INTRODUCTION
This was the first assignment that was given to me on very first day of my 4 month In-Plant training in Vigyan Ashram. It was given by Prasad Patil sir on 15/08/2024. This assignment was based on Solidwork which is the software that I learnt in the 1 month training at IGTR.
DESCRIPTION
This was our first assignment in the Vigyan Ashram just to get use to the process of designing. As during our interview we were asked about what we have learned in our previous training. So we told the courses we did the previous month which was Solidworks. And also in the mess of the ashram stands for vessels were needed so taking these points under consideration prasad sir decided to give us our first assignment as designing of the vessel stands. As we were the group of four so he told us to make four different designs and one of the design was to be finalised.
16/08/2024
Firstly, we went to the mess to take the dimensions of the vessels for which we wanted to design a stand. Then we took all the measurements of the vessels including a Plate, Bowl and Spoon. The measurements we took were as follows:
For Plate: Diameter = 33cm , Height = 2cm
For Bowl: Diameter = 7.7cm , Height = 3.8cm
For Spoon : Lenght = 15.5cm , Width = 3.6cm
Not only this but for the convenience of the design of the stand we also took the dimensions of the previous stands which were noted as 26cm in length and 15.2 cm in width
17/08/2024
After taking the measurements and dimensions of vessels and the old stand Prasad sir told us to make a rought design one our notebook of our own and all the design should be different from one another. So we started making our designs. For that I took the reference of the dimensions that I took and depending upon the dimensions I designed a stand. While making the design I made one slot for the plate. The diameter of plate that I measured was 33cm so i kept the length of the slot 20cm so as to keep the plate partially penetrated into the slot and as the thickness of the plate was 2cm I kept the thickness of the slot as 2.5 cm to allow the plate to freely pass through it.
similarly, by taking same points in mind I created a slot for spoon as well. And for bowl I made a L shaped structure on the right side edge which is lifted 4cm for hanging the bowl. In this way I finished my rough design
18/08/2024
After the rough sketch was completed we showed it to Prasad sir. Then he told us to make calculation on how much will be the pressure of all the vessels and what is the bearing capacity of our respective structures. So we made the calculations as per shown below :
CALCULATION :
Force = Mass * Acceleration = 0.600*9.8= 5.88 kg m/s = 5.88 N
Also Area = Length * Width = 0.265*0.15 = 0.03975 m^2
Now, Pressure = Force / Area = 5.88 / 0.03975 = 147.95 N/m^2
By taking some pressure of water assume approximately Pressure = 200 N/mm^2
This is the pressure that will act on the stand
Now, let us calculate Ultimate Stress , by assuming F.O.S as 2
As we know Ultimate Stress = Allowable Stress * Factor of Safety = 200*2 = 400 N/m^2
20/08/2024
Till now we had found out the dimensions of the design, ultimate stress and also figured out the material of the design which is MS sheet. But there was one thing missing which was IMP to create a model in Solidworks which we had not found till now was the thickness of the sheet.
So for finding that we used the ISO sheet for MS sheet. As the ultimate stress for our design was 400 N/m^2 which we converted to N/mm^2 which is 0.004 N/mm^2.This value is much smaller than that of the lowest value in the ISO sheet for MS sheet so we took the smallest range of thickness of the sheet which was 0.4mm < 0.8 mm. At that time in the market 0.8 mm sheet was only available so we purchased 0.8 mm sheet for the design.
After all the dimensions were decided we started creating the model on the Solidworks software. Following is the model that I created:
21/08/2024
After creation of model I showed it to Prasad sir. Then the next step he told us to estimate the cost that will be required for making the model. firstly we are find out the area of the flat metal model. But in Solidwork , the area is given by going to the evaluate command and then going to measure. So the area did not have to be findout.
Calculations For Cost Estimation:
Net Weight = Total Volume * Density of MS
Total Volume : Area * Thickness = 54460.45 mm2 * 0.8 mm = 43568.36 mm3
Net Weight = 43568.36 mm3 * ( 7.8 * 10-6 Kg/mm3)
Net Weight = 0.34 kg
Now, Cost of MS steel per kg = Rs 65
Cost for 0.34 kg Mild Steel = 65 * 0.34 = Rs 22.1
23/08/2024
Till this day the CAD design of the stand was finalised. The next step Prasad sir told us to cut the flat design of the stand on a cardboard by using Laser Cutter Machine. For that we had to save the CAD file in Dxf extension. After that we copied the Dxf file in the pendrive and went to Fab Lab. Then we put the file in the RD works software to make the RD file and also set the speed and power of the laser cutter. Power given was 90% and speed 30 mm/s. After that we removed the pendrive and attached to the Laser Cutter machine.
For switching on the Laser cutter following Steps are followed :
On the Main Switch > Isolation Transformer > On Stabilizer > On Industrial Cooler > On Main Laser Machine Switch > On Emergency Switch > On Lamp
For starting Laser cutting operation following steps are followed :
Going to the file > Select the Udisk+ > Select the Read Udisk > Select the Copy to Memery > Esc > On Exhaust Switch > On Laser Switch > Select Model > Start
24/08/2024
As we were given four different individual models so all four of us created four different model by laser cutting.
Following are the four models created by us :
On this day we had discussion with prasad sir related to all four models. The conclusion was that all the four models has some of good and bad qualities so Prasad sir told us to combine all four models and make one model in a group. So we created one model which is given below :
25/08/2024
On this day we had a discussion on types of stresses with Prasad sir and Dixit sir. In this discussion they explaines us what are tensile and compressive stresses and what is difference between them.
Tensile Stresses : The ratio of increase in length to original length of the body when it is subjected to pull force.
Compressive Stresses : Ratio of decrease in length to original length of the body when it is subjected to a pull force.
After that we went to workshop and learned about types of welding in workshop.
Following are the types of welding that were in workshop :
1. CO2 Gas welding
2. Arc welding
After that we again went to DIC lab and converted the model of vessel stand to dxf file and copied it into pendrive. Then we again laser cut the model in FAB Lab by repeating same previous process of laser cutting. Following is the result we got :
26/08/2024
On this day we had discussion about the model that we cut on the laser cutter and Mahesh sir told us to make the slots for the screw. Then we went to kitchen to get and idea from the previous design at that positions we have to create slots for the screws. Then we edited the design again in solidworks and added the slots for the screws. In this design we arranged the vessels and also came to know that the length of the slot for the plate is large that the plate was slipping through the . So we decreased the length of the slot as well. Earlier it was 32 cm and we edited it to 30 cm. Then we again Laser cut on the cardboard using Laser Cutter by repeating same previous process. Following is the model that was created :
After creation of model we were told to estimate the cost of the material required so we estimated the cost.
CALCULATION :
Net Weight = Total Volume * Density of MS
Total Volume : Area * Thickness = 76899.29 mm2 * 0.8 mm = 61519.432 mm3
Net Weight = 61519.432 mm3 * ( 7.8 * 10-6 Kg/mm3)
Net Weight = 0.47 kg
Now, Cost of MS steel per kg = Rs 65
Cost for 0.34 kg Mild Steel = 65 * 0.47 = Rs 30.55
02/09/2024
On this day we showed the previous model to Prasad sir and a small discussion happened where he highlighted another problem that in this current design the after keeping the plate in slot it will touch the wall. And he set another condition that modify the design in such a way that the plate after keeping in the slot should not touch the wall. So we started modifying the model again on solidworks. After we made the required changes again we converted the file into dxf file and repeated the previous same procedure for laser cutting in Fab Lab.
Following was the model obtained :
After completion of the design we were told to estimate the cost of this new design. So we estimated the cost by doing same calculations as before which are mentioned below :
CALCULATION :
Net Weight = Total Volume * Density of MS
Total Volume : Area * Thickness = 111276.93 mm2 * 0.8 mm = 89021.544 mm3
Net Weight = 89021.544 mm3 * ( 7.8 * 10-6 Kg/mm3)
Net Weight = 0.70 kg
Now, Cost of MS steel per kg = Rs 65
Cost for 0.34 kg Mild Steel = 65 * 0.70 = Rs 45.5
03/09/2024
Again we showed the new model created to the Prasad sir and then he told us to bring some more modifications in the new design and also focus on some cost cutting. So we again edited this new design and we came to know that the part that we created to hold the plate and avoid it from touching the wall contains a lot of unnecessary material which results in increase in the cost. So we decided to remove the unnecessary material from that part.
24/09/2024
We went to workshop to plasma cut our vessel stand design. But there was some problem with the machine because it was not used for a long time. We did not started cutting the final design because of the machine issue instead we took old sheets of metal and started cutting on them. We tried many times but thewe were unable to cut.
25/09/2024
As the plasma cutting machine was repaired we went to workshop again to cut out design. Before cutting the design first Mahesh sir explained us how to operate the plasma cutting machine and after that for practice he gave us small parts to cut by ourselves as a assignment then all three of us did that.
After that we again used old sheet for trail then the problem occured was that the machine was unable to cut the holes of our required dimensions properly. We made some attempts but it was causing same problem so Mahesh Sir told us to change the design and increase the size of holes and reduce the number of holes. So for that we again went to DIC lab and edited the design.
27/09/2024
As the design was updated according to the limitations of the plasma cutting machine so we started cutting our design. This time one more problem occured because the sheet was not plane. Due to that the machine was unable to cut it properly. Then we took the new sheet that was already present in the workshop for cutting. With the help of mahesh sir we cut the design 7 times as 7 stands were needed.
28/09/2024
The designs were cut so next step was to grind them so that the edges should not hurt while holding the stand. Today we did the grinding operation of the stands. I didn’t used the grinder before that but while doing grinding of our stand I learned to use it.The edges of the stands were not difficult to grind but the areas in middle of the stand were so difficult to grind and we were not able to grind them. So for that we used hand grinder that too I had not used before so I learned to use it and grinding of all the stands were done.
29/09/2024
All the stands were grinded properly the next step was the bending operation. The bending was quite difficult because we used the 1.2 mm sheet instead of 0.8 mm sheet which we were going to use because 1.2 mm sheet was available that day and it was plane as we required for cutting. We used bending machine in the workshop for that operation. Some parts were unable to bend on the bending machine which we had to bend by some other method and adjustments. Mahesh sir helped us in the bending operation. Bending not happened perfect as desired so we make use of hammer to make the parts straight that were disturbed during bending operation.
30/09/2024
Some stands were remained for bending so we started doing it. All the stands were properly bent today.
01/10/2024
The next step after grinding was powder coating. Mahesh sir helped us in doing this. Before powder coating we first cleaned the stands in the acid. It was needed because the acid cleans the surface of the metal and also removes some rust if it is present on it. After that the stands were hanged in the powder coating machine. Then powder was sprayed on it with a special gun. After that the stands were removed out of the machine and then they were placed in the container for heating upto the temp of 150 degrees. It took about 2 hours to complete.
02/10/2024
Today we installed the stands in the kitchen. We first bought screws of 4 mm from the market. Then we fitted all the stands on the wall before that we first removed the previous stands. The last three stands were fitted using the tar because screws were not possible there due to windows grill. And our first assignment was completed
