Oliver, The shaft is supposed to be 3mm diameter but is currently out of stock so I am unable to go and double check. I wonder if you were sent the wrong coupling, is it just a very tight fit or completely different?

Hi, I have tried pushing them both together but the shaft isn't going in. They both measure at 3mm. Maybe the 3.175 adapter might be better suited for this product? If so, can I call to arrange the return of this?

Oliver, You can of course return the coupling, I will get it checked out and by then we should have the motors back in stock. We may just need to pass a 3mm reamer through the coupling. I would not suggest going up a size to 1/8, let's do it right. We will of course refund your 1st class cost for the return. If you have a 3mm drill bit, you could try to see if that will spin through the coupling. We will sort it one way or another.

Hi there, I've been able to pop a 3mm drill bit through the coupling, so I think the motor dimensions might be slightly off. Is there a number I can contact to take this further? Thanks

Oliver, Contact number is listed on the website but tech queries are through this Q and A. We are waiting for the motors to come in so we can check but maybe the manufacturer got it wrong and they are indeed 1/8 (3.175). Just return any bits you wish with a note explaining what you require us to do. For example, modify or exchange the coupling. Hope that helps.

Oliver, This motor came back into stock today and we can confirm that the shaft is 1/8, not 3mm so we will update the product details accordingly. Now we know this, we can better address the problem. If you return the coupling we can bore out one end to 3.175 (1/8) and return it to you.

Peter, Thank you for pointing this out, yes a typo and should be 5-pole.