Cherry Pi II Released

Quick (from memory) BOM :-

Plastic parts as on Thingiverse
RAMPS
Mega 2560
RRD Smart Controller
4 x steppers driver (I use 4988)
12v 5A PSU
4 x NEMA 17 stepper motor
5M GT2 belt
3 x GT2 pulley
12 x 10mm spherical neodymium magnets
6 x 5mm ID aluminium tube @ 225mm
12 x M5 10mm SHCS with heads milled to cups with 10mm ball end mill
9 x 2020 extrusion @ 250mm
3 x 2020 extrusion @ 600mm
9 x Openbuilds mini V wheel kits
250mm diameter mirror
6 x 16mm x 5mm x 4mm flanged bearing (top belt idler)
4 x 13mm x 6mm mini microswitches
56 x M5 8mm SHCS
59 x M5 half nut
59 printed T nuts
3 x M5 50mm SHCS
12 x M3 10mm SHCS
J Head hotend
Extruder (I use Greg's Wade as per Richrap's 3DR)

Probably a handful of other assorted nuts and bolts. Molex connectors. Wire. Mains lead.

Andy

Oh really cool thanks a lot Andy! I'll begin to order the stuff.

If I understand right, the magnet are not used if I use the wheels? Is there a place I can see the build instructions?

edit: Forget that, I found that the magnet are for the arm.

Edited 3 time(s). Last edit at 05/20/2014 08:16PM by nka.

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- Sebastien Plante (nka)

Hello Andy,

I found almost everything (and ordered almost everything).

Is this what you are using for the Extruder? [www.thingiverse.com]

OpenBuilds Wheels are out of stock. Dont know where to find them for now! Maybe I'll go bearings routes if I dont find wheels.

What are the specs for the Microswitch (except for the size) ? It's for 12V? High Current? Most I found are 20cm long, but 6mm large. I might have to modify your design before having it print!

I think there's 3 x 25mm fan missing from the BOM. I added those.

And FSR ? Do I only need 3 FSR or I also need a voltage divider? [www.phidgets.com] (edit: Seems I only need the sensor, Aduino will do the rest...).

Edited 6 time(s). Last edit at 05/21/2014 05:06PM by nka.

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- Sebastien Plante (nka)

Hi Sebastien

The extruder I use is by Richrap for his 3DR [richrap.blogspot.co.uk]

I moved away from FSR as I had sensitivity issues. I designed a new effector with a microswitch that uses the hotend as the z probe. I find it much easier to use.

Thanks, I find out that the printed part were included into the "print list" of your Thingiverse !

The effector with microswitch is the one with 3 fans on Thingiverse? edit: Looking at the STL, seems not. Could you upload it?

I only need the 3 Mini Microswitch (or 4 with the effector?), j-head hotend and tube, the flanged bearing and the wheels if there's notthing else missing on the BOM (hope so, cause most stuff will take about 1-1½ month for delivery.)

I also need to figure out how many part of each I need to print. Cause I need to send this to someone to print them for me (as it's my first printer... ).

Why 6 bearing? We only have 3 top pulley?

edit: I found the wheel! Now, I'm wondering, you say "mini v-wheel" ( [snbinc.ca] ) but the image show the v-wheel delrin ( [snbinc.ca] ) and I'm wondering if it would not be better to get the v-wheel solid ( [snbinc.ca] ) ?

Found Mini Microswitch : Omrun D2F-01L, 13mm x 6mm x 4mm

Thanks for all of your help !

Edited 5 time(s). Last edit at 05/21/2014 09:52PM by nka.

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- Sebastien Plante (nka)

Hi Sebastien

I used these microswitches [www.ebay.co.uk].

I've attached the new z probe effector files, one for J Head one for E3D. I've also attached the new files for mini v wheels. You are correct. The files on Thingiverse are for normal sized V wheels. Mini are better.

I used these printed T nuts [www.thingiverse.com] they are great, and cheap

I use my own design filament spool holder [www.thingiverse.com]

You need 6 bearing for the top idler because each one is two flanged bearings sandwiched together.

As far as plastic parts go you need :-

3 x bottom stepper mounts
3 x top idler mount bracket
3 x top bracket cover
3 x carriage (whichever you decide to use)
3 x rod carrier (to suit carriage)
1 x effector (you choose)
1 x hotend holder for effector (to suit effector)
1 x RAMPS bracket
1 x LCD bracket
1 x extruder body
1 x extruder guider
1 x herringbone gear large
1 x herringbone gear small

Good luck with your build.

Andy

Edited 1 time(s). Last edit at 05/22/2014 02:45AM by AndyCart.

Very cool thanks!

In the new Effector, you removed the fans? It's okay without it?

Do you like the J-Head or E2D more?

I only need to find the hardware part needed for the Greg Extruder. Seems to have some different version. I think I'll trust this BOM ( [store-9oviwe.mybigcommerce.com] ), everything seems easy to get... just not sure about the Hobbed Bolt.

And I also need some Flexible Tube!

I found the HotEnds at some places, just need to decide the one I'll order (original, clone?).

Also, my printer is asking, what about the infill, layer top/bottom/perimetre ?

Thanks!

Edited 1 time(s). Last edit at 05/22/2014 11:53AM by nka.

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- Sebastien Plante (nka)

Hi Sebastien

Fans are necessary for small areas with PLA. But they don't need to be on the effector. I place an 80mm fan on the edge of the print bed. Or use the effector with fans. Up to you. I like j heads. Whichever you choose make sure you get the Bowden version. The extruder needs three 608 skate bearings, a hobbed bolt (make your own it's fairly easy), two 50mm M3 screws, three M3 nuts, three m3 10mm screws, one m3 8mm screw, one M8 nut and some M8 washers. You will also need either a short length of rubber hose or a couple of springs and a 20mm length of 8mm diameter steel rod. You will also need the 1/4 NPT pneumatic fittings to hold the 4mm PTFE tubing.

I print all the parts at 0.3 layer height and 33% infill. 2 perimeters and 0.9mm top and bottom layers with a 0.4mm nozzle.

Andy

Edited 3 time(s). Last edit at 05/23/2014 01:53AM by AndyCart.

Hello Andy,

I've been looking at the design for the Effector. I understand that the switch is always Closed. When the Nozzle hit the glass, it "push" the top of the effector, making the switch "Open". Right? Do I need the spring of the weight of the nozzle was okay for this?

I'll updated my BOM. I'll need to find spings, dont know where to get those ! (edit: Fastenal seems to have those... nice!)

Thanks for the printing specs. I can't wait to begin printing... that's where it suck to order from China...

Edited 1 time(s). Last edit at 05/25/2014 09:39PM by nka.

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- Sebastien Plante (nka)

Hi Sebastien

It doesn't matter which way your probe switch operates. You can change it in firmware anyway. I have mine set normally open i.e the spring holds it closed. When the probe hits the bed the switch opens. It keeps it the same as the tower limit switches (which are wired normally closed) i.e they are all closed until something hits them.

As far as springs go, you could just use a couple of rubber bands. I bought a box of assorted springs from Ebay (250 mixed for £5.00) this also gave me springs for the extruder and loads of spares!!! As long as the switch reliably close with pressure off the nozzle you're good to go.

Make sure you post some pictures of your build. Good luck and happy building.

Andy

Edited 1 time(s). Last edit at 05/26/2014 03:35AM by AndyCart.

Oh, didnt know I could buy assorted spring on a box! Very nice! I ordred some too... will look better !

I have pretty much everything ordered! Still need the hotend (Seems to only find Copy from China... and from US, cost a lot of shipping) and all the M3/M5 screws (Cost more than I was expecting, I'll try to buy them from where I work).

Edited 1 time(s). Last edit at 05/26/2014 09:22AM by nka.

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- Sebastien Plante (nka)

Andy,

Have you noticed any unwanted nozzle movement problems with this design? My version of HoloPed's Thing:189393 (recently removed by creator in MakerBot patent protest) kept lifting away on the hinge axis from the print surface on early layers or with the slightest over-extrusion even with a few wraps of a heavy rubber band for the spring. I eventually used a cable tie to hold the hinge closed, and planned to re-design the part to add a cam knob over the switch end to lock the hinge after calibration. Just curious if yours has the same problem.....

I didnt try it and didnt see the HoloPed version. But Andy's version is using a hinge and everything is hold "tight". Nozzle should not be able to move except up and down a little oblique. Raising like / .

What could help if it's still moving, it's using bearing to "tight" everything.

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- Sebastien Plante (nka)

HoloPed's original version (someone else's build pictured below) had the switch above the hinged plate:



Andy's re-design is a vast improvement over the original. Removing the hotend for maintenance requires dismounting the switch in the original design, whereas Andy's rework has it in the base and out of the way. (When you do not have the proper small screws for the switch and decide to attach it with glue instead, this becomes a problem!)

The hinge pins were not the cause of the play. It was all in the spring or rubber band, that couldn't seem to hold it closed when printing the first few layers and/or over-extruding. The nozzle would tilt up as it dragged the surface, and I couldn't find the correct balance between too much spring and having the switch work.

Anyway, since my PLA HoloPed version melted down last week, I'm going to try Andy's revised version in ABS and see how it works with my E3Dv5.....

Edited 1 time(s). Last edit at 05/26/2014 08:09PM by vreihen.

Hi Guys

I've never noticed an issue with hotend movement with either the slightly modified Holoped version I used on Cherry Pi or my new version for Cherry Pi II. I would always suggest the effector is printed from ABS. I've had too many go 'floppy' when using PLA. With the extra small micro switches I've been using I've found that the tiniest spec of CA, applied with the end of a tooth pick, holds them firmly in place during normal use but a slight twist with a screw driver pops them out if required. Those teeny tiny screws are way too fiddly for my old fingers!!!

I've used this Chinese J Head
[www.aliexpress.com]
It works o.k with a bit of work. I normally bevel the PTFE liner tube where the filament enters the J Head body, just after the pneumatic connector. I also make sure the pneumatic connector is pressing tightly on the PTFE liner. Lastly, a bit of PTFE tape wrapped around the threads on the aluminium block stops any potential leakage. I've used two now and they have printed very well.

Andy

Edited 1 time(s). Last edit at 05/27/2014 02:06AM by AndyCart.

I got all the stuff ordered. Only need to find someone to print the parts. I already received some of the parts (extrusions, arm tube, wheels, psu, bearings, microswitch, etc...)

Andy, I tried to "import" your file into SketchUp. I dont know if it's import, but most file dosent seems right with lot of artefact. What are you using to edit/create them?

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- Sebastien Plante (nka)

Hi Sebastien

I use Sketchup for all my design work then export as .stl and clean up with Nettfab Basic. Look for a plugin for Sketchup called Cleanup. It works great on imported .stl files.

Andy