Sunday, 20 September 2015

Off topic

V2 still In progress, but not fast enough.

There are a few funny reasons:
• I have 2 apps on Google play and AppStore - totally 4 apps.
• Apple new iOS 9.0 broke all 2 my application - 2-3 hours per day sleeping during last 7 days.
• One of my Android app suddenly reached tops in one big region - I did 6 updates during last 2 weeks.
• Because of previous - database for game push, options and etc grows on 10% in 2 days (10-15K installs per day) - some time required to fix it.

In a few days I hope come back to V2 development.

P.S. My idea with inverted belts seems to be successful - I installed 1 belt and after 3 days belt tension the same.

Friday, 14 August 2015

Scara 3d printer cost calculations for V1

Approximate cost calculation for V1:
  • 51$ — 5 Nema17 (you need only 4, so you get 1 for spare parts)
  • 32$ — Ramps 1.4+5 Dvr8825+LCD (you need 4 drv8825, so you get 1 for spare parts)
  • 7$ — E3DV5 (china made) with 1m PTFE tube (0.5m for spare parts)
  • 2$ — extruder gear
  • 6$ — gt2 pulleys and gt2 belt
  • 5$ — 6mm smooth rods (2x20cm)
  • 4$ - 4 LM6UU linear bearings
  • ~10$ — ball bearings+bolts+screws+other stuff
  • 10$ - external power supply 8.5A 12V

Total: 127$ (with power supply, but without ABS filament — approx 200g)
NOTE: All prices from my aliexpress orders, free shipping to my country, no taxes (in my country taxes begins only from 200+$).

NOTE2: V2 seems to be in the same price level, but not cheaper.

Ways to save costs:
  • ~8-10$ - get rid of of LCD module 
  • ~5-7$ - Replace one Nema17(for gearbox) to small 2.5$(28BYJ-48 12V) stepper + printed high ratio spur gears.
Not a lot.

More global idea:
Replace 2x10$  Nema17 steppers to cheap DC MOTOR + Hall Sensor + L293N + gearbox. The main problem is a backlash free gearbox. I think gearbox should have approx 1:100 gear ratio.

Backlash free gearbox ideas.
  1. Looks like it is possible to combine 2 stage of 1:10 belt driven gears. Belt driven gear theoretically backlash free. 1:10 belt driven gear is a 16 teeth gt2 pulley and 160 teeth pulley (~101mm diameter), or use more stages with less teeth pulleys (seems like better due to the less belts length).
  2. Planetary gears - at least 2 stages required - i tried to print - seems like printed does not work well.
  3. Hypocycloid Gear - looks better but seems like it does not work due to printing precision, plus vibration may affect print results.
  4. Harmonic drive - not tested
  5. Classic gears - seems like not backlash free, there are a few ways to decrease backlash, but i not sure.
NOTE: It is just an idea

Wednesday, 5 August 2015

Printrun is forked

My first ideas:
  • Add mark to show center of ccordinated - DONE
  • Fix or rewrite ugly 3d viewport rotation (is Repetier like viewport rotation) - DONE

Sunday, 26 July 2015

Seems like current version of Scara 3d printer is done.

12 hours of continuous printing time.
Summary is 3d approximately.
Quality is enough for current version.
In a few days I will finalize scad and file and ... v2 development.

Ideas for v2:
• x8 or x9 gear ratio (current is 5, with x8 precision will increased in 1.6)
• Belt path will be shortened twice (no belt couplers at all)
• No teeth on big pulleys at all (more precision, easy to print).
• Smaller dimensions (but with the same print area).
• A lot of improvements - more modular and service friendly
• Z axis will be improved (at least 2 bearing for each rod and may be threaded rod, more modular way to attach - currently is hard to upgrade without disassembly)

Sunday, 19 July 2015

Scara arms redesigned to match e3d v5

Note: This is not original e3d v5 (I did it on lathe), but sizes matched to e3d blueprint.

Saturday, 18 July 2015

Scara hot end

Current PTFE based hot end is bad.
I have super idea how to use cheap and common E3D V5 (long).
Idea in short: One end effector arm is extended a little bit and hot end will be attached to this place (actually any extruder), firmware math required a few extra calculations.
Wait for images in near future.

E3D V5 like hot end on aliexpress

Tuesday, 14 July 2015

Sunday, 12 July 2015

Scara updated extruder

After a few first tests extruder completely redesigned. (Old Spring loaded extruder is not good)

Monday, 6 July 2015

Programming RAMPS 1.4/Arduino via Bluetooth

My way to update firmware via Bluetooth (I used HC-05 module wired to AUX-1).

1) In Arduino IDE choose bluetoth serial port you need.
2) Run upload process.
3) Press and release reset button on Ramps. (see NOTE)
4) Wait until finished.
5) Press and release reset button on Ramps to restart new firmware.
NOTE: About 3) - Your need some luck to catch good moment, me usually press and release reset button after "stk500v2_ReceiveMessage():" message in Arduino log window. Everything is going ok when green serial led starts blink continuously.

Saturday, 4 July 2015

Voltage regulator on Arduino Mega

Voltage regulator on Arduino Mega is not good.
Too weak to supply power to LCD adapter and Bluetooth module.
Was damaged by third run. Replaced to LM7805.

Wednesday, 1 July 2015

Sscara photos

Current state.
State: arms still not fixed, nozzle is absent (work in progress)

Small SCARA OPENSCAD intermediate result 2

Status - "Work in progress".
All parts are designed and (mostly) printed.
Major improvements - to keep strong structure i decided to use Aluminium L type profile for base and for bed (sizes depends from .your local stores, my 15x15x1.5 for base and 10x10x1.2 for bed support)
GitHub -

Tuesday, 23 June 2015

Small SCARA OPENSCAD intermediate result

Status - "Work in progress".
Z Platform - is not started yet.
Hot end - i have a few ideas, seems like it would be PTFE body with 6mm stainless steel barrel (or PTFE barrel), e3d v5 heater box and e3d nozzle.
All other parts are designed and (mostly) printed.

GitHub -

Monday, 8 June 2015

Small Scara git hub repository

Git Repository created -

Current state:
  • Both pulleys 
  • Nema17 and belts layout done
  • XY axes support parts completed
  • End stoppers layout done
  • C# app added to visualize reachability and forbidden areas.
A few parts printed - see my previous post. 

Sunday, 7 June 2015

Sunday, 31 May 2015

Scara based 3d printer - why?

My idea is to create SCARA (or 5 bar) based mechanics 3d printer with minimal size.
All my 100% prints are less than 100x100mm size.
Сurrrently is have delta based printer (custom design) - but:
  • Noise - too much noise during printing
  • Size - my current printer is 31x41x70 cm size - hard to place it on a table
My idea is to create small 10x10cm print area 3d printer  but with general sizes as much as smaller.


Lets have a look to current printer mechanics:

  • Cartesian XYZ - 10x10cm required much more size because of caret size (4 linear bearing spaced by some distance due to backslash minimization)
  • CoreXY - the same problem as with  mechanics above.
  • Delta - a little bit smaller but 3 steppers located as 3equal length triangle will take more than 10cm in size.

SCARA - most space friendly mechanics.

Scarа math.

Math for my new (super micro) 5-bar 3d printer
Seems like Marling Firmaware contains SCARA mechanics but only with centered axis for x and y arms - this is will be my base for 5-bar fork.

Aliexpress stuff

Cheapest NEMA17 steppers

This is the start of my 3-rd 3d printer based on 5-bar mechanics.