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# Shredder converted to Imperial system (Inches)

This topic contains 87 replies, has 24 voices, and was last updated by  henry 2 years ago.

11

Hello everyone π

After several days learning CAD and some 3D modeling tools, I have finally finished my conversion of the Precious Plastic Shredder to imperial units.

This is a request that tons of people have been making for months and there are a few machine builders who have managed to convert the drawings to inches, but for some reason no one else has shared the converted files with the community (something I consider very selfish).

These files have been checked from every single angle to make sure they will fit correctly. While these have not been used to build a real shredder yet for their final test, I will send them myself to a laser cutting company soon and will post the results here as soon as possible.

Without further ado, here are the technical details:

Steel equivalents
3mm = 1/8″ = 3.175mm
5mm = 3/16″ = 4.7625mm
6mm = 1/4″ = 6.35mm

Original metric design (inside lenght)

14 x 5mm rotating knives = 70mm (BOM shows 15 knives but only 14 are used in the shredder)
13 x 6mm spacers = 78mm
70mm + 78mm = 148mm total hex length (plus 85mm on each side of the hex bar)

New imperial design (inside lenght)

14 x 3/16″ rotating knives = 66.675mm
13 x 1/4″ spacers = 82.55mm
66.675mm + 82.55mm = 149.225mm total hex width (plus 85mm on each side of the hex bar)

Parts that had to be resized:

*Hex bar
*The original Hex bar had a total length of 318mm, with a central hex length of 148mm and 20mm diameter round ends with a length of 85mm each end.
*The imperial Hex bar has a total length of 319.225mm, with a central hex length of 149.225 and 20mm or 3/4″ diameter ends (you chose) with a length of 85mm each end. You can round this number to 320mm, or just do what I did and buy 1ft of hex bar, since you only need one end of the bar to hook up the motor, there’s no need to have 85mm of round bar on each side. Buying 1 ft of bar is normally cheaper than getting a custom cut. With a 1ft bar (304.8mm), you will end up with 85mm on one end of the bar, 149.225 in the center and the remaining end of the bar will be 70,575mm.
*Side panels (front, back)
*The front and back panels remains the same except for the slots where the middle panels are connected.
*The 1/4″ “side” (front, back) panels have 2 slots on each side, and those slots were originally 3.2mm wide to allow the 3mm middle panels to fit in and have some clearance. In inches, those middle panels are 1/8″ thick (3.175mm) and I made the slots 3.3mm (0.130″) wide to allow for 0.125mm clearance
*Middle panels
*The middle panel needed to be extended to fit the increase of length. The original panel was 149mm wide, the new panel is 150,8125mm wide (5.9375″).
*Also, the holes at both sides of the panel had to be enlarged, from 3mm to 1/8″
*The side inserts that connect the middle panels with the side (front/back) panels had to be enlarged a little bit, from 6mm to 3/16″
*Finally, all the slots (3 from the top and 5 on the bottom) where resized, repositioned and aligned to adjust to the new panel dimensions
*Side 1
*Adapted top and lateral inserts for 1/8″ thickness
*Side 2
*Adapted top and lateral inserts for 1/8″ thickness
*Bottom 1
*Resized from 149mm to 150,8125mm wide (5.9375″)
*All slots resized and repositioned proportionally to the new part length
*Bottom 2
*Resized from 149mm to 150,8125mm wide (5.9375″)
*All slots resized and repositioned proportionally to the new part length
*Top 1
*Length increased to 5.9375″ and all slot dimensions resized to fit into the middle panel slots
*Top 2
*Length increased to 5.9375″ and all slot dimensions resized to fit into the middle panel slots

*****************************************************

*IMPORTANT: For the imperial version of the shredder I decided to use the 1″ hex bar files modified by @keesdeligt, since it’s much easier/cheaper to get 1″ hex bar than 27mm. Also, make sure to read the changelog at the bottom of this post, it shows important information about the hex bar and bearing spacers.
*Original BOM shows that for the part “Fixed Knife Small” 15 pieces are needed, but actually only 14 pieces are needed
*Original BOM shows that for the part “Knife3″ 5 pieces are needed, but actually only 4 pieces are needed. The total amount of knives used in the shredder is 14 not 15.
*This redesign of the shredder was made for black steel which is available in 1/8″, 3/16″ and 1/4”. It is my understanding that Inox Steel is available in different gauges. If you are interested on an imperial design of the shredder using inox steel gauges, just contact me and I might design a new set of files for inox steel gauges. I have zero knowledge on whats available for inox steel so you will have to tell me.
*This shredder design is based on the 2.0 version of the shredder, however, all the changes from 2.1/3.0 are fully compatible (new hopper and new sieve design)

Soon I will be sharing as well a new set of files in Imperial units for a Shredder twice as big, something like THIS

Changelog:

4/Feb/2018
*Fixed minor sizing issues with frame parts
*Appart from the .iam assembly file, I also included the assembly in .stp and .igs format
*Added pdf files with hex bar measurements, one for a 1″ hex bar with 3/4″ bores for 3/4″ bearings, and another for a 1″ hex bar with 20mm bores (original).
*While it is true that this design is made for Imperial units, there might be some people who already purchased UCFL204 bearings with 20mm bores, and that’s the reason why both hex bar designs were included.
*Added 2 additional files for the 1/8″ and 1/4″ bearing spacers for 3/4″ bearings in the DXF folder.
*If you are planning to use 3/4″ UCFL204 bearings then you will need to lasercut the files “1-8inch 2x BearingSpacer for 3-4inch Bearing.dxf” and “1-4inch 2x Bearing Spacer for 3-4inch Bearing.dxf”, and delete the files “1-8inch 2x BearingSpacer for 20mm Bearing.dxf” and “1-4inch 2x Bearing Spacer for 20mm Bearing.dxf”
*If you are planning to use 20mm UCFL204 bearings then you will need to lasercut the files “1-8inch 2x BearingSpacer for 20mm Bearing.dxf” and “1-4inch 2x Bearing Spacer for 20mm Bearing.dxf”, and delete the files “1-8inch 2x BearingSpacer for 3-4inch Bearing.dxf” and “1-4inch 2x Bearing Spacer for 3-4inch Bearing.dxf”
*Added 2 additional files for the 1/4″ bearing spacers for 3/4″ bores in the DXF folder.
*In case anyone is interested, found this deal on UFCL204 3/4″ bearings https://goo.gl/7Bg2WP

7/Feb/2018
*Fixed 0.007″ offset on “Bottom2” and “Top2” parts, updated download package with new dfx, ipt, igs and stp files

9/Feb/2018
*I was told by my waterjet cutting company that they had problems opening the DXF files because they were in 2018 format and they only supported AutoCad 2013, so I added an separate folder into the download package with AutoCad 2013 format files and kept the 2018 files as well because why not…

23/Feb/2018
*Finally received the water cut pieces and after a visual inspection and a few measurements with my caliper they look perfect. I’ll upload some photos soon and will report back once I have assembled the shredder

02/Mar/2018
*I finished sanding and grinding all the parts and also milled my jimmy-hex-bar (more info HERE). So far everything looks perfect and all the pieces fit as expected, you can see some pictures at the botom of this thread HERE. I’ll upload more content in the next 1 or 2 days once I finish the shredder and it’s fully assembled.

16/Mar/2018
*Habemus shredder π I just finished assembling the shredder and it runs smoothly, so we can call this design a success! Some pictures down below.

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### In reply to: Shredder converted to Imperial system (Inches)

hero
04/02/2018 at 04:56
8

Adding some people who might be interested:

### In reply to: Shredder converted to Imperial system (Inches)

dedicated
04/02/2018 at 17:30
2

If you’re using imperial (which by the way should be erased from the face of the earth :P) then keep it consistent and use the hex shaft and any other dimensions in imperial, not mm. i.e, the bearings could be imperial too (3/4″?) instead of 20 mm.

If you can export the 3d files to .stp or .iges, they are more standard file types so that other people can open the design
There are some interferences between the sideplates, something not aligned correctly, there’s a difference of 0.1 mm between the tabs (see picture)

did a 2D drawing of the shaft as it is but may need some revision. As standard I’d machine it with a keyseat for a key, a plain coupling will slip.
https://www.dropbox.com/s/3b0dx85inj7w6vh/shaft%20v1.pdf?dl=0

good work !! thanks for sharing olivier

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/02/2018 at 10:32
3

Thanks a lot for checking the files @javierrivera, I really appreciate it.
After spending a while trying to find out what was wrong, I discovered that 2 pieces where off by 0.007″ and that was causing that the parts could not fit correctly. Also, some constraints were set incorrectly.
I just fixed the problems and uploaded the files again π

Your suggestion of using 3/4″ instead of 20mm for the shaft bore makes sense, I included an additional hex shaft design and 1/8″ spacer for both 3/4″ and 20mm bores. I just want to make sure that if someone already purchased ucfl204 bearings with a 20mm bore or if someone already got their hex bar machined, they will still be able to use these files without having to get another set of bearings or another hex bar.

I’m not familiar with cad formats and don’t know which ones are more common than others, but following your suggestion I included .stp and .igs CAD assembly files as well.

Regards

### In reply to: Shredder converted to Imperial system (Inches)

helper
05/02/2018 at 22:49
2

@xxxolivierxxx This is great! Awesome work on doing this. It really needed to be done. The lack of metric steel in North America really adds a large cost to those trying to start out, so this should really, really help!

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/02/2018 at 23:04
1

I already sent those files to my local WaterJet company, as soon as I get the parts back I’ll report a status so that other people in the community can be more confident about using them π

### In reply to: Shredder converted to Imperial system (Inches)

helper
09/02/2018 at 17:28
3

Awesome! Keep us posted on how those turn out. Continuous improvement makes the PP program more and more accessible, which is awesome.

### In reply to: Shredder converted to Imperial system (Inches)

starter
10/02/2018 at 00:05
3

What motor did you use to attach to this imperial shredder? Would That cause issues with the hex rod not fitting?

### In reply to: Shredder converted to Imperial system (Inches)

hero
13/02/2018 at 01:09
3

@lukeryberg25 All that info is on the main post. The hex bar has to be 1″ (original design used 27mm) and then it is up to you if you want to mill the ends of the bar to a 20mm diameter or 3/4″. I included bearing spacer files for both sizes so you can use the ones you prefer. For the motor, you just need to find one with a minimum of 300n.m (around 1.5kw)

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/03/2018 at 06:55
5

Some pics

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/03/2018 at 07:43
6

More

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/03/2018 at 07:46
4

More

### In reply to: Shredder converted to Imperial system (Inches)

hero
05/03/2018 at 07:55
4

More

### In reply to: Shredder converted to Imperial system (Inches)

hero
17/03/2018 at 06:11
2

Final result

### In reply to: Shredder converted to Imperial system (Inches)

hero
17/03/2018 at 06:34
3

π

### In reply to: Shredder converted to Imperial system (Inches)

new
30/03/2018 at 20:13
3

Would someone please send me or direct me to any prints to make the shredder in standard English units? I found the CAD, thank you!

I’m working with a possible machine builder in the midwest, I’ll post something once we identify lowest cost options.

### In reply to: Shredder converted to Imperial system (Inches)

starter
07/04/2018 at 21:32
1

Hey there! What size flat stock are those sheets the parts were cut out of?

@xxxolivierxxx

Thanks!

### In reply to: Shredder converted to Imperial system (Inches)

hero
10/04/2018 at 17:11
1

@dixon Sorry for the late answer, the steel sheets were 1/8″, 3/16″ and 1/4″
All that info is on the topic.

### In reply to: Shredder converted to Imperial system (Inches)

starter
10/04/2018 at 18:52
2

Sorry, I am referring to the length and width. I have a machine to use, but it’s owner is… prickly and won’t do the nesting prior to purchasing to tell me what size of material to order, and I have been struggling with nesting the parts to figure out what size I will need.

@xxxolivierxxx

### In reply to: Shredder converted to Imperial system (Inches)

hero
10/04/2018 at 19:02
6

@dixon Ah, I see.
If it helps, this is the amount of material I was asked to provide by my local water jet company:

1/8″ = 250 x 700mm sheet
3/16″ = 500 x 700mm sheet
1/4″ = 480 x 500mm sheet

In the pictures below you can make yourself a better idea of how to arrange the parts:

### In reply to: Shredder converted to Imperial system (Inches)

starter
11/04/2018 at 00:03
2

That gives me a better idea, thank you very much!

### In reply to: Shredder converted to Imperial system (Inches)

starter
17/04/2018 at 01:49
2

@xxxolivierxxx
Thanks so much for these. I have my material on order and will probably start to cut out the parts this week. I was able to source a motor and gear box (all the calculators say it’s under sized) but I’m hoping that I can make it work by pre-cutting out sections I know will be difficult.

Once I get some parts being made I will be sure to upload some pictures.

Thanks for converting them!

### In reply to: Shredder converted to Imperial system (Inches)

hero
17/04/2018 at 01:51
1

@yukonelius My pleasure, glad to hear that you found the files useful. Please create a new topic and share the progress of your shredder construction process π
Which motor and gearbox ratio did you find?

### In reply to: Shredder converted to Imperial system (Inches)

starter
17/04/2018 at 02:46
1

I found a 1750rpm 1/4HP dc motor with a 50:1 ratio gear box.

Should give me about 50Nm and from all the threads on this subject it seems too small. Time will tell.

I will start a new thread once I get some parts cut out.

I figured I would do my best during assembly to get everything really cleaned up and I am actually going to sharpen the blades and cutting surfaces to give it a better chance.

I will have all this in my thread when I start one.

### In reply to: Shredder converted to Imperial system (Inches)

hero
17/04/2018 at 06:09
2

@yukonelius I’m sorry to dissapoint you my friend, but you are wasting your time. Your motoreducer will give you 48.11 minus efficiency loss, and that will has troubles even shredding veggies. If you don’t believe me, then watch for yourself, this is a 63N.m motor:

### In reply to: Shredder converted to Imperial system (Inches)

new
28/04/2018 at 18:27
3

Hey there. I got the info from this post to share with the printer I found.
This is what they gave me for the quote:

1Side Plate β 8.27β x 5.31β β Plus .25β 304 Stainless Steel β Laser Cut: \$33.25 ea β X 1

2Bearing Spacer β 1.35β OD .8β ID β Plus .25β 304 Stainless Steel β Laser Cut: \$5.50 ea β X 1

3Knife Spacer β 1.97βOD β Plus .25β 304 Stainless Steel β Laser Cut: \$7.50 ea β X 1

4FixedKnife Small β 5.2β x .96β β Plus .25β 304 Stainless Steel β Laser Cut: \$9.25 ea β X 1

5Knife 1 β 3.89β x 3.89β β Plus .1875β 304 Stainless Steel β Laser Cut: \$10.50 ea β X 1

6Knife 2 β 2.76β x 4.36β β Plus .1875β 304 Stainless Steel β Laser Cut: \$11.25 ea β X 1

7Knife 3 β 2.89β x 4.72β β Plus .1875β 304 Stainless Steel β Laser Cut: \$11.25 ea β X 1

8FixedKnife Big β 2.14β x 5.2β β Plus .1875β 304 Stainless Steel β Laser Cut: \$6.75 ea β X 1

9Bearing Spacer β 1.59β OD .88βID β Plus 11 ga 304 Stainless Steel β Laser Cut: \$2.75 ea β X 1

10Sieve Bracket β 4.77β x 2.00β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$6.00 ea β X 1

11Side β 5.32β x 1.18β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$6.50 ea β X 1

12Bottom β 1.30β x 5.87β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$9.75 ea β X 1

13Top β 1.18β x 5.87β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$6.50 ea β X 1

14Middle β 6.34β x 5.31β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$13.25 ea β X 1

15Side β 5.32β x 1.61β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$8.00 ea β X 1

16Bottom2 β 1.61β x 5.87β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$8.25 ea β X 1

17Top2 β 1.61β x 5.87β β Plus 11 ga 304 Stainless Steel β Laser Cut: \$8.00 ea β X 1

Will these work in order to fit well with other pieces and designs? This is my first job with a laser cutter, and first step into Precious Plastic work.
I’d love some reassurance that they will work out okay.

Thanks!

### In reply to: Shredder converted to Imperial system (Inches)

hero
01/05/2018 at 20:21
1

Hello @kidtasticplastic

Everything looks good, the 11 gauge steel is not exactly 1/8″ but with some tweaking and adjusting you can make it work

### In reply to: Shredder converted to Imperial system (Inches)

new
01/05/2018 at 20:33
2

Thanks @xxxolivierxxx

I’m SO excited to begin my project!

### In reply to: Shredder converted to Imperial system (Inches)

hero
01/05/2018 at 23:54
2

You’re welcomeΒ @kidtasticplastic

Fyi, Justin Carven is selling assembled shredder kits in USA in case you are interested, you can find him hereΒ https://www.facebook.com/groups/293443417731185/?ref=group_header

### In reply to: Shredder converted to Imperial system (Inches)

starter
04/05/2018 at 03:00
2

Hey @xxxolivierxxx, I’m not sure if this is easy to check, but do you know if these files are any different from the ones posted in this thread: http://onearmy.world/community/forums/topic/plans-in-standard-units-not-metric/ ? I’ve had people asking me for the imperial unit design and sharing those files but now I feel like I need to send them two links. Did you make any changes besides to the parts determining the overall width of the shredder, and the interlocking corners in the frame?

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