That is adjustable resistor.

 

hi rite ok thank you ..

 

Try adjusting the small potentiometer and see if you can run any slower.
A couple of options, there is many designs for simple Triac controllers out there on the web, you maybe able to adapt or modify the one you have as they traditionally go down to zero rpm.
It may mean that you would have to reverse-engineer the present one and draw the circuit out, which in this case is very simple.
There is also another option with a Universal motor, there are some similar to what you have from the same supplier, but PWM for DC motors, which you can use on your Universal motor, the only thing you will need is a bridge rectifier and maybe an electrolytic capacitor, this version should also take you down to zero rpm.
Max.

 

I think that design is similar to this one:

 

thank you both for your replys i dont really understand but trying to learn is there a simple diagram i can search for on google sorry to be thick but thats why im here.. for help cheers

 

There are quit a few similar to the one ISB123 posted, just Google Triac controller, some have the component lists for them.
Also it would be worth tracing out the one you have as a learning curve, it only has half a dozen components.
Max.

 

thats what i need thanks max il go away and give it a go cheers

 

The photo of the controller shows a trim pot at middle-right that might be the 'lower speed limit' setting: have you played with it?

 

hi jw cheers for reply i havnt yet only just understood what it does so i will be trying that first..this mornings.. thanks

 

hello ..just a little update turning the screw on the trim pot slows it down a lot but just not to zero so thanks to you ppl im getting somewhere now thanks

 

It is possible you may be able to change a resistor and get it down even further.
Max.

 

hi max thanks would you know which id need to change and which rating to start with please any other help appreciated

 

Like I mentioned before, if you were to use a similar circuit as an example and trace the existing circuit connections out, it should be possible to suggest a change, probably to a resistor connected to the blue trim pot.
Max.

 

thank you max i do struggle to understand but sticking with it cheers for taking the time ...dave