Router sub base help (Macallister 1500w)

[Charlotte]

I've been making a trammel for my router but have run into problems.

The internet says that the "done" thing is to remove the plastic sub base that comes with the router and replace it with a 6mm MDF home made one. I've found that the base casting is lower around the bit so I figured that since I don't need a particularly deep plunge, I would sandwich the factory sub base with mine. I found that the screws (M4?) are a weird pitch. Anyone any ideas? should I just drill and re-tap? I'm pretty worried about doing it as I don't have a pillar drill.

Thanks
C

 

[George_N]

Hi Charlotte,
personally I wouldn't make a sub base out of MDF as it isn't durable enough. You would be better getting hold of some perspex (acrylic) sheet, 6 mm should be ok. MacAllister routers aren't exactly top of the range so the casting of the base may not be dead flat, which may be a problem in the fitting of a sub base. If yours is anything like my TrendTech (The old B&Q house brand), the factory base is held on with lightweight M4 screws but there are also three M6 tapped holes in the base that are better for attaching the router to a baseplate for the router table or for an auxilliary sub base. All the tapped holes in the base should be standard ISO general purpose metric threads...M4 has a pitch of 0.7 mm and the M6 has a pitch of 1 mm. As said, the casting probably isn't great so the threads may need cleaned up. As these holes are usually blind ended a bottoming tap would be the best tool for the job.