Alternative boss for interior rear view mirror?

[sprint95m]

A very common problem on our cars is a split mounting boss rendering the interior mirror unuseable.
A while back there was this thread with assorted ideas.....
https://forum.triumphdolomite.co.uk/vie ... lit=mirror


I am thinking about revisiting this topic because I have a broken mounting boss.
Having been told that a late Spitfire has the same mounting hole configuration but too short a stem
(the visors can't be properly used)
https://rimmerbros.com/Item--i-GRID0058 ... AeEALw_wcB
What I am toying with is using a Spitfire stem and mounting boss along with a bespoke spacer in conjunction with a Dolomite mirror
to allow the correct use of the sun visors.


One of my friends is really red hot at design and 3D printing so getting a spacer made won't be a problem.
What I am wondering is this, what is the likely demand if any, for such a spacer?


thanks

Ian.

[new to this]

Ian

I was going to get a new mirror mounting block made i was thinking off using alli,but 3D printing may be better idea,why cant you copy the original design

Dave

[sprint95m]

Dave, it may well be that I am over thinking this….

The boss is designed to fail if the mirror suffers impact.
By replacing the boss with a different material I won’t know what the failure point is.
Using the Spitfire boss should keep the failure point where it is designed to be.

There is mention of this in the thread that I posted a link to.


Thanks
Ian

[new to this]

Dave, it may well be that I am over thinking this….

The boss is designed to fail if the mirror suffers impact.
By replacing the boss with a different material I won’t know what the failure point is.
Using the Spitfire boss should keep the failure point where it is designed to be.

There is mention of this in the thread that I posted a link to.


Thanks
Ian

Ian

The way i was going to make the mirror bracket,was drill a hole in the plastic base so the mirror stem fits inside and use grub screws to hold the stem in place that should be weak enough for the mirror to brake off if involved in an accident

Dave

[xvivalve]

https://www.thingiverse.com/thing:48951 ... 2Wzp4BVJD8

[new to this]

https://www.thingiverse.com/thing:48951 ... 2Wzp4BVJD8

Are they available to buy

Dave

[Mad Mart]

I can 3D print one! The only trouble is I only have orange atm with red on the way. I guess I can buy some black too.

[Mad Mart]

Thanks to Andrew Dutton for the design.

I printed this one in PLA because that's all I have at the moment. Andrew suggests ABS which, I agree, would be better. This was a very tight fit, initially, but a bit of scraping with a scalpel soon had it fitting better. I think if I printed it on its edge rather than flat on the bed, I can get rid of the ridges on either side.

[TrustNo1]

I use Triumph 1300 mirrors, not for the purist but they fit and do the same job

[captain_70s]

I have a wingard mirror with a suction cup on it for extra stability. I think it's from a BL era Mini or Austin 1100 or something. The holes in the plinth lined up with the holes in the headlining perfectly.

[sprint95m]

So the answer is no.


For myself, I will try to use the Spitfire parts that I have.




Thanks
Ian

[captain_70s]

Eh?

There is a free .stl file with the 3D model to print a new plinth just 5 posts up...

The failure point in the result of an accident in a car as flimsy and light as a Dolomite is of complete inconsequence. If you have a crash severe enough to throw you into the rear view mirror you're probably going to have the pedals coming up to break your knees or whatever you've hit coming through the door... As well as the force of the leverage due to the length of the arm being easily enough to shatter plastic under considerable force and the cup and ball mount swinging out of the way if not.

[geeksteve]

The failure point in the result of an accident in a car as flimsy and light as a Dolomite is of complete inconsequence. If you have a crash severe enough to throw you into the rear view mirror you're probably going to have the pedals coming up to break your knees or whatever you've hit coming through the door... As well as the force of the leverage due to the length of the arm being easily enough to shatter plastic under considerable force and the cup and ball mount swinging out of the way if not.

Even if it does come off as it should, the next stop for your face is the windscreen so your day is going to be slightly ruined either way!

[xvivalve]

The 'failsafe' was designed prior to compulsory seat belt legislation, after which the likelihood of contact with the mirror was significantly reduced...for front seat passengers, at least.