Page 1 of 1

New Build Spindle Options/Questions/Opinions

Posted: Wed Jul 30, 2014 10:45 pm
by Atomist
I ordered all the components to build a Shapeoko 2 with NEMA23 motors and most of the common upgrades I've seen on this forum. I am looking to purchase either a DW660 with a SuperPID or going with a large watt spindle and inverter. I guess my question is this...by the time I spend the money for the Dewalt/SuperPID with how I want it setup, I'm looking at $300+ american dollars. To purchase a 1.5kw spindle setup is going to be close to the same cost. Can anyone who's been down this path or know's more than me(should be everybody heh) care to comment on the pro's/con's. I don't necessarily need a 1.5kw spindle bc I know that's really too much spindle for the machine to truly utilize but it's just an example. I am considering a less powerful spindle but I would want something at least as powerful as the Dewalt, if not more. Which brings me to my next question, what size spindle would be comparable in power to the Dewalt? This is my first foray into CNC so this is all new to me. I like to think I'm a pretty capable person but having no experience first hand leaves me at a loss. Any help, comments, suggestions would be greatly appreciated. I will be doing a build log to help share my journey. Needles to say I am pretty excited and chose the Shapeoko 2 largely because of the community I saw here.

Also, since I've already purchased the DW660 dust shoe :P If I were to change to a spindle, do you think I'd still be able to utilize it? Obviously depending on the spindle.

Thanks in advance.

Re: New Build Spindle Options/Questions/Opinions

Posted: Thu Jul 31, 2014 12:43 am
by WillAdams
I've tried to put everything into the wiki: http://www.shapeoko.com/wiki/index.php/Spindle_Options

I have a number of misgivings about the DW660:

- has to be modified to make changing bits easier while mounted
- not designed for extended continuous operation
- main bearing is held in a plastic housing / body

If you're going to get a PID, I agree that it makes better sense value-wise to get a ``real'' spindle. Routers and trimmers seem to be rated for peak power, so you shouldn't necessarily have to go the whole 600 Watts of the Dewalt --- how much less would be equivalent is something we don't seem to've worked out yet. I know some people have really criticized the 300 Watt spindles for lacking power, and that's never been the case for the DW660, so it's definitely less than a one-half or two-to-one ratio. On the other hand, if you just get a 600 Watt spindle you'll know it's definitively as powerful if not more-so than the cut-out tool.

The DW660 dust shoe should be easily adaptable to any other spindle --- I'd adapt it by mounting it to the new spindle mount though, either by adding a projection the same diameter as the collar on the DW660, or by (carefully) drilling holes to affix the top piece to the spindle mount --- as a last resort, (very carefully) enlarging the hole to match the new spindle.

Re: New Build Spindle Options/Questions/Opinions

Posted: Thu Jul 31, 2014 8:28 am
by cvoinescu
The main problem with DW660 plus speed control is cooling. Like many motors of that size, the DW660 is cooled by a fan on the motor shaft, which works fine at high speed and low to moderate torque. When you reduce the speed and increase the torque (by using closed-loop speed control), the cooling becomes insufficient.

Re: New Build Spindle Options/Questions/Opinions

Posted: Fri Aug 01, 2014 1:28 pm
by danimal
cvoinescu wrote:The main problem with DW660 plus speed control is cooling. Like many motors of that size, the DW660 is cooled by a fan on the motor shaft, which works fine at high speed and low to moderate torque. When you reduce the speed and increase the torque (by using closed-loop speed control), the cooling becomes insufficient.
That is the main problem, and you will run into overheating very quickly.

Really the hands down best solution I have found is the Makita RT0701C. There is a cheap chinese mount that works perfectly with it, and a dust shoe is very easy. I have a pic of mine, it is just some craft foam cut with scissors and a hose clamp.

I burned through two sets of bearings in my dw660 so the cost was more than just getting the makita. When you start milling more, with more complex jobs the total job time will quickly become several hours of straight run time. This is too hard on the dw660 and soon you will start to see the bearing temps shoot up, then the horrible runout is soon to follow.

First I was running my DW660 with speed control and I attributed the bearing failure to inadequate cooling. It did run really, really hot. Then I ran it as designed for a few more months and the same thing happened to the new OEM bearings. It ran much cooler, and lasted twice as long as the first set of bearings but that was still only about 6 months. I think that the plastic holds in too much heat leading to bearing failure due to the extended operation. Plus the body is molded with a taper that makes alignment and mounting much more difficult.

Image