Constructing the Mendel parts out of MDF (Part III)

(1)

Well, at this time i didn't have time to continue milling the parts of reprap. But i said in previous post i'll show you some of the tools i used to shape the parts.

At first i have to say that a rotary tool, which is a tool that speeds too fast (maximum 35.000 rpm) is a vital one.

disk for wood (2)

• With this rotary tool and a disk specially for wood (photo 2) i cut the parts.

special drill bits (3)

• For the inside shapes (circles especially) i used a bit that it's similar to common drill bits, but cuts the wood horizontally except from vertically (photo 3). 

bit for details (4)

• Then, with a sharp bit i did the details (photo 4).

sander (5)

• And with the sander smooth the edges (photo 5).

Also the holes made with a common drill, because the rotary one can hold only 3-4mm bits. Just make sure the holes are perfectly placed.


For example, the part shown at first picture made like this:

1. Cut the part from the rest of the MDF sheet.
2. Draw the layout of the part.
3. Mark the center of the holes.
4. Get the holes done.
5. Use the special drill bits for the inner circle and the biggest part of the 3 rectangular shapes.
6. Do the details with the other bit (4)
7. Use a rasp to smooth the inner circle and rectangular shapes.
8. Use sander for the rest.

The process is similar for most of the parts. But  it's better for some parts to mill them while not cut from the MDF sheet.

Constructing the Mendel parts out of MDF (Part II)

Step 2: Drawing the parts on the MDF.

drawing on the way (1)

Drawing the parts isn't something tough, but you have to be patient and careful for a good result.
At the left photo you can see almost everything you will need.

Notice: Remember what i had mentioned previously, that the outline isn't so important as the innner dimensions are.



Define a reference point to start drawing on the wood. The best is one machine-cut side because you know it's a straight line.
Get the paper and place it in line with the end of MDF or the ruler (photo 2).

placing the paper part (2)

  


At the photo you can see that i used the ruler in order to be sure that the paper is placed correctly. In other cases you use a combination of rulers to get the paper where you want it. Here you will need the corner ruler because it makes your life easier.

Drawing many parts (3)

Drawing many parts (4)

Using the rulers to draw many parts on MDF and not drawing and cutting one by one. The space needed between parts is about 5mm to be sure you'll not mess them up.

2 consecutive parts (5)

This is how the job is done. Draw a big area with parts and then start cutting. Also don't draw one piece of everything, but better draw all the replicas of one and then go for the next.

Notice: Better remove the wood from the inside of the parts before you split them because it will be difficult to hold them tight while milling them.

I can't remember something else from this procedure. If you miss anything feel free to contact me.
Next post will be about the milling and the tools i used.

Constructing the Mendel parts out of MDF (Part I)

Continuing from the previous post, the reason i chose this method was the lack of money and the tools i already had on my garage. I assume you have downloaded Inkscape and the .svg files, so I'll start...

Step 1: Printing the .svg files (Inkscape tutorial)

     In order to print the parts you must first select the area which you will print so press File->Document Properties(or Ctrl+Shift+D) and then select in the Page tab, in the Format field the option A4. Also select the desired measurement system you do want in the up right corner (General). Now you can see the area which will be printed. Just move the file and place the parts you want inside the area.

You can see the parts in 1:1 scale by selecting View-> Zoom-> Zoom 1:1.

The axis top and left are in the measurement system you picked before. Click on them and drag the mouse in the drawings so that the lines will appear.
On the bottom of the window you can see the coordinates of the line while you have it selected. On the top toolbox you can see the coordinates of selected object.

Selecting the size (3)

Moving the print area (4)

 Now you just print all the parts in paper, and start cutting with a scissors or a razor. You have to cut only one blueprint from every part.

cutting the inner shapes (5)

Notice: You can remove the paper from the inner holes with a razor at this moment and transfer it to wood or you can first cut the outline of the parts and then finish them.
Take care that you have to be very careful with the distances from hole to hole etc, rather than the exact shape of the part for the majority of them.

Constructing the Mendel parts out of MDF (Intro)

In order to save some money i'm trying to make the parts of Mendel out of MDF (wood). The construction is still in progress, which means i can't tell you for sure that this idea will work. I used the files for laser-cutting from http://reprap.org/wiki/LaserCut_Mendel#Downloads. Download the .svg files and use the Inkscape to open them. This files are used to drive a laser cutter, which will produce easily the parts. If you don't have, then you will need patience and enough tools to shape them.
The process in short is:

• Print the files in the original size
• Cut each piece
• Draw each piece on the MDF
• Cut it, not with much details
• At last edit each part in order to reach the desired detail.

Not very easy as you can see, but if you got already the tools the cost is 10-20 euros! You can save 150-200E. The process goes on...I'll come back with more details in a few days, presenting an almost step by step guide.

 Some photos to get an idea :)