cheap CNC machining service for short tubes etc... similar to oshpark?

so many times I would like to be able turn/mill my own metal parts for too many different reasons… I even considered buying a small lathe just for personal use, maybe one day I will :slight_smile:
Talking about flashlights, think about how many new possibility would be available. So, do you know of any cheap online CNC machining/prototyping service, which could be ok even for just 1 or 2 samples? Just like Oshpark does for PCBs… a whole light would be out of question, but I think maybe small and simple parts might have a reasonable cost, especially if we found an asian service :p… think about short or extender tubes for example.

Actually I have found many of these websites, but for most of them a quote must be requested so I have no idea of the price at the moment. I only got a quote for one of them (which happen to be an italian company by the way) where you can have an immediate automatic quote by uploading a .step file instead of asking for a normal human made quote… but the price was just unacceptable for our use (about 100 USD for a 18350 tube). I can expect the other services that require a manual quote to be less automated and so their prices to be probably higher.

Anybody tried this route in the past? or any other ideas? even group orders for popular lights could be an option… I remember there was at least another thread about that, but it had no luck at the time… maybe now that good 18350 cells are available, the interest in putting 18650 flashlight on a diet has grown :wink:


CNC and ” cheap” usually just don’t go together too well. 8^) Set up labor alone is a major part of the cost. Onesy twosies lend themselves to just straight up non-CNC machining and will likely be less costly. Bigger runs different story. But for just “samples” it’s gonna cost up regardless. I take it there are no machinists in your area that can do prototypes.

Someone that spent $5K, $10K, $50K on a CNC is not going to bother machining one off parts at cost. Especially from random hobbyists that don’t know what is involved.

I think you are better off trying to find existing lights that might lego with your desired light. 100USD actually doesnt even sound terrible if you don’t consider the purpose. If it was some precision machined high performance car part of the same size it may not “seem” as high.

I know that, but most of what you are pointing out should also apply for Oshpark and it should not exist… but for some reason (I guess matching many similar orders is probably one of the key points) it exists and you can get custom pcbs for a few dollars. This idea came to my mind just because I got to know about Oshpark… otherwise I would have not even bother googling or opening this thread :wink:

I was thinking at light bodies because being turned parts they could require no mechanical set up at all (on some CNC lathes the metal rod to be machined is just pushed through the jaws… that’s how non standard screws are made, for example). From this point of view, manufacturing a few custom PCBs is probably not too different than manufacturing a few custom turned parts.

” I take it there are no machinists in your area that can do prototypes.”
There’s probably plenty of them, but they will just laugh at me if I ask for a “prototype for personal use”… same as above, I think if there’s any chance to have custom stuff made for a reasonable price, as less as possible human work should be involved… especially if we are talking about europe and not asia.

You are right and we are all doing that, but that works for so few lights… this thread is for all the others. Actually another option is cut the original tube and join the two threaded ends together, but again for so few lights is possible to buy just a spare tube…

Machinery and tooling for metal parts (i.e. torch tubes) is much more expensive than that needed for cutting circuit boards.

BTW set up labour includes all the computer drawings and importing into cnc programs such as Mach 3. This is likely to take more time to do than for the cnc to actually cut the product out. Hence lots of places don’t like to do one-offs or small runs.

Circuit boards are made thousands at a time and it is not hard to squeeze a small design onto some free space and just cut it out at the end of the manufacturing process.
A custom CNC job needs to have someone spend time programming the tool path, and the machine needs to spend time working on your piece alone since each machine can usually only work on one at a time.
You might want to do some research into CNC machining processes.
$100 for a tube is pretty normal.
Most places will charge a minimum price because it is a waste of their time for anything cheaper.

Local professional machinists may not laugh at you IF you pay them their prevailing wage for the task at hand. They know how much time it takes to machine something better than you. If you tell them you can do it “this way” they’re gonna come close to say, “Well, YOU can do it YOUR way, but this is the WAY I do it.”

Otherwise they’ll think you think their business is some kind of non-profit charity and on top of that you’re also a better machinist than they are. And then if you continue to take any more of their time the exit door is the next thing they’ll take you to. :))

That is your best option if you have several custom parts you would like to make. 5 to 10 different parts (not the same) would probably cost what you would pay to get started making your own and it’s loads of fun. :wink:

You seem to be into the field. “Circuit boards are made thousands at a time and it is not hard to squeeze a small design onto some free space and just cut it out at the end of the manufacturing process.” I think the same applies for Swiss type lathes, for example.

Again, what you say is definitely the main problem with a generic CNC machined prototype (that’s why I did not even think requesting a quote for a flashlight tube on the websites that I have found in the first post). But I’m not convinced this also applies for simpler parts… for example, I would not be surprised if a service such as the one I’m thinking about would exist for laser or waterjet cut metal sheets (the closest thing to pcb I can think about). Why can’t it be the same for simple turned parts (such as custom screws… or flashlight tubes :wink: )?

For example:

in the case of swiss lathes the “one at a time” problem doesn’t exist. As for the code, maybe I’m wrong, but for simple parts such as the ones we are talking about I think it can be generated by the CAM software with little or maybe even no human work.

Your video still shows the parts being made one at a time.
To make more than one at a time there need to be multiple machines running in parallel.

Also unlike PCBs the tooling and stock needs to be changed for nearly every custom part that is requested.
Using a 4” diameter piece of aluminum would be a waste if one parts needs to be 3.9” and another part needs to be 1”.

Another thing is that PCBs are mass produced at millions per day.
How many people are ordering small quantities of custom laser cut sheets of metal or CNCd tubes?

Basically either get your own lathe, and make the stuff yourself, using your own time, manually and at lower precision, or you pay the price to get a custom CNCd high precision part.
The only way to get both a CNCd quality part and low cost is if you order in bulk, and then the price for several thousand units will be cheaper per part, because it can be quickly manufactured as shown in that video.

Uhm… you are right I should at least give it a try… after all I don’t have to ask for an exact quote, just giving a phone call to 2-3 machine shops asking a generic question should be enough… something like “I know you usuallly do much more serious stuff, but would it be possible tu turn a tube in the 20 mm OD, 50 mm length range, threaded at both ends and if so what costs are we talking about in the ballpark?”

Don’t tempt me… I knew flashlights were an addicting and expensive hobby… but I wouldn’t have thought to jump from spending 10-50 USD to 500-1000 :stuck_out_tongue:

Buying your own machine, you could make those parts for around 10 bucks depending on size and where you buy your stock.
Most machine shops I know of charge between 50 to 100 dollars a hour. And there gonna want specific measurements and thread sizes.
You might try member CNCman, he could probably get you a close estimate of what would be the cost and what you need.

Ummm… I don’t think so. I had an estimate for two small parts (spinner button, and another similar sized piece) and was told by two machine shops that the guys they use (external) would cost $300-500 to make the file needed for machining. The cost of those parts to be machined would be a few hundred, at least, to setup for one part. Each additional part would cost a $5-10.

I think if all you are looking for is a bored tube with threads, no styling, a manual machine would be the best route. $100 sounds like a steal for a one off part.

PCB machining can use three type of tools: diamond saw, carbide drill or carbide mill. Saw and mill are usually one size only (once they put in place they work until they are worn-out). PCB shape is usually simple, it is made from flat sheet and there is very small probability that something would go wrong way and tool will be broken. Tools have fixed position (Z axis), if you provide pcb files - they dont require extra work, files can be loaded and machine starts milling.
Even simple flashlight parts may require many cutting tools. You have to spend some time to figured out how part can be made if you have simple 4-tools toolpost. Bigger machine can make life little easier but anyway in most cases you have to make changes in tools and their position after previous work. Even this dont garantee great precise, most critical places have to be measured after machining and this changes can be made after production of first prototype. Part and tool position dont have big spare place, you need to worry about touching non-working tools to the part. Most parts require two-side machining, if you dont want to have jaw marks in your job you need to use soft jaws (and yes you need to bore them to the size you will clamp). Even if you provide some 3d model, it wont shorten time required to setup machine for your part and this is the reason why you always will pay extra 0.5-1.5 machine hours if you want to make few prototypes on cnc lathe.

talking about flashlight tubes, probably even less… for most lights it should be possible to start from one of the 2-3 usd spare tube easily available, instead of starting from scratch from a standard raw tube… so one just have to cut it and thread it, getting anodization as a bonus :stuck_out_tongue:

With a nickname like that he seems THE MAN :smiley: I’ve read his presentation thread I’ll write him a pm to invite him to join the discussion :wink:

Thank kiriba and the all the other guys.

I’d like to point out the last part of my opening post :wink:

the CNC service is just one of the options… other ideas? most of all, I can’t believe I am the only one interested in custom tubes… except the ones that were interested and ended up buying a lathe :stuck_out_tongue:

I’ve just did some brainstorming, I think it will be useful if I update the first post with other options one could evaluate… I’ll update it if someone has feedback or other ideas.

  • This website its worth having a look at: Seems like similar parts (aluminum or steel threaded tubes) are made for 30-40 USD shipped to Europe.
  • Asking a local machine shop:
  • Starting from a cheap spare tube from the few models available and do all the work you can do by yourself, then asking a favour to someone working in the field. In my case the only problem is the threading… all the rest I can do by myself (cut it to size, cut the oring grooves, turn the portion to be threaded and make the relief groove).
  • As above, but figuring out a way to cut the threads with some DIY… should not be impossible for soft materials such as aluminum… or maybe even some polymeric material with a copper sleeve for the electrical contact (water pipelines might be a ready made option having already the aluminum layer). Ok, this last one sucks: if the material is soft enough, maybe it could be even possible to screw it in place and make a “self tapping tube” :stuck_out_tongue: (the material has to be stable enough with the temperature to not detach when the head gets warm).
  • As above, but turning the aluminum tube and press fitting/gluing a plastic sleeve at both ends.
  • As above, but turning the aluminum tube and press fitting/gluing a molded threaded part made in some misterious way (some resin maybe).
  • As above, but 3d printing the sleeves (or the whole tube) and then smoothing the threads by hand (brushing/sanding/whatever)

This is a Video on cutting outside threads with a manual DRO lathe.
This is a 10 minute video showing the cutting process. Now whats left out is the 30 to 40 minutes of setup. Setting up the right gears for the threads specified (my lathe you have to manual install them) setting the right speed (mine has to have a belt pulley change) centering the piece if using a 4 jaw chuck with a dial indicator (this video appears to be a using a self centering chuck, since he only tightens one jaw) checking your start and finish points with the threads, finding and installing the threading tool on center. His also using a live center which takes another 5 minutes or so to setup. He has already turned the outside diameter down to the correct size to cut his threads (the time depends on how much material he had to remove to get to the desired thread diameter). Now the 10 minute video starts and you begin to cut threads and this is just the outside threads on one end. This takes a lot more time than one would imagine especially if you don’t double check yourself and end up screwing up and have to start all over again.
Just a little insight on how many processes it takes just to cut one thread, oh and I forgot to oil the machine up before I started.
Some of the newer more expensive lathes have time saving features that will reduce the time but it’s still a involved process.

Sooner or later Fedcas is gonna realize (reality) unless you’re family and close friends there IS NO FREE LUNCH nor FAVORS when it comes to professional machinists. :))

There are a few options you can do, first, if there is enough interest in a particular battery tube of the same type of flashlight, then the cheapest option is to draw it upon CAD and I can try to help with a prototype to verify fit and functionality, then go to the manufacturer of the particular flashlight company with a viable CAD file and the number of tubes and ask if they are willing to make a small production run on them. They will be the cheapest option because they already have all the necessary equipment to do everything including anodizing, less the pcb boards for the springs and circuitry.

I will post a pic of a Haikelite 8 x 18650 extension battery tube for your info with dimensions so you can what is necessary to accomplish this first process. Give me an hour or so because we have the Grandchildren again tonight.

You could try 3D printing if you just want to play with how some different designs feel. But $100 for someone to use their years of experience in CNC, VERY expensive lathe, and hours of their time is a good deal.