Ziggy and Blossom can sympathise with poor Alfie - they too used to be scared of the clippers. They tolerate them really well now. They aren't ready yet for me to roll them over to do their armpits but, it will come with patience and training. Im sure someone will be along to give you some great training tips. In the meantime though I will tell you how I made progress with mine:
I clicked and treated mine for sniffing the clippers when they were off. I also used to keep them next to me and casually handle them when I was relaxing. Once happy with the presence of the clippers when off, I then slowly introduced the touch of the clippers by stroking my dogs with them while still turned off - alternating strokes between the clippers and my hand. For mine, the fuss and cuddles was the reward at this stage for calm behaviour. Next I moved onto switching the clippers on but, away from my dogs and on the lowest/quietest setting. At this point, I went onto using food rewards as thier motivator again. I just sat with the clippers running while I watched TV. It wasn't long before they got used to the noise. I then upped the anti by casually moving the clippers around a little. Once comfortable with the movement, I then reduced the distance of the clippers by moving them closer but, not enough to worry them.
For the next step of touching with the clippers running, I put my dogs on a higher surface. First though, I went back to clicking for strokes with the clippers off and with the clippers on but, still and away from them. Slowly I moved them forward - clicking and treating.
Once I was ready to actually use them, I found clicking/ treating difficult. So, I smeared the grooming arm on my table with goodies such as primula cheese/butter/baby food/peanut butter. A touch of the clippers earned a lick of the arm. Before I bought my grooming table, I used the worktop in the utility room and smeared the treat over the windowsill and the boiler casing
Ziggy and Blossom are much better with the clippers now. The process I've used has taken a lot of time over lots of little sessions but, it has built their trust for grooming. They need doing again now but, I've not used the clippers for a while. So, I will have to go back to basics myself.