Another "which one?" question

[David Kenagy]

I want to make my own clock dials, using 0.04" sheet brass. These dials are just under 7" diameter.

The attached image is close to what I want, and was made by etching with ferric chloride on a photo-resist. That method is inconsistent, with almost a 90% failure rate. But I can get fine detail as well as wider etched areas to accept the dark wax that's used to mark the numerals. I'm not going to pass these clocks off as 18th C., but I want buyers to consider them as a competitor for those antiques. In the attachment there is a larger square plate with the numbers and minute ring, as well as a round piece that was etched all the way through. I know that a round CNC bit can't make the sharp joints seen in that overlaid piece, but if I go the CNC route, the machine would have to do well at the main dial. Price point: at $2,000 I'd wonder why I hadn't done this long ago. At $5,000 I'd be satisfied, as long as it does everything I need. Over $6,000 I couldn't justify it...pay somebody else to do it.

The Nomad 3 (by Carbide 3d) says the right things, but a seller's claims won't really tell me whether I'll get precision equal or greater than what I already have. I like their policy of selling the full software without a 'subscription'.

So I don't know:
- Can any CNC give me very sharp, very tiny script (see the name, printed near the center of the overlaid piece, and the stylized "K" symbols between the Roman Numerals).
- Will a machine that's excellent for these dials still be excellent with a 2' x 2' bed (or greater) for the day when I go to CNC wood projects? I can see a CNC for roughing out floral 'carvings' (etc) in clocks or furniture.

What would you folks buy to do this work?
Dial.jpg

[Jim Becker]

Sharp corners are indeed possible to engrave on metal like that with a CNC using V-Carve techniques and appropriate tooling. You can absolutely engrave what you show with CNC. (You mention 3D printing which is a completely different thing...it's additive rather than subtractive)

The biggest challenge with sheets of non-ferrous metal is workholding...a good vacuum system or use of superglue/tape or double sided tape come into play to keep things flat which is required for the engraving. For production work, vacuum is the way to go, IMHO. Cutting metal does require a bit of housekeeping consideration as you can't use the kind of dust collection that one can use for wood products due to fire hazard. And metal shavings are "not fun" to clean up.

For working metal like this, you'll get the best results from a machine that's equipped with a spindle that can be directly managed by the CNC machine controller software. Spindles are friendly for tooling as they generally have a lot more options for collets, especially when using very small tooling for the kind of work you want to do. Router motors are screaming loud and often do not provide as much speed control as spindles...and whatever speed control you have with a router motor is manual. Sometimes an incremental change in RPM provides better results in cut quality as well as for chip load which is what keeps the tooling from getting hot and dulling quickly.

My recommendation would be to shop for your second machine first and make your investment closer to your upper limits. You'll have the best chance of hitting your goal that way. You don't need a "big" machine for the work you propose, but you will be happier if you have a quality, well engineered tool to work with.

[David Kenagy]

I edited the "3d printer" term...as you recognized, I meant CNC. It will now make more sense to the next reader.

Before I started thinking about using CNC on brass dials, I'd been thinking about the Shapeoko Pro. I'll use your feedback in re-looking at these tables with bigger beds than the Nomad. Their cost is lower than my limit...which aspect does a more expensive machine overcome?

I'd enjoy reading what companies folks prefer, especially with features that made them prefer theirs. A web search only bombarded me with advertisements. Videos by users almost all love whatever machine they bought.

[John TenEyck]

Yes, I'm one of those folks happy with the machine he bought, a OneFinity Journeyman. 1F even makes a CNC specific for milling metal, though any of their models will mill brass and aluminum. I milled some thin brass on mine last week w/o issue, other than chips everywhere as Jim mentioned. I used the Makita trim router that's on my machine and had no issues, but you can easily add a spindle to any 1F and still stay under your budget. The noise issue everyone talks about with a router is a non-issue once you turn on the dust collection system, unless you are lucky enough to have that located outside your shop. At 10 - 15K rpm the Makita is not very loud and is completely lost when I turn on the dust collection and the bit hits wood. My friend has an Axiom with spindle. In all honesty, it's just as loud when it's running. Get a spindle if you want, but not for the lower noise during actual use.

You can use most any software you want. I purchased V-Carve Pro with the machine and it does everything I need, and way more than I am yet capable of. Including the software and spindle, should you feel it necessary, you would be under your budget. I was at $4200 all in. The 16 x 16" Machinist model lists at just under $2K, plus software, spindle, etc.

John

[David Kenagy]

For working metal like this, you'll get the best results from a machine that's equipped with a spindle that can be directly managed by the CNC machine controller software.

I've narrowed my choice to the OneFinity, which can mount a spindle, but they don't sell or make a recommendation for one. What companies should I look into?

[Jim Becker]

I've narrowed my choice to the OneFinity, which can mount a spindle, but they don't sell or make a recommendation for one. What companies should I look into?

I am not personally familiar with the spindle market, so hopefully, others can make suggestions. My Camaster came with an HSD spindle which is an Italian made, air cooled product. There are options that are more affordable for the more value priced CNC machines...some as low as a couple hundred dollars, but try to balance cost with quality and be sure the spindle uses standard "ER" collets as collets are "disposables" that occasionally need to be replaced. Like if you drop them on a concrete floor.

[Alex Zeller]

I bought an HY (Chinese) spindle from Amazon. I got a 2.2kw package with an HY VFD and a water pump. The water pump was worthless but the spindle and VFD have been great. I was planning on using a name brand water pump anyways (I think I got a Little Giant fountain pump). I was expecting it to be dustier that it is so I got the water cooled spindle. In hindsight it doesn't get that hot in my basement and with a dust shoe that accepts a 4" hose there's almost nothing so I probably would just get an air cooled spindle. I guess if you plan on doing 10 hour long projects water cooled with a water cooler might be worth it. I just use a 3 gallon bucket.

If you want to get a nicer spindle I've heard there's some German ones on the market that are very good. I just didn't want to invest the money until I was certain of what I wanted. As far as the Chinese spindles go you need to get a 2.2kw spindle if you want to use 1/2" shank bits (which I did). You'll want a surfacing bit to flatten the spoilboard. I bought a CMT one with inserts for about $75. It's almost 2 1/2" in diameter so it makes quick work of whatever I'm trying to flatten. I'll often just run the edges of rough cut boards through the jointer to glue up boards then put them onto the spoilboard and manually surface them VS using the jointer and planer.

The CMT bit has a 12mm shank which could be an issue for a router but for a spindle you can get collets of any size. I bought a half dozen balanced nuts for the spindle for cheap and collects for each size I use. The collet snap into the nut so having a set for each size is convenient. Since 12mm isn't used very often the collet and nut stay on the surfacing bit which i store in the plastic box the bit came in.

[Alex Zeller]

This is the spindle I bought from Amazon. The tubing was too short for my setup. This is the water pump. it's not a Little Giant, but a Danner that's made in the US.

[Jim Becker]

I bought an HY (Chinese) spindle from Amazon. I got a 2.2kw package with an HY VFD and a water pump. The water pump was worthless but the spindle and VFD have been great. I was planning on using a name brand water pump anyways (I think I got a Little Giant fountain pump). I was expecting it to be dustier that it is so I got the water cooled spindle. In hindsight it doesn't get that hot in my basement and with a dust shoe that accepts a 4" hose there's almost nothing so I probably would just get an air cooled spindle. I guess if you plan on doing 10 hour long projects water cooled with a water cooler might be worth it. I just use a 3 gallon bucket.

Water cooled spindles seem to be aimed more at the hobbyist machines. Air cooled appears to rule on the more industrial focused CNC setups. Both are just fine if used as designed, regardless of how long you run them.

[ChrisA Edwards]

I have the same spindle as Alex on my Onefinity. It's extremely quiet while spinning at 10K-18K rpm, nothing like any on my traditional Festool, Bosch pr PC wood routers.

I read that a lot of noise from a router is actually air moved by the fan in an air cooled router.

I did install drag chains for my X and Y axis, something the Onefinity does not come with, but was a relatively cheap and easy mod to do. The drag chains also carry the water tubing to and from the spindle.

I have a HD 5 gallon bucket with a small water pump that supplies the spindle and also acts as the return for the water. The water returning from the spindle, while running, rarely gets to 90F, so I don't provide any additional chill/cooling method to the water.

[Gary Campbell]

Guys...
FYI.. I have owned/sold dozens of Chinese spindles from .8kw (1hp) to 3.7kw (5hp). I have been very fortunate, or lets say for the most part my customers have been, in that there has only been 1 failure that I am aware of.

Chinese watercooled spindles got a bad rap for the most part due to cooling failures. One, because the pumps are cheap. And two, and much more prevalent, is that the customers used the stupid water buckets and then let them fill up with sawdust. The pump eventually plugs, overheating the spindle which then blows up. Use a closed system with a radiator and an anti corrosion additive (not antifreeze) and you may run for years.

Are they as good as the US or Italian made spindle units? Maybe not. But any customer (or CNC mfgr) that would select a hand held router, made for occasional use instead of the lowest quality spindle is simply making a mistake.

[Alex Zeller]

I used a plastic bucket that had chlorine tablets in it. The cover twists to lock itself onto the bucket. Both of the water lines go through bulkhead fittings on the bucket itself and the lid has a grommet for the power cord so nothing can get into the bucket. I also have a flow meter on the return line so I can see how much water is flowing. It also has a switch so if the flow gets too low it'll stop the CNC.

[David Buchhauser]

I used a plastic bucket that had chlorine tablets in it. The cover twists to lock itself onto the bucket. Both of the water lines go through bulkhead fittings on the bucket itself and the lid has a grommet for the power cord so nothing can get into the bucket. I also have a flow meter on the return line so I can see how much water is flowing. It also has a switch so if the flow gets too low it'll stop the CNC.

Same here - I use a sealed 5 gallon plastic bucket with hoses going thru grommets in top, flow indicator mounted up next to spindle, and a small amount of anti-freeze added to water to help inhibit any possible corrosion. My 4HP spindle was purchased on Ebay from a seller in Viet Nam. It takes BT30 too holders using ER style collets.

David

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[ChrisA Edwards]

Can you guys post a link to the flow meter please.

[John TenEyck]

Guys...
FYI.. I have owned/sold dozens of Chinese spindles from .8kw (1hp) to 3.7kw (5hp). I have been very fortunate, or lets say for the most part my customers have been, in that there has only been 1 failure that I am aware of.

Chinese watercooled spindles got a bad rap for the most part due to cooling failures. One, because the pumps are cheap. And two, and much more prevalent, is that the customers used the stupid water buckets and then let them fill up with sawdust. The pump eventually plugs, overheating the spindle which then blows up. Use a closed system with a radiator and an anti corrosion additive (not antifreeze) and you may run for years.

Are they as good as the US or Italian made spindle units? Maybe not. But any customer (or CNC mfgr) that would select a hand held router, made for occasional use instead of the lowest quality spindle is simply making a mistake.

Time will tell. I have about 4 months on my little Makita router so far, with many 4+ hour carves on it. Budgets are a reality for many hobby level users. I'm happy 1F offered the option of a mount for a router or a spindle. I saved at least $500 and greatly simplified getting up and running by going with a router. Doesn't seem like a mistake to me.

John