Lift Plates and Pulleys

On Saturday I attended the Model Engineering Show at Sandown Park, and one of the items I picked up was a 150mm square sheet of 2mm Aluminium sheet to make the Z lift plates from.

In reality I only needed a strip about 46x120mm to make 4 lift plates from, but it never hurts to have extra in case of mess ups or future projects.

As I could cut 5 out of a 46x150mm strip, I decided to make 5 and just use the best 4.

I cut the strip off the sheet with a hacksaw and then further chopped this into 5 again by hand with the hacksaw.

I de-burred the edges of each piece with a file before stacking them together and milling the edges so that they were all rectangular and all the same size.

I then drilled 2 x 5.5mm and 1 x 10mm hole through the entire stack before using a square file to turn the 10mm round hole into a 10mm square hole.

Here are four of the finished items.

and here with the cage nuts installed.

The 150mm square sheet cost £2.00 (about $3.12), so the 46mm strip to make 5 of these cost me £0.61 (2.00/150*46) (about $0.96) and about half an hour in the garage, The cage nuts cost me nothing, as I have hundreds of these that I have acquired over the years from installing servers in 19″ racks.

The likelihood of these bending is pretty slim – I was struggling to bend the 150mm wide sheet, so bending 46mm pieces will be even harder, and it is not like they are going to have huge forces attempting to bend them out of shape when in use.

I printed a GT2 48 tooth pulley for use with the Z axis to “gear it up”, and this printed well enough to use, this took 3871.7mm of filament (9.6cm3) for a cost of £0.133. I could if necessary purchase this item from SDP for $3.46 (about £2.20), but I will see well how the printed one works first.

Here it is with an M3 nut and grub screw installed sat next to the 2 pulleys I made for the rotational axis.

I also had several attempts at printing GT2 20 tooth pulleys.

Unfortunately my printer nozzle, at 0.4mm, is just too thick to print these 1mm teeth with any degree of accuracy and there will not be enough teeth engaged to prevent slippage – even with nearly all the teeth engaged, on the pulley with the most well defined teeth, I can easily rotate the pulley inside the belt loop.

As such I will buy some metal ones from Robotdigg for $1.85 (about £1.18) each – even people who heavily advocate printing ones own pulleys use shop bought metal GT2 pulleys for 20 teeth and under, so no shame here.

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