teletech

That's actually a very reasonable price for an Abbot in the USA.  Once in a while I've seen someone asking that for a Ferret!

The US government won't sell armored vehicles to it's citizens and bans re-import of US-made armored vehicles (with some exceptions for WWII and prior, etc.), so there's a *lot* of pent-up demand.  Can you imagine all the yanks who wear a 1911 to go to the corner store and have a loaded AR15 in the trunk NOT being able to get fun toys like that!?

So, yeah, we're crazy for guns and vehicles over here and have almost zero domestic supply of AFVs.  That often makes for some very high prices when things do come up for sale.

Very sad about the gun being cut, but it's impossible to import anything over 12Ga/.505" into the US anymore and California is even more restrictive.  There are a few pre-1989 imports around, I was quoted around $50,000 for a live 76mm gun (just the gun) for a Scorpion if I wanted one!

Some US soft-skins as well.

https://themarket.bonhams.com/us/listings/vickers/fv433-abbot/c810b221-784a-43b0-a741-a37c80cefdb0?status=live
https://themarket.bonhams.com/us/listings/leyland-motors/fv4201-chieftain-tank/90aad57c-19f9-49a9-8354-b61ec0701d57?status=live
https://themarket.bonhams.com/us/listings/dodge/wc63-1-12-ton-6x6/88233c25-383e-4fd2-b3c6-e8add54c758d?status=live
https://themarket.bonhams.com/us/listings/gkn/fv432-armored-personnel-carrier/1734e472-186f-4117-8988-fa2bc930d214?status=live

I very much hope they go high enough to quell this temptation I'm feeling!

Surely you don't consider a ski-waxer curious? 😄

19 minutes ago, hauptmanngurque said:

If you are looking for sealing, I think it is important to change the rear pivot axle seals, or at least their rubbers (personally some of mine are mounted wrong and with deformed rubbers) but these are difficult to find. The O-ring that sits in the pivot axle channel is a standard size (BS334) in X-ring or quad-ring version (in mine some of them were normal round o-rings) of course it is essential to change the sleeve bushings for new ones. any excess play in the pivot axle will have an effect on the lack of tightness of the assembly.  By the way, the 3-3/16 sleeve bushings have a slightly smaller external diameter than the original ones.

I plan on changing the rubbers on the rear seals and am very interested in knowing if anyone has found a suitable replacement or if I'm going to have to make new ones.

I read in the manual that they used X-ring originally but switched to standard o-ring for the ones on the end of the shaft.

Good to know about the 3-3/16" issue.  I guess if it's too small then I'm back to using oilite bearings and turning them to size as a replacement.  Double the money, more time, and I'll want my mechanical engineer to do more math, but that's cheap compared to not getting it right!

10 minutes ago, Fatboy said:

Isn't the engine Johann is using the later AJ6/16? Which iirc has a much stronger block than the old xk6? Designed to be the base of a diesel unit that never was iirc...

jaguar AJ6 on Wikipedia

 

Ah, that may well be, pardon my ignorance of the "new" model then.

4 minutes ago, David Herbert said:

In respect of the seals, it is common practice in tracked armored vehicles for the seals in the suspension and wheel hubs to be primarily designed to keep dirt and water out. Keeping lubricant in is secondary as regular maintenance can usually be ensured by standing orders.

David

Very good point.  In this case they failed on both counts, but I suspect poor service was the root cause there.  In my case, I don't plan to run it often but would like my floor to stay at least mostly clean, so I'm willing to optimize for quality of seal vs. longevity (within limits of course).

I'd spoken to a mechanical engineer about alternatives and the early math did suggest that oilite bearings should work fine.  I found one that had the correct ID and length, but was too large in OD.  I'd have to make a little fixture for the lathe and turn them down, but that's an easy job on a self-lubricating material!  I went shopping around and found some for about half the price of my first source, so was waiting for the final math when I found what seems very much like the perfect item for the job.  It's got a layer of PTFE on top of the layer of bronze, but that should work just fine.  I do wonder how thick the Bronze layer is, but I guess I'll order one and find out.

https://asbbearings.com/collections/3-id-steel-backed-ptfe-lined-inch-sleeves/products/zu-48zu32

Now I need to decide on the O-ring to seal the outside-end of the pivot-arm shaft.  originally I think they may have been square or X in cross-section, then changed to round.  I'm thinking the double X profile might be the best and wondering what material and hardness to use for best lift and the least leakage?

7 minutes ago, johann morris said:

I used what was available at the time and time will tell how well it will work. I was amazed when I tried it in, how well everything lined up, in both height and side to side, it makes one wonder was there a common design in use.  I thought the CVRT' s used a JAG J60 engine unless yours is a diesel, not that I know much about CVRT's.

Jon

I understand the allure of the available and sympathize.

They did use the J60, and they were awful, part of the reason there were several replacement powerplants used.  They derated the motor in the CVR(T) to make less power, and that did help.  The Jag motor was brilliant and far ahead of it's time when it was designed and originally produced, but as it grew from a 3.4L to a 4.2L motor without any real redesign and Jaguar was always lacking the funds to recapitalize, so the design and tooling didn't improve.  The result was a motor with major problems with overheating, block-cracking between the cylinders, and a pronounced tendency to chuck the #4 conrod through the side of the block. 

Inspecting the pivot-arm bearings made clear they were going to need wholesale replacement.  Most are heavily worn and many are worn all the way through the brass/copper layer.  In more than one case, I found .030" of wear and that wasn't to the bottom of the scratches!:

Lacking outside advice, I went ahead and had a run at it, using a thin layer of primer on the back of the brackets and then a thin squeegee of the aircraft-certified anti-corrosive mastic.  Tightened things to whatever I saw online for that size bolt in aluminum, and called it done.  Hopefully nothing falls off.  All of the hull-sde threads were good, so that was a relief!

I had some of the mastic squeeze out of holes and between plates, but mostly feel like I got a good balance going.  I avoided the really rough stubs and otherwise just picked the best-looking ones for installation.  I might consider sleeving some of the really worn ones, but I feel like the ones I have are pretty OK for now.

The audacity to build a replica tank from scratch is astounding and amazing to me.  The sheer number of parts and hours is beyond my comprehension, it's taken me years just to fully disassemble a CVR(T) and start going the other way and yet here you are!

That said, I can't imagine putting a British engine in even a pretend German tank.  Organ rejection seems likely.  The Jag motors were objectively pretty bad anyway.  I'd have suggested the Ford I-6 300 as a much more robust engine and Ford was a supporter of Germany at that time, so it's at least not in direct opposition.

6 minutes ago, AmmoMan said:

01FF40 defending Bakhmut

Nice to see it pretty much doing what it was built for, just a little farther east.  That much brush over the air intakes is going to be an issue when it's warmer or once it filters through the louvers and packs up on the radiator and I'm not sure the mudflap art helps with camouflage.  Seems the MOD-given ones have the dischargers intact but the civilian-held ones couldn't go with dischargers, is that really the case, or have some slipped through?  Pity they don't have the GPMG fitted as they would be a great comfort facing the human-wave attacks of the mobiliks.

A familiar profile on the title picture, though we don't se it again in the piece:

A very slight movement of the microswitch and it will now turn off (barely), so mission accomplished!  Bit of a mystery why first it didn't turn on (oxides on some contacts?), but I'm willing to call it fine now.

Thanks for the support and assistance.

Now, what does the stowage bracket look like so I can carry it in style?

The angled plate isn't removable, so I have to remove the eyepiece assembly and pull the tube spacer and the tube to gain access.  Luckily it wasn't a big job at all, thanks for the pics so I knew I wasn't going to have a big pile of gears or springs or anything!

1 hour ago, philm1 said:

Not as yet as they are not readily available in NZ.

Heh, there is that.  I'm waiting with more than a little trepidation on a shipping quote for a pair of 353s to USA. >8-O

Ugh, I hated to break the paint, but here we go.

Yes, I have a tube (dated from 1994).  Removing the front cover also removes the down-converter and disconnects it from it's mating DB9.  Pin 1=24V, Pin 2=6.8V, Pin 3-Gnd  Seems to work OK.  Only about .3V across the LED so I don't know if it's current-sensitive or something else, but it's part of the downconverter so at least I know it's nothing to do with the heater.  Dug around for a couple DB9 connectors and hooked the downconverter up externally and the unit started working fine!  put the converter back in the housing, unit still works fine, so... Oxides on the DB9 that needed breaking loose?

Or, is it something else.  the thing I thought of as off, on, ND filter, iris does not have a position where it actually turns off power to the tube now.  SO, the switch was somehow open no matter what and in the act of disassembling the unit a bit now it's always closed?  seems odd, but it's all I've got for now.

Heater OFF, NV OFF: 5.2K ohm

Heater ON, NV OFF: .16K

Heater OFF, NV ON: 5.19K

Heater ON, NV ON: .13K

Pin C is tied to the chassis, 0Ohms.  I never see anything but infinity from C/chassis to A or B, so that confirms what others said.  Given the various resistances, it seems a certainty the heater is working and some part of the Image intensifier electronics are at least in the circuit.  I guess I'll have to open it up if I want to know more.  My fear now is the HV PS is shot or even that the sight was demilled and the tube removed.

I've been making covers so I can sandblast and paint the hubs and pivot arms without grit getting into the bearing areas.  In doing so, I've had to really realize what deplorable shape my pivot-arm bearings (bushings) are in!

They need pretty much wholesale replacement.  So, where does one find 20 new bearings?  They are apparently copper-covered steel, so just making some isn't likely to happen.  I was thinking that for the few miles a year I was likely to drive, perhaps I could make new ones out of brass, bronze, oilite, or even one of the fancy UHMW plastics.  Have people had much experience with the act of replacing these or making new ones?

43 minutes ago, G8RPI said:

OK that is a new model to me. It is basically the L7A1 sight design adaptoed to fit in the L5A1 mount. Earlier versions used just an adaptor plate between the two. I have a couple of those adaptors.
It is unlikey to need positive on two pins, particuarly if you are seeing no countinuity on pin C. You mention pin B twice, can you correct?

I'll check the L7A1 body I have later.

I corrected the typo, one fuse holder is connected to A, the other sees B.  II didn't see continuity on pin C, but it was the end of the day and I neglected to check it on the higher ranges and with reversed polarity to see if there was any path from a or B to C with the heater or illumination switches on.

The reason I haven't just started pulling it apart is partly the condition of the paint is so nice, I hate to mess it up by removing screws.

Thanks for identifying it as likely L7A1-derived, this suggests that going in from the flat plate just about the viewing section is likely to give me the best view with the least disturbance to the unit.

On 3/5/2023 at 10:32 AM, G8RPI said:

Do you have continuity between pin A and the fuse holders?
Are you sure of the model number? I can't find a reference to a L18 A1.
I have L5 A1 and A7L1 units. Any photos ?

 

Interesting!  Pin A has continuity to the fuse holder near the plug, Pin B has continuity to the fuse holder farther from the plug.  This suggests that this NV sight might need pin B after all.

6 hours ago, Mars said:

What exactly do you need prints of? What are you trying to do?

I'm trying to refit the clansman VRC-353 radios into a Spartan that had them removed and Bowman gear fitted.  So, I need the shelf they were fitted to, or drawings of that shelf.  So, if the Clansman gear you got to install in your vehicle had the radio shelf, I was interested in pictures or measurements of it.  If your Clansman gear didn't come with the shelf, then it's not relevant.

6 minutes ago, Mars said:

I am using the vehicle as a technology demonstrator, so installing original radios isn't in the plan.

 

I've removed the Bowman radio racks and am designing new rack systems in it's place.

 

What are the 353s? I take it that is a specific radio configuration?

Ah, got it, just Clansman for intercoms then.  I did see an interesting article about interfacing Clansman gear to COTS radios recently: http://www.vmarsmanuals.co.uk/newsletter_articles/clansman_interface.pdf

Yes, the 353 was the most common radio fitted to the CVR(T) range vehicles.  They are 50W boat-anchors in the 6M band.

1 hour ago, Mars said:

I did acquire a Clansman system that I need to install after I remove the rest of the old radio wiring.

 

I believe it was 1-2 weeks before the war started that I put the deposit on it.

Are you installing the radios as well, or just the intercoms?

If you have the mounting hardware for the 353s, I'd love pics and/or measurements.

Well, the good news is my cable seems correct: A=24V, B=GND, C is actually a short wire that looks like it could be intended as a local RFI ground to chassis.

The bad news is my sight does nothing at all when I hook it up and power it on.  Fuses are present and have continuity.  No HV whine, no eyepiece illumination, and also no indicator lamp (I don't know if that's for the heater or NV).  I'm a little reluctant to take it apart without knowing which bits will disturb the iris, does anyone have some guidance on this?