My Tiger Tank Project

[Exhibitedbrute]

I like the crew movement idea and as someone who does shows it’s certainly something I could get behind. For example my Cromwell won’t have a battle system but a crew like that and a smoking gun would make quite an exhibit. Great work and a good idea

[Jimster]

Thank you! It’s certainly fun and easy to do. I tend to be a bit whimsical at times

[Exhibitedbrute]

But at least you don’t go cutting parts of you thumb off, it’s a good idea and really adds to the realism. You may notice from many of my totm entries though I have figures I don’t use them on my tanks as quite often they look better without

[Jimster]

Caution! The following is a rant and may contain offensive language and man crying. Not pretty.
Well son of a *=#+%! I bought a DKLM PDSG to have the best gearbox and it started slipping and now won’t even crawl over my shoe! I took the side plates off but see no obvious destruction. Maybe some worn gear teeth but this unit is practically new and now out of production (of course). So I bought a Heng Long dual current drive gearbox (looks like a DKLM knockoff). The turning motor works fine but the main drive motor doesn’t move until full throttle is held for a couple of seconds then it takes off like a scalded dog for a very brief moment and then quickly grinds to a stop. I’ll be damned. I try to get the best components to keep from having problems but then this crap happens.
I ended up ordering a pair of Taigen V2 4:1 gearboxes and a couple of 390 motors. Going to keep it simple but I hate the noise these gearboxes generate.

[jarndice]

For goodness sake Jimster, Are you trying to alter the Universe ? This is how the system works--- You send large sums of money to China and they send you Crapola,
So what is the reason for such distress old friend twas ever so,
What do you think drinking cabinets were invented for?
I just call it life and hope I get lucky one in five times of buying anything that works from the PRC.

[MITCH]

Hi Jimster, this can come from a slip of the motor pinion on the motor shaft. It would be interesting to take the motor apart to check this, it might allow you to keep the PDSGB block ...

[Will01Capri]

Never good when these things happen
However is there a way to reduce the NVH on these more simple gearboxes i wonder?
Maybe a rubber isolator pad under the gearbox sandwhiched between the metal casing and the tank hull would help slightly?
I just wonder if a cover could maybe be fashioned also over the top with a isolator material to reduce audible noise.
The noise from these units though does tend to be due to poor meshing of gears with not so great profile and they run loud.

As for the other gearboxes which slips or doesn't move till it has alot of throttle. One sounds like a spline maybe and the gear has slipped out of mesh or the spline has shredded and the gear spins sort of freely on the shaft. I don't know how well these gearboxes split apart, but if it already broke i would just go for it and try methodically to lay it out in order of removing the part and make sure you lay it out in the correct orientation so you can re-assemble.

As for the other one which jumps, that sounds like something is out of round or bent. Causing alot of restriction until the higher current allows a greater level of torque to overcome the restriction. Rather than being bent however, it maybe a simple thing like a bearing is worn so the gear mesh is out of alignment or a bush is not seated correctly.
Although i have also seen on cheap gears that they are machine so they have alot of runout and they do not run true. In which case you are forced to do drastic machining or replacement.

Unfortunately these things are made for mass production volume rather than good quality
Sorry if that hasn't helped

[Ludwig von wigbearer]

Jimster, I had a problem with one of my DKLM gearboxes, I removed the side plates and all I needed to do
was to tighten up a grubscrew on one of the gears.

[Jimster]

Shout out to Erik at Imex once again. I ordered new gearboxes and motors Sunday night and had them in my mailbox today! Holy cow! I’ll install them this evening and report on their performance later.

[Jimster]

Here’s my report: No offense to Taigen but these gearboxes are not staying in my tank. I’m sure they’re great for speedy IR battle maneuvers but for my style of driving they’re way too noisy and jerky. I’m going to have to figure out some way to correct my DKLM unit or figure out the problem with the Heng Long dual current unit’s main motor. I’ve got to step away from this and spend more time on my Kubelwagen and gunboat projects.
Having a reliable, quiet gearbox in my Tiger is becoming very expensive and frustrating. I wish there was a reputable place to have these units repaired. I’m afraid to tear into them too far past my skill level but at this point what do I have to lose?

[Jimster]

By the way, Ludwig. I’ve removed the two side plates but I’m unsure of the grub screw your mention.
The only grub screws I was aware of are the ones on the output shaft gears. Didn’t notice any under the side plates.
I’ll look again.

[tankme]

I have several sets of the sealed HL CNC gearboxes in both the speedy and slow versions. I like them a lot. They are quiet, powerful, and cheaper than the PDGBS or the HL equivalent. The only downside is that they are pretty heavy and I had to get creative to mount them since the screws are on the underside of the gearbox.

Here they are mounted in my SU-152:



And a speedy set in my T-72:

[Jimster]

Those look like solid gearboxes. Good looking cover.
I dug a bit deeper into the gears on my PDSGB and found this:

phpBB [video]

I’ve now shimmed them with heavy duty aluminum foil to reduce the floppy movement and I’ll try them out tomorrow. I’m not really sure if this is the actual problem.

[Jimster]

Apparently my shim experiment made an improvement. My Tiger is once again able to climb over my shoe without stopping from gear spin. Not sure how it’ll perform outdoors yet. In the meantime, I need to figure out what the problem is with the Heng Long 580 motor on my dual current gearbox.
I have to say that after driving one of these PDSGBs it’s impossible to go back to rtr style boxes.

[Jimster]

That shimming wasn’t a good fix but I made things right tonight! I’ll make this a quick follow-up post. I replaced the Heng Long drive motor with the smooth running DKLM motor and replaced the small Heng Long drive gear with the larger DKLM “slow” gear. These parts were absolute direct replacement fits. However I did have to remove some plastic from the HL body to allow for the larger DKLM gear. No big deal. Now it runs smoothly and quietly again and climbs obstacles like a mountain goat. I will sleep better tonight.

[jarndice]

You must be one of the younger fellows
You actually waste time sleeping
Sounds like a good fix for the gearbox my friend , amazing how good we get at miniature engineering in this hobby

[Jimster]

Comatose is kind of like sleeping. Isn’t it?

[EAO]

Jim,

Just got back from the Arkansas pucker brush. Ah, tranny problems! Not having a powerful, tractable motor is a bummer indeed! As for noise, just turn that amazing speaker that Stian made for you up to 11! Gear noise, I don't hear no stinking gear noise! "What was that honey? I can't hear you now, I'm fighting a tactical withdrawal from Leningrad!"

Cheers,
Eric.

[Jimster]

Go figure. A Tiger tank with a sketchy transmission. Doesn’t get much more realistic.