Why building yet another 3D Printer ? (Part 3)

Sourcing parts to build something can be tedious. In this short part, I will give you some hints to find what you need, save time, energy and may be some money.

Carson Arias

My constraints are the following:

• Fair Quality for the Price (on the cheap side).
• Fair price for the Transport (this can be an issue).
• Enough quantity to fix mistakes, perform some experiments and have some spare parts to not be stuck.

For all the 2020 Aluminium profiles the best overall price for my location is a German company called Motedis near my home. I bought also some 2020 specific parts: nuts, acme screws, acme brass nuts. They can cut to length, perform machining if you need for a fair price (about 3W to 4W in general to have the order delivered). For my location I found that the optimal price for an order must not be greater than 100€ without VAT otherwise I will pay much more for the transport (not linear).

For all 3D Printing small parts (mechanic/electronic) + power supplies, I buy directly from China via Aliexpress or from German Warehouses of some Chinese companies (low cost transport, no custom tax, no additional VAT) via Ebay in general. From an experience point of view, it is very good but you really know what are you going to buy or sometime willing to take a risk to see if it is ok.  Personally, among all the parts I bought the only bad surprise was 2 extruders with a bad centering of the bearing supporting the filament that need tinkering for the pressure of the spring that will be slightly too high, otherwise so far so good. It can take up to 2 Months to receive an order and even more if it the "New Year" period when people takes vacation.

On Aliexpress, if you need more than one part, you need to take the time to compare several sellers and to include the price of transport and the number of parts (sometimes splitting orders too). Also, something that is not well known when using "Aliexpress shipping" and combining different parts with a given vendor (not all of them) you will pay slightly less shipping but there is a limit to find on the size of the order, otherwise you will pay the full price.

An important thing to understand is the Aliexpress dispute system: to be safe you need registered shipping. When you buy, the vendor does not receive any money, he just sends the parts (the vendor is paid a few days/weeks on your confirmation). If you see something is going to be delivered too late and it is still in transit, you open a dispute and you ask for money back. When you receive an item, you take your camera, you record while opening the packet, you check everything is fine and if it is ok, then you confirm that it is received, otherwise you open a dispute.

When searching parts in Aliexpress, try the english word and if possible the chinese word. Try also different keywords because some products have slightly different names: if you have a just a few vendors this is a good sign you need to find other keywords. 

A nice feature of Aliexpress is the cart system that can holds for weeks the list of items you are interested into, so you can take the time to compare several vendors.

Vendors I bought from:

• Big Tree Tech: 200x200 MK3 Heated Bed, Polulu Stepper Drivers
• EARU AUTO: SSR HeatSinks
• EARU: SSR 220V/40A
• linkcnc Store: LMK8LUU, KFL08, SK8, LM8UUA, KP08, 5015 12V Fans
• Shenzhen Sun-Lite Power Co.,Ltd: 500W PSUs in 12V and in 24V (I have nearly 1000 Hours on the 24V)
• ANYCUBIC Official Store: Nearly all parts for 3D Printers (pulleys, endstops, open belt, closed belts, HotEnds, Extruders, Bowden Tube, Inductive Sensor, Motherboard, Brass Graphite Bearing for Ultimaker2) -> There are cheaper alternatives: prices and transports increased since December 2016.
• Shenzhen Ali Brother Technology Co., Ltd.: 220V 600W 400*400mm SiliconHeatPad

For general electronics, I buy in general from Mouser or Reichelt with some specific brands.

In the forthcoming part, I will talk about the start of the pre-assembly of the 3DPrinter and the "in situ" design/prototyping phase.