Is othermill worth it? - Page 1
Forum section: electronics / general

author: thatguyyouknow
author_rank: Contributor
timestamp: April 05, 2017, 04:14:37 pm
content: I need a means to create fast PCB iterations and I'm currently looking into milling machines. I've generally heard bad things about milling machines but only positive things about the "othermill" milling machine but haven't been able to find any extensive down to earth reviews of it.Is the othermill more simple and reliable to use than the other milling machines? I have no experience with milling machines, am I making a mistake looking to buy one?I need to create many iterations of pcbs for R&D of my various projects and waiting for pcbs to come back from the fab everytime is proving impracticle so it would be worth the price to me.Has anyone owned or tried an othermill machine? Any advice ?

author: BroMarduk
author_rank: Unknown
timestamp: April 05, 2017, 04:34:57 pm
content: I don't have one, but had the opportunity to use one a few times. There are some limitations, but for quick prototyping a PCB it worked quite well. It can take Gerber files directly and I was able to successfully create a 2-sided board (which for obvious reasons is the most it can do). You have probably read about the limitations - FR-1 materials only, the alignment is important on a double-sider but is achievable, 6-mil tracing widths (Pro only - I believe the non-Pro is 10 mils) and vias are a bit of a manual process. If you can work around the limitations it can be a great prototyping tool. I did 6 boards in a day (all different) that functioned great (my mistakes excluded). My biggest issue was with a slot that had to be configured as overlapping holes to get it to work correctly.The Othermill Pro is definitely on my list, although I may wait for the next version before making a purchase. I wish I still lived close to the friend that had it sometimes.

author: nctnico
author_rank: Super Contributor
timestamp: April 05, 2017, 04:58:12 pm
content: I'd look at etching boards. It is cheaper and just as messy as milling boards.

author: thatguyyouknow
author_rank: Contributor
timestamp: April 05, 2017, 05:03:00 pm
content: Isn't etching a tedious process and very mistake prone?

author: langwadt
author_rank: Super Contributor
timestamp: April 05, 2017, 05:43:02 pm
content: Quote from: thatguyyouknow on April 05, 2017, 05:03:00 pmyeh, just like milling pcbs is a tedious and very mistake prone process

author: BroMarduk
author_rank: Unknown
timestamp: April 05, 2017, 07:19:00 pm
content: I certainly don't want to dis any method of creating a board, because they all have their place. Milling, just like etching gets easier the more you do it and master the nuances of each. The reason I believe that CNC milling a board is nice is that you can design your board then when ready create it with minimal effort. You may have to do it multiple times to get it right, but the actual effort required is small compared to etching and drilling.I could easily justify the time savings if I did a lot of boards. Since I only do it on occasion, I have not pulled the trigger a CNC mill. There are cheaper options out there from China and many plans to build your own - Eventually I will try something.

author: thatguyyouknow
author_rank: Contributor
timestamp: April 05, 2017, 07:51:08 pm
content: Yeah, I'd rather make mistakes with the minimal effort of machines than the manual effort of etching. Is the othermill worth it over cheaper options?

author: nctnico
author_rank: Super Contributor
timestamp: April 05, 2017, 07:59:39 pm
content: Quote from: thatguyyouknow on April 05, 2017, 05:03:00 pmNo. It is similar to cooking a meal. Stick to the recipe. Photo transfer is the easiest but you have to keep the developer and PCB material at room temperature. A spray etching machine with Ferric Chloride (infinitely re-useable by adding Hydrochloric Acid from the pharmacy) can etch a board in a couple of minutes. The most important part is to find good PCB material and do some exposure/development runs to get the right exposure time.

author: rocco
author_rank: Contributor
timestamp: April 07, 2017, 06:22:16 am
content: Quote from: thatguyyouknow on April 05, 2017, 04:14:37 pmI can't speak about the Othermill because I've never used it, but I'm in the process of launching a professional PCB mill called Prometheus. Photos on my site:www.zippyrobotics.com. What I can say is that for what Prometheus can do in terms of trace/space, it's more affordable than anything else on the market that's comparable (as far as I know). You can find cheaper machines, but I have yet to see one of them that can do 4 mil trace/5 mil space, or have a 50,000 RPM spindle. I believe it's even less expensive than the Othermill Pro. My goal is actually to deliver equal or better performance as an LPKF machine but for about 1/4 the cost. I wrote gerber import software called ProCAM which lets you bring in your gerbers and generate the tool paths. Prometheus is controlled from within ProCAM. I've tested imports from Eagle, KiCad, Altium Designer, Circuit Maker, and Diptrace so far. ProCAM also has surface tracking built-in to maintain proper depth of the bit as it cuts an uneven board surface.Prometheus is slated for $2,299 retail/$1,799 pre-order (pre-orders only get charged when preparing for shipping, not in advance). Spindle is 50,000 RPM which allows for higher feedrates all else being equal. Spindle runout is less than 2.5 microns, which means that you can use really tiny (like 7-mil diameter) square end mills without breaking them on contact, like you would with a hobby-grade spindle. Max feedrate screams at 3,800 mm/min (150 IPM). Prometheus uses precision-ground linear guideways - not unsupported round rail. The frame is aluminum and stainless steel. The lead screws are made in the US with a lead accuracy of +/-.0003 in/in. I also have something up my sleeve for solder mask supportbut we'll see if it works.In one pic on the site you can see two 4-mil traces separated by 5 mils. That whole board was done with 5-mil isolation (just as a test).

author: bitwelder
author_rank: Super Contributor
timestamp: April 07, 2017, 05:57:11 pm
content: Maybe you could check if there is any hackerspace near you that might have an Othermill, hear their opinion and perhaps also try the machine?