Category: Other projects
Small, fine mandrel press
The project
This customer project involved the production of a small mandrel press for small and delicate components. The mandrel press is also suitable for pressing bearings and pins in and out.
Material used:
- 2 x aluminium blocks
- 1 x gear rack (module 1) 15 x 15 x 250 mm
- 1 x gear wheel (module 1, 21 teeth, original bore 8 mm) with Ø 23 mm
- 3 x feather key 5 mm
- 1 x stainless steel V2A for the rotary head 30 mm
- 1 x stainless steel shaft - ground Ø 12 mm
- 1 x stainless steel shaft Ø 8 mm as toggle
- 2 x bearings for stainless steel shaft Ø 12 x 18 x 4 mm
- 1 x circlip for shaft Ø 12 mm
- 4 x plastic covers
- 4 x VA - M6 x 60 mm hexagon socket screws with lock nuts
- 2 x cap nuts M8
- Remaining material 30 x 30 mm square material for the base frame
- Some paint
Tool used
- Milling machine F400-G
- Lathe PM190-V
- Dividing attachment
- Reamer 12 mm fit H7
- Flat countersink
- Countersink
- Collet chuck
- welding device
- Tailstock
- Radius milling cutter
- T-slot cutter
- Cutter head
- Pull-down vice
- Edge finder
- Broach 5 mm
- Drill
Step 1
Machining the front aluminium block
First, the two aluminium blocks were face-milled from all sides and then milled to the appropriate size (65 x 55 x 30 mm).
In the next step, a groove (central, 8 mm) was milled into the front aluminium block for the gear rack. The groove was then widened once from above to a depth of 5 mm on the left and right so that it corresponds to the outer dimension of the rack (15 mm). In the next step, the lower T-slot (5 x 20 mm) was produced using the T-slot cutter.
Step 2
Milling the groove in the rack
The groove was then milled into the rack on the left and right as a guide. To do this, both grooves were made 5 mm deep and 5 mm wide using a 4-edged milling cutter. With hardened material - in this case the gear rack - milling the grooves can take some time. After machining, the rack should run cleanly and without play in the aluminium block.
Step 3
Machining the rear aluminium block
Firstly, the bore for the shaft was made with a diameter of 12 mm. Then the seat for the ball bearings was milled 4.2 mm deep on the left and right, the shaft was clamped and space was created for the gear wheel. Care should be taken to ensure that there is enough space next to the gearwheel to insert the feather key.
Step 4
Turning the gear wheel
As the gear wheel was too wide for the gear rack, it was turned to 15 mm in the next step. The hole in the gear was drilled from 8 mm to 11.8 mm and then reamed to 12 mm using a machine reamer (tolerance class H7).
The broach was used to press the driver for the gear wheel.
Step 5
Milling the keyway for the feather keys
Firstly, the shaft with a diameter of 12 mm was clamped in the lathe and the groove for the circlip was produced on the left-hand side using a parting tool. The shaft was then centred on the left and right with a centring drill so that it could later be clamped more easily on the dividing head on the milling machine. The shaft has a length of 105 mm.
In the next step, the dividing head and the tailstock were positioned on the milling machine and the grooves for the feather keys were milled. In this case, two pull-down vices with 100 mm jaw width were used for clamping and aligning the dividing head and tailstock. This means that longer components can also be clamped and the dividing head and tailstock can be quickly and easily clamped and aligned on the work table.
Step 6
Manufacture the rotary head
The next step was to produce the turning head for the press. To do this, the sides were turned lengthways and flat. A bore of 11.8 mm was then produced and reamed to 12 mm using a reamer (tolerance class H7). The keyway for the feather key was then pressed and the gear shaft including the rotary head was mounted with the feather key and clamped together on the dividing head. The next step was to drill the hole for the toggle. This was sawn to the required length. In addition, 0.2 mm holes for the M8 thread were pre-drilled at both ends of the toggle and then the threads were cut.
Step 7
Joining the aluminium blocks together
To be able to screw the two aluminium blocks together, four holes were first drilled. If required, the blocks can also be rounded with a corner cutter or radius cutter.
Step 8
Manufacture the body
In the final step, the body of the mandrel presses was manufactured from square material. The material was cut to the required sizes and the individual parts were welded together.
The following offcuts were used as material:
- Square tube: 1 x 250 mm, 1 x 64 mm, 2 x 130 mm
- Flat material: 2 x 100 x 30 x 5 mm, 1 x 65 x 30 x 5 mm, 3 x triangles as gusset plates
Step 9
Finished mandrel press
A reduction from 1/2" to 3/8" was also installed on the mandrel press to enable a flexible mount for the rack. This means that different sockets can be fitted for bearings.
Contact details
If you have any further questions about the project, you can contact the builder by e-mail.
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