back to table of contents


LAZOLA Construction Manual, Sect. 2

Cutting, drilling and bending the metal parts for the glass frame



2.1     The metal glassframes  
  2.1.1   Preliminary Remarks  
  2.1.2   Cross section:
Function of the metal glass frame and of bothe wooden frames		  
  2.1.3   Overview over the metal parts of the glass frame  
2.2     Preparing the cutting of the parts for the glass frame  
  2.2.1   General hints and parts list  
  2.2.2   Reading the cutting layout  
  2.2.3   Examples for applying the positioning jigs when using the folding bench Clip 2.1 Clip 2.2 Clip 2.3
2.3     Making the metal templates for the frame parts  
  2.3.1   General notes  
  2.3.2   Cardboard models of the side parts of the metal glass frame Clip 2.4
  2.3.3   Explaining the differences of the various frame parts Clip 2.5
  2.3.4   Marking and cutting the metal template 6s L T Clip 2.6 Clip 2.7 Clip 2.8
  2.3.5   Labelling the metal templates to be made Clip 2.9
  2.3.6   Marking and cutting the metal template 6s R T Clip 2.10 Clip 2.11
  2.3.7   Marking and cutting metal stencils 6w L T Clip 2.12
2.4     Preparing the side parts of the glass frame for bending  
  2.4.1   Marking and drilling the parts of the frame by means of the metal templates Clip 2.13 Clip 2.14
  2.4.2   Cutting out the side parts of the frame Clip 2.15
2.5     Manufacturing the rear parts of the frame  
  2.5.1   Making the metal templates for the rear parts 7 (Ls and Lw) Clip 2.16
  2.5.2   Marking, drilling and cutting parts 7s and 7w Clip 2.17
2.6     Bending the parts for the glass frame  
  2.6.1   Place parts 6s L+R into the folding bench and bend to 90° Clip 2.18 Clip 2.19
  2.6.2   Inserting parts 6w L and R for bending Clip 2.20
  2.6.3   Bending parts 7s and 7w Clip 2.21
  2.6.4   Drilling holes in the templates for storage Clip 2.22
2.7     Manufacturing the remaining parts of the frame and part 11  
  2.7.1   Making parts 8w and 9w Clip 2.23 Clip 2.24 Clip 2.25
  2.7.2   Making parts 10s and 11s  
    2.7.2.1 Cutting parts 10s und part 11s  
    2.7.2.2 Completing part 10 Clip 2.26 Clip 2.27 Clip 2.28
    2.7.2.3 Drilling and bending part 11  
  2.7.3   Cut back-wall reinforcement plates  
      Differences in the Cooker Lw:  



2.1
The metal glassframes

  
The parts of metal glass frames . . .
    are made of galvanized sheet metal

2.1.1
Preliminary Remarks

Basic aspects concerning the cutting of the sheet metal parts were mentioned in the first chapter.
To avoid unnecessary waste, the glass frame parts have been included into the layout suggestions for the partitioning of the sheet metal plates (see appendix A2). An overview of the glass frame parts, their measurements and the required cutting-jigs is given.

2.1.2
Cross section: Function of the metal
glass frame and of both wooden frames

The metal glass frame (a) protects the underlying wooden frame (b) with the glass panes (c and d), glued from both sides, from sunlight. 4mm wooden strips (e) are placed on all sides on top of the wooden frame as a height compensation.

Laterally, the flange of the metal frame (a) reaches over the edge of the outer box (f). This protects the cooker during short spells of rain. The box frame (g) lies under the upper flange of the outer box. Thus, the inner (h) and the outer (f) box are connected, while preventing a loss of heat by conduction.

Both wooden frames are protected from sunlight and screwed to the metal parts, so they cannot deform.





2.1.3
Overview over the metal parts of the glass frame


  • The metal glass frame of both cookers, the Ls and the Lw, is made up of three parts: two parts that form the sides (6) and half the front each, and the rear part (7).
  • The side parts get a notch cut in on top and then they are bent to 90° to form the combination of side and front part.
  • The point where the two parts meet is covered by part 10s – for the Ls. A wooden handle is screwed to part 10s from the front.
  • The metal frame is put on the wooden frame and fixed with stainless steel screws.
  • For the Lw, an additional 270 mm plate (8w) must be placed between the two front parts.
  • Like part 10s does on the Ls, part 9w covers the gap between the two front parts on the Lw.
  • The handle for the Lw is larger than the one for the Ls
Labeling of parts 6 - 9
The numbers in frames indicate the numbers of the jigs with which they are cut. The digits beside or below indicate their length.

Note regarding Glass frame parts 6b and 7b:
The length for the frame parts 6w and the corresponding trimming aid is 1005 mm. This is longer than the nominal width of the KFT sheets. In fact, these sheets are up to 1005 mm wide.


2.2
Preparing the cutting of the parts for the glass frame

2.2.1
General hints and parts list

  • The adjacent parts list* is identical with the List in section 1.3.1. It gives an overview of the number of parts needed for one cooker glass frame Ls and one Lw, as well as for a template of all parts which will replace the paper templates.
  • Of each part one more item is cut for respective templates.

List of parts:
for the glass frames of 1 small and 1 wide LAZOLA (Ls+Lw) and for the corresponding metal templates
Part number Quantity of parts Quantity of templates Number of parts in total
6s L 1 1 2
6s R 1 1 2
6w L 1 1 2
6w R 1 1 2
7s 1 1 2
7w 1 1 2
8w 1 --1) 1
9s 1 1 2
10w 1 1 2
11s 1 1 2

1) The parts of the left and the right glass frame of the Ls differ slightly. Therefore, two different metal templates are required.



2.2.2
Reading the cutting layout

See also the clause “Legend” after Clip 1.3

Additional information:
Arrows downward cover all parts which are cut with the jig concerned (use Jig 10 for cutting all 7 parts to width, and Jig 11 for cutting four parts to length).
Arrows to the right with numbers below indicate the length of the part to be cut.

Example of the order of cutting:
The four 6w parts have already the correct length
  • Cut first 4 strips with Jig 10 to 79 mm width.
  • Then cut the 4 6s parts with Jig 11 in one to a length of 940 mm.
  • Finally, the 4 6s parts are also cut with Jig 10 to 79 mm width



2.2.3
Examples for applying the positioning jigs when using the folding bench

    To cut 79 mm wide strips use the positioning Jigs 1.1-10 in order to place the plate on the folding bench.
  - Once the plate is adjusted, fix the plate, remove the jigs and cut the plate. (no video clip)



    Use positioning Jigs 1.1-11 to position a 1000 mm plate that is to be cut to a length of 940 mm.


Important NOTE:
In the meantime a much simpler solution has been found for Jigs 1. The new jigs are adjustable, so less jigs are needed.


    Use a hard steel object to remove the burr that almost always appears at the lower side of a cut. Do this for all edges that will be facing outwards.
 



2.3
Making the metal templates for the frame parts

  

2.3.1
General notes

First prepare the metal templates (T) that will be used to mark and drill frame parts 6s and 6w. Most of them differ slightly from one another.

2.3.2
Cardboard models of the side parts of the metal glass frame

    A cardboard model (of the left side part for the Ls) is used to demonstrate the bending process and to show what the finished part will look like.
 



2.3.3
Explaining the differences of the various frame parts

All four side frame parts are largely the same. For all of them:
  • a triangle is cut,
  • the part in the front area is cut narrower
  • Almost all 4.2 mm holes are drilled in the same places.
Additional:
  • a rectangular cut is removed for part Ls L
  • a further hole is drilled in three parts at different points.
    (See also clip 2.5, 5 00:16)
1 0:00 6s L gets an additional hole ahead.
2 0:04 6s R gets an additional hole further back.
3 0:08 6w L does not get any additional hole
4 0:12 6w R gets an additional hole further back (6s R)
5 0:16 Parts 6w L and 6w R are a few inches longer at the front.
   
Note: For the cutting of cardboard models of all four parts, there is a copying template in Appendix A1.4
 



2.3.4
Marking and cutting the metal template 6s L T

1 0:00 Use a steel nail and Jig 2.1 to copy the marks of the paper template for part 6s L onto the plate that will become the metal template.
2 1:40 Use the punched points to mark what has to be cut out.
Note: The template shown in the video is inverted. (See new template)

 

    Cut out the marked parts of the metal template 6s L T with tin snips
 

    Cut out the rectangular notch with a chisel on a steel support. A heavier hammer could be suitable as support.
  - Use a file to remove all burrs. (no video clip)
 



2.3.5
Labelling the metal templates to be made


The further frame parts provided for metal stencils are processed by means of this metal template. (See Clip 2.10 and Clip 2.11.)

   

Label the four metal strips provided for the further metal stencils before processing, in order to avoid later confusion. After labeling 6s L T, the video stops. The three further template parts 6s R T, 6w L T and 6w R T are labeled in the same way
 



2.3.6
Marking and cutting the metal template 6s R T


1 0:00 Place the finished metal template 6s L T on the as far only labeled template 6s R T. (Both are largely mirror-like).
2 0:20 Use the template 6s L T to mark the cut-outs
3 0:36 Transfer all holes (except the "light blue"one)
    Important note:

The rear end of all frame parts must actually touch the side stop of the jig. This was neglected in this clip.

The additional holes in three of the four metal templates (light blue) must be marked by means of the paper stencil on which they are marked.
 

    Cut out the marked metal template 6s R T.
 



2.3.7
Marking and cutting metal stencils 6w L T and 6w R T



1 0:00 Place the metal template 6s L T on 6w L T.
2 0:07 The front part of the metal template 6w L T is longer than that of 6s L T. Therefore, place the parts with the rear end against the side stop of Jig 2.1.
3 0:21 Transfer the marks of the metal template 6s L T to 6w L T
  - Cut out the marked template. (No video clip)
  - Use the metal template 6s R T in the same way to mark the metal template 6w R T. (No video clip)
 



2.4
Preparing the side parts of the glass frame for bending

2.4.1
Marking and drilling the parts of the frame by means of the metal templates

  
    Successively label, mark and cut all four frame parts of the corresponding metal stencils.
 

    Place the metal template 6w L+R T, which has already been punched but not yet drilled, onto the cut-out corresponding frame parts and drill the punched parts together with the respective frame part in one go. - Check whether the additional (light blue) holes have been previously punched.
(The holes in the template serve as guides; in serial production such parts are drilled in stacks of up to ten in one go.)
   
 



2.4.2
Cutting out the side parts of the frame

1 0:00 Cut only the small strip at the front edge.
2 0:44 The triangles are only cut after bending the parts, (see sect. 7).
 



2.5
Manufacturing the rear parts of the frame

  

2.5.1
Making the metal templates for the rear parts 7 (Ls and Lw)

1 0:00 Tape the paper template onto the already cut out metal templates 7s and 7w
(the video only shows the template 7s, but the 7w is prepared in the same way).
2 0:28 Mark the metal templates.
3 0:58 Connect the punched points using a steel nail.
4 1:14 Cut out the templates.
 



2.5.2
Marking, drilling and cutting parts 7s and 7w

1 0:00 Use metal templates 7s T and 7w T to mark the frame parts.
2 0:29 Drill holes at the punched points through the templates and the underlying frame parts. (see the note after Clip 2.14)
3 0:40 Cut out the parts.
 



2.6
Bending the parts for the glass frame

The figure below shows all glass frame parts:
  • Left: Left frame part Ls bent and template for this part
  • Center: Right frame part Ls bent and template for that part.
  • Right: Right and left frame part 6w L and 6w R and metal template
    6w L T. (The metal template 6w R T was previously on the back of
    6w L T
 

2.6.1
Place parts 6s L+R into the folding bench and bend to 90°

  - For adjusting the angle of the bench, test with scrap metal plates that have roughly the same length as the parts that have to be bent.
Short pieces are bent with the same setting more strongly than long ones. (no video clip)
1 0:00 Insert part 6s L into the folding bench (as done before with the cardboard model) with the triangle (not yet cut) on the right hand side.
2 0:05 Turn around part 6s L. The triangle (not yet cut) remains visible at the right hand side for the operator (not visible in the video clip).
3 0:17 Adjust the position of the part, using Jig 2.2 and clamp it.
4 0:24 Now bend the part to 90°.

1 0:00 Insert part 6s R into the folding bench like part 6s L, but with the not yet cut triangle on the left hand side.
2 0:20 Jigs 2.2 are used for the bending of all parts of the frame; this assures that the frame has the same width all around.
 



2.6.2
Inserting parts 6w L and R for bending

1 0:00 Insert 6w L in the same way as 6s L and bend.
2 0:20 Insert 6w R in the same way as 6s R and bend.
 



2.6.3
Bending parts 7s and 7w

The adjacent picture shows parts 7s and 7w bent and as templates
    Insert part 7s in a way that the lateral flanges are hidden while bending.
 



2.6.4
Drilling holes in the templates for storage

    Drill holes into the templates. The board on top gives a good hold to the drill.
(You will need less force if you drill a 4 mm hole first.)
(Parts 8w T, 9w T, 10s T und 11 T need these kinds of holes too.)
 



2.7
Manufacturing the remaining parts of the frame and part 11

  

2.7.1
Making parts 8w and 9w

  - Cutting parts 8w and 9w to size from 74 mm wide strips. (No video-clip)
1 0:00 Transfer the paper template onto part 9w in the usual way.
2 0:52 Drill part 9w together with its punched template 9w T.

    Place part 9w in such a way, that the side with the holes at its edge is hidden beneath the clamp bar.


    Bend part 8w from either side. This part has got no holes.

 



2.7.2
Making parts 10s and 11s

2.7.2.1
Cutting parts 10s und part 11s

1 0:00 Cut parts 10s from a 100 mm plate strip using Jig 2.3a Place a board between the strip and the side stop of the guillotine shears.
2 0:25 Cut parts 11s using Jig 2.3.b (This clip gives an idea of what serial production would look like.)



2.7.2.2
Completing part 10

1 0:00 Transfer markings from the paper template onto part 10s T using Jig 2.4
Holes must be absolutely parallel with the
2 0:30 Drill 3.5 mm holes into parts 10s and 10s T in one go.
3 0:51 Label the parts.
4 1:02 Bend part 10s like part 9w was bent.



2.7.2.3
Drilling and bending part 11

  - Mark and drill part 11s in the same way as before part 10s mark and drill. (no video clip)
1 0:00 Bend the already drilled part 11s to 90° using Jig 2.5a The drilled side remains visible.
2 0:17 Insert the part already bent with Jig 2.5b and bend it as far as possible.
3 0:38 Finish the second bending by hand and press it flat, using the folding bench.
This part will be applied to the reflector support only in sec.8, Clip 8.11



2.7.3
Cut back-wall reinforcement plates

In sec. 7, Clip 7.10 , the glass frame hinges are riveted to the back of the cooker. For greater stability of the back part, reinforcement plates are attached *, for Ls 2 pieces, for Lw 3 pieces. They are

The minimum. 60 x 100 mm or larger sheet metal pieces made of wastepaper. (Kein Video-Clip)

* For the application of the parts see chap. 3, Clip 3.9, from sec. 03:07



Differences in the Cooker Lw:

All the special features of the glass frame parts were considered in the previous instructions.
The only further difference in the Lw:
The stove has a different glass frame support than the L3s, so the angle plate (part 11) is obsolete 2.7.2.3