Hey Openbuilds members! My name is Justin and I am new to the CNC world. I have been buying a few parts from Mark over the past two years in order to create a prototype product I have designed. I have built a functional prototype out of Openbuilds parts and some custom spec Machine Shop parts I had made. I am at my last stage of mass production but I am stuck/hung on the mass production of one final punchlist item. My cosmetic trim parts. To date I was heating acrylic half rod to get the shape I wanted for the prototypes. This was a long and arduous process that offered no consistency in my end results. Recently I have had a 3d file created to 3d print these parts. The problem here was the surface finish was not to my liking and the parts were brittle. As this cosmetic piece sits on the front end of a vehicle, I need impact resistance. This has led me to the inevitable conclusion I could CNC machine these parts out of high impact ABS or even aluminum. At this stage I am debating whether getting a machine and learning the process makes sense, or would it be more cost effective to find someone who is a "hobbyist" and have them help me out on a contract basis. Would this even be feasible to create on a CNC? Thanks in advance everyone! Looking forward to your responses! Justin
Here is a better video of the functionality. Sorry for the YouTube auto stabilization giving the video a jello effect:
Here is an older revision that will demonstrate how I was using OpenBuilds parts: The open and close function is actually faster than shown (it was running off a Dremel Battery in the video). I have also used a larger pinion pulley to increase the speed of the retraction and deployment. As previously stated the doors and their trims are the last hurdle to my mass production. Can you guys help a garage inventor/entrepreneur out in getting to the finish line? Regards! JP
Maybe 1 - 2 a month right now. I want to square 20 of these away right now so I have stock on hand though.
If ABS is acceptable, I would suggest having someone CNC a mold for you and then just pressing them out of the ABS.
If I had a plate mill I'd be more than willing to give it a go but unfortunately I don't. With the number of Cbeam mills that have been built however, there should be someone here willing to give it a try.
Thanks Rick. This is my first foray into manufacturing. I didn't mean to put you on the spot. I'm just seeking wisdom right now on the best way to proceed. I have no problem learning and doing it myself as you can see, but there is always a rather large time investment that comes along with that and I can alleviate the trial and error phase by relying on those with experience like you to point me in the right direction. This project has dragged on longer than I wanted it to. I'm ready to close the door on this chapter of my life and graduate to the next level. To do that I am humble enough to admit I need some help. If anyone here like yourself could assist, I would be eternally grateful. Thanks again for your insights. JP
You presume me to be more of an expert than I am. Generally my suggestions are little more than what I would try if I were in need of accomplishing something myself. Such is the case here. No experience whatsoever with plastics, merely a general idea of how pliable they can become when softened. If I were in need of accomplishing this, I'd sandwich a sheet of ABS between a couple of milled form plates and enclose the plates in a much larger pair of press plates with some screws to add pressure as shown below and then throw it in the oven and heat it through. Not hot enough to liquefy it, merely hot enough to get it soft enough to where it becomes fairly pliable. And then tighten the screws. Obviously there are plenty of things that could go wrong here. Shrinking, curling, bonding to the molds, trapped air, or requiring more pressure than the screws can provide just to name a few. So before jumping in with both feet and spending real money on properly milled mold plates, I'd probably start with a simple test jig made up using a couple of large coins as the form plates to get a better idea of just how workable this suggestion is. It would also provide an opportunity to try various heating temps to get a better idea of what temperature is optimal. But again this is only a suggestion. CNC milling is always an option just expect to drop $75-$100 per piece for a 3rd party to do it for you or $800-$1000 investment for a machine if you want to do it yourself. Injection molding is also an option but costs there quickly get out of hand unless you have a way of doing it yourself. Good luck with the project.
@Justin Pandelo first I would like to say what a really cool project you have here, Love it! I think Rick is on the right right track with the heat /mold idea. If you do not need really high detail and do not mind some post processing you may want to consider vacuum forming as well. You could look at kydex for the heat forming plastics as well. All the best please keep us in the loop we want to watch this one go places! Mark
@Justin Pandelo pretty rad design mate Another option if you can make a quality master of the part, is to make up a mould/s using Silicone RTV and pour the part with a Casting resin.
Wow, How cool is that.. Nice project. I agree with Moag, Casting the part would be my approach to this. If a plastic part is needed; Resin casting would be perfect and repeatable. check "smooth-on" or "alumilite" for materials you would need for mold making and the resin for casting ( lots of resin options ). The initial work put into the master part / mold will show in the end product and really cut down on final clean up. If a aluminium part is wanted. I would go with a simple match plate pattern including your runners and gates and sand cast the part.
@Justin Pandelo while floating around the internets found a interesting article that you might just find helpful for your build.. Have a read when you have time. Resin Casting: Going from CAD to Engineering-Grade Plastic Parts | Make:
Thanks Moag, that was interesting reading Especially the info on Renshape460. I've been keen to find another carving medium of this type. The problem is that I'm in the UK, and that probably means they won't ship it to here, or that the cost would be prohibitive. I'll make enquiries and see what they say. From past experience, if it is available in this country, it will cost three times as much. But, must be positive and hope. Great article though. Many thanks.
I'll give it a spin and get back to you. Nope, no luck there, but I will try an email, just to see about shipping it out. Although I reckon size, if not weight, will be the cost factor. Still, we'll see.
First of all I want to say thank you for the overwhelming show of support here. It is funny, as I read through the various replies, I could see my own conceptual phases over the years. The doors have presented a unique problem for me as they are both cosmetic and electronic and need a degree of impact resistance and structural rigidity. It has been a long and arduous road and I am thankful to my girlfriend of almost 4 years for letting me Tony Stark a design in the home office and living room for so long. She has really been a saint. I have sent ot a few of these grilles and gotten some feedback on the design and QC issues. Thats what has led me here to try and slay this last dragon with an Ox or maybe someone who can act as my right hand in mentoring me with an Ox. At the present moment I am looking closer into the solutions presented here and appreciate the research and in Rick's case actually creating a model to help explain your proposed solution. Amazing work! Sorry for the delay in replying here, its been a busy week. I'll check in again shortly after reading further into this thread. I'm raising a glass to you all! Thanks again! JP
This looks to be exactly what I needed Moag! The Two part process is ideal for obtaining the "windows" and the recess on the back of the trims that accommodate the LED boards. It appears I could even cast the finished parts in the colors I need for cosmetic reasons (black and sparkle silver). Very good share my man!
Would anyone be interested in trying to work together in creating a mold for this out of aluminum based on this concept: Also is anyone close to NJ? I would be happy to drive and of course front the costs of material and your time. I want to get this done inside of the next week or two.
