spindle size question

[anton]

I've ordered up a 10HP ATC equipped Columbo with

my Techno Premium router...........however, an

acquaintance in this business advises me that a

7 HP spindle would have been more than sufficient

for working with hardwoods, MDF and occasionally

acrylic. Not sure yet, but presume that I'll

be doing 2 and 2-1/2 D stuff to start. We're

not a volume shop, just four of us. Also, and

somewhat surprisingly, the mfr. claims that the

price would only come down around one thousand

dollars dropping to 7HP from 10HP. Does this sound

about right? I'm paying $12.8K for the 10.

Comments appreciated.

 

Anton Stayduhar

Contour Woodworks, Inc.

[Allan]

Well the 1K price diffrence sound a bit light. The diffrence in cost of the motor and speed controller plus mark up would be about that. Is ther any change to the spindle dia?

 

I would get the larger motor even if your not going to use the power. The motor and speed controller will last longer, and a larger motor would run more efficently.

 

Allan

[chris m]

The actual useable horsepower on any machine for prolonged cuts and reliable performance is almost always considerably less than the number they use to advertise. For example, on one of my Okumas, advertised as 10 hp, the "30 minute" horsepower available is 10 hp, but the "continuous duty" horsepower is only 7.5 hp. Now, you're probably thinking "I don't make any cuts longer than 5 minutes, so the 30 minute rating might as well be the continuous rating"; not quite. While technically true, this practice would put a serious beating on the machine, lessening reliability and machine life. Since you are a small shop, I would imagine you'd like the machine to last for 10 years (or 15, or 20), the best way to do that is to invest in the most rugged machine you can afford. You see a lot more 15 year old Matsuuras and Mori Seikis than 15 year old Haas' or Fadals for that very reason.

 

Whew.. sorry about the sermon, but this very issue (underpowered machines) is a constant problem in my shop..

 

The short version is:

 

Buy the 10 HP spindle, you can never, ever, have too much grunt, especially for what sounds like very short $

 

C

[Guest CNC Apps Guy 1]

I'm with Chris. Horsepower is like, RAM, Hard Drive Space, and money(arguably).... You can never have enough.

 

If they have a 20HP, consider that motor.

 

JM2C

[McRae]

With a router I would be inclined to use the higher horsepower. This will and should give higher spindle speeds.

 

Power = torque * rpm

[Claus@Cimco]

Hi Andrew

If it is RPM you are missing go for the smaller motor. Normally the smaller motor has a higher max RPM because of its lower moving mass. It is very hard to design a highspeed highpower motor, I have never seen a 20Kw/40000RPM but there are lots of 5Kw and some 10Kw out there.

 

Claus@cimco

[bryan.davis]

HP is king get as much as you can, spindle speed and torque are trade offs of each other, and with wood you will need less torque so you an afford to have the head regeared to give you higher spindle speeds

[limitless creativity]

torque at the spindle could be more inportant than HP.

 

HP at the motor will give you different torque depending on if it is a geared head or direct drive. You may need a 30 HP direct drive to get the same torque as a 15 Hp geared drive.

 

check all considerations when looking at your aplication.

 

Mike

[bryan.davis]

Thats not exactly true, torque isnt a major concern when your cutting wood, plus torque is a function of HP, ie you can get more torque a given spindle speed with a higer HP motor.

 

Gearing is important though, a lower HP motor can give more torque than one of a higher HP, but that is created by sacrificing spindle speed, further you can often get higher spindle speeds with a belt driven spindle than with a geared spindle, but you are sacrificing the torque transmissability of the drive chain.

 

It all boils down to how the machine is built AND what you are using it for, without any extensive experience with wood machining I would be looking for a head with high spindle speed and high horse power

 

The following formula does correctly define all three factors.

 

Power = torque * rpm

 

tfr

 

rpm = Power / torque

 

and

 

torque = Power / rpm

 

either way you look at it more power gives you more torque AND/OR more rpm.

[limitless creativity]

check all considerations when looking at your application.

 

There are 10000 and 15000 rpm geared spindles of course wood application would use higher rpm's but I believe you may not have to worry so much on torque.

 

Mike

 

[ 06-22-2002, 06:20 PM: Message edited by: limitless creativity ]

[McRae]

Claus -

 

The equation I put forth is true and your synopsis is true if you are holding variables constant. However the question posed - what should I do... Then the answer as evedenced by Bryan (someone else who knows what is talking about) is to get More Power!!

[ERIC14779]

All you guys are right

 

and your statments are good......

 

but this Techno Router is by no means a "Machine tool" type device.

 

take a look at their web site www.techno-isel.com and you will see that it is a light weight machine.

 

Anton IF you are ordering a short gantry machine then it may help to get the 10 HP Spindle. if you are geting a 12" or 18" gantry then I would be concerned with the stiffness of the machine.

 

We have a 40" x 50" X 12" Techno series 3 machine with the 3 1/2" Porter cable Router motor on it. And We have to take light cuts with it and not able to do anything other than plastic and wood

 

NO Aluminum....

 

I think that they use a 10 HP spindle Drive for either the 7.5 or 10 HP Spindle. You should also check with www.pdscolombo.com and see what they cost direct.... you may be suprized at the mark up.

 

I suggest that you GO and see the dealer cut some sample parts that you plan on cutting. I hope that the new machines they are offering are better than the ones we have. Both in rigidity and in operator interface (operating like a real CNC control)

 

[ 06-24-2002, 01:28 PM: Message edited by: ERIC14779 ]

[chris m]

It can't be too much less like a real machine tool than a Fadal...

 

C

[Trevor Bailey]

I am also in the market for a router at this time. I would stay awawy form Techno, except if you are going to put it in your garage. The best solutions I have found thus far are:

 

1) Heian

2) Komo

3) Multicam

 

Each of these guys were very helpful when it came to explaining HP verse RPM and all the factors inbetween. It all comes down to what you are going to be using the machine for, the speed you want to get the parts off the machine, and last but not least, the quality of your product. The above three mentioned, were all very helpful in discussing those things with me. I will be going to the woodworking show in Aug 22-25 in Atlanta. These guys have made it real hard to make my mind up. It should be a great show.

[Claus@Cimco]

Hi

 

Anton don't need a highpower spindel exept if he bought a more rigid machine, What he need is a direct driven high speed spindel for a router. This baby aint build for 100mm insert cutters, or cutting Inconel. Routers are for wood and plastic. And very few routers can do a good job in alu, they are not rigid enough and a high power spindel can't do anything to change this.

 

Btw Columbo makes fine spindels for routers and many Italian machinebuilders are using them.

 

Claus

[ERIC14779]

Trevor

 

dont forget Quintax they have a lower cost 3 axis panel cutting router called "Pacer"

 

www.quintax.com

 

along with their full on rigid 3 axis machines built here in the USA in Akron OH.

 

We have one of their 5 axis machines Very NICE....