When you dedurr cast pieces it is essential that the machine is equipped in the best way.
if you make the wrong choice, YOU KILL YOUR PROCESS.
If you have to deburr a piece, you need contact wheels.
Maybe you have always thought that all contact wheels are all the same.
Magari hai sempre pensato che una ruota vale l’altra
Maybe you have always thought that there is no difference between on wheel and another
But it’s not so!
You’re wrong. And this mistake can really compromise your competitiveness.
Thousands of times I’ve heard: “if the process works, then the wheels we have chosen are fine!”
But it’s not like that!
The fact that the process works does not depend on write choices.
It’s true, by combining the thousand processing parameters one wheel is the other…
but are you doing a mediocre productivity???
….Are you sure that your competitor does not produce in half time than you need?
Exactly for these doubts that you should not take random choices;
NO CHOICE HAS TO BE A RANDOM ONE!!!
I want to guide you to the choice, in the end it’s alla scientific matter.
the first problem to analyze is the machine on which the wheels are mounted.
The machine on which you use the wheel greatly makes the difference in choosing the right wheel.
If I tell you to use the best solution for the process, but this solution is beyond the machine capabilities, then it is an incitement to throw you into the abyss.
So first I prefer to clarify the types of machine and for each one I’d like you to recommend the optimal choice.
the machines on which you can debar die-cast pieces are distinguished in these categories:
Manual
Robotic with rear axle drive system
Robotic with front wheel drive system without compensation system
Robotic with front wheel drive system and compensation system
Manual
When you perform the deburring process by hand, the choice of the wheel is much easier. You immediately feel if the wheel helps you in removing the material and you see if there are defects or not. Usually are used hard and smooth wheels, to quickly remove and reduce the vibrations generated by machining.
However, you just need to try 2 or 3 types and you will immediately understand your favorite choice. By hand you can not really push the process, because if you go beyond the parameters, the operator will not resist.
Robotic with rear axle drive system
Robotic machines really allow you to think differently. The robot is able to apply truly important work force and at the same time to draw perfect space trajectories.
the first type of machines we are going to analyze are those born first, in the eighties. these machines are very limited, but are still produced by different companies (even if I do not really understand why).
These machines provide for the contact wheel to be mounted on a spindle and the motor has to be placed on the work unit bottom: the motion drive train happens by the same grinding belt.
These machines are very widespread, because there were the first and because this solution is very cheap to implement.
the problem of those machines is that they limit the choice of the contact wheel.
If you do not take certain contact wheels, the won’t stay straight and you can not work!!
The motor is very far from the work area and if the wheel does not help in keeping it straight while the processing the belt moves and…. CRASH!! The wheel breaks down!
So the choice must be made to put the machine in the right working order.
the wheels to choose have to be hard (over 40 shore) and wide. We also need to choose wheels with a large diameter (from 350 mm to 500 mm) to help the belt not to move.
You can try to use soft wheels (many do that), but then the robot moves in slow motion. When I see them working, I want to ask someone if what I’m seeing is true or if I have hallucinations!
Practically, on these machines you CAN NOT USE SOFT WHEELS!
This type of machine is a real disaster; I have never built a machine like that.
Robotic with front wheel drive system without compensation system
This type of machines come from an improper use of manual units: There are “machines” where a robot was placed in front of a manual unit.
Let’s go back to the initial speech, all in all it works… but how that?
As it is without compensation system the wheel must compensate for the lack of the machine.
So the wheel must auto adapt to the piece.
in this case the contact wheel has to be soft, and the support belts have to be very flexible.
The contact wheel has to behave as the compensation system should do: following the shape of the piece without ruining it.
The problem of this solution is the cycle time becoming enormous: the wheel is not aggressive in processing (it can not be so, otherwise it would not compensate) and therefore the robot must move slowly.
The types of wheels to be be used are those called “sponge leather”. They are a mix of leather containing a neoprene sponge.
With these wheels the result is not bad (in terms of quality and cycle time). The problem is that these types of wheels get damaged during usage. You will lose the sponge from the wheel when the wheel is working.
these machines are still a disaster but a bit better than before!”
Robotic with front wheel drive system and compensation system
Questa tipologia di macchine ti permette di fare scelte in base al TUO processo.
ONLY when you have such kind of machines, you CAN really chose the contact wheels.
This type of machine allows you to make choices based on YOUR process.
Machines of this type have a motor activating the spindle where the contact wheel is mounted.
The compensation allows the best use of every type of wheel: it allows to work following the shape of the piece even if the wheel is hard, or to remove a lot of material with grooved wheels.
If you have machines like this one you can say that you are really free!!
Let’s talk about how to make the choice based on your process.
If you have to remove a lot of material (for example on casting ingates)you have to use hard enough grooved rubber wheels (60 shore), but if you have to work larger surfaces you should use soft wheels with materials without memory.
The wheels should not be too soft (under 30 shore), otherwise they will not quickly remove the material.
It is essential to use wheels with the right diameter. Once, it was thought that to work with a robot wheels with large diameter were better. Today this myth is definitely overtaken.
If the wheels are big, then they cost a lot of money… and in any case they do not last longer!
But you can not even choose too small wheels, otherwise the RPMs needed to work will get too high and the wheels will overheat..
So you have to choose wheels from a diameter 200 to a diameter 300 mm.
The width of the wheel also makes the difference. You can not choose wheels that are too wide (because you can not reach all parts of the piece), either too tight wheels (otherwise the belts do not last enough).
CHOOSE A CONTACT WHEEL IS REALLY DIFFICULT!!
It is very easy to choose one to get a mediocre result, but it is very difficult to obtain excellent results. Even if you are not an expert, you have to find a way to solve doubts: you just have to try!
Have you got a machine that lets you use any kind of wheel? or not?
If your machine is of the last type, so there are no problems…
If you have machines that are not up to par, then you are really conditioned.
