[jalvim]

Hi all,

This is the first time I'm posting anything so sorry if I do something wrong!!

I have a problem - I'm developing an automated machine to grind soft materials (mainly cork), I have built several cnc's from scratch in the past, so most of the work was a walk in the park, but I'm really against the wall when it comes to the spindle/router I should use (can use is more what I want to say at this point).

Here's the thing, in the past I have always used hi-frequency spindle (tipicaly max.24000rpm) for my cnc's, be it the hwaianwhatever cheap ones or really nice ones from tecknomotor, depending on the needs - but now I need to use grinders that are between 40mm and 100mm, so I need torque at low rpm... I know if I buy a really good spindle I can probably get away with it, but I'm not going to make that kind of an investment in something that is really not going to be used properly, and that is probably goint to overheat (this is a machine that will be working hours on end).

One of my first thoughts, as I am even ready to forget the speed control, was adapting something like this - MSD13-0028/CONT | Parvalux MSD13 Inductive Reversible AC Motor, 1 Phase, 95 W, 220 V, Flange Mounting | Parvalux - but due to it's weight it's not a good solution. I have thought about just picking up a regular spindle and make a gearbox for it, but it would take too much space on the machine.

Any suggestion would be very appreciated as I'm really out of ideas and don't know of any spindle (or motor I can adapt) that fits the requirements...

[handlewanker]

Hi.......I am in a similar position as in needing a smallish motor with lots of grunt and able to spin up to 5,000 rpm. with lots of torque, and also have lots of torque right down to very low revs.

The application is for a 3025 bridge mill to mill steel.....not much space on the Z axis mount to have a 1hp motor and belt drive spindle etc.

The solution I "think".....and this is hypothetical...... will solve the problem is to go to a small hydraulic motor on the mill driving a spindle with belt drive and the electric motor and pump off the mill etc.

EBAY has a hydraulic motor for A$250 and a pump too for the same price.......a 3/4hp electric motor to drive the pump is needed too.

I don't know if these are available in your area, but the application would give you a small compact unit with the hydro motor at 100mm diam and 125mm long......you don't need to have the electric motor and hydro pump on the machine as it can be placed under it on the floor.
Ian.

[talootfouzan]

500$+ investment and in the end u dont have even 1 hp,
if you have this budget you can buy from alibaba some high power electric motor,without all this hassle,

[handlewanker]

Hi, I don't think you know or understand the potential of hydraulics......as the solution I posted is only an example of the potential for a milling application, no further discussion will be entered into for this particular application.
Ian.

[awerby]

If it was me that had to do this, I'd find a pulley-type spindle and run it with a regular induction motor like the one you linked to. If that's too big, get a smaller one. You can set up the pulleys to give you whatever speed you want, and if you use a high-speed motor you can gear it down to give you more torque. Your choice of spindles will be driven by the arbor size on the grinder heads you're using - how big is that? If you can't find one that works for you, you can build one using a pair of angular contact bearings to hold the shaft.

[jalvim]

Thanks for the feedback!

One of my first thoughts was a hidraulics motor as they have the low rpm and hi torque (I'm not talking about HP, two diferent things). The thing about these motors is they are usualy very heavy and big, but I have found some that might fit my needs ( Amazon.com : Century Electric UST1102 1-Horsepower Up-Rated Round Flange Replacement Motor (Formerly A.O. Smith) : Swimming Pool Pump Parts : Patio, Lawn & Garden ). My doubts with this kind of motors is that they probably don't have acceptable runoff in the rotational axis, does anyone have any experience with these kind of motors?

Pulleys are my second choice, but that will make me redesign the whole machine because I only have room to place a motor or spindle (the motor/spindle stand needs to be ajustable). The arbor size will be around 8mm to 12mm, so I don't think it will be a problem...

Jorge