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.
Skip to main content
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!
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!
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.
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.
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
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.
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)
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
Hi Mark,
no problem, i’ve send you an email.
-Marius
10 months later
Ops, seems like the problem is solved
16 days later
From what I can see here is the part is printed upside down in PLA.
The design is simple so start on Tinkercad and make all your parts for your first session and see where that goes.
I see that your letters dont follow a curve. This lends itself to extreme simplicity and ease of effort in working the design.
After that you have a starter library for next set of parts.
Don’t do cad? This makes your whole project a larger problem than it has to be.
Flexibility upfront is the key. I have found there are 3d printers that don’t do cad. How can this be?
I have a PRUSA i3. I used Tinkercad to create a Bowen hot end holder. Took 3 days. I then created a x axis holder for a Dremel remote tool. 1 day to create, 3 days to print, 5 days total to get it on the printer. It isnt that tough. Precision? Extreme. I used digital calipers to measure the Dremel then went straight into cad. I have a long history in the creative arts so perception to drawing to cad to device wasnt that tough. I hope you fair well in your endeavour. Sometimes take a step back and dont rely too much on others when you know you can get something done by most of your own efforts.
My thoughts are to make metal deposition moulds for injection. This will drop your costs quite a bit and give you the detail you need but doesnt solve the two color part. Or find somebody with a dual color print box, cad up a test, and send around for test. 2nd option is the cheapest by far with no real commitment and gives you something really quick to fondle in your view thereby giving something tangible to change your perceptions. Its the only way to get the rocks out of the way. Fustration always breeds complexity in the beginning.