Router bit diameter

I am curious as to one of the statements in the Handibot Safe Use document. Specifically, the statement "Do not use router bits with a diameter in excess of 1/2” (12.7mm) in your Handibot." The Dewalt 611 manual states "Do not use router bits with a diameter in excess of 1-3/8" (34.9 mm) in this tool."

Is the issue vibration, drive motor related, bit speed, or something else entirely?

I have the Amana Tools: AMS-132 18-Pc Signmaking Advanced CNC Router Bit Collection, 1/4 Inch Shank, which includes 4 bits with a diameter larger than 1/2", namely:

• 45751 Carbide Tipped V-Groove 90 Deg x 1-1/4 Dia
• 45756 Carbide Tipped V-Groove 120 Deg x 1-1/4 Dia
• RC-45711 In-Tech Insert Carbide V-Groove 45 Deg x 11/16 Dia
• RC-2248 Insert Solid Carbide Mini Spoilboard Surfacing, Rabbeting, Flycutter, Leveler & Surface Planer 1-1/2 Dia

I can understand I should not use the RC-2248 as it's cutting surface is two 12mm knives, and the diameter exceeds the routers recommended maximum diameter. However, the others are within the routers performance envelope, and cutting surface would be dependent on the depth of cut.

So can someone explain the 1/2" limitation?

Thanks in advance,

M

With respect to motor load--I think that if you adjust the feed rate and pass depth--you can use a bit up to the recommended size for the dewalt router.

However--when the tool is all the way forward in the Y axis--it is only 0.5" away from the front, inside edge of the base. I like to keep at least a 0.25" buffer between my cutter and the tool frame to avoid the risk of cutting into the frame. I think that this is the main concern about using oversized bits--accidental damage to the tool frame.

Thanks, Brian - that makes a lot of sense so much so it was a facepalm moment!

Cheers,

M