Improved Z lower mount If anyone is interested, I've just pushed an improved version of the Z lower mount to my GitHub repository. I decided to replace the countersunk screws with regular M4 x 12 cylinder head screws after I noticed that my original ABS part had broken: [attachment 47940 IMG_20150126_180203.jpg] I believe in general it's a bad idea to use countersunk screws exercising a lot of sideward pressure, because these parts apparently tend to break at the layer bonds. Well, but my improved part provides some additional space for M4 washers, so I think the holding forces can spread more evenly. I really don't believe this one is going to crack anytime soon :) [attachment 47941 IMG_20150126_181254.jpg] https://reprap.org/forum/read.php?340,460964,460964#msg-460964 Mon, 07 Sep 2026 08:42:05 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?340,460964,467469#msg-467469 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,467469#msg-467469
Doug]]> dougal1957 Ormerod Sat, 07 Feb 2015 13:45:05 -0500 https://reprap.org/forum/read.php?340,460964,467328#msg-467328 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,467328#msg-467328
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dougal1957
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dmould
The only cylinder heads I've worked on were all held with studs and nuts, so I don't believe I have ever seen a "cylinder head screw" :-)

Dave

Some Fords (And prob other makes) use what looks like a CapHead screw but quite often have Splined drives similar to a Torx Screw.

The last time I worked on a car to do anything more involved than change a wheel or bulb was about 40 years ago. I have noticed that they have changed out of all recognition these days and seem designed to prevent DIY maintenance - some even need special tools and significant disassembly to change a spark plug. Changing a headlight bulb in my present car is quite a business, and pretty much impossible to do in the dark.

Dave]]> dmould Ormerod Sat, 07 Feb 2015 07:39:30 -0500 https://reprap.org/forum/read.php?340,460964,467025#msg-467025 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,467025#msg-467025
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dmould
The only cylinder heads I've worked on were all held with studs and nuts, so I don't believe I have ever seen a "cylinder head screw" :-)

Dave

Some Fords (And prob other makes) use what looks like a CapHead screw but quite often have Splined drives similar to a Torx Screw.]]> dougal1957 Ormerod Fri, 06 Feb 2015 13:26:05 -0500 https://reprap.org/forum/read.php?340,460964,466982#msg-466982 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,466982#msg-466982
Dave]]> dmould Ormerod Fri, 06 Feb 2015 11:28:43 -0500 https://reprap.org/forum/read.php?340,460964,466949#msg-466949 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,466949#msg-466949
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zombiepantslol
Out of curiosity, is there any actual difference between cylinder head screws and cap head screws, or does it just depend on the area of application?
Cap head can be round while cyilnder head is well a cylinder?]]> tstone Ormerod Fri, 06 Feb 2015 10:24:06 -0500 https://reprap.org/forum/read.php?340,460964,466923#msg-466923 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,466923#msg-466923
I'll keep in mind these screws are called cap head screws, I didn't know there was any difference betwen them - LEO doesn't even know that expression. Out of curiosity, is there any actual difference between cylinder head screws and cap head screws, or does it just depend on the area of application?]]> chrishamm Ormerod Fri, 06 Feb 2015 09:50:06 -0500 https://reprap.org/forum/read.php?340,460964,466493#msg-466493 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,466493#msg-466493 I make this mistake myself from time to time Zylinderkopfschraube is the literal german translation of the above.
while not being a a specialist in the matter I think the automotive part has the same german name]]> auser Ormerod Thu, 05 Feb 2015 13:40:36 -0500 https://reprap.org/forum/read.php?340,460964,465597#msg-465597 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,465597#msg-465597 jsv555 Ormerod Wed, 04 Feb 2015 07:44:58 -0500 https://reprap.org/forum/read.php?340,460964,465585#msg-465585 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,465585#msg-465585 Thanks.
Just an FYI the cylinder head screws are called Cap Head Screw. Cylinder head screws are mostly associated with the automotive industry.]]> jy_oc_hx Ormerod Wed, 04 Feb 2015 07:20:41 -0500 https://reprap.org/forum/read.php?340,460964,461470#msg-461470 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,461470#msg-461470 steve0-uk Ormerod Tue, 27 Jan 2015 10:44:07 -0500 https://reprap.org/forum/read.php?340,460964,461196#msg-461196 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,461196#msg-461196
James]]> jamesf Ormerod Mon, 26 Jan 2015 23:39:34 -0500 https://reprap.org/forum/read.php?340,460964,461077#msg-461077 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,461077#msg-461077
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zombiepantslol
..I believe in general it's a bad idea to use countersunk screws exercising a lot of sideward pressure, because these parts apparently tend to break at the layer bonds.

Absolutely agree, thanks for improving that!

Erik]]> ormerod168 Ormerod Mon, 26 Jan 2015 15:56:55 -0500 https://reprap.org/forum/read.php?340,460964,460998#msg-460998 Re: Improved Z lower mount https://reprap.org/forum/read.php?340,460964,460998#msg-460998
Dave]]> dmould Ormerod Mon, 26 Jan 2015 13:31:20 -0500 https://reprap.org/forum/read.php?340,460964,460964#msg-460964 Improved Z lower mount https://reprap.org/forum/read.php?340,460964,460964#msg-460964 Z lower mount to my GitHub repository. I decided to replace the countersunk screws with regular M4 x 12 cylinder head screws after I noticed that my original ABS part had broken:

[attachment 47940 IMG_20150126_180203.jpg]

I believe in general it's a bad idea to use countersunk screws exercising a lot of sideward pressure, because these parts apparently tend to break at the layer bonds. Well, but my improved part provides some additional space for M4 washers, so I think the holding forces can spread more evenly. I really don't believe this one is going to crack anytime soon :)

[attachment 47941 IMG_20150126_181254.jpg]]]> chrishamm Ormerod Mon, 26 Jan 2015 12:42:54 -0500