Trick to replacing 1020 pinion gears with brass ones?

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For the last few weeks, I've been fighting on-and-off with replacing the pinion gears on my 1020 with brass ones.  These are the ones sold by @Jeff_Birt, and were purchased from his website.

 

Can anyone else who has done this advise me as to how best to press on the brass gears?  I'm concerned that with the amount of force it feels like I'd need to use to get them to press onto their respective shafts, the risk of bending a shaft would be pretty high.

 

My preference would be to not modify (emery paper, etc.) the shafts as that would rule out ever using nylon gears again at some point in the future.  It's unlikely that I'd want to, but this is an area where I'd like to keep it stock.  I'm open to doing some light filing of the inner diameter of the brass gears, but will need to get a smaller set of needle files in order to do that.

 

LATE EDIT: yes, I did try the C-clamp method shown in his instructional video, but with no success so far.

[_The Doctor__]

keep the mech relatively cold and the brass relatively hot... work fast and the brass will slide on and then cool pulling and fusing tight.

Edited September 12, 2021 by _The Doctor__

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23 minutes ago, _The Doctor__ said:

keep the mech relatively cold and the brass relatively hot... work fast and the brass will slide on and then cool pulling and fusing tight.

Makes sense, and I'm pretty sure that I could create that relative temperature difference with a duster can.  Will give it a shot.  Thanks

[rockdoc2010]

if you have a rat tail micro file you can remove a little bit of brass from the installation side and that will help get it started and in position to press on with the clamp

[+x=usr(1536)]

Pinion gears are finally on.  Frustratingly, it's a 'two steps forward, one step back' situation, but I'll come to that further down.  Did manage to also fix an intermittent power issue by reflowing the solder joins at the main power connector, so at least that was an easy repair.

 

Back to the gears: tried the cold / hot method, but didn't really have any success.  I suspect that I just couldn't get the shaft cold enough using duster spray for the gear to be able to go on easily.  Still, it was worth a shot.

 

I did use a pointed needle file to open up one end on each of the gears enough that they could stay on the shaft while gingerly manipulating tools around them.  The file wasn't anywhere near small enough to go through the entire bore of the gear, so just the very outer edges were widened.

 

The 2" clamp worked fine for pressing on the gear on the paper feed roller side.  It was slightly fiddly, but nothing terrible.

 

As for the gear on the pen movement side...  That one was a complete and utter b***ard.  Eventually, I dug through a container of random nuts, bolts, and screws and found one that was in-between 5/8" and 3/4" (15mm to 18mm) long.  I put the head of the screw up against the moveable part of the clamp, and very carefully worked it onto the gear until they were in contact.  This gave just enough clearance to be able to press the gear on without disturbing any of the others, which was a huge plus.

 

Frustratingly, I managed to lose the C-clip that holds the main gear in place on the paper feed side the last time I was trying to get the brass gear on that side to fit.  This means that every known issue on the 1020 is fixed, but it's not yet usable.  I'll see if I can't track down a suitable clip this week; worst case, I may be able to scrounge one from something else.