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I felt starting a new thread for this separate of both the modeling thread & the Military History thread would be appropriate, since we're going for technicalities here. Who the gently caress are you and why should I care? I work for a WWII era collection & work on many various vehicles from the era, including a few exceptionally rare ones. Based on my experience & research I'm also fairly familiar with vehicles I've never touched. I'm also well versed in the mechanical functioning of firearms, mainly of the WWII variety. So questions on those are also fine. Don't ask me what all the little stamps mean, but do ask me what that spring does. Pix or it didn't happen.  So anyway, first set of questions I got in the Modeling thread; Nebakenezzer posted:I did have a few questions about the Kettenkrad. First, how complex is the transmission? I'm guessing that if you wanted the left and right treads to rotate independently, then the transmission needs to be more than a drive shaft running to an axle. Second: where does the Kettenkrad's engine come from? It's some 30 hp Opal engine - was that a 1930s economy car engine or something? Third: how complex is the steering mechanism? I know that the front wheel at speed can make little adjustments without any change in the tread's rotation (a pretty neat little idea.) How does steering imput translate into changes in left and right tread rotation?  Here's model I found online, as I can't find my phone right now to get actual photos. This is not the whole thing, to the left there should be the cooling fan and radiator, however this is what the engine looks like when taken out for maintenance. From left to right in the image: Engine, with the air filter on top, a water reservoir at the back, then the clutch assembly, where it turns light grey is the gearbox, and at the very front is the differential, and on either side, those hubs are the steering brakes. The model is rather accurate, on the left of the gearbox at the bottom you can see the brake pedal. The bolt holes on the steering brakes attach to a short driveshaft that connects to the drivewheel via a gear. The Gearbox has 4 gears, in low and high, for a total of 8. 3 gears forward, 1 reverse. The Kettenkrad does not drive like some tracked vehicles where track can lock completely, or even turn the other way. Inside those two hubs at the side are drum brakes, which are activated using the steering handlebars through a lever connection. It steers mainly by slowing down one side over the other. However, should these brakes fail, it does still have a (rather poor) turning circle using only the front wheel to turn. The actual 'stopping' brakes (activated by the pedal, or a lever which is not attached in the photo) are located inside the drivewheels which turn the tracks. They are also drum brakes. That should answer your first and third questions. The engine itself is from an Opel Olympia. Next question?
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Mar 29, 2015 20:50
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OK, that makes sense. Instead of "complex mechanics" its "just retard the power going to the front tracks and let friction do the rest." Neat. Thanks for the thread.
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Mar 29, 2015 21:46
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Do you work on tracked stuff often? Like tanks, halftracks etc? How much do you worry about just driving around in a muddy paddock for whatever reason and having a track get thrown or a trans blow up with no replacements available anywhere?
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Mar 29, 2015 22:26
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I don't know if you can watch these ( http://www.bbc.co.uk/iplayer/group/p00hl622 ) but in the first one, Breakaway, there's a tank gunnery training simulator. 16:55 to 17:20. It's postwar but might still have been used before, maybe, I don't know. Do you have any more information on these, and how they work? I get that the general principle is scaling down projectile and charge, but I wondered if there were any neat tricks, mechanically speaking. The US seems to have gone with a different system: http://www.lonesentry.com/features/f34_tank-gunnery.html simplefish fucked around with this message at 23:03 on Mar 29, 2015 |
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Mar 29, 2015 22:55
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Slavvy posted:Do you work on tracked stuff often? Like tanks, halftracks etc? How much do you worry about just driving around in a muddy paddock for whatever reason and having a track get thrown or a trans blow up with no replacements available anywhere? There are two tracked vehicles I work on regularly, the aforementioned Kettenkrad, and a Universal Carrier. There's also a OT-810 that I'm scheduled to work on sometime in the future. Replacement parts are a constant worry, but you learn to adapt modern equivalents, or to find original surplus. Original surplus is significantly easier for Allied vehicles, and vehicles that stayed in service post war.  Kubelwagen/Schwimwagen engine spares tend to come from old Beetles. The Universal Carrier's engine is a fairly standard Ford V8, same for the clutch, diff & gearbox. Scariest moment I've ever had was driving the Universal carrier though an old quarry and having a 4 meter piece of rebar get jammed into the track. We got a steel spike out of the toolbox and hammered it out. Later we consulted the manual, and it turns out that spike is meant for exactly for that purpose. simplefish posted:I don't know if you can watch these ( http://www.bbc.co.uk/iplayer/group/p00hl622 ) but in the first one, Breakaway, there's a tank gunnery training simulator. 16:55 to 17:20. It's postwar but might still have been used before, maybe, I don't know. I can't as I'm not in the UK, however based on your description I recall reading about the system, it works similar to the Boys AT Rifle trainer:  Basically, a cartridge with similar/scaled down ballistics properties shooting at scale cutouts. Mechanically speaking, it depends on the gun. The Boys rifle trainer just had a .22 Enfield slapped to it, other guns could have temporary sleeve inserts to make the barrel smaller, such as the K98 .22 Conversion.
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Mar 29, 2015 23:10
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Earlier in the post that spawned this thread you said that Kettenkrad tracks are ridiculously overcomplicated. Got any photos/diagrams of a disassembled link/track with parts laid out? I can't even imagine what goes into 70 parts per link 
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Mar 29, 2015 23:19
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Pierzak posted:Earlier in the post that spawned this thread you said that Kettenkrad tracks are ridiculously overcomplicated. Got any photos/diagrams of a disassembled link/track with parts laid out? I can't even imagine what goes into 70 parts per link  It's about 70 if you count the needle bearings (part '9') as individual parts. Since they're not held in when it's disassembled, I do count them as individual parts (there's 30 per 'side' of track link). It's worth noting that the part labled '2', ie the main cast piece is hollow where that bulge is, it's not simply a cylindrical hole through where the pins/bearings are, and has a grease sump in it.
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Mar 29, 2015 23:24
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N17R4M posted:I can't as I'm not in the UK, however based on your description I recall reading about the system, it works similar to the Boys AT Rifle trainer: Thanks for the quick reply! It's not quite what I mean though, but I'm sure it works on a similar principle. This one's just a little more complicated:    Down the far end is a sand sculpted hillside terrain with scale model trees around a target
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Mar 29, 2015 23:34
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N17R4M posted:
Holy gently caress that is insane, especially for WW2 military tech. As a fan of hardware you can fix in the field using a hammer/wrench/screwdriver,  Also, ever worked on a TKS? 
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Mar 29, 2015 23:36
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I have sadly never worked on a TKS. They are adorable things though  Keep in mind you have to regularly grease those tracks, by unscrewing the bolt keeping the sump closed, screwing in a grease nipple, then greasing it, removing the nipple and replacing the bolt. It has 80 links. There was no field repair manual for anything past oil changes or track replacements. Engine or break trouble, they'd be shipped back to NSU for refurbishment. simplefish posted:
Ah, basically its a reconstruction of a turret with a similar optics and control setup. I'm not sure those have firing guns, or just target spotting training. If the guns fire it'd be a .22 of some sort. I'll see what info I can dig up tomorrow, as I'm rather curious now. N17R4M fucked around with this message at 23:46 on Mar 29, 2015 |
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Mar 29, 2015 23:43
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In the video, it does shoot something into the sand, and the red flag I think is for live ammo
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Mar 29, 2015 23:46
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N17R4M posted:
 Are the tracks for other German vehicles similarly complex? I know there's a stereotype about German stuff being overly complex, but holy poo poo.
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Mar 29, 2015 23:48
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LostCosmonaut posted:
Halftrack tracks are similar. Tank tracks are simpler. The over engineered part is a well earned stereotype. If theres three bolts holding something in, you can bet one of them will be a different size. 
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Mar 29, 2015 23:51
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I showed the tracks to my friend, who's a bit of a gearhead and extremely interested in military equipment. He theorizes that the reason for the overengineering and constant greasing is because the tracks are all-metal or almost all-metal without rubber buffers between the links, so they're basically built as a mini suspension system with grease circulation to handle the abuse of metal-on-metal. Is this accurate?
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Mar 30, 2015 00:41
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N17R4M posted:Halftrack tracks are similar. Tank tracks are simpler. Those kettentracks are absolutely retarded. How do you judge what system the fasteners use? I assume all the german stuff is straight metric sizes, but do they use metric threads as we recognise them today? What about allied vehicles? chitoryu12 posted:I showed the tracks to my friend, who's a bit of a gearhead and extremely interested in military equipment. He theorizes that the reason for the overengineering and constant greasing is because the tracks are all-metal or almost all-metal without rubber buffers between the links, so they're basically built as a mini suspension system with grease circulation to handle the abuse of metal-on-metal. Is this accurate? That seems unlikely, you don't use bearings or grease as suspension of any kind even if you're a meth-addicted nazi. The vehicle has suspension, the track pins and bearings don't deal with the weight of the vehicle, which is transmitted directly through the track link itself. They just need to deal with the stretching and compression of the tracks being pulled around the vehicle. Slavvy fucked around with this message at 00:53 on Mar 30, 2015 |
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Mar 30, 2015 00:50
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chitoryu12 posted:I showed the tracks to my friend, who's a bit of a gearhead and extremely interested in military equipment. He theorizes that the reason for the overengineering and constant greasing is because the tracks are all-metal or almost all-metal without rubber buffers between the links, so they're basically built as a mini suspension system with grease circulation to handle the abuse of metal-on-metal. Is this accurate? Not at all really. They do make the tracks very bouncy if you drop them, but it's mainly there for traction. Fact of the matter is, a sealed system like that is great to reduce wear, if you can keep it sealed. There are rubber seals holding in the grease to either side, should those fail once you're in the field and some dirt got in your grease, guess what, your grease just turned into an abrasive paste. Say bye to your bearings. Tracks like the Universal carrier's/most tank tracks are unlubricated for this reason. In fact, the manuals very specifically state never to lubricate them. The suspension on the Kettenkrad is a standard German torsion bar setup, with every wheel save for the front most one being on a separate torsion bar. The chassis rises a good 3 inches when the engine is out. Slavvy posted:Those kettentracks are absolutely retarded. How do you judge what system the fasteners use? I assume all the german stuff is straight metric sizes, but do they use metric threads as we recognise them today? What about allied vehicles? Nuts & Bolts are standard metric size and threads for the Germans. The British ones are generally Whitworth, though I swear I've come across a metric one here and there, those were most likely added in post-war restorations. I can't comment on American vehicles. I do know Russian threads are weird though, having say, a metric head, but Whithworth thread.
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Mar 30, 2015 10:03
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Where do you source your drawings / plans from?
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Mar 31, 2015 10:00
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No Pun Intended posted:Where do you source your drawings / plans from? Google'd sources to be honest. A few manuals were copies I requested from the Bovington archives, a service they offer for a few quid, a few are from private sellers who reproduce the manuals. If there's anything in particular you need, I can check if I have it or have a source.
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Mar 31, 2015 10:46
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Is there any cool non-military stuff you can share?
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Mar 31, 2015 13:38
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Vegetable posted:Is there any cool non-military stuff you can share? I've spent some time studying and working as an Avionics Technitian, ironically my apprenticeship was with the Air Force. My knowledge is mainly in military items, I mean many of them have civilian counterparts (looking at you kettenkrad), and utilize civilian technologies (Ford V8 for example). So I guess it depends on your definition of cool non-military.
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Mar 31, 2015 14:17
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The Universal Carrier has what I assume is a flathead Ford V-8? Is it a 221 or a 239? Were they all flatties, or was it like the Sherman, IE: we have a rail car full of X, that's what this production model is getting.
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Mar 31, 2015 15:15
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MrYenko posted:The Universal Carrier has what I assume is a flathead Ford V-8? Is it a 221 or a 239? The one I have under my care is a 221, that is a 3.6 Liter for us Europeans. However to my knowledge there are different variants. I'm not entirely sure about the logistics of manufacturing them however.
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Mar 31, 2015 15:29
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Thanks for posting this. I'm a WWII geek as well and am really into German vehicles. I've always wondered how the tracks on the Kettenkrad and things like the SdKfz 251 series were built. Classic Teutonic over-engineering. Adorable.
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Apr 1, 2015 00:05
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Do you have a list of vehicles in your collection? What's the rarest of the bunch?
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Apr 1, 2015 00:09
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wtfbacon posted:Thanks for posting this. I'm a WWII geek as well and am really into German vehicles. I've always wondered how the tracks on the Kettenkrad and things like the SdKfz 251 series were built. Classic Teutonic over-engineering. Adorable. chitoryu12 posted:Do you have a list of vehicles in your collection? What's the rarest of the bunch? That's really not the point of this topic, I'm not in a position to publish our full inventory in either case. It's not just vehicles however, it's military technology in general, this includes things like various encryption devices, optics, communications etc. People tend to overlook the small items when they're parked next to an anti-tank gun. N17R4M fucked around with this message at 10:07 on Apr 1, 2015 |
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Apr 1, 2015 10:05
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N17R4M posted:I'm recall reading that the 251 is even more complex, maintenance wise at least. I've not worked on any other German Halftracks so I can't comment personally, but that was the word on the street with maintenance crews. Pretty complicated, yeah. 
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Apr 1, 2015 17:55
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This may be a huge effort-post, but whats your opinion on reliability problems of the Panther tank? Specifically, a late war model where they had ironed out the teething issues, but not too late where the factories were getting bombed and things got lovely.
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Apr 1, 2015 18:08
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N17R4M posted:Google'd sources to be honest. A few manuals were copies I requested from the Bovington archives, a service they offer for a few quid, a few are from private sellers who reproduce the manuals. If there's anything in particular you need, I can check if I have it or have a source. Mostly odd ball tanks (like the Vickers independent) but I am quite interested in anything with tracks really.
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Apr 2, 2015 09:22
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Saint Celestine posted:This may be a huge effort-post, but whats your opinion on reliability problems of the Panther tank? I'll see what I can dig up, I've never had to do any detailed research on tanks before. Ensign Expendable would probably be the person to ask about that. No Pun Intended posted:Mostly odd ball tanks (like the Vickers independent) but I am quite interested in anything with tracks really. Shoot an email to Bovington. They have copies of many of the manuals, blueprints etc that they will copy and mail you for a few pounds. Only tracked manual I have is a hard copy of the Universal Carrier Manual, and I don't have time to scan it all.
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Apr 2, 2015 12:49
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Saint Celestine posted:This may be a huge effort-post, but whats your opinion on reliability problems of the Panther tank? This seems like a microcosm of German 1944 problems. source quote:8. General Considerations So a) the blockade had a significant effect by eliminating Mo from the German economy, which required increasing the C content which created new problems with weld quality and shatter resistance, and b) quality of manufacturing declined as, for example, the heat treating could easily be fixed if it was found in QC checking (it was treated to 400-1000F and quenched instead of 1200+F and quenched. That gently caress-up is easily reversible by re-treating it to the correct temperature) Why the quality dropped I have no idea though. Bombing? Slave labor? e: Obviously there were problems other than just the armor, but I suspect they were all the same root cause - loss of required exotic metals and reduction in manufacturing quality. Maybe throw in logistics problems too? Captain Postal fucked around with this message at 17:09 on Apr 2, 2015 |
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Apr 2, 2015 17:05
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Germany was having problems with alloys for a while at that point. For instance, nickel was gone from helmets in 1940 and tank armour in 1941. Soviet tests of a PzIII handed over by the Germans after the defeat of Poland showed that the armour cracked and fell to pieces easily when hit. By 1944 , the combination of dwindling metals and thicker armour that was harder to make and weld, German armour quality dropped drastically.
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Apr 2, 2015 17:44
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N17R4M posted:Shoot an email to Bovington. They have copies of many of the manuals, blueprints etc that they will copy and mail you for a few pounds. Only tracked manual I have is a hard copy of the Universal Carrier Manual, and I don't have time to scan it all. Wait, Bovington will seriously mail you copies of that poo poo if you ask? I gotta get on that.
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Apr 2, 2015 21:55
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I guess that sort of answers the Panther Question.chitoryu12 posted:Wait, Bovington will seriously mail you copies of that poo poo if you ask? I gotta get on that. Yep. It will cost you a few quid, but nothing gouging. If they lack a particular manual, they might refer you to somewhere that does. I've always used them as my first reference anyway. Bitter Mushroom posted:How did you get this job?
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Apr 3, 2015 00:18
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N17R4M posted:Yep. It will cost you a few quid, but nothing gouging. If they lack a particular manual, they might refer you to somewhere that does. I've always used them as my first reference anyway. I think I'm seriously going to contact them and ask about it. Thanks! Edit: Actually got a question for you. Tanks and other tracked vehicles have historically used both steering wheels and steering levers for control. With WW2 tech in mind, what would you say is a superior option for easy control in both combat and transport terms? chitoryu12 fucked around with this message at 01:30 on Apr 3, 2015 |
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Apr 3, 2015 01:25
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chitoryu12 posted:I think I'm seriously going to contact them and ask about it. Thanks! Levers are the way to go. Universal Carrier has dead zones like no tomorrow, and is incredibly hard to steer accurately at low speeds. e; Bovington's archives can be contacted through library at tankmuseum.org
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Apr 3, 2015 10:43
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I know the Tiger had both levers and a steering wheel. Do you know what was preferred for steering by people who actually have to drive the thin?
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Apr 3, 2015 19:42
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chitoryu12 posted:I know the Tiger had both levers and a steering wheel. Do you know what was preferred for steering by people who actually have to drive the thin? If memory serves even the halftracks have the levers. Those are for emergency situations, evasive maneuvers, very sharp turns etc, not for general use. My co-worker who's driven a OT-810 calls them the "Fun Levers", because you pull one sharply at speed and you start to drift. There's a video on youtube of someone doing that, but I can't seem to find it.
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Apr 3, 2015 21:09
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About 10-12 years ago, someone was selling a mechanically restored, all-it-needs-is-paint OT-810 about 2 hours away of me. Asking price was like $16k. I was 22 at the time and seriously considered getting a loan to buy it. Alas, I would've had nowhere to store it and it would've been an enormous money sink, but drat if I don't kick myself sometimes for not jumping on it.
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Apr 4, 2015 00:26
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wtfbacon posted:About 10-12 years ago, someone was selling a mechanically restored, all-it-needs-is-paint OT-810 about 2 hours away of me. Asking price was like $16k. I was 22 at the time and seriously considered getting a loan to buy it. Alas, I would've had nowhere to store it and it would've been an enormous money sink, but drat if I don't kick myself sometimes for not jumping on it. That's the problem, you need a drat barn or warehouse to store a beast like that and maintain it properly.
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Apr 10, 2015 19:26
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