I mounted my plunge router to a new router table this weekend. I discovered very quickly that it is difficult to adjust the router bit height, as the springs (the very heavy springs!) end up fighting my efforts. Yes, I can use the micro-adjustment mechanism, but due to the awkwardness, I basically ended up taking the router and insert plate out of the table every time I wanted to make a change.
Am I doing something wrong? Is it okay to use my plunge router on my router table? Is it safe?
As others have said, yes it will work, but but...
1) It's more common to mount a fixed-depth base in the table, and switch the router motor between that and a plunge base for other work. Fixed bases are relatively cheap, which makes dedicating one to this purpose a good choice, and many routers are available as kits with one base of each type precisely for that reason. And it's a lot easier to move a motor unit from base to base than to attach and detach the base from the table or plate every time you switch modes of operation.
2) The advantages of a plunge base mostly don't apply when using a router table. The use of a table plate as a baseplate defeats many of the advantages of working handheld
3) Commercial router lifts generally don't use the manufacturer's base at all; they act as another base and you mount the motor directly in them. Homebrew lifts may do that or may use a base, but generally if they use a base it will be the fixed base.
Is it okay to use my plunge router on my router table? Is it safe?
Yes, it's okay to use a plunge router in a router table, but some work better than others. Safety practices might vary depending on the type of mechanism your setup uses for the router lift, but generally speaking, using a plunge router in a router table is just as safe as using a fixed-base router.
Am I doing something wrong?
Some plunge routers are actually designed to be used as router lifts with above-table adjustments, and you may want to check your router model to see if it has an above-table height-adjustment feature built-in. Some fixed-height router bases such as the Bosch RA1161 (and the "undermount" RA1165 which is identical but without any handles) also feature above-the-table adjustment via a long hex key.
That said, it is easy to modify some plunge routers to function as router lifts, by drilling an extra hole in the base and replacing the depth adjustment rod.
If your router isn't very amenable to the above modification, some homemade router lifts are designed specifically to work with a plunge base, with or without drilling an extra hole. The general idea is that you create a screw-driven mechanism to compress the plunge router's springs, rather than sloppily muscling them to the right height yourself.
Other commercial and homemade router lifts, such as the JessEm Mast-R-Lift that grfrazee referenced, or Steve Ramsey's homemade router lift based on plans in Shop Notes #121, allow you to install a router motor directly into the lift. This typically requires a router with a removable/swappable base. Many router lift designs will not work with a plunge router that has an integral, non-removable motor.
Commercially-available accessories for plunge routers such as the DeWalt 625
As I mentioned earlier, if your plunge router has an integral, non-removable motor, it is not compatible with most commercially-available router lifts. Here are some commercially-available alternatives/aftermarket mod kits:
Veritas Router Bit Jack
(Source)
Router Raizer (similar to previously-linked DIY replacement of adjustment screw)
(Source)
I think most router tables are set up to use a fixed-base router.
For example, the Jess-Em Mast-R-Lift pictured below specifies using a fixed base router. The lift mechanism itself provides the height adjustment, thus the plunge function of the router is redundant.
I don't think it's unsafe to use a plunge-type router with a lift so long as you have the plunge mechanism effectively disabled and the base immobilized. However, I'd hazard to guess that you have a higher chance of the router binding on a part of the lift since plunge routers tend to have odd pieces sticking out.
Also, it's worth noting that some router tables only accept specific router models, so bear that in mind for what you end up buying/using.
Plunge router in router table?
It is definitively possible (and safe).
You should make sure your router has enough power, though. A router of the "1000W class" is not very suitable, although it is of course still possible to use it in a router table.
However, first of all, it will be a bit weak, and on top of that the smaller models have a smaller routing stroke. You will, depending on the construction, lose anywhere from 3mm to 10mm because you have to subtract the plate's thickness. So, with a little router that maybe only has 45-50mm stroke total, you may end up with something that soon reaches its physical limits.
Using a "middle class" router (1400W) which usually have 65-70mm stroke works fine, and of course a 2200W router will rock (they tend to have another 20-30mm of routing stroke extra).
At least three DIY manufacturers that I know and two German professional-grade manufacturers (Festool and Maffel) build router tables exclusively with plunge routers. That demonstrates that it's not just possible, but actually someting that works.
You can of course build one yourself at a fraction of the cost. Basically what you need is a plate (resin coated multiplex is fine) with a hole, and four legs. And well, a vertical stop that locks in a t-ridge, with a piece of plexiglass on top for safety.
Using a standard $25 scissor car lifter (as shown here) provides a very easy way of adjusting depth. You can either fix the router in the plate with a few screws, or you can plug two fitting steel rods that are fixed in the table into the holes where the parallel guide is normally mounted (the holes are made for that purpose, so no worries there).
Much more sophisticated builds are possible, of course... I'll leave that for homework.
Am I doing something wrong
It sounds at least unusual that a router should be so stubborn. I almost always operate with two hands on the handles to be on the safe side (if both hands are on the handles, no hand can be somewhere else, this helps keeping your fingers, also fixing the clamp once you've plunged in takes the left hand). But in principle, I could easily, without effort, handle my router with one hand.
From the obvious (forgot to open the screw?), I can only think of needing some cleaning and oil as probable causes.
When opening the clamp (the one that holds the router bit), always be sure to pay attention that you don't hit the steel rods that the router slides on with your wrench. Also, don't close the screw clamp much harder than necessary. It needs to hold firm, but you aren't trying to smith the rod into a different form.
Although they're stainless steel, I could imagine that if one is negligent and keeps squeezing and hammering against them them with the wrench for years, it's possible to make bumps and scratches that impair a smooth slide. But still, making dents into steel should take some continuous abuse, so I don't think that's very likely.
Either way, you'll see if they are nice and smooth after cleaning.
I have mounted my PC 890 plunge router in my router table and have removed the springs. This makes bit height adjustments very easy. Bob and Rich Rosenthal used this set up in their shows in late 90's.
