Trolley for Moving Medical Equipment

In context of a project for our university course, my team and I build a trolley for carrying around medical equipment like a ventilator. The goal was to create a support trolley, which would be easy to drag along, even for children.

Tools:

• Band saw
• Power drill
• wood drill (10 mm diameter)
• bits for screwheads
• circular saw
• jig saw
• files for metal and wood
• sandpaper
• band saw
• plate shears (to cut the sheet metal)
• measuring tape
• marker/pen
• hot glue gun

Materials and other supplies:

• wood boards (20 mm thickness)
• 400 mm x 500 mm (or larger)
• 4 pieces 50 mm x 60 mm (or larger)
• steel profile bar ca. 2 m; 36 mm x 36 mm (we used HILTI MM-C-36, a company donated those)
• steel profile bar base (we used HILTI MQV-2/2 D, a company donated this)
• you can recplace this with steel angles and screws + nuts
• 4 wheels (100 mm diameter)
• 2 with breaks
• 2 without breaks
• sheet metal (ca. 800 mm x 500 mm)
• washers in different sizes
• screws
• M8 x 35 (with fitting nuts)
• wood screws (~35mm and ~15 mm)
• 2 metal angles (fitting for your profile bars)
• a plastic container ( ca. 200 mm x 200 mm x 40 mm)
• styrofoam
• Linseed oil

Optional electrical parts:

• electrical components (see reference link later in the guide)
• powerstrip

You can skip this if you have a precut 400 mm x 500 mm board.

Otherwise measure the 400 mm x 500 mm on the larger board and mark it, afterwards use the circular saw (or any other usable saw in case you don't have powertools) to cut it out.

Mark 5 stripes with the measurements 220 mm x 10 mm with the first one starting 70 mm away from the 400 mm long side of the baseplate. They should be centered on the baseplate. Afterwards use the wood drill to drill a starting point for the jig saw in the end of the stripe as seen in the picture. Use the jig saw to carefully cut out the stripes.

Use sandpaper and/or a file to smooth the egdes of the cuts. After that coat the area around the slits with ~4 layers of linseed oil to make them resistant to water.

You can skip this step if you have four precut 50 mm x 60 mm boards.

Measure and mark four 50 mm x 60 mm parts in your wood board. Afterwards carefully cut them out using the circular saw (or any other saw you have available).

• Mark up up the spots for the wheels (helps with aligning the base extensions). One extension per corner of the baseplate, the 60 mm side aligned with the 500 mm side of the baseplate, the 50 mm side aligned with the 400 mm long side of the baseplate.
• Align the wheel with the base extension as shown in the picture (a clamp can help here)
• Use your powerdrill and 4 wood screws with washers to attach the wheels to the baseplate + extension.
• the wheels with brakes go to the side without the drain
• Afterwards you have the base trolley, halfway there.

You can skip this step if you have precut steel profile bars.

We used a bandsaw for metal. A Crosscut saw also works, or you get profile bars in the right length.

You'll need

• 1x 560 mm
• 2x 430 mm
• 2x 330 mm OR 1x 330 mm and 2x 150 mm if you want to attach a socketstrip

Afterwards use a metal file to get rid of any sharp edges, be careful to not cut yourself!

Attach the two 430 mm bars with angles to one of the 330 mm long bar as shown in the pictures. Afterwards mount the frame onto the baseplate and attach it with screws, washers and nuts. Three screws per bar are sufficient.

The last picture shows the optional positioning if you attach a socketstrip. Make sure the gap is centered.

As a final touch use hotglue to attach styrofoam pices to the corners of the bars, make sure they stick out over the edges of the baseplate. This will ensure any damage of collisions can be minimized.

Please refer to this guide for the optional attachment of an IoT platform and various sensors.

https://link.foerster.engineer/elektro-anleitung

If you follow this guide, you can attach the resulting sensorbox at the opposite site from the drain on the underside of the baseplate. You can either attach it via glue or screws. For the power supply of the sensorbox we recommend to drill a small hole into the baseplate, right next to the position of the socket strip to funnel the cable of the power supply through.

First of all a small tutorial on how to bend sheet metal:

https://www.youtube.com/watch?v=KdMtecvnPRI

•    Cut out the measurments of the sheetmetal as shown in the pictures and afterwards bend it accordingly.
•    Disclaimer: you do not have to use those exakt measurments. Fit them according to the container you want to use
•    After you have bend it, attach it to the baseplate under the drain slits via screws and washers

If you have a rail base like we did, you can just attach it centered onto the onto the profile bar next to the drain and fix it screws and nuts. Alternatively attach metal angles to either side and fix those with screws and nuts. To finish it up, attach a piece of styrofoam to the top end of the pole.