Do I have rocks in my head?

[markgrigsby]

I have print job that I thought would be fairly straightforward, but I’m having trouble finding any information anywhere that will tell me if this is possible. My print job is a small disk about the size of a nickel with printing (Arial bold 20pt) on it. I would like it in two colors. I have 4000 unique versions of this job (only printing is different) and have no idea of how many of each I’ll need. It could be 10 and it could be 1000! I would like the printing embedded into the disk.

The thing is that I read all this stuff about the resolution on 3D printers being phenomenal, but the quality of the results I’ve seen remind me of the old dot matrix printers compared to today’s laser printers.

I can design this with CAD, but don’t want to go to that much effort if this is either not possible or not cost effective. Am I not asking the right questions? I’ve attached a copy
cap design2.pdf (181 KB)

[gabriela3d]

@Alex3DHubs is this something you can help with? thanks

[MB3D]

Hey there,

if i understand you correctly you don’t own a 3d printer and want these coins/disks to be made, right ?

First of all to print you need a 3d model. There is software, that can creat a 3d model out of a screenshot but these won’t work for this thing as it is not just a flat model.

For amounts going towards 1000 pieces (with the same text) it could be too much for 3d printing as injection molding is cheaper then,

but with the variation in models (you said 4k different texts) and two colors, injection molding is very difficult/impossible.

What do you think on how much of those disks you will need at first and where should they be shipped to ?

I would like to take the challenge and use my dual extrusion (two colors) printer to give this a try.

Do you have a special wish on what material should be used for printing this ? I’d recommend standard PLA as it is easy to print,

available in very much colors and -most importantly- cheap.

Regarding the actual printing:

What are the tolerances on this ?

Does it have to be this text or could i change for example the text style for ease of printing ?

Specific colors that should/shouldnt be used ?

I offer blue, yellow, red, green, metallic grey, orange and white PLA at 0,4€ per cm³ (cheaper price/cm³ when your order demands much filament)

Please contact me if you are interested, i could send you sample parts with all colors listed and will start modeling the disks upon your response.

-Marius

[geekfablab]

Hey Mark, it’s certainly possible, but you’ve got a lot of tricky features in the print that would throw amateur Printers for a loop. The “button” on the underside of the print makes the rest require support material. That support can lead to an imperfect surface on the underside of the “nickel”. Not a huge deal, but something to be aware of. Having the lettering should be OK. Having it be in a 2nd color is slightly tricky. Unless the printer has dual extenders, the person running the job will need to “Indiana Jones” in the 2nd color mid-print. Hot-swapping in a 2nd color isn’t very hard, but it can negatively impact print quality, and it would be a huge pita to do 4000 times. Also, based on the way 3dhubs prices by volume, this job wouldn’t pay very well for the effort, equipment and skill sets needed. That might make it tricky to find someone willing to undertake the task.

[MB3D]

Why not print this upside down, then you don’t need support and the 2nd color for the letters can be pulled mack by a lot after a certain height (depth of the letters) to stop that nozzle from oozing and creating blobs on the surface

[mickeypop]

It sounds like what you really need is to 3D print just the prototype for dimensions and fit. Once proven i would seriously look to injection molding (Much cheaper in quantity) and ink printing on the surface latter.

There are printers that can print directly thru the computer bypassing setting up the screen, then printing the piece on a jig so alignment will be perfect

To buy such a printer would be costly. However, look into the armature electronics on the web. Several have modified inkjet printers to print directly on PCB boards for baking then etching. I use a modified HP and can print 6pt font size.

With a modified printer like that all you would need is for it to fit your jig and use oil based ink cartridge instead the standard water based ink. Then you could lay it out in word or most any printing software that gave you control of the layout. Your jig could just be a 1/4 - 3/8 plywood carrier with rows and columns of holes fto hold the neck of your buttons

REF http://www.instructables.com/id/Converting-an-Inkjet-Printer-to-Print-PCBs/

http://www.pabr.org/pcbprt/pcbprt.en.html

Just a thought …

[geekfablab]

Replying to myself… Would you consider painting the lettering? You could get a shallow pool of paint that might achieve a very similar effect to the dual color without involving a hot swap or a dualie. Been running it thru my mind today.

[markgrigsby]

MP -

I don’t think injection molding is the right answer because I have 4000 different iterations of this thing and a fairly low volume. So, to me, this seems like a perfect application for a 3D printer if I can get the resolution right.

I looked at your instructable for converting an inkjet printer to print printed circuit boards and it is quite clever. You also have some very interesting projects on your website!

The idea about printing on these little caps with oil based ink isn’t really what I’m looking for. I would really like something that is more like a keyboard key which is injection molded. I have thought about having a bunch of these injection molded with no printing and then etching them with my laser but the contrast isn’t enough. I’ve also though about subtractive manufacturing if there is such a thing. I mean if 3D printing is additive manufacturing, why isn’t taking a thicker sheet of plexiglass and removing the part I don’t want with my laser. It would be a lot of stinky work and would take more time than I need this to take.

Thanks again and if you have any other ideas, please let me know!

[markgrigsby]

Oh, I would definitely print this upside down because I can get a prettier surface for the top and so I don’t have to have any support things to clean up afterward. I agree that the color for the letters shouldn’t go all the way through the disk part. I initially wanted a domed top, but gave that up because supports would be required no matter which way the cap was printed!

[markgrigsby]

NS -

It is really the two color lettering that I’m having problems with. If I had a printer, I would get one with a dual extruder just because of the amount of work involved in hot-swapping a 2nd color. I also imagine creating a whole bed of these things at once and each one may be different. The printer wouldn’t care about that.

Also, I’m going to end up needing a lot more than 4000 of these. I have 4000 unique caps, but I may need anywhere from 10 to 1000 of each of those 4000 caps. Certain ones of these things will sell better than others so as I find out which ones I sell more of, I’ll know which ones to order more often and order more of at a time. I don’t want to keep a gigantic inventory of these things around.

[markgrigsby]

I don’t think painting is going to give me the effect I want. And, I’m concerned that it would wear off and the customer would be left with a dud! Keep running it through your mind and let me know if you come up with anything.

What I really want is that new HP 3D printer that is going to have about 10,000 nozzles spraying blobs of plastic around like an inkjet printer does. But, alas, it isn’t going to be available until 2016 and will most definitely be out of my price range.

[MB3D]

If the parts (beside the color) are the same, or at least you have just a few different designs, then you could concider getting these parts made with injection molding and glue on a sticker with the text. Did you read my comment about the offer to print those parts? -Marius

[Rifle]

I have a Zcorp 250C that can print in multi-color with the appropriate resolution you are looking for.

The printer uses a powdered gypsum medium that is sealed with a cyanoacrylic inflitrant.

This is not plastic, so it may not be what you are looking for.

[markgrigsby]

Marius -

Thanks for your reply. You are correct in that I don’t have a 3D printer and would want these things made for me. The 3D model isn’t a problem. It will be quite annoying to change that 3D model 4000 times, but once its done, its done. If I ever need more than 1000 of a single cap you are right that injection molding is a better choice. I don’t want half of them injection molded and the other half 3D printed though and I know some of these will never have more than 50 or 100 of a single cap.made.

I’m thinking that PLA will be the best choice of material but am open to other ideas. As far as tolerances go, I haven’t though about that. These will fit in things that are injection molded and the only thing that will be different will be that certain brands may need larger or smaller diameters for the post. But, all of a single brand would the same size. I’ve thought about making that center post smaller than I need and including maybe 4 little things that follow the length of the post, but are fairly small in width. This way, the tolerances can be higher because the 4 little things would act as tolerance adjustors. I have attached a 2d drawing of this looking from the bottom of the post to the top of the disk. I know this is a fairly crude drawing, but it was fast and easy.

The font of the text can be changed if a different font will provide greater clarity. As far as colors go, I think something like a yellow base with blue or black printing would give the best contrast. I’m in the US (Colorado to be specific) and I think I saw that you are in the Netherlands. No need to send samples now, but if you think this can be done I’ll go ahead and create a STL file for you. Then, if you can try it and just send me a picture of how it turns out, that will be fine with me to start.

If we need to take this offline, please don’t hesitate to let me know. I guess I’m still confused by the absence of 3D printed items with contrasting lettering though!

Thanks again!

Mark
cap with tolerance adjustors.pdf (89 KB)

[geekfablab]

Find someone with an objet - same thing

[markgrigsby]

Marius -

I just replied to your other message, but I did think about having just a few designs and putting a sticker on the top. I wanted something that looked a little more professional and, as someone who is in business, I don’t want something people can just print another label for and stick it on the top when they need to change the lettering. I thought about putting little spikes on the top to prevent this, but it isn’t a very consumer-friendly approach to a product. I also thought about texturing the top so stickers don’t stick well. I’m not going to worry about this part right now.

Thanks again!

Mark

[3Dscaleworks]

Hi mark,

Diameter and the ridges should not be a problem . If you make a print run be sure not to print one at a time but but in series of ten.

Ridges an different diameters should be any problem but to fit you should always keep in mind the tolerance in printing. Printing filament always deviates from your original paramaters in design.

3greetz

John

[3Dscaleworks]

Oh injection molding is only intersting above 10.000 pieces because moldcosts are high!

[MB3D]

Hi Mark,

i have started printing the coin part. Due to the very high contrast of the colors the black shines a little bit through the yellow color. I’m trying to fix this by printing the coin flipped on it’s side. Then the second nozzle is never touching the print unless this nozzle actually prints.

As you can see i have used my own font that is optimised for printing it, i have to make a tiny adjustment for the flowrate of the first layer, so that the lines are smoothly fused together. I have other coins which have a smoother surface, but these have more black filament fused with the yellow background, so that they are not really representative for the final prints.

The final version will most likely look like this one, exept that the shadow from the black filament fused with the background will be gone and the lines are smoothly melted together to a solid coin. I have also added another picture of a test lego brick that shows the real yellow color aswell as what you can expect as a smooth surface when choosing my hub for printing. (I broke the knobs off the lego brick to test layerbonding)

I’ve printed the coin slightly larger then supposed to be, so that i can figure out the best settings when printing small, downsizing the print is no problem.

The hexagonal shape of the upper part will not be necessary to archive high quality prints.

However i have thought about recessing the letters and having a solid black disc inside of the upper part.

The yellow surrounding would be printed above the black disk and by that the lettering appears.

I’ve got some other ideas on how to get the cleanest yellow while maintaing absolutely filled black letters.

Please tell me if you are still interested in having these parts printed. Please contact me so that we can discuss further details of the print. Also i then would like to explain further ideas on how to improove the models geometry and design.

-Marius

[MB3D]

Hi Mark,

how do you think about the followig color combinations, yellow and black is one of the most readable combinations but as i said in the comment above the yellow color doesn’t cover black spots of oozing (i am working on it with good success, pictures will follow today or tomorrow).

-Black and red

-Green and red

-red and white

-dark blue and white

-dark green and yellow

the list cointains the text color at first, then the background color.

Hope to hear about your progress and opinion,

Marius