Is this a symptom of whipping?

[strangerep]

Hi All,

I'm running a long straight bit in my Triton router with a template
guide to get a large-radius roundovers on the end of 200
ballusters. (This is as described in the earlier thread "Need Advice
about GMC Router...".)

I'm following Template Tom's advice about using the router in
handheld mode with a template, but I'm getting "striations" randomly
along the cut section. (Not sure what the correct term is - it looks
like the cutter is biting very slightly deep in random places.) The
striated pattern varies on different pieces, so the template is
not the problem. I suspect this is occurring because I'm trying to
use my existing long straight 1/2" diam cutter with one of the Triton
template guides, whereas Tom suggested I use a much wider 16mm
cutter (to minimize whipping) with a 40mm Hitachi guide, both of
which I'd have to purchase separately (and now I wish Triton's
accessory box came with a larger selection of guides.) :(

I've tried using different speeds, moving the router ultra-slowly, all
in various combinations, but it still happens. It also happens in places
where almost no timber is being removed, as well as places where
about 5mm is being cut off.

Is my problem occurring because I'm not using the wider cutter?

Thanks in advance.

[Grunt]

I think you need to ask Al, he's the expert on whipping around these parts.

[strangerep]

I think you need to ask Al, he's the expert on whipping
around these parts.
An amusing reply, but... is there no one around here who can
give me a helpful answer?

[felixe]

You may need to post a photo, not sure what the "whipping"
is that template tom is specifying, maybe it is to do with the length of the bit moving under load and that is why he is recommending a thicker diameter cutter.
Besides, if you are rounding over ballustrades or handrails, why are you not using a roundover bit with a bearing? I used a large CMT roundover bit for the handrails on the back stairs, and I used a router table, feeding the rails over the bit and used 2 people and had no issues.
Just wondering!

Regards,
Felixe.

[strangerep]

You may need to post a photo, not sure what the "whipping"
is that template tom is specifying, maybe it is to do with the length of the bit moving under load and that is why he is recommending a thicker diameter cutter.
Besides, if you are rounding over ballustrades or handrails, why are you not using a roundover bit with a bearing? I used a large CMT roundover bit for the handrails on the back stairs, and I used a router table, feeding the rails over the bit and used 2 people and had no issues.
Just wondering!

Hi Felixe, thanks for your reply.

My current PC facilities are rather primitive right now, and I'm unable
to post a photo. But yes, "whipping" means the slight movement of a
long bit under load, (though I still find it amazing that a 1/2" diam
piece of tool steel can deform noticeably at that speed).

Regarding why I'm not using a large-radius roundover bit, that has
already been discussed in the previous thread "Need help with GMC
router [...]". There were two problems: (1) my roundover bit is 1.5"
radius, or 3.5" total diameter. That won't fit through the base of
my router (nor any other normal router I know of), so a collet extension
would be required; (2) I'm a routing novice, and Template Tom thought
the template+straightbit option would be safer. I'm doing this by myself,
i.e: no possibility of anyone to help me.

Cheers,