Well here goes... Aluminium frame router design

[CharlieRam]

Hi Silyavski, the rails and bearings are 20mm profiled from chai, they are 75mm long plus 15mm for grease nipple which I haven't added to my sketchup model yet. I originally spaced the bearings 250mm apart from outer dimensions but was told 200mm was fine, this then gave me 150mm depth of cut instead of the original 100mm I planned so I have no issue going back to 250mm spacing if it will help.

The front Z plate is 20mm thick steel with 15mm X 50mm steel spacers glued and bolted to the plate and then the carriages are bolted onto this, the way I see it is the spacers should give me the added rigidity, would it help if they were surface hardened to make them stiffer because that is the only difference I see between having the rails mounted to the Z plate.

I am just finding it hard to understand why flipping the rails will introduce vibration as dean stated and I can't understand how the plate can bend as it has the bearing blocks on each corner. I am planning on having two spindle clamps as you suggested, in fact, it was there on earlier iterations, I must of deleted it!

Jazz, yes it is the workpeice that resonates in my example but the rubber absorbs a lot of it and I am thinking if I tensioned the rubber over the front of the Z plate it would absorb some of the resonance created in the steel Z plate if that is indeed the issue (steel instead of ally?).

Thanks, Charlie