I purchased a bag of 40mm props sometime ago via Banggood and when delivered they’d sent a 1mm bore instead of the 1.5 I ordered 
So they’ve sat in the draw ever since, now me being me thought I might be able to up cycle them and bore out the middle to 1.5.
So I’ve purchased a finger/hobby drill and a small set of drill bits, I suppose my question is has anyone tried this and was it successful???..
I hate throwing things away and want to make use of everything but for what props cost to what the drone costs I don’t think I’d be messing incase one let’s go, also the possible consequences of what happens when the drone hits the ground.
I’ve done quite a few, keep it squared, initially don’t force the bit too much…
You need a pillar drill to bore straight…hand held drills are fraught with cockups😊
and you need to clamp the prop hub to the table,
A non-centric hole will course you unwanted results 
It’s all down to experience, take your time and learn how to do it, it’s only .5 mm you’re drilling out.
The other alternative to hand or pillar drilling is to use a hand reamer, not sure you can get a reamer that small though.
Post a picture of the prop….
There is this sort of thing to help out as well: https://yourfpv.co.uk/product/2mm-prop-hole-drill-bit-kit/
If you can clamp a guide on top of the hole, you can pull it off with a hand drill, otherwise the pillar drill seems like a more reliable solution…
Looking at the solution above, you might even be able to 3d print the “guide” with the proper dimensions of the 2 m2 sscrew holes and the center one of your choice…
Drone rotors rotate very fast, therefore any slight deviation from dead centre will probably cause considerable vibration. I agree with the advice to use a pillar drill to keep the hole precisely vertical, also the rotor must be clamped dead flat to the working surface.
You say you have a “bag” of props, so you could try a set of four, and use them if they don’t vibrate too much. Obviously, vibration will also stress the rest of the drone’s structure, and mess up your video and pictures.
Another option could be to sell them here, if yu can give the exact specs.
I think I’m going to knock up a small jig I.e drill the required hole in a small piece of plate as a guide then tape the prop to to the plate…
See how it goes 
Try heating your shaft up with a lighter then press the prop on.
The motor shaft that is
I started a design of a mini pillar drill the other day which was something I’d meant to do ages ago that utilises a standard pin vice, I have got 10mm carbon tube off an old project…but for tiny max 3mm holes I’ve never had an issue “hand jobbing it”
Yah the drill set iv purchased has a rang of bits going from 1mm 0.25 and 0.50 so I could pop a .25 down it to start and them move to .50.
Dont think its going to be a big deal, and if the worst comes to the worst I can be the guinea pig for boring out a 1mm hole to a 1.5 
