Chris Williams' Journal

This is the question asked and my solution posted on OFF Topic
Here: https://www.mgexp.com/forum/off-topic-forum.47/my-makita-hand-planer-an-oldie-and-a.5016366/
These are some pics of the cutter head.




I’ve stripped it down as far as I think I need to to try and extract the broken screw in the Aluminium.
Probably my own fault. I don’t remember doing this and it’s probably just a couple of years since I must have but I’m pretty sure I must have put these in with some loctite. Idiot move.
Anyway, this one just broke the head off flush.
It’s only the guide to hold the cutter while you adjust the depth but adjusting the cutter is difficult enough without having the guide flopping around as well.
The brass screw is just in the other hole for reference.
Any thoughts on how to get this out. Haven’t tried anything yet, don’t want to make it worse.
Anyone had successfull experience with dissolving loctite?

After some discussion this is what I did.

NEVER, EVER, have I had this much success doing something like this.

I'm back home now and had a go at this. the plan was to heat soak it in my oven for an hour or so and I used the hottest setting I could. The oven has a self cleaning mode which heats the oven to about 300º C. It may not get that hot, the highest temp written on the dial is 250º and there's 3 graduation marks after that so it the marks prior to that are any guide, it may be about 280º. anyway it was hot enough to 'blue' the shaft.

After letting it cool in the oven for about 2 hours after switching off, I hoped the Loctite would be degraded enough to allow me to use a sharp push and maybe turn the screw a little so I could work it out.

No such luck and I didn't want to muck up the top surface so I gave that away.

After a bit of deliberation I thought, 'what the heck', I'll set it up in the drill press and see if I can run a small drill through the centre.

Used a new 2.0mm drill bit, centre punched an estimated centre and very warily drilled a hole through the middle of the screw. Took it really slowly and that went well.



I think I had it pretty well centred. I checked the drilling size for a 4mm x 0.7 thread and it was 3.3mm. Okay, so I went to 2.5mm and got this, which then told me it's not in the centre. Hmm, not much chance of doing anything about that!



Then I remembered Haps comment about using a mill. I don't have a mill, but with a more rigid drill bit and the vice locked down, maybe I can get a 3mm drill to cut more precisely in the centre.
I have a set of stubby drill bits so I used the 3mm drill from that and set the vice off centre in the direction the hole needs to move to.
Taking the drilling VERY slowly I may be able to centre everything up and take that drill through to the end of the bolt.
To my surprise, I was able to do that without any deflection of the bit.



And achieved what I thought I would never be able to do. I could see the thread inside the hole all the way around.



Then very gingerly I started the tap into the hole after attempting to pick out some of the remnants of the screw and blowing out the residue with compressed air.
Taking it slowly and after each turn, taking the tap out and blowing out any residue, I successfully cleaned the thread out.



And this is what I got.



Put a good screw it and success. It's a bit loose as it starts off but as the screw gets deeper it doesn't have too much play.



Really pleased with the result.
These are the drills and the tap that I used.



I'm calling this done! I'll have to get a new set of screws. I might see if I can get some just a little longer.
Thanks, everyone for your input.