Speed Control for Clutch Motor

[MarlinDave]

Hello, 

I have a Consew 225 with a clutch motor. Too fast for my use for leather. Built a belt and pulley speed reducer, approximately 3 to 1 ratio. Helps but not where I need to be. Lengthened the arm on the clutch motor linkage and getting close. I wondered about an electric speed reducer like you use to plug a router or other power tools into. Anybody ever tried one of these? I built a speed control with a light dimmer switch yesterday. Worked a while but at some point the motor kicked out and I was able to get it going again. Did not expect this to work but wanted to try. Not enough power (600 watts maybe). Would try a router speed control if it would be safer for the motor. I know about servo motors, but really don't need to spend that much right now as I pretty much give all my work away. Thanks. 

[kgg]

1 hour ago, MarlinDave said:

I wondered about an electric speed reducer like you use to plug a router or other power tools into.

Your clutch motor is probably a 1 hp (745 watts) and with a typical speed of 1750 rpm. That motor on startup could have a inrush current draw of 6 times that of normal current draw (~6amps) on initial startup. Anytime you reduce the input voltage on a motor the motor will run hotter and it will draw more current in order to keep it's wattage rating until it blows the motors inline fuse or circuit breaker in the main electrical panel.

My opinion is that you have done almost all the normal mods except for reducing the size of the pulley on the motor. However until you master feathering the clutch you got what you got or until you install a servo motor which will set you back about $150 USD.

[MarlinDave]

It has the smallest motor pulley as well. 

[Wizcrafts]

1 hour ago, MarlinDave said:

It has the smallest motor pulley as well. 

Aside from learning to feather the clutch, you're best alternative is to swap the motor out for a servo motor. like this one.

[Tigweldor]

I would advise you to just add a VFD to reduce motor rpm.

I built a portable unit (s) - you can then use it on different machines.

If you build one - you might as well build two - very little more effort needed.

Sell the better looking one - the one left over cost nigh none.

hope that helps you out,

Hans

Who actually prefers the superior ability to feather a mechanical clutch system manually via pedal over the electronic version and runs all of his 3-phase clutch motors over such device(s) as shown in the pics.

It´s sort of like driving a truck with a manual or automatic tranny - on the automatic you cant really feather the clutch.

Anyway, this is definitely one of the most fruitful DIY projects you can make for yourself - trust me.

I actually consider it as a TOOL to manipulate the motor to perform the way I need it for my exact application.

You will never ever want to miss it again.

You can program in a stop mode - so your motor comes to a complete stop within x amount of secs when you press the stop button or by switch - it transforms the old clutch motors into a whole different beast.

Edited 6 hours ago by Tigweldor

[MarlinDave]

Thanks for the ideas. I considered a VFD for some 3 phase machine shop items I have. Built rotary converters for 2, one came with a static converter box. I was always scared of VFDs because so many have problems with them. The clutch is not smooth at all - grabs all at once. It takes off fast, then slows. 

[Tigweldor]

Naaaah - the only prob is, that you have to sit down and read/learn how to set the parameters within the different programs and sub-programs of your particular VFD.

And they are all a tad different - but lots of info an the internet.

You just gotta go through all that data entry step by step for the first time or to change/readjust settings to your likings - but all in all they are "bullet proof"

Edited 5 hours ago by Tigweldor

[Digit]

I've had a positive experience with a cheap Chinese VFD (see Powering three-phase skiver motor), but note that clutch motors are designed for continuous running at a constant speed. Their built-in cooling fan is designed to provide adequate cooling at that speed. If you lower rpm for any prolonged time, the motor will draw more current (increasing heat production) and lower the fan speed (decreasing cooling). The combination will risk your motor to overheat and burn through.

You say the clutch isn't operating smoothly. Could it be that it's clutch plate deteriorated from long-time use at slipping speeds?

I have no experience with clutch motor clutches, but does anyone perhaps know if these are wet or dry? And if wet, maybe the oil has leaked out and needs replacing?

[Tigweldor]

The clutch motors usually all have conical bell type clutch plates and the clutch lining is very similar to brake lining.

Often after woken up from decade long slumber, oil and grease have hardened, rust has formed - action is inferior - service is needed.

A well tuned and properly set up mechanical clutch system is a pleasure to operate - at least on my motors they are - and that is no witch-craft.

As to skivers - many people think that by having activated the sharpening wheel and sparks have quit flying - the bell knife is now sharp. Well only half way home - you still have to eliminate the burr from the inside of the bell knife. You omit that step - results will be poor. Cussing will get loud. Manufacturers and engineers blamed. All cause of the burr.

Edited 4 hours ago by Tigweldor

[MarlinDave]

The motor was new on the machine when I got it. Might have 20 hours on it. 

[Tigweldor]

I live in Germany.

National companies like Kobold, Quick, Efka have always delivered top quality.

The older the mechanism - the more "German" it was in design - and with as little as possible plastic in the whole concept.

And a lot more "service friendly" than many new "let´s produce cheap" construction concepts.

I can not speak for (newer) clones of them, stemming from far east of Asia.

 

Edited 2 minutes ago by Tigweldor