Plate for Machining No.4 Bodies

[paulseamus]

Jmoore

Thanks for both the picures of your machining plate and the accompanying notes.

Is is possible to post a picture of an action held in the plate?

I am sure that I have seen such a pic previously but a search of your qpast posts has been unfruitful.

To use a bastardised golfing term (NAGA) in the world of Machinists I am a bit of NAMA. (Google NAGA and you should work it out.)

Given that pre-qualifying statement, I believe that Holland and Hollands strength was to consistently produce durable zeroed rifles, in quantity, under the all the duress that the Axis powers could muster.

On the assumption that we are not trying to acheive a 15 minute cycle time, it must be possible to achive a similar result with a suitable lathe, milling machine, the correct techique and high degree of craftsmanship.

My personal preference is to to fit and mill the front pad from a base casting and the rear pad from flat stock, as per the H & H process. It's not that I have an issue with reproduction pads, it is just that the correct process offers a higher dregee of legitimacy.

I have a buddy who runs a large Automotive casting plant. He can cast the base front pad, i've just got to work out how to convince him to do a batch.

Not been a machinist, I need guidance as to a source for a suitable sheel mill cutter.

Cheers

Paul

[jmoore]

Is is possible to post a picture of an action held in the plate?

I am sure that I have seen such a pic previously but a search of your qpast posts has been unfruitful

Unfortunately, there's no "in use" photos, as most of that work occurred before the fairly recent addition of a digital camera. You are probably remembering the last pad repair, which managed to not require the plate, being a simple screw replacement and resoldering.



The partially sheared screw shows why one ought to just go ahead and replace them!



But, as to your request, due to the recent move, it may be a while before the plate "resurfaces"! Two new roll-around toolboxes will help, but everything is still in boxes as we move equipment and build storage space. If you don't mind, it'll probably be just a stripped spare regular old No.4 Mk.I* barreled action for demonstration purposes.

Not been a machinist, I need guidance as to a source for a suitable sheel mill cutter.

I'm going to speculate that there's nothing out there you can just order from stock, but I could be happily wrong!

There's various options. Hollowing out a regular endmill might do, but it's less than theoretically optimal, as the face is slightly relieved toward the center. Thus the bracket would only make contact directly adjacent to the spigot.

A spotfacing or counterboring tool is a better choice, I think. Fairly common aviation type cutting tool. They typically have a small pilot hole for changable guide bosses, enlarging that hole is the challenge. EDM would work, but might not leave a good finish on the sides of the spigot. Maybe EDM roughing of the hole with a cleanup grind or maybe a tiny carbide boring tool. This is the likely route I would take.

Another possibility is something called a "Stud off" cutter. Generally a thin walled end cutting tool for removing swaged studs that retain brake discs or drums. The drama being the "thinwalled" part! Haven't fully investigated this option.

ETA1: Some more: If you have heat treat, then you could make a single point cutter from tool steel bar stock. Very possibly how Hollands did it! ETA2a: But be prepared to either make several, or having a means to fine tune the spigot diamater after heat treat. If required, you are back to the dramas associated with the earlier options.

Possibly the most flexible option would be to adapt some carbide insert tooling for the job. A Kennemetal NRD3125LK insert has possiblities, but getting the back relief corrected for the tight radius would require some mods. The real bother comes from making an insert holder with just the right geometry. And adapting it to a boring head.

Probably a small pointy insert on a sweep type boring head (or "facing boring head") would be easier, if you don't mind the expense of the "SWBH". Wolhaupter made a very nice one!

ETA2: As for generating the radius or chamfer on top of the spigot, use your imagination. Not a super critical area.

[tbonesmith]

All this work and tooling cost lots and lots of money and time. I have been putting together this type of kit for some years with regular reasonably large financial outlays, and I still have thousands to spend. Plus the ongoing time factor. I thoroughly understand the motivation to do it yourself, learn it yourself, and in every way "make it your own", but if you really look at it in the light of day for what it is, I think this project would be better served by you finding a real No4T body with pads, and building on that.
As I said I completely understand your motivation here and I don't mean to be discouraging, but don't underestimate the size of the learning curve if you're starting from scratch.

[Peter Laidler]

I'm glad that you said that TBone........... making these body holding etc etc jigs is one thing for a huge workshop doing this stuff every day but for the home workshop, it just somehow looks or sounds like an effort to production line or industrially convert No4T bodies. We already have a good example of a home grown abomination elsewhere on the site that looks as though it was done without the benefit of a body clamp (and even sharp tools now that I think about it......)

Nope........... I'm not so sure........

I've put my steel helmet on and await the incoming mortars

[Brian Dick]

Let the mortar rounds come in. Save your money and buy the real thing with or without scope. Then when you get it all together; even if it has to be fitted properly, (DRP: my arthritic hands hurt from fitting your brackets. lol!!), you'll actually have a decent investment instead of a service rifle that can never be put back to original. My 2 cents. Steel pot on!!

[trooper554877]

The person asking for the info has no intention of going commercial. He is asking because he has been let down by a supposed expert gunsmith who totally buggered up a repro conversion costing not only the conversion but the rifle itself. no -one wants a buggered converted No4 He is obviously thinking of doing it himself or getting someone to do it for him who he can trust.
It's OK for you people who can afford a genuine No4T at the rate of around 4-8 thousand dollars here in Australia.
I thought through the generosity of Peter Laidler providing an instruction for a suitably minded person to be able to attempt the process, that asking for the details of the plate to eradicate any probable errors would have favourably be looked upon. Obviously not.
Just for info, I have done one of these conversions myself which worked quite successfully. I can fully understand someone wanting as much guidance , advice, tricks and the benefit of some of the most highly regarded expertise from all over the world here on this forum.

Cheers
Ned

[jmoore]

My interest is not in actually creating ersatz "T"s, but rather in building an understanding of how it was originally done. Supposedly there's a photo of the converted lathe somewhere, but as it has yet to surface, it's been mostly a mental exercise. The plate in no way attempts to replicate Holland and Holland's approach- quite the opposite! It's merely a holding fixture for repair work . As a production tool it is wretchedly inefficient.

(BTW, we used to spend hours and hours studying Curtiss P40 production line photos for the express purpose of generating tooling that could be used to produce fuselage and wing assemblies that would be interchangable and indistinguishable (minus the tiny Curtiss identification and inspector's markings) from the original. That study DID pay off. Recently talked to my old partner in insanity and he's back building Curtiss products like mad. Folk["collectors"] in this case are happy to have new flyable gear- a completely different mindset- and rightfully so!)

With the availability of reproduction scopes, brackets, etc. it seems reasonable to build new workhorse shooters with the understanding that some nefarious types will try and pass them off as collectibles. We can't stop the swindling, but I'd sure rather folk wear out ersatz "T"s in competition, etc, and save the real thing for minimal use so folk in the future will have something left. But without proper set-up, the ersatz version won't perform as well as they could otherwise.

[muffett.2008]

Oye Ned, you been chewing on them cranky pills again?

Just an interested onlooker here, intend doing one myself shortly, all info soaked up like a sponge.

[trooper554877]

Oye Ned, you been chewing on them cranky pills again?

Just an interested onlooker here, intend doing one myself shortly, all info soaked up like a sponge.

sometimes I wonder mate!
might know of a genuine No32 becoming available shortly if interested.

If I can bungle my way through to do one of these conversions, then you will **** it in!!!!
cheers and happy shooting now that your there!! DOH
NED

[Brian Dick]

Strictly my opinion Ned. Maybe worth half the 2 cents if that. My opinion on this subject has never changed. I've seen too many perfectly good No.4's buggered forever and I'm a bit of a purist. I can't afford perfect No.4 T rifles either at todays stupid auction prices but I can tell you that a patient man will find one for much less eventually. I just finished servicing a matching 1943 specimen complete with scope for one gentleman and I'm finishing one of DRP's brackets for another really nice one "as we speak". They were both purchased at very reasonable prices IMHO. Brian