Belovac Vacuum Forming Machine

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Belovac Vacuum Forming Machine
Belovac Vacuum Former Main.jpg
Owner/Loaner PS:One
Make/Model Belovac BV E-Class
Arrival Date 2018
Usability yes
Contact User:Rtystgeeke
Where Hot Metals
Authorization Needed yes
Hackable no
Estimated Value tbd
Host Area Hot Metals


Belovac Vacuum Forming Machine Area: Hot Metals https://wiki.pumpingstationone.org/wiki/Belovac_Vacuum_Forming_Machine



Overview

This vacuum forming machine has been donated by SAIC and is currently installed in Hot Metals area. A Danger Committee was formed and the machine is ready for member use pending authorization.

How to Get Authorized

Authorization for this machine is on demand and viral. Please make a request on Slack to see when an Authorized member is available and coordinate an authorization.

Please review the information on this page, in particular the Safety section before meeting.

Please bring your own materials, as there is no guarantee there will be any available. A few sheets of thin 12in x 12in ABS/HIPS would be ideal.

Current Status

This machine is working but requires maintenance and improvements (see list below).

Vacuum Forming Process

Vacuum Forming, is a type of Thermoforming,which is the process of heating a plastic sheet and stretching it over a mold. As the plastic cools, it hardens, permanently retaining that shape.

This device can handle any thermoformable plastic up to 3/8" thick.

Depending on which platen/frame that is used, the machine can accept 3 sizes of plastic sheets. 12inx12in, 24inx24in and 24inx48in. The usable area in those sheets after being secured in the frames being 9.25inx9.25in, 21inx21in, or 21.5inx45.5in.

The "buck," mould or form, may be any sturdy shape that can tolerate a bit of heat. Wood, MDF, metal, and polyester resin work well. Avoid shapes with hollows underneath because they have a tendency to collapse. Shapes with undercuts, or shapes taller than they are wide, will be very difficult to remove from the formed plastic. Paint, shellac, or epoxy resin can cause the hot plastic to stick.

The oven must be used only for vacuum forming. Please do not attempt to use this machine to dry materials or anything other than its intended purpose.

Other related tools/skills:

  • ShopBot Auth - to create molds out of MDF with the CNC.
  • Woodshop Auth
    • Band saw - To cut flashing (excess material) from thick finished parts with Vertical Band saw.
    • Panel Saw - to cut sheets of plastic to correct frame size.
  • 3D Printer Auth
    • to create mold to cast plaster buck

Usage Steps

The process consists essentially of inserting a thermoplastic sheet in a cold state into the clamp area, heating it to the desired temperature with the heating elements, and then raising the buck/form/mould from below. The trapped air is evacuated with the assistance of a vacuum system. Once cooled, the platform is lowered to release the formed plastic part from the buck/form/mould.

The following instructions are an initial release of how to run the machine.

Please review Safety section below the Instructions.

Please provide feedback or feel free to make edits.

Steps Diagram/Picture 
 Power On Procedure
  1. Turn on Wall Power

Note: Check that plug below panel is connected. It may be disconnected.

Bvf main power.jpg
  1. Turn on Machine Power
 Bvf machine power.jpg
  1. Push bar forward to close frame clamps and secure overall frame.

Note: Do not use as handle when pushing/pulling frame into position.

Bvf frame clamps.jpg
  • Select desired Valve configuration on bed/platen/platform.
  1. Both Valves closed for 12inx12in frame
  2. Left Valve Closed and Right Valve Open for 24inx24in frame
  3. Both Valves Open for 24inx48in frame
 Bvf platform valves.jpg
  1. Connect Pneumatic Hose. This allows one to raise/lower the platform.

Note: It can be borrowed from the CNC Plasma Cutter, if not in use.

Note: The main valve with yellow handle, behind the CNC Plasma cutter, above the large tank, may be closed if there is no air.

Bvf pnuematic hose 01.jpg Bvf pnuematic hose 02.jpg

  1. Secure Buck/Form/Mould to Vacuum table. If it is heavy enough and does not stick, it may not need to be secured.

Note: it is recommended to have the mold be a bit taller than desired part, to allow space for cut separation.

  1. Check seals around material and mold.

Note: If material is not thick enough, it may slip out of the frame.

  1. Raise part way to make certain mold lines up with frame.

Note: It is a 3 position pneumatic valve. Up position raises platform. Center position, holds platform at current position. Down position, lowers platform.

  1. Insert sheet of material into Frame.
 Bvf frame open small.jpg
  1. Close the frame latch to the secure the material.
 Bvf frame latch small.jpg
  1. Select Number of Heating Elements to turn on.

Note: currently only using middle/center

Bvf heater select.jpg
  1. Select On Percentage Duty Cycle (0%-100%) for Heating Elements. It is on a 15 second timer.

Note: This controls the cycle time of the heating elements being On (at dial), then Off (top of timer).

Bvf heat duty cycle.jpg
  1. Turn on Heating Element

Note: You will see the Timer begin to rotate counter clockwise and audibly hear the contactors/relays energize.

Bvf control panel.jpeg
  1. Move material frame into heater by pushing on front of slide.

Note: do not use frame clamp bar as handle.

Bvf heat 1.jpg
  1. Close Vacuum Valve (facing valve, rotate clockwise, with handle position pointing to the left at final position.)
  2. Turn on pump, to begin to build vacuum.

Bvf vacuum valve.jpg Bvf control panel.jpeg

  1. Visually check if heating element is on and if material is warming

Note: The heating elements will visibly glow red.

  1. Visually check if material is sagging and ready.

Note: It will visibly sag and look like a dome.

Bvf heat 1.jpg Bvf heat 2.jpg

  1. Pull Material frame forward (towards front/away from heaters) completely forward until it stops.

Note: Do not pull on frame clamp bar. It will open all 3 clamps if pulled on.

  1. Inspect Plastic is ready (sufficiently heated/soft).
 Bvf frame forward.jpg
  1. Make certain area is clear before raising bed/platen/platform.
  2. push lever up to raise vacuum bed/platen/platform.

Bvf platform.jpg Bvf platform lever.jpg

  1. Open Vacuum Valve (rotate counter clockwise, with handle position pointing down at final position).
  2. You should see the plastic part quickly take the shape of the mold.
  3. Monitor pull of material over mold.

Bvf vacuum valve.jpg Bvf vacuum pull.jpg

  1. Close Vacuum Valve to Turn off Vacuum, when part is ready.
  2. Allow part sufficient time to cool, before separation. This time frame is dependent on the thickness of your material.
  3. Push bed/platen/platform lever down to lower platform and pull mold away from formed part.

Bvf vacuum valve.jpg Bvf platform lever.jpg 

Shutdown Procedure
  1. On Control panel, Turn Heater switch to Off position.
  2. On Control panel, Turn Vacuum switch to Off position.
  3. Open Vacuum Valve (rotate counter clockwise, with handle pointing down), to release any remaining vacuum in the tank.
  4. Push platform lever down, to release air pressure from pneumatic hose. (Hose will momentarily whip around at next step if air is not released)
  5. Disconnect pneumatic hose. Return to CNC Plasma Cutter.
  6. Turn off machine power.
  7. Turn off Main Wall power.
  8. Make certain material frames are closed and not left open. (where they can snap shut accidentally)

Bvf machine power.jpg Bvf main power.jpg 

Cleanup Procedure
  1. Cleanup any unused material or scrap.
  2. Throw away failed part pulls in dumpster. Do not leave in Hot Metals area.

Safety

The Vacuum Former has an oven surface for heating and softening the plastic. It is made of multiple panels (total 6) infrared radiant heating elements, draws a total 80,000 watts (top and bottom), and reaches full operating temperature depending on Active heating time set on the timer.

The most likely source of problems would be for someone to leave the plastic under the heater for way too long and set it on fire. To help avoid this error, we are only using the center top panel for heating. Warning: Ignoring safety protocol is cause for revoking authorization.

Fumes from most plastics are not expected to be significant when the machine is used properly (i.e., nothing is on fire). If fumes do turn out to be a concern, the machine can be retrofitted with a fume hood. Then connected to the existing exhaust duct for the Forge. To improve air quality, turn on the forge exhaust and open the front door by the plasma cutter computer.


Warnings

Danger/Warning Description Mitigation
Hot sm.png HOT SURFACE - Metal Frame holding material and handles will be hot. Wear Gloves during operation
Fire sm.png FIRE - Material may catch fire while heater is left on. DO NOT Leave Unattended
Crush sm.png CRUSHING - Make certain there is nothing obstructing the platform, before pulling the pneumatic lever raising the mold to frame. Make certain steel material frames are not left open. They can fall forward, quickly snapping shut. Clear All Obstructions
Shock sm.png ELECTRIC SHOCK - High Voltage machinery (3 Phase Power) required to run motors and heating elements. Visually check that power cabling is secure, grounded and undamaged before operating and touching metal enclosure. Check Cabling

Machine Information

Company page: http://www.belovac.com/manual_deep_draw.html

Training Resources

Videos


Materials

NOTE: Materials are not provided. Member must bring their own materials for use with this machine. Please consult material selection guide to select appropriate plastic sheets for thermoforming.

Example Materials for use with the machine below:

Materials for Buck/Form

These are an example of some materials that can be used for molding. The material needs to be heat resistant. It should also have a flat base for stability on the platform.

Materials for Forming

Information on safe thermo-formable materials in sheets.

Material Selection Guide - https://www.toolcraft.co.uk/vacuum-forming/advice/vacuum-forming-help-material-selection-guide.htm

Incomplete List

Plastics Distributors taken from tk560.com

Order full sheets 4'x8' and cut to desired size with panel saw.


Tips & tricks

Creating an appropriate Buck/Mold

  • Part should have a flat base
  • No overhangs
  • Pay attention to draft angles


Trimming Part

  • Depending on the thickness of the material, a band saw or box cuter can be used to trim excess flashing from the final part.


Troubleshooting

How long does it take to heat the plastic sheet?

  • This depends on which material and thickness is specified.

How do I know when the plastic is ready to form?

  • Generally speaking it is necessary with any new material to establish the correct heating cycle. Plastic is ready to form when it becomes soft and pliable especially nearer to the clamping frame. This is known as glass transition temperature (Tg). Once you have established the time you can set the heater timer for accurate and repeated heating cycles.

Why is the plastic webbing on the mold?

  • Material is too hot.
  • Insufficient vacuum.
  • Excess of material. Use reducing windows.
  • Poor mold design.

Why can't I achieve good definition on the finished part?

  • Material too cold
  • Mold too cold.
  • Insufficient vacuum.
  • Insufficient vacuum holes in the mold

Why Is the plastic thinning over the mold when formed?

  • Sheet cooled whilst forming.
  • Mold design with insufficient draft angles.
  • Too thin plastic gauge.
  • Pre-stretch required.
  • Plug assist required.

Why does the plastic bubble and pit when heated?

  • Material is Hygroscopic which needs to be pre-dried prior to forming.
  • Overheating.
  • Mold or plastic sheet too dusty

Why does the plastic stick to the mould when I try to release?

  • Mold not fixed on baseboard.
  • Insufficient draft.
  • Mold undercuts.

Maintenance and Repairs

  • Get Running - DONE
  • Add equipment sticker to machine for wiki info
  • Fix platen/frame rubber seals
  • Build basic test mold for demos and training. (PS1 Logo or Mask)
  • Move vacuum gauge to before the valve, to measures the vacuum the pump is pulling (right now it's after the valve, so doesn't read anything useful)
  • Install Additional/Larger Vacuum Tank to the system for more capacity
  • More powerful Vacuum Pump
  • Temperature Monitoring
  • Mount Control Panel Box to machine DONE
  • Put on locking casters, or more permanent blocks/skid (machine is very heavy)
  • make the platen stationary and the heater roll (complicated)
  • Reduce the footprint of the machine (complicated)

Authorizers

Member Authorization Times
Andrew Camardella By Request

How to Become an Authorizer

Get an ok from the area host. Successfully run an authorization supervised by an authorizer.

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