Flycutter Balance Problem / Question

[Subwayrocket]

I would call Don and discuss with him, he will probable tell you your bearings are shot in the quill head.

My bearings are not shot in the quill head ... it's a new machine . If my spindle were chattering around, i'd lose the mirror finish at 650 Rpm . It still gives a mirror finish at both 370 & 650 but as I've said, I don't like the shimmy it produces at 650 so I've ran it at 370 Rpm . Suburban clearly states that this is an un balanced tool
From the Suburban website "
The FCS style fly cutter is NOT a balanced cutter. The safe rpm limit for each machine will vary
based on the size and rigidity of the machine. Never start your spindle at over 650 rpm. Serious
vibrations can occur at higher rpm, which could damage the machine and / or cause injury to
the operator. If higher rpms are required, start off under 650 rpm and gradually increase the
speed, noting machine vibration. NEVER exceed 1200 rpm on any machine that is not FULLY
GUARDED."

 

[Andre]

I would report the problem to Suburban. If they made a fly cutter that looks pretty but does not function correctly. Then their design team needs to go back to the drawing board…Dave.

Making an adjustable radius flycutter perfectly balanced is impossible because anytime you move the bar the balance changes.

This is simply why big flycutters are not meant for small machines.

Sent from my XT1053 using Tapatalk

 

[george wilson]

You need to use a milling machine of sufficient weight and rigidity for that cutter. At least a Bridgeport size mill,I would suppose. An expensive,professional tool like that is not made for a hobby weight mill.

 

[chips&more]

Making an adjustable radius flycutter perfectly balanced is impossible because anytime you move the bar the balance changes.

This is simply why big flycutters are not meant for small machines.

Sent from my XT1053 using Tapatalk

Sorry, but it is not impossible. I can think of at least two ways to design it so it’s balanced. And I’m sure there are many more ways that can be thought of…Dave

 

[TOOLMASTER]

run it slowwwwww

 

[Subwayrocket]

You need to use a milling machine of sufficient weight and rigidity for that cutter. At least a Bridgeport size mill,I would suppose. An expensive,professional tool like that is not made for a hobby weight mill.

Do you have any input on the question I posed ? I called Suburban and inquired before buying this fly cutter.
This is why I am running it in the above video at 370 Rpm with no vibration at all, and I think the finish is good. My questions are about adding some "x" weight to the other side of the bar to possibly balance it , so I could run it at 650 Rpm . I have fly cut at 650 Rpm and I still get a mirror finish but some slight shake to the entire machine so I stick with 370Rpm. Of course I would obviously like to have a 2 ton Cincinatti , but this is what I have ...and that's why I posed the question above. Seems if I tapped the back side of the bar with a 5/16-18 allen bolt, I could possibly cut some slices of lead lug ...and thru trial and error find what works. As I said, it's not a death shake at 650 Rpm , but it is noticeable ...so I run it at 370 , which requires slower table feed and takes a little more time .

 

[chips&more]

Do you have any input on the question I posed ? I called Suburban and inquired before buying this fly cutter.
This is why I am running it in the above video at 370 Rpm with no vibration at all, and I think the finish is good. My questions are about adding some "x" weight to the other side of the bar to possibly balance it , so I could run it at 650 Rpm . I have fly cut at 650 Rpm and I still get a mirror finish but some slight shake to the entire machine so I stick with 370Rpm. Of course I would obviously like to have a 2 ton Cincinatti , but this is what I have ...and that's why I posed the question above. Seems if I tapped the back side of the bar with a 5/16-18 allen bolt, I could possibly cut some slices of lead lug ...and thru trial and error find what works. As I said, it's not a death shake at 650 Rpm , but it is noticeable ...so I run it at 370 , which requires slower table feed and takes a little more time .

If you go and attach lead with a screw to this boring bar and run it up to +600rpm. Please be mindful of the centrifugal forces going on. We don’t want to hear about lead weights flying off and knocking out teeth, eyes or other terrible stories.

 

[Subwayrocket]

If you go and attach lead with a screw to this boring bar and run it up to +600rpm. Please be mindful of the centrifical forces going on. We don’t want to hear about lead weights flying off and knocking out teeth, eyes or other terrible stories.

obviously not ...lol Just doing this off the top of my head and rounding off , a 5" bar sticking out a little, lets say a 3" radius ...so that's makes a 6" diameter circle. 6x3.14 ...let's just say a 20" circumference . 650 x 20" + 13,000 in/min , 13,000 inches is 1080 Ft/min , 1080ft/min x 60min/hr =65,000ft/hr , divided by 5280ft/mi comes to roughly 15 miles per hour at the cutting insert. I'm aware of the risk, and take measures to avoid All unnecessary risks, such as plexiglass when testing things . I should know better than to pose a question like this in a forum .... you say you can think of at least 2 ways to do it ? What are they ? I'm looking for suggestions and if you have a better idea, it is appreciated , in the meantime I run it at 370 .

 

[JR49]

I am very confident that you can figure a way to balance the flycutter. My only reservation is that, by the time you make up something to balance it at 650 rpm, you maybe could have it finished at 370rpm. But then, once you have the "Balancer" made, it will be a lot quicker next time. So, hey, don't listen to me, balance that sucker! JR49

 

[Billh50]

I made my own large fly cutter with 2 tool bits. One on each side so as to keep it balanced when running at higher speeds. So basically it was an adjustable 2 flute cutter.