# Thread: Design of a vibration table

1. ## Design of a vibration table

Hello people,

If anybody would want to make a machine from Epoxy Granite, one thing is certain.
They would need to have a vibration table, the vibration table arrange`s the particles of the aggregate, this is neccesery to have a well packed mixture and thus a mix with a low quantity of epoxy. This will result in a stiff total material.

So, if we have the aggregate packing formula right....,
we got the right epoxy and the design of the machine is right, calculations cann be made for a vibration table.

Last couple of days i did some more reading about designing such a table,
made a excel sheet with the calculations from this website:
http://www.decavibrator.com/math.shtml#vi
My maximum weight of epoxy granite machine part is around 25 Kg,
the motor i would like to use is 10 Kg, the weight of the moving parts of the vibrating table is around 30 Kg and the wooden mould is 15 Kg.
This makes a total weight of the vibrating mass of 80 Kg.

The motor spec`s are:
http://cgi.ebay.de/NEU-OLI-Ruttler-N...item53e1a04299
3000 RPM (50Hz)
3,15 Kn centrifugal force
6,22 Kgcm working moment
230V 1 phase operation possible

If i would use this motor with all specs from table/motor and would run the motor full power, this would result in a amplitude in motion off 0,75 mm and a acceleration of 3,8 G. (this is 3000RPM)

If i would let the motor turn at 2000RPM, then the amplitude stays the same and the acceleration would be 1,7 G

What i think i cann conclude from this is:
The max. centrifugal force and rpm that a motor cann deliver in relation with the mass of the vibrated parts, determins the value of the amplitude.
If we juggle with these parameters, we cann determin the acceleration.

Hope somebody cann give me some feedback about this, if i`m on the right track i can procede with a CAD design and do some EEM/fatique analyses, vacation starts in a few days so all the time...

All info is welcome.....

In the attachment the excel-sheet.

Kind regards,

Roy B

2. Hi Roy,

I think your spreadsheet is correct. Those formulas on deca vibrators page are a bit tricky the way they switch units and deities only know what they actually did since they have dimensionless magic numbers.

Regards,
Cameron

3. Yeah, think so to,

numbers are a bit strange... just filled a app. form in by Vibco.
If i got the results i will post them overhere..

Kind regards,

Roy.

4. ## 1ph 3ph 230V 400V

dubbel post...

5. ## 1ph 3ph 230V 400V

This motor:
http://cgi.ebay.de/NEU-OLI-Ruttler-N...item53e1a04299
Runs on 3 Phase and i think 230V or 400V (is this true, does it keep the same spec. is the difference only the amps..?)

I got from the wall 1 phase 230V,
This VFD i found has a 1 phase 230V input and a 3 phase 230V output.
Should this work with the same CF specs etc...
http://cgi.ebay.com/1-2HP-230V-GE-1P...em53de0263cbld this vfd power the motor?? with the same CF specs...??

Kind regards,

Roy

6. Roy,
It's logical for a dual voltage motor to maintain it's specs on both voltages:

Watts= Volts*Amps

To make a vibrating table with up &down motion you would require 2 motors.

The VFD shown would be ok for 1 motor only

Best regards

Bruno

7. I agree with Bruno that the VFD shown is a bit light for 2 motors.

If you get a 1HP VFD, you should be able to run two motors if you are trying to do vertical only vibration. I've got my two 1 horsepower vibrators working on a 3HP VFD.

8. Hey Bruno,

Yes it is... I figured it out.

The 230/400 stand for the way you wire the motor star/triangle.
So either way they have the same power.

Only thing i have to look at is that it is 220V input in VFD.

How do 2 motors with 2 vfd`s run the same speed, so only up/down force is generated?

Think i will go for circulair vibration...

Kind regards,

Roy

9. Aaah, was to slow with the posting,

either way,
once read that a circulair motion also works, the vibrator guys overhere say it could be done...

What would be the difference between circulair or only vertical?

10. Roy,

If you run the motors in opposite directions you get a case where the eccentric weights are moving opposite ways horizontally and thus the center of gravity in the horizontal direction is constant while that int he vertical direction is doubled. It has been suggested in some of the literature that up and down only vibration does a better job of settling the materials. I haven't verified this however.

--Cameron

11. Oooh guys....

Thought i really was on the right track, know the principle off only up/down motion,
didn`t understand how the motors would turn synchroon, but a vfd is frequency controlled, so.......

Heard you have to turn the rotors in the same position,
Yes it is a good idea to have to......\$\$\$\$
But yeah, a table isnt made for 1 week, so that would justify the extra cost.

I try in the next days to design a nice new cnc mill to make on the table, had the last 6 months a post-academic course in Fatique from a retired proffessor from DAF (trucks), try to link this at the table since it is a good subject for it.
Just some points off design, offcourse no real test etc..
If you guys like i will post some cnc mill pictures in this thread.

Kind regards,

Roy

12. My study is really annoying, no money all the time and every few weeks new technical knowhows on different subjects.
My ideas keep changing....

Do, i like it...

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1. ###### ? Bekijk onderwerp - Bouwen van een EPOXY GRANIET machine en meer...
10-08-2013, 06:03 PM