Makerbot MK8 Throat Mounting Block (Single / Dual)
Nozzles and hotend parts · 2 styles · 2 options in stock
Hotend parts for 3D printers — nozzles, heater blocks, heat breaks, thermistors. The parameters are listed in order of importance: the one at the top decides the most, and no amount of care further down makes up for getting it wrong.
This page lists 2 options: Style / variant Double nozzle aluminum block / Single nozzle aluminum block. From ¥2.47.
The parts of this item
Figure 1 — A nozzle comes down to four numbers: thread, hex flats, orifice, overall length — match all four and it cannot go wrong
What each parameter decides
Every parameter below shows the real range available on this page, and what goes wrong if you pick it wrong. Work through them in this order and you will not go far wrong.
| Parameter | Available here | What it decides | If you get it wrong |
|---|---|---|---|
| Style / variant | Double nozzle aluminum block / Single nozzle aluminum block | the structural and shape differences | it will not fit, or it will not do the job your mechanism needs |
How to choose, step by step
- Which part — Nozzle, heater block, heat break, thermistor or heater cartridge — each is sized on different logic.
- The interfaces — M6 or M7 thread, tube diameter and connector type all have to match the hotend you already have.
How the options on this page are distributed
Figure 2 — how the 2 options on this page are spread across each parameter: the bars on the left show how many options sit in each band, the panel on the right shows the real range of every parameter and how many steps it has.
Variant quick reference
| Style / variant | Part no. |
|---|---|
| Single nozzle aluminum block | P3-073-DPTLK |
| Double nozzle aluminum block | P3-073-SPTLK |
Reading the part numbers
| Part no. | Configuration |
|---|---|
P3-073-DPTLK | Style / variant Single nozzle aluminum block |
P3-073-SPTLK | Style / variant Double nozzle aluminum block |
You can order by part number or by selecting the parameters. The part number is fastest, but it does not always encode every parameter — the selector on this page is the authority.
6 common mistakes
- Nozzle threads are M6 or M7. Measure the thread OD: 6 mm is M6, 7 mm is M7.
- Voltage has to match. A 12 V cartridge on 24 V burns out immediately.
- Thermistor B value has to match. The wrong B value puts the reading tens of degrees out.
- Change parts hot. Turning a nozzle out cold snaps the heat break.
- Measure before you order. Take the old part off and measure it, or send us a photo with the caliper reading — that beats guessing from a model number every time.
- Everything here is in millimetres. Where a size is imperial, convert it: 1" = 25.4 mm, 1/4" = 6.35 mm, 3/32" = 2.38 mm.
When to replace it
You do not replace this until it fails — but "still looks usable" and "still reliable" are two different things. Any one of these and it is time:
- The nozzle orifice has grown or the flow is off-axis, and wall thickness is uneven.
- Weeping at the heater block thread, or carbon build-up.
- The thermistor lead is broken and the reading jumps around.
Fitting and use
Before wiring
- Confirm voltage and polarity first. Reversed, it is destroyed on the first switch-on — there is no second chance. DC parts especially.
- Wire with the power off, then check continuity and insulation with a meter before you apply power.
- Crimp or tin the wire ends. Twisting bare strands onto a terminal gives a high-resistance joint that heats up.
Mounting
- Leave the heated parts some air. Do not mount them against plastic or against the cable run.
- Parts with a direction (fans, check valves) have an arrow. Reversed, you lose most of the airflow or flow.
- Fasten it properly. Vibration loosens terminals, and loose terminals are the most common electrical failure there is.
First power-up
- First power-up from a current-limited supply, or through a fuse. If something is wrong the damage stays small.
- Run it unloaded first, measure current and temperature, then add load.
- After 30 minutes feel the terminals and the cable. Anything noticeably warm means high contact resistance — re-crimp it.
Three things not to do
- Do not connect or disconnect under power unless it is explicitly rated for hot-plug. The arc damages the terminals.
- Do not run above the rating. It works for a while, then it does not.
- Do not skip the earth or the fuse. You save a few yuan and risk the machine.
Matching parts
- Silicone sock, cleaning needles, spare heater cartridge
Lead time, custom work and shipping
- Stock sizes: dispatched in 1–2 working days, subject to stock
- Custom: non-standard sizes, materials and treatments are possible — send quantity and drawing
- Shipping: from Shenzhen; domestic courier by default, DHL or dedicated line for export
- Volume: quantity pricing available, contact us for a quote
If you cannot find the size you need, or you are not sure which one fits, send us the problem you are solving — what machine it goes on, the dimensions of the part you have, what it has to achieve — and we will match it.