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Type 85 Fuze Time Detonator

2

2trok

Member
I am trying to refurbish an inert, fired, Type 85 T&P fuze for demonstration purposes, but I cannot remove the Time Detonator. Any suggestions? My only recourse seems to be to drill it out.
In that case does any member have a spare replacement inert Time Detonator they could let me have?

Martin
 
2trok said:
I am trying to refurbish an inert, fired, Type 85 T&P fuze for demonstration purposes, but I cannot remove the Time Detonator. Any suggestions? My only recourse seems to be to drill it out.
In that case does any member have a spare replacement inert Time Detonator they could let me have?

Martin
Click to expand...
 
The time detonator under the nose cap in a No. 85 fuze? Drill out the grubscrew and unscrew the nose cap - standard right hand thread. You may need to heat and quench it to get it off.
Note the base plug in these is a left hand thread if you want to get at the percussion detonator device
 
I have removed the nose cap, but the time detonator is recessed into the body of the fuze. If I use a screwdriver in the end slot there is only a very slight movement - a few thou' only. I had previously soaked in WD40, then heated and quenched the whole fuze in order to dis-assemble it. Maybe I should try that again.
The base plug will not be removable as it has somehow got a crossed thread.
Martin
 
Yes, it may take several heat/quench cycles. You may also need to use an impact driver to loosen the screw (with the fuze in a vice with soft jaws)
 
Hi Darkman, I do not think we are quite talking about the same thing. I have attached a picture with a couple of diagrams to explain my problem.
Martin

Type 85 Fuze.jpg
 
2trok, what you are trying to remove is the time pellet - third and fourth images below. On a long-functioned fuze, the time pellet is effectively cemented in with old burn residue and other muck. Alternate cycles of heat, ice water, and WD40 should get it to move.

The screw slot in the pellet is for loading with black powder when it was made, and can be used to jiggle the pellet out - the pellet head won't unscrew from its body because it is pinned by a brass pin as shown in the third image. The last image shows the recess where the percussion cap would sit, and the fire holes of the pellet.
 

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The time pellet was completely immovable, so in the end I had to drill it out.

So back to my original post - does anyone know where I might obtain an inert time pellet as a replacement?

A related question. Is the thread on the bottom of a No. 80 fuze the same as that on a No. 85 fuze (which is 2" diameter 14tpi BSW), so that either would then fit into the adapter ring which was on the No. 85 fuze.
 
2trok said:
The time pellet was completely immovable, so in the end I had to drill it out.

So back to my original post - does anyone know where I might obtain an inert time pellet as a replacement?

A related question. Is the thread on the bottom of a No. 80 fuze the same as that on a No. 85 fuze (which is 2" diameter 14tpi BSW), so that either would then fit into the adapter ring which was on the No. 85 fuze.
Click to expand...
YES the thread is 2" x 14 Conduit and both fuzes have the same threads.
I have starter and finishing taps but some projectile nose threads are a bit under size so tight to clean threads. I had an undersize tap made for me.
I use a 4 cutter threader to straighten bent external fuze threads or a lathe IF the fuze can be gripped safely.
 
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