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Punched base rivets

Posted: Fri Jul 12, 2019 10:24 am
by nearlymint
I thought we had a thread started for these somewhere, recently found this one and I have another already in the collection exactly the same. Strange how its the same rivet as well on both models.
MB54a<br />Mb54a
MB54a
Mb54a
MB54a.JPG (80.57 KiB) Viewed 3027 times
J

Re: Punched base rivets

Posted: Fri Jul 12, 2019 11:24 am
by GHOSTHUNTER
There has been discussion of 'Chissel Cut' rivets where the head only has two indentations but not sure if there is a specific thread/topic, they may be scattered through the threads relating to the models with chissel cut rivets.

I have not seen the type you are showing which looks like a chissel type tool has been used four times across the head but the indentations (or grooves if you like), are evenly spaced suggesting an actual tool existed just for the purpose of making that unusal finish on rivets.

Ghosthunter.

Re: Punched base rivets

Posted: Fri Jul 12, 2019 2:17 pm
by yellowfoden
This will be a handy thread Jason, nice pic of the 54a.

This is quite different to the chisel cut on your K19 Scammell tipper and having rechecked a couple of my models it is also different to the M-5 Harvester but the M-10 Dinkum dumper does have the 8 indentations although flatter. I have also added a 10c Sugar pic and 46 Mercedes to show that punched and chisel cut differences so that new collectors can see what we have been referring to.

Jason, the wheels on the 54a have the wide centre radial tread, is it the same on your other 54a with the punched rivet please?

Bert

Re: Punched base rivets

Posted: Fri Jul 12, 2019 3:03 pm
by Idris
Very, very interesting but, at the same time, very, very odd.
It seems reasonable to assume that the two rivets were spun consecutively on the same machine by the same operator. If so, this cannot simply be a case of using the wrong tool. Could it be something to do with the rivet being overlength and splitting instead of splaying? Which variation code is it?

Re: Punched base rivets

Posted: Fri Jul 12, 2019 9:07 pm
by nearlymint
Hi Bert,Hugh
The model is a code 5 on Nicks list(not sure about the flat olive code 6) for both, thanks for the info Bert I have added a few pictures of models I have the same as yours. My other 54a looks like it has the same wheels.
My other 54a.
MB54a
MB54a
MB54a Punched rivet.JPG (93.04 KiB) Viewed 2974 times
M10
M10
M10
M10.JPG (90.49 KiB) Viewed 2974 times
M5
M5
M5
M5.JPG (80.94 KiB) Viewed 2974 times
J

Re: Punched base rivets

Posted: Sun Jul 14, 2019 9:23 am
by Idris
I've been thinking about this.
Based on my tenuous grasp of mechanical engineering, my understanding is that spinning a rivet would rely on plastic deformation of the metal. In this particular case, the metal seems to have torn. Now, we quite often see rivets with a single tear in them, presumably when they have been pushed down too soon, i.e. before the metal was hot enough to deform and stretch. Could it be that what we are seeing here is the product of clumsy rivet spreading, that the operator did not wait long enough before applying pressure?
As an alternative theory, I see that across to the rivet is slightly obstructed by the axle. Could it be that, for whatever reason, a batch of these were put through with the baseplate already fitted with wheels and axles and Lesney, making the best of a bad job, spread the front rivet as best they could?

Re: Punched base rivets

Posted: Mon Jul 15, 2019 6:15 pm
by nearlymint
Hi Hugh,
Maybe the theory of baseplates that already have wheels could be a way to explain why both models I have are the same, I am sure I have more so as I find them I will add pictures.
Cheers J

Re: Punched base rivets

Posted: Tue Jul 16, 2019 4:45 am
by Tinman
yellowfoden wrote: but the M-10 Dinkum dumper does have the 8 indentations although flatter.
That seems to be a pretty common set up for the M-10 Dinkum Dumpers, can't remember one that wasn't that way.

Re: Punched base rivets

Posted: Tue Jul 16, 2019 11:33 am
by yellowfoden
Tinman wrote:
yellowfoden wrote: but the M-10 Dinkum dumper does have the 8 indentations although flatter.
That seems to be a pretty common set up for the M-10 Dinkum Dumpers, can't remember one that wasn't that way.
Hi Joe,

The later M-10 Dinkum Dumper (red hubs) has the pivot rivet and was the standard shape so they may have found a way to limit the pressure to enable the rivet to pivot. This is one of my M10 has the trailer that has never been moved and is either tight from pressure or dried paint. This example sports about 6 tiny fractures. A long time collector and friend in the States found it for me back in 1987 and I have resisted the temptation to move it. It simply will have to carry its load in a straight line. :) :)

Given the M-6a 18 wheeler has a very successful standard rivet for the trailer pivot produced two years before the M-10 it is interesting that they tried the punched star type.

Bert

Re: Punched base rivets

Posted: Tue Jul 16, 2019 11:37 am
by yellowfoden
Idris wrote:............... I see that across to the rivet is slightly obstructed by the axle. Could it be that, for whatever reason, a batch of these were put through with the baseplate already fitted with wheels and axles and Lesney, making the best of a bad job, spread the front rivet as best they could?
Hi Jason,Hugh,

Each time I have looked at the images from Jason of both of the 54a’a I only see rivets that have been pressed before painting indicating both rivets on each have a good coat of undisturbed paint. The light spots I am seeing on the star shaped rivet looks to be glare/shiny spots. Could Jason please confirm there is no paint missing.
On the star formed rivet of the M10 I posted, the trailer arm is riveted before painting and can be clearly seen as having no paint loss.
A quick check is to see if where any part of the rivet is in contact with the base may show the flow of paint intact, i.e. not broken.

Bert