Re: [CAD_CAM_EDM_DRO] Re: Video of my resonance

Hi Dave,

Try this link for the video.

http://s90.photobucket.com/albums/k259/peterapalais/?action=view¤t=CNCPlasmaroutertableresonancemovie.flv


I have cut and pasted the information about my table from word pad. It is below.

Rack:

Pitch: 3.1416

Pressure angle: 20 Deg.

Spur gears:

Y axis:

Number of teeth: 15

Outside diameter: 17

Pitch diameter: 15

Torque Nm: 0.4

Direct drive, 270oz/in stepper motor spring loaded onto the rack.

X axis:

Number of teeth: 24

Outside diameter: 26

Pitch diameter: 24

Torque Nm: 1.3

Two 1200oz/in stepper motors. One slaved of another. With a timing belt reduction.

Belt reduction:

Gear ratio:

X axis:

2.5714285714285716

Small pulley on motor shaft:

Pitch: GT2 (5mm)

Number of grooves: 28

Pitch diameter: 1.754"

Outside diameter: 1.709"

Large pulley that has the final drive pinion on:

Pitch: GT2 (5mm)

Number of grooves: 72

Pitch Diameter: 4.511"

Outside diameter: 4.466"

Axis Information:

Y axis:

Steps per mm: 42.441218911807147101264748400

Maximum resolution: 0.0236mm 10x Microstepping

Maximum resolution: 0.2356mm No microstepping

X axis:

Steps per mm: 68.209101822547205245734657800

Maximum resolution: 0.0147mm 10x Microstepping

Maximum resolution: 0.1466mm No microstepping

Stepper motor performance characteristics

Stepper 200rpm 400rpm 600rpm 800rpm

270oz/in 220oz/in 200oz/in 125oz/in ------------

1200oz/in 850oz/in 380oz/in 320oz/in 200oz/in





Hopefully this should answer what you asked.

How much spring pressure, well I have that spring done up pretty much really tight. I know that I do need to have a larger diameter pinion, as it is better for power transmission and all that.

The motor specification sheets, mention something about radial load on the bearings to be 450g. Does this mean that If I have it tensioned really tight onto a belt reduction setup, that It is not allowed to have so much tension that it puts more that 450g of sideways pull onto the motor shaft? If so, well that is probaby a concern then cause the timing belt is super tight.

Having said that, I might take off all the timing belts and run the motors at the same speed. Maybe the timing belt is tensioned too much and causing the shaft to force it into every step of the motor, thus going clunk clunk clunk?

Any ideas on that?

Peter

Australia

----- Original Message -----
From: turbulatordude
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Monday, September 25, 2006 10:13 AM
Subject: [CAD_CAM_EDM_DRO] Re: Video of my resonance


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "apples0_17" <apalais@...> wrote:
>
> Righto,
>
> I have finally managed to take a video of the vibration and noise
> that it is
> making.
>
> I think it is because the motors are going to slow, and each and
> every step goes
> clunk, clunk. clunk.
>
> At the start of the movie the gantry is moving slow, it is doing a
> referencing
> move to home. I then hit the Esc. key and jogged it forwards and
> backwards at a
> faster speed to show you that there is no vibrations at this speed.
> If you
> listen carefully you can hear a sligt bit of vibration as it winds
> up to full
> speed and then again when is slows down from top speed. Obviously
> this happens
> when it goes throught that speed area? then it goes past it and then
> it is all
> good.
>
> So now that you can all see the video and know exactaly what I am
> talking about,
> what do you all think is causing it?
>
> http://s90.photobucket.com/albums/k259/peterapalais/?
> action=view¤t=CNCPlas\
> maroutertableresonancemovie.flv
>
>
> Peter
> Australia
>

Hi Peter,

I did not find the video, but I do have a question.

What size gear rack ?
what size spur gear ?
how much spring pressure do you have ?

I think the sping pressure might be too high and the spur gear too small.

Dave






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