Super-PID Router Speed Controller
 

Here is a interesting Router Speed Controller that monitors the speed of the router as it is cutting.

http://www.vhipe.com/product-private/SuperPID-home.htm

I thought it might be of interest to others.

looks awesome! I may just have to have one of these. Thanks for sharing the link.

It also gives you full rpm control and on/off from Mach3. And RPM down to 5000.
I've been using one for over a year now.

Hi Nils

I have constantly thought how others using routers without speed controllers must suffer when cutting more difficult materials.
To the point where cutting plastics at 30,000 RPM all you would mostly get is melted plastic not cut plastic.
Also rotating really big cutters at full RPM - that's just scary !!

Regards
Ross

You might notice that guys with routers (and no true speed controllers) tend to talk of higher RPMs than the spindle guys, for the same material/bit/etc. That is because the standard router's speed droops off when it takes load and isn't turning as fast as one thinks. With the digital controller, the droop in speed is insignificant and the displayed speeds are comparable to that displayed on a spindle VFD.

With the Super-PID, the actual rpm is displayed on the unit by using an optical sensor on the spindle shaft.

I hate to say it, but by the time you buy a Milwaukee "3.5 HP" router and the PID, you have exceeded the price of just buying a 2.2kw spindle and VFD.

Yes, but you can rebuild a router (bearings and brushes) for $30. When the spindle dies, it's another $350. I've read enough "dead spindle" threads to be a bit leary of the chinese spindles.

Spindle bearings should easily last 4-5 times longer than router bearings, and have much less runout.

Because the Chinese spindles do not come with instructions, beginners do not know that you have to warm them up at low speeds for a few minutes before starting cutting. Beginners also do not know that the very first time you hook up a spindle, you warm up for 25 minutes per low speed setting.

The other big spindle advantage besides runout and keeping full torque at low speeds is that you get much more useable power. Hook that "3.5HP" router up to a Kill-a-watt meter and you quickly see that it is actually less than 2HP .

James, I don't know if you have actual experience of running both routers and spindles. We have done both and after killing a good many spindle bearings, it is very tempting to go back to routers with proper speed control. The major reason for not going back is noise.

We have used them both. Low speed torque and like you said, noise are both pluses for the spindles.

Cutting aluminum sure needs slower RPM than wood, LOL.

I've been using 10-15HP HSD spindles for 15 years with no warmup, and have needed one rebuild, after 8 years of 40hours/week use.

The manufacturers of the $150,000 routers these spindles are on do not tell you to warm them up, and honestly, it's usually not practical. You can't run a spindle for 5 minutes every time you need a part. And an electric fan cooled HSD will be cooler in 2 minutes of not running then it is when the machine is turned off.

Regarding price. I'm building a dual spindle router right now. Right now I'm leaning towards using PC 892's with a Super-PID.
2 - Porter Cable 892's + 1 Super-PID = ~$550
2 - 2.2KW spindles and a Hitachi VFD = ~$900
I know the spindles are more powerful, but they're virtually the same diameter. And you can't really compare a 1.5Kw spindle, due to it's smaller collets that can't use 1/2" tools.

The reason we chew up spindle bearings is because we cut many textures involving the repeated plunging of big (~40mm) ball-nose bits.

I also think the whole warmup story is overdone. Sure, if your shop has cooled to below freezing overnight, it is a good idea to do a little warmup first. But, tools are there to be used - not nursed. :)

http://www.pdscolombo.com/engineering_maintenance.php

Warm up IS called for by the manufacturer.

Our Haas mill displays "Spindle Warm Up Not Completed" if you try to start a part cold. It has an internal clock so you can run the warm up sequence before you open the shop in the morning.

I guess that $389 for a replacement spindle once every year or so could be covered by the profit from a single job, but killing the bearings in a $4000 spindle might hurt a bit.

It would be fun if someone had the time and money to run two spindles side by side for a year or two. One always warmed up, the other used cold. Would one fail before the other?

I share Gerald's experience, plunging 50mm ball nose too hard kills spindle bearing in a hurry. I now plunge a lot slower... BUT can't be too slow or it will char the wood. Its a matter of compromise.
When I cut texture, 2.2kW is what its required but I now upgrade to 3kW (4hp) spindle which not only gives a better safety margin & most importantly more constant rpm when cutting through varying depth. mind you, cutter do go blunt when you put them to work & it need more power as it become less sharp.... I'll go for 1000hp spindle if I can afford it :P
BTW, Near the equator, we don't warm up the spindle. No body with the right mind will do that here....

Spindle warmup is required for accuracy work ... You all know the thermal expansion... I have once started the intricate engraving with cold spindle and when i did the next pass on the same i got 0.05mm more depth of cut then the initial run due to warm up spindle...