3hp or 5hp spindle?

[georgew]

I have decided to replace my PC router with a spindle, Colombo, Perske or Fimec. The decision I have to make now is, should I spend the extra money to go up to 5hp. The diference for the Colombo 3 to 5hp jump is about $500. I cut hard wood, acrylic and recycled plastic up to about 1.5" thick.

I know it is always betters to have a little more power than you need instead of a little less power than you need. The PC has worked for me for 5 years or so. It does bog down and I have to take things slow and shallow.

Any feedback form experienced 3 and 5hp users would be appreciated.

Thanks
George W.

[Brady Watson]

George,
I have the 5HP and it is more HP than I will probably ever need on my PRT...but if I upgrade to Alpha speeds it will allow me to make full use of the additional speed without concerns of bogging. The 3HP is perfectly adequate for just about anything you will cut at a good range of speeds...it is a bit lighter and smaller than the 5HP unit. The only thing that I don't like about the 3HP is the cheesy collet nut and wrenches. The 5HP one has a better nut and wrench configuration and that feature alone I feel is worth $500 in busted knuckles.

Either one you choose will be a HUGE difference over a standard router. It will finish the tool off the way it should have been...you'll see!

-Brady

[lto]

George,

I have the 3HP Columbo. The only time I've run out of power has been while surfacing oak plank using a 2 1/2" diameter insert tool. One downside to the 3HP spindle has been my inability to run a straight,1/2" diameter, single O-flute tool on account of excessive vibration caused by the O-flute geometry. I understand from Onsrud that this tool can be used successfully in larger spindles, I'm not sure how much difference it would have made if I had the 5HP.

For any of the work you have been doing with the PC, the spindle will do it at higher feed rate with much less noise.

[elcruisr]

I run a 5 hp colombo at nearly full tilt on all sorts of 3/4" sheet stock, plastics up to 1", 1 1/8" particle board and hardwoods to 1.5". I run mostly 3/8 and 1/2 tooling. It is not so much that you'll run out of power but you also have to think of the heat generated by pushing the spindle to it's limits. Overheated spindles have very short bearing lives. I monitor temps throughout the day and I can find even the 5 hp is pushing the temp limits when working in a full production mode. I don't think a 3 hp spindle would survive long in my application.

[gerald_d]

Is it correct that the 5HP needs 3-phase power while the 3HP can be fed single-phase? If so, this may be a deciding factor.

[georgew]

I have single phase only at my shop. The Colombo dealer can supply an inverter that will run the 5hp spindle on single phase power, but it's expensive. If I had 3 phase power I could get the 5hp spindle from this dealer for less money than the 3hp. The power inverter for the 5hp is over $1000. I am still leaning toward the 5hp though.

I made a mistake calculating the costs, 5hp is only bout $300 more than the 3hp for single phase.

[richards]

I've only had experience with the 3hp, but it's more than adequate for everything that I can hold with my vacuum system. I watch the temperature rise quite carefully when I'm doing extented runs, but the spindle seems to top out right around 120-degrees, which is about 20-degrees lower than the 140-degree limit. Most of the temperature rise seems to come near the end-of-life for the cutters. Normally the spindle draws about six amps when cutting, but near the end-of-life for the cutter, it climbs to about 8 amps.

I didn't realize that the 5hp and the 3hp have different collet wrenches. The collet wrench on the 3hp is the only thing that I totally dislike about the spindle.

Normally, with a 3/8-inch compression cutter cutting away, I just stand back and enjoy the show.

[gerald_d]

Out of curiousity, what is this huge difference in collet wrenches? Can't see it here (http://www.pdscolombo.com/accesory_collet_nuts.htm).

[richards]

On the 3hp spindle, the top wrench is standard, the bottom wrench looks more like a loose-toothed curved comb (to fit the grooves in the nut). The bottom wrench tends to slip, and because it's spaced about 2-3 inches below the top wrench, replacing a cutter requires two hands, one hand on each wrench. It's just a little awkward. (With the PC7518, I always used one hand on both wrenches - like a scissors - to keep from over-tighening the nut.)

[richards]

I should have said 'gap-toothed' curved-comb in the previous post. There's nothing loose about the wrench.

[Brady Watson]

3HP Colombo wrench at the top
5HP Colombo wrench in the center
Common spindle shank wrench at the bottom


5276

-Brady

[gerald_d]

Why don't you just change wrenches and/or nuts? The ER family of collets/nuts/wrenches is very standardised and interchangeable between spindle brands. (There are exceptions, of course. Perske uses a 1:10 taper while the ER standard is 8 degrees)

I purchased the Fimec without a nut or collets since I have 3 stockists here in Cape Town that carry universal ranges of ER collets and accesories. Here (http://www.rego-fix.ch/english/) is the company that developed the ER collet.