Complete list of fasteners for the Sintron Kossel

Question

TL;DR

I need a complete list of fasteners (bolts, nuts and washers) for the Sintron Kossel.

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Has anyone bought this kit, and knows the answer, or knows where this is documented?

A complete list would be great, but in particular, I need the dimensions (M2.5/3/4/5? and length) and quantity of the bolts (and nuts) which:

• fasten the PCB mounted mechanical switches to the PLA rectangular end stop spacers/holders, and;
• fasten the PCB mounted mechanical switches and the PLA rectangular end stop spacers/holders to the extruded 2020 aluminium.

I have:

• Searched the web, but to no avail;
• Read the product page, which states only "screws and nuts provided";
• Contacted Sintron, but not had an answer;
• Obtained the Sintron build manual but there is no list contained therein, nor contains details about the fasteners relating to the endstops, and;
• Obtained the Blomker manual, from which the Sintron manual is copied, but that also has no list (as well as not being relevant with respect to the endstops).

Note that I am only interested in the fasteners specifically for the Sintron Kossel and not the Kossel in general. The Sintron uses the PCB mounted mechanical switches (with four holes), and not the simple barebones mechanical switches (with two holes), and uses 2020 aluminium¹, not 1515 OpenBeam:

Why? Because I purchased only the 3D printed parts from Sintron, and I am sourcing the rest of the parts cheaply, either locally or from Chinese suppliers on eBay.

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¹ In my particular case, there is an additional complication. The profile of the non-standard/non-"European" 2020 extrusion that I am using, does not take T-Nuts, only M5 hexagonal nuts (it is unbelievably difficult to find the standard 2020 extrusion in Bangkok). Combine that with the fact that the Sintron kit uses only M3 nuts and not M5 (I only discovered this after purchasing the printed parts kit (see the email from Sintron, in my answer below) - not through lack of research, but because there is no available list of fasteners), then I have the problem of finding a nut to use (see Fat hexagonal M3 nuts, with outer diameter greater than 6 mm).

Here is a photo

Answer 1

I found two lists for the Kossel mini (the documents you referenced are for a mini, so that is what I am assuming you got). One as a Google Doc and one as an order sheet

Both seem to list all the fasteners.

Here is a Sintron mini carriage assembly and it lists the hardware included

I found an ebay listing for the Sintron 2020 Rails. The recommended screws are M3x20mm and here is the infor on the required t-nuts.

Happy building.

Answer 2

For the M3 t-nuts, could you use this printed solution. You are just attaching a PCB; so, it you wouldn't need that much strength.

Another excuse to use your 3D printer. ;)

Answer 3

After examining the guide (Kossel mini instrution by sintron technology_v2) and the printed parts kit, I came up with an 99.9% complete parts list. The lists relating to the effector and autoprobe mount maybe slightly incorrect:

##Parts List

###Listed by Printer part/section:

####Fasteners

#####BOTTOM VERTEX (QUANTITY = 3)

For each:
10 x M3 x 8 mm
10 x M3 nut (T-nut)

#####TOP VERTEX (QUANTITY = 3)

For each:
5 x M3 x 8 mm
5 x M3 nut (T-nut)

1 x M3 x 35 mm
1 x M3 nut
1 x M3 washer


#####IDLERS (QUANTITY = 3)

For each:
1x M3 x 25 mm
4x M3 Washers
1 x M3 Nut
2x F623ZZ

#####MOTORS (QUANTITY = 3)

For each:
2 x grub
4 x M3 x 8 mm
1 x 16T/20T GT2 pulley

#####EFFECTOR

6 x M3 nyloc nuts
6 x M3 x 25 mm

4 (5?) x M3 x 16 mm <<==, or
2 (3?) x M3 x 16 mm <<==
2 x M3 x 20 mm <<== For the auto probe, if mounting the autoprobe directly on to a collar, above the hotend, and not on to the flange on the Sintron PLA collar

4 (5?) x M3 nuts <<==

2 x M3 x 8 mm <<== fan mounted to Sintron PLA collar
2 x M3 nuts <<==

1 x PC4-M6

Note: Some additional bolts are required for the mounting of the hotend. It is unclear what these are. See link.

#####VERTICAL CARRIAGES (QUANTITY = 3)

For each:
2 x M3 x 20 mm

#####ROLLER CARRIAGES (QUANTITY = 3)

For each:
2 x M3 x 10 mm
1 x M3 x 25 mm
3 x M3 nuts
3 x M6 x 25 mm
3 x M6 nut    
2 x M6 washer (optional)

#####ENDSTOPS (QUANTITY = 3)

For each:
1 x M3 x 8 mm <<==
1 x M3 nut (T-nut)
3 x M3 x 8 mm <<==
3 x M3 nut

#####SPOOL

6 x 625-2RS Bearing (or 625zz)
5 x M5 x 20 mm
1 x M5 x 25 mm
6 x M5 nut
6 x M5 washer
(or 7 x M5 washer – there is a discrepancy between the kit (7) and the manual (6))
3 x M3 x 8 mm ?
3 x M3 nut (T-nut)

#####EXTRUDER

1 x M3 x 40 mm
1 x M3 x 8 mm
1 x M3 x ?? mm <<==
2 x M3 nut (T-nut)

1 x PC4-01

#####AUTOPROBE

Note: This is optional

2 x M2.5 x 12 mm
1 x M2.5 x 12 mm
2 x M3 x 8 mm <<==  If mounting the autoprobe on to the flange of the Sintron PLA collar (if mounting directly on to a collar, above the hotend, then these are not required, and 2 x M3 x 20 mm replace 2 x M3 x 16 mm on the effector)
2 x M3 nuts <<==  If mounting the autoprobe on to the flange of the Sintron PLA collar (if mounting directly on to a collar, above the hotend, then these are not required)

Safety Pin 2.5 mm
Spring 23.5mm

Terminal Block
1.5mm Allen key

Note: Some additional bolts are required for the mounting of the autoprobe, as well as the hotend. It is unclear what these are.

#####GLASS BED

3 x M3 x 8 mm ?
1 x M3 x 20 mm
4 x M3 nut (T-nut)

#####RAMPS

Note: This is optional, as mounting on the top will interfere with the spool

2 x M3 x 35 mm
2 x M3 nuts
2 x M3 nuts (T-nut)

###Total Parts:

####Fasteners

#####BOLTS

Size, Length, Quantity
M3, 25, (1×3)+(6)+(1×3) = 3+6+3 = 12
M3, 8, (10×3)+(5×3)+(4×3)+(4x3)+(3)+(1)+(2)+(3) = 30+15+12+12+3+1+2+3 = 78
M3, 16, 5
M3, 20, (2×3)+(1)+(2) = 6+1+2 = 9
M3, 10, (2×3) = 6
M3, 35, 3
M3, 40, 1
M6, 25, (3×3) = 9
M5, 20, 5
M5, 25, 1
M2.5, 12, 3

#####GRUB SCREWS

Size, Quantity
?, (2×3) = 6

#####NUTS

Size, Quantity
M5, 6
M6, (3×3) = 9
—
EITHER

M3, (10×3)+(5×3)+(1x3)+(1×3)+(5+2)+(3×3)+(1×3)+(3×3)+(3)+(2)+(2)+(4) = 30+15+3+7+9+3+9+3+2+2+4 = 90

OR

M3, (1×3) + (1×3) + (5+2) + (3×3) + (3×3) + (2) = 3+7+9+9+2 = 33
and
M3 T-slot nut, (10×3) + (5×3) + (1×3) + (3) + (2) + (4) = 30+15+3+3+2+4 = 57
—

#####NYLOC NUTS

Size, Quantity
M3, 6

#####WASHERS

Size, Quantity
M3, (1x3)+(4×3) = 15
M6, (2×3) = 6
M5, 6 (or 7)

####Bearings

Size, Quantity
F623zz, 6
625-2RS, 6
OR
625zz, 6

####Printed Parts

TBD

####Structural

3 x 2020 x  750/600 mm
9 x 2020 x 360/240 mm

####Electronics

1 x Arduino Mega 2560
1 x RAMPS 1.4
5 x Stepper drivers
3 x PCB mounted mechanical switch
3 x Stepper motors
1 x Extruder stepper

####Belts

3 x 16T/20T GT2 Pulley
GT2 belt (5 meters)

####Other Parts

Safety Pin 2.5 mm
Spring 23.5mm
Terminal Block
1.5mm Allen key
9 x Delrin wheels
9 x 696zz bearings

1 x PC4-M6
1 x PC4-01

###Uncertainties

The fasteners required for the following parts is, as yet, unclear

Effector/Hotend mount
Autoprobe mount
Additional Extruder holder screwpoint

###Assumptions

Hotbed frame mounts (assumed to be M3 x 8 mm)
Spool frame mounts (assumed to be M3 x 8 mm)
Endstops (four M3 x 8 mm are used, not just one)

See also Kossel - Sintron parts list.

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I have a partial answer from the suppliers:

Hi

Good Day !

thanks for your contact.

we use M3 bolts + T-nuts .

i suppose the problem is , you don't have T-nuts , right ?

T-nuts is used for 2020 extrusion.

with warm regards.

james

I replied for a clarification of the length required:

Many thanks for the reply.

I have two types of 2020 extrusion, with differing profiles: one that takes T-Nuts, and; one that takes regular hexagonal M5 nuts.

For the T-nut extrusion I have both M3 and M5 T-nuts.

However, the second type of 2020 extrusion takes regular M5 nuts. Regular M3 nuts will not stay in place, unless I can find some M3 nuts with a larger outer diameter, greater than 7 mm.

With respect to the M3 bolts, what are the lengths required? Are two lengths used? One length to secure the endstop switch and holder to the 2020 extrusion, and then another length to secure the remaining three holes? Looking at the diagram in your build guide, it seems as if only one bolt is used to secure the endstop switch and holder to the frame, is that correct? Are any other bolts used to secure the PCB mounted switch the the endstop holders.

I thank you in advance.

Best regards

I followed this up with a second email

Hi again James,

Following on from my previous reply.

Firstly, I have found that flanged M3 nuts will work perfectly, in the extrusion that will not accept T-Nuts.

Secondly, what I really am looking for is a list of the lengths (and dimensions) of the bolts used throughout the Sintron build. In particular the endstop bolts. Rather than having to iteratively deduce each bolt, a list of the bolts used would be very handy.

I thank you again in advance for your kind consideration.

Best regards,

I received a second reply from Sintron

Hello Friend.

for endstop . it's M3*8mm .

i am collecting the list of them for you soon.

thanks.

james

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