DIY Peristaltic Pump: Cultural Teachings of Glorious Nation of Kazakistan

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OK central holes done.. it's getting late here in the UK - I may stop for now here and continue tomorrow..

20210901_224342.jpg
 

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Very cool.
What a great job....

You should offer DIY kits!
Or
Drawings, wiring and building instructions and the program... then we would all love you!!!!
LOL

keep the update coming.
 
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Very cool.
What a great job....

You should offer DIY kits!
Or
Drawings, wiring and building instructions and the program... then we would all love you!!!!
LOL

keep the update coming.
The most interesting parts are still ahead! Keep reading, there will be updates every day (and at some times during the day - every 15 min). It will be a relatively rapid project - although with the amount of pictures and text/explanations I will be adding, it's going to take a good couple of weeks!
 
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OK central holes done.. it's getting late here in the UK - I may stop for now here and continue tomorrow..

20210901_224342.jpg
Here's the first point where certain accuracy is required: the central holes need to be completely vertical or else the disk will wobble. Vertical drilling can be made with a drill press stand (if you have one) or one of these V-guides that I use:

20210902_072507.jpg
 
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Now the next step is tricky:

you need to drill 2 vertical holes in a thick piece of wood: these are 5mm (central shaft) and 4mm (rollers) the centres are 18mm apart


Once the holes are drilled:
- insert the 5mm drill bit so that it sticks out -
- insert the 4mm drill bit so that it sticks out by a tiny bit (1mm)

20210902_074334.jpg

Now you can skewer one (only one!) of your disks and by rotating it around 5mm drill bit - scratch a circle, this is where the 6x m4 holes will be drilled

20210902_074552.jpg

20210902_074608.jpg
 

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Using compass - find 6 points on the circle that are same distance from each other (by going in circle and checking at every try if you come back to the point where you started)
20210902_080154.jpg

Using 4mm drill bit - drill tiny craters where you marked your 6 points

20210902_080556.jpg

Now you can skewer your disk on the 5mm protruding drill bit and start drilling holes - the tiny craters will help you position the 4mm drill bit where you want it. Each time you finished drilling a hole - take out the 4mm drill bit from the wooden guide and remove all acrylic debries.

20210902_081333.jpg

Once one disk has been drilled - skewer both disks on the 5mm drill bit again. Drill your first common hole:

20210902_081441.jpg

Insert an M4 screw into the drilled hole and drill another hole on the opposite side

20210902_081739.jpg

Continue drilling holes in the second disk - each time inserting M4 bots into holes that were already drilled:

20210902_081951.jpg
 
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Once all holes were drilled - DO NOT remove M4 screws - you want to create a mark (shown below as a diagonal scratch on both disks), such that you will later know how the 2 disks are to be aligned:

20210902_082508.jpg

Take out the screws and using a pointed drill bit lightly drill a crater for countersunk screws (only on one disk!):

20210902_082928.jpg




20210902_085929.jpg
You can now try ball bearings on your rotary bit:

20210902_083351.jpg
 
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The most complex part of the rotary bit is finished - but that's not to say that the rotary bit itself is done yet!

We now need to make a 15mm thick inner core with a m3.5 nut inside that will be used to keep the rotary bit firmly on motor shaft

The inner core can have a maximum 22mm diameter (otherwise it will start to touch ball bearings).

20210902_091038.jpg
 
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To build the inner core, I cut a strip of acrylic 22mm wide (it will be sanded down to smaller diameter later), draw 3 square pieces with a centre and drill a 5mm hole in each centre. The hole needs to be as vertical/accurate as possible.
20210902_095511.jpg
20210902_095953.jpg

Only after the holes have been drilled - I cut this into 3 square pieces

20210902_100247.jpg
 
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I use a long M3.5 screw to heat it over fire and create a an initial screw channel.

20210902_100743.jpg
20210902_100750.jpg

I then join the 2 pieces together and drill channel using 3.5mm drill bit.

20210902_101036.jpg

The finished hole is nice and centred between 2 pieces.

20210902_101109.jpg
 
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I then again heat up the M3.5 screw (now with the nut attached) and burn the nut placeholder. The nut needs to sit closer to the central hole (than edge) - when the screw is tightened, the nut will push out against the outer layer of acrylic.

20210902_101611.jpg

All 3 pieces are then skewered into the vertical drill piece (and a new M3.5 nut is inserted), Tensol 12 is applied between layers and it goes into oven for 15 min fast curing.. I use the wooden platform in order to ensure that the resulting central hole is absolutely vertical.

20210902_102853.jpg

20210902_104554.jpg
 
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The square piece can now be made round using a simple file (or any other advanced world tools you may want to use - if you have electricity!)
 
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I used electric bench grinder to round the central core piece.. the shape considerations are cosmetic - if you can fit a square piece, that would do as well!

Checking that central core does not touch ball bearings.

20210902_122851.jpg

These are the 2 important things to check:
- ensure the hole for M3.5 screw is in between ball bearings (or else you won't be able to assemble it!).
- the nut should be between bottom 2 layers (the central core has 3 layers in total)

Then apply Tensol12 and back to oven for fast curing..

20210902_123451.jpg

20210902_124423.jpg
 
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You will need 12 thin small washers - to ensure ball bearings outer ring does not touch the acrylic disk (they shouldn't - if acrylic is completely flat, but it's not always so flat). I could not find them anywhere - they are too small for a real washer, so I simply made them from 1mm copper wire:

20210902_133313.jpg
 
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It appears I ran out of M4 nuts - I will buy them today and post a picture of the fully assembled rotary piece later.
 
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as can be seen here ball bearings are protruding by approx. 2mm, therefore small imperfections in acrylic disk really play no role (other than aesthetics)

20210902_162332.jpg

The skew that will keep the roller firmly on motor shaft can be seen here...
20210902_162254.jpg

I need to shorten 6x M4 screws by a few mm.. I will do that later.
 
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Some general comment on roller/pivot assembly. The roller is the most important part - it needs to have ball bearings attached at the same central distance from motor shaft.

A single ball bearing that's not central will result in pivot assembly wobbling and producing extra noise (it will still work - but with increased noise). Therefore when making the roller the 2 most important things are:
- that the central hole is perpendicular to the disk surface
- that all ball bearings are at the same distance from the centre
 
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Now I am going to some work on pivot assembly:

I start with this terribly shaped thing I glued last night:

20210902_181525.jpg

I use a 52mm sanding belt

20210902_181533.jpg


One minute later I get this:

20210902_181939.jpg

I then start working on the overall aesthetic shapre of the pivot, most things are done by cutting bits off using
handsaw and filing imperfections down using a file
 
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