Single flute bits

[watswood]

Does anyone have experience with using single flute bits? I picked up a few single flute Courmat 1/2" up/dwn spirals and am experiencing higher vibrations, especially at specific frequencies, with the bit just spining in the air(not cutting). I chucked up a 2 flute 1/2" spiral and there are relatively no vibrations. Is it normal for single flutes to vibrate more? I tried cutting with the single flute and the cut quality and performance was great.

[rookie432]

I prefer a single flute cutter on my PRT with PC router. It is easier to get your chiploads correct to get superior cut quality. However I havn't noticed any vibration differences. You may have a bad bit(out of balance). I do love courmat cutters though.

Bill

[lto]

Take a look at your tool, does it appear like it might have most of it's weight on one side? We have 1/2" single o-flute tools that we found we cannot run in our 3 HP spindle because of the imbalance/vibration. A larger spindle would be less affected by the imbalance of the small tool.
We do successfully run single o-flute up spiral tools in 3/8" diameter, great for soft plastic.

[watswood]

It does appear to have more weight on one side. I guess this would make sense with single flutes. I'm not sure if a tool like this 'can' be perfectly balanced like a 2 flute. With my vfd I can tune in a frequency it likes, so I'll keep trying it out.
I purchased 3 bits and all 3 bits respond similarly. Courmat has a special on these at $25 ea. They said there are fewer customers in need of single flutes with all the big/fast machines out there.

[gerald_d]

Eugene, those air-cutting vibrations are actually resonances of your ShopBot. It is useful to induce those vibrations in your machine because it can help you to track down loosely seated V-rollers, for example. Therefore, before trying to smooth out the cutter, first feel all over your gantry, rollers, z-slide, spindle bracket, etc. for stuff that may be loose.

[watswood]

Gerald, It looks like you found a new use for single flute cutters. Here is what I found:

2 0f 8 v-rollers loose on the z-plate
y motor bracket slightly loose
3 of 4 bolts mounting spindle plate to spindle not tight(re-tightened with lock-tite)

Though the single flute cutters still vibrate more than 2 flute, my bot sounds better, tighter. I'm running a 2000 prt, so my gantry and y car are not as stiff as the new alpha's. My 5hp spindle casing seems to have the least vibration. With that said, are these vibrations I'm experiencing with the single flutes harmful to the spindle bearings, or are they designed to handle it?

[gerald_d]

Those air-cut vibrations are not harmful to the spindle bearings - as you said, the spindle casing has the least vibration. The spindle bearings take a lot more load while cutting, and there I would say that a cutter with more flutes will put less stress on the bearings. Then it is not a question of weight balance, but of the "chopping" action of the cutter.

[gene]

Hi Guys,
Does anyone use insert tooling with their bot ?
If so what are the pro's and con's of this ?
The reason for asking is i use a 1.25" flat botton v carve bit to put a groove in cabinet doors, I am getting tooling marks that i have to sand out. i would like to eliminate this if possible, i've tried slowing the cuts down and speeding things up but to no avail Help Help help
any sugestions will be appreciated . Thanks Gene

[edp]

Gene -

We use an Amana #RC 1154, 1/2" shank x 1/2" dia. single flute replaceable carbide insert bit when cutting 1/2" marine ply and are very pleased with the cut quality and the low cost of using replaceable cutting edges. These bits are double edged so they can be reversed after the first edge is dull. If you plan on trying one order a few extra retaining screws just in case. The bits plunge well and will cut the ply in one pass with minimum sanding afterward.

[gene]

E.F.Pionkowski
about what are the cost of the holder and blades ? do they stay indexed good?
Gene

[jhicks]

Never used Amana but was quite pleased with the Her Saf system. Same reversable/replacement blade feature. We had tried/used conventional router type V's on Color core, HDU, and wood but were never quite pleased with the cut. The HerSaf delivered the best we've seen yet in Color Core and HDU with 90, 120, and 140 degree cutters 1" and larger.
Not sure if you will eliminate all tool marks but hope it helps

[gene]

Hi Jerry,
I was intrested in the cost factor , to see if its worth while or cost effective. i loooked at vortextools and the cost of the holder was about 385.00 with the inserts being 24 and up . if all else fails i'll look at the IWF in atlanta in the fall. now i'm using the standard shank tooling but they dont seem to last . Gene

[jhicks]

Gene, I may be misinterpreting what your doing/asking but the Her Saf is basically a 1/2" threaded arbor which costs $7.00.
One adds a blade holder head for say a 120V by simply threading it to the shank. The head for V's of assorted angles cost $65.00.
I believe the head comes with the cutting knife/blade in it plus maybe 1 extra . Inserts are single sided on the Head but reversable when dull so you have 2 sharp bits effectively with one insert. I thought it was odd that the v's only had insert on one side of the v but they cut nicely for us. Looks like they have the inserts at $10.00
Check it out or call them they were quite helpful for me. Suggest a call to their help desk for any clarifications or catalogs. Nice folks in Sunny California.
4005 El Camino Real Atascadero, California 93422
Phone (805) 466-1563 -- Fax (805) 466-1947
(800) 553-9344

www.hersaf.com (http://www.hersaf.com)