is one I raised from a photo of an Ariel Atom that I want to stick on the back of my Touareg. OK, from a different thread I know that Pledge "Future" is the sealer I should be using and these parts were ordered polished and are much smoother than the first generation. I am not concerned about those issues, the issue that has me concerned is the obvious layering of the rings that occur in both badge prints. I had modeled them on an arc and that may be the "my bad" on this issue. Anybody have an opinion on if I should try to fill it and sand smooth? I have chromed many full sized bumpers back in the day and you just took them in and they made them right. I doubt that ChromeTech is going to any effort to make these right as there is no money in it for them. You can feel the ribs with your hand, but, they are very slight after the polishing (bombardment with plastic pellets)

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Posted · Report post

I have had a lot of HotWheels Chrome plated and Gold Plated.

The final results all depend on just how smooth you prepare the substrate.

Any tiny mperfections and scratches will always show.

Most platers do not want to work with anything that isn't properly prepared.

Do your parts from the 3D Printer come out perfectly smooth?

CadillacPat

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Posted (edited) · Report post

No they do not. They are beaten into smoothness by being shaken in plastic beads about 5 mm across. You do lose the sharp corners in the process. They are now smooth to the touch, but, you can definitely feel the printing ridges.

You posted my fear that any scratch or surface blemish will show. I am determined to get this to the Chrome guy, but, I want to give the parts the best chance for success. Is there the modeling equivalent of glazing putty?

Edited by NormL

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Posted · Report post

No they do not. They are beaten into smoothness by being shaken in plastic beads about 5 mm across. You do lose the sharp corners in the process. They are now smooth to the touch, but, you can definitely feel the printing ridges.

You posted my fear that any scratch or surface blemish will show. I am determined to get this to the Chrome guy, but, I want to give the parts the best chance for success. Is there the modeling equivalent of glazing putty?

I'm wondering if you could intentionally design the part so that the final shapes are defined by the eventual polishing medium (plastic beads in your example), rather than the printer itself. Sort of an intentionally "not quite finished" print out, followed by the plastic pellets which would refine and bring out the details by making too wide lines narrower, too sharp edges smoother, and too shallow valleys a bit deeper. Sort of a poor man's way to beat the limits of current 3D printing resolution?

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Posted · Report post

Well now that is an interesting thought. I have always viewed it as detail removal device. You could do the too wide lines narrower and the too sharp edges smoother, but, I am thinking that making too shallow valleys a bit deeper is chasing your own tail. No, it wouldn't work, ... I have gone back and forth with Shapeways many times, they have a different set of standards for polished and the model must be bulked up from a plain print. In other words any gains made would have already been lost in the "bulking" process

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Posted · Report post

Isn't Chrome Tech a Vacuum Chrome process for plasti?.

Seems like I had some 1/18 1989 HW Batmobile wheels chromed by them a long time ago.

Even if you say your material will hold up on a Valve Cover, do you think the Chrome Tech materials and process will??

What about spraying it heat resistant Silver and going for a textured metal look?

CadillacPat

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Posted · Report post

I am going to have to defer to your expertise here. I have never chromed plastic. What destroys or is problematic in their process? Bob did have the Atom badge in his hands and his issues were porosity and smoothness. I was reading all about the Alcad chrome product on here and I was going there if ChromeTech did not work. My friend has spend quite a bit on this car right now, so, I really want to chrome these if possible. Thanks for your input

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Posted · Report post

How about just plan sanding it smooth? If it's a plastic still you can sand it down smooth over the edges and if they are still high or low then fill them like we do normal parts. Bob use electric platting I think and I know he has done a ton of my stuff and it has all came out good. I can not see this stuff being more warping then resin could as that stuff does not take a lot of heat to warp like a chassis or bumpers. Also what machine are you working off from if I can ask? I seen two different machines and one of them makes the parts as smooth as a resin part is and the other not as smooth but very close to it.

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I know from bondo'ing my fenders that the plastic does not sand easily. I was thinking of glazing putty and sanding it, I don't know if that is a chroming issue. I guess I could always re "future" it

Maybe you are correct and I should have chosen a different print. The Atom is Shapeways WSF, the Scarab valve badges are Alumide and maybe FUD a deposit (smoother) style would have been a better choice. Deposit printing does not have the heat capability or strength that I felt I needed.

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Posted · Report post

I am going to have to defer to your expertise here. I have never chromed plastic. What destroys or is problematic in their process? Bob did have the Atom badge in his hands and his issues were porosity and smoothness. I was reading all about the Alcad chrome product on here and I was going there if ChromeTech did not work. My friend has spend quite a bit on this car right now, so, I really want to chrome these if possible. Thanks for your input

What I mean is, will the plastic chrome film (chrome plate) from Chrome Tech, melt?

I would take some sprue or chromed pieces that you have laying around and lay them on the Valve Cover to see how the chrome reacts to engine heat.

I don't think it will pass muster.

CadillacPat

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Posted · Report post

Ahhhh!

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Well I thought long and hard about it and decided that the heat resistance of the chrome material should be fine and there is only one way to be sure. I also looked long and hard at the layering lines and decided that they were part of the background and not the message and might actually look better with the radiation from center. I shipped it off yesterday. I emailed Bob and got an email back stating why did I "Future" it??? Oh well, we will see, I may be paying for some Bob time to un-Future it ....

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Posted (edited) · Report post

So what was the floor wax supposed to be for?

Did you test any plastic chrome to see if it would melt under the high temperatures under the hood?

Up to what temperature is the badge itself supposed to be safe?

CadillacPat

Edited by CadillacPat

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Posted · Report post

Well, I don't have any chromed plastic sitting around ... So these basically are the test pieces. I do believe that if I did have any it would have been styrene anyway and i would not have ended up with a true representative test. The Alumide is heatproof to 172°C/342°F according to their website, so, the base material will be fine. We will see regarding the chrome

A operable cooling system should be keeping the base engine in the realm of 180°f-190°f and the cylinder heads do get hotter than that, but, the covers will not even get close to 342°. The engine is basically a 500whp n/a SBC that will not be worked very hard in a very light car.

Yeah, I should not have sealed it ... that one is on me. Thanks again for your input Pat!

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Posted · Report post

I talk to the tech support from where I just order my machine regrading all of this and plus your trouble's with smoothness, They told me that either one or two things are going on for the smoothness of the part as your machine or there is not calibrated for either the size of what you are trying to do or the specs of there ca;obration could be more.

For chroming they garentee that the electic chrome plating like what we have know'n from Chrome Tech can be done and will not burn or warp the part as it's being chrome plated as if it's ABS plastic this is a very hard plastic once heated and cooled off.

If I was you I would take the time and call the people and talk to them and not play email games or nothing like this as they can under stand you better on the phone and know what you are trying to do with it.

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This is a Shapeways print and I cannot control orientation. It is also sintered and it sounds like you are speaking of an extruder or a deposit style. It is one of those base decisions, I chose the strength of sinter over the dimensional accuracy of the other two. For modeling, then yes an extruder or deposit style is probably better. For what I do, I deal mostly in sinter for strength and it helps that it is cheaper. i am printing a little 1/24th scale jack in a deposit style in the 2006 Ariel Atom thread and I fully expect it to be smooth.

The heat issue is from the location that the parts will be sitting not the chroming process. They will be sitting on a 1:1 cars valve covers.

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Posted · Report post

It's not the Chrome Tech process that will harm the parts with heat.

It is the heat from the engine that will either harm the materials of the badge or more likely the thin Chrome Plastic film .

CadillacPat

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Posted (edited) · Report post

They are badges for the valve covers of this

Edited by NormL

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Posted · Report post

How about looking into the process by which Trophies, are chrome plated. It could be more durable than Paint.

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Maybe naivety on my part, but, I was assuming that Chrome Tech was using that process or better. I haven't had much luck with trophy people anyway. About a year ago I tried to get a point cloud of my car in crystal. That is what you see all of the time and I have the point cloud. Well, ... their computers are set up to take an stl file and convert it to a point cloud and they make what you want. I could find nobody that that knew their software well enough to just use the point cloud. Oh I heard, yes we can do it, but, no they couldn't. So I was left with modeling the entire car from a point cloud so they could take the model and make a point cloud :rolleyes: Left me with a fairly low impression of their "technicians", at one point I was told that "we are just not set up for someone that knows more than we do"

Edited by NormL

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Posted · Report post

Regardless of what process could be used, Chrome Tech, or even real Chrome Plating on metals,

It's the prep work that counts, things have to be super smooth.

It still boils down to attaining a high grade finish, with a Home 3D Printer at this point in time, producing lasting products using high end durable plastics.

Norml, if you add up the cost of your machine, materials, taxes, delivery, everything and base it as the cost for this one badge,

What would it be?

CadillacPat

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Posted (edited) · Report post

Pat, I am hardly a proponent of home printing yet. As I have stated before, the printing industry is changing too fast to invest yet. I did almost buy a Boeing cast off though. I am using the Shapeways printers, specifically their $950,000 laser sinter machine. While I would love to have one sitting in my office it would make the cost for my printing in the $25k range per piece, LOL. I am sure their deposit machines are much more reasonable, but, that is really their concern. Mostly what I do is use this for rapid prototyping and there are a lot of services for that. I haven't been able to beat the cost of Shapeways yet, even though some of their rules are very irritating.

The more expensive badge to my door was $26.84 the other one is about $0.50 cheaper. We will see how good they look when they come back from Chrome Tech. The car they are going on looks stellar and they need to belong to it.

Edited by NormL

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Good luck Norml, would like to see the pics when you get it back from Chrome Tech.

You posted your info in such an objective and honest manner that I knew I could get real ansers from you, thanks.

There has been a position by 2 or 3 here that full tilt machines, producing perfect durable Models and all their parts, all done with the simple touch of a button, using styrene plastic or something comparable, with software no more complicated than using our present InkJets, at home InkJet prices (let's be generous and say $300), are being used successfully by Hobbyists or will be in a couple of months.

One day, sure, but not today, not for quite sometime to reach all those prerequisites.

Industial uses, sure, but it would be quite an outlay of cash for a Hobbyist to make 1/24 scale wheels and such.

You are using your machine for what I hear others say they use theirs, prototypes, or to see how things look at different scales.

Hope it all holds up under the hood.

CadillacPat

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I will definitely post the completed pics, good or bad. I think we are at the time that a hobbyist could use the technology, but, why buy a printer. Just use a service like Shapeways. If you need more fidelity than they bring to the table, then outsourced to a printing service that is a little more quality like www.moddler.com Wheels can be modeled to a very high precision and printed there. That was brought up in the 3D printing thread in general section. This can be done now, but, the cost will be very high, but, is it really? If you print 6 things a year their big expensive printers will do a better job and I doubt you will have spent as much as buying your own and maintaining it and in a year, your's will be obsolete. The user that brought it up was splitting the cost by printing one set and casting many to spread the cost, perfect use of the tech.

As far as when, my cell phone does a lot of stuff I never thought that I would want and I am still not sure that I want. They came on very quickly.

"he'll try to have you burned at the stake for being a witch" was what was said about you in my Atom thread. Fair warning, I may be big, but, I am wiry!

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"he'll try to have you burned at the stake for being a witch" was what was said about you in my Atom thread. Fair warning, I may be big, but, I am wiry!

that's hilarious Man,

Some people should just let others do the thinking for them, if you know what I mean.

Probably another 12 year old that snuck in under the wire.

CadillacPat

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