Early Tiger 1 from sPzAbt 503

[cahlfors]

Thank you Bob!

The fixed fender didn't last long:

The support bearing idea comes from Liam Mahoney in Australia. There is a bigger need for it on the tiger II:s, but I figured I could test the idea here. If a motor comes loose, the gear still can't get out of alignment.

The model is not totally untreated. It does have a clear coat from rattle cans. That said, a proper etching primer most likely does a better job of not letting air or water sneak in underneath.

The wheels were disassembled completely and cleaned in the ultrasonic cleaner, together with the hubs:

There were issues removing the bearings initially, but as soon I had disassembled the wheels, they came out of the hubs easily. There were only a handful bearings that were jammed, but I decided to replace them all with new stainless. I'm not looking forward to disassemble all the wheels again anytime soon! They looked rusty on the outside and the seals got damaged in the removal process. I don't think it's a good idea to glue bearings in place?

Lots of wheel rings came loose in the cleaning process. None of them had been glued with the black Loctite 480. Some were glued with silicone caulking, which I used initially in 2010, so that's pretty good mileage still. Many had been glued with a Loctite allround glue specially designed for metal, rubber, etc. Totally useless!
As part of regular maintenance, I glue the rings that have come loose with Loctite 480. Eventually, all rings should be gone through.
Using ordinary tie straps produces a bulge on the rings, where they don't quite stick. This looks ugly and is a problem that might spread when driving:

To avoid this problem, I used this method using 3D-printed rings that the wheels are pressed into while curing, suggested by MrTyko here on the forum. He hasn't dared to try it himself yet, but I can report that it works very well, indeed:

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[mrTyko]

Good that the molds work well.
Hopefully I'll get my Loctite tomorrow, so I can start gluing too.
Robert

[cahlfors]

I have been working very diligently making new parts for the running gear:


The hole is drilled and milled up in a helix to the proper size:

Parts in process:

Finished parts:

But, what is it?
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[RC_BobM]

Chris whatever they are they look really good! wheel spacer?

Are you running the steel track on your Tiger? I just got a set myself from Liam for my Late T1. How does the model perform with the steel track? Are the ALum sprocket ok with steel track? Do you think the motor shaft bearing would be mandatory upgrade?

Thanks, and HNY!
B

[mrTyko]

Chris whatever they are they look really good! wheel spacer?

Are you running the steel track on your Tiger? I just got a set myself from Liam for my Late T1. How does the model perform with the steel track? Are the ALum sprocket ok with steel track? Do you think the motor shaft bearing would be mandatory upgrade?

Thanks, and HNY!
B

Nice to hear about the tracklinks from Liam, I will recive my in a day or to also for my Late T1.
Robert

[mrTyko]

Great work you made there Christoffer.

[cahlfors]

You are both going to love your steel tracks - congratulations and thanks for the cheers!
I asked Liam to make steel sprocket rings for mine, but he backed out of it eventually and asked me to order from A-tek. I got their last steel set, but never installed them. The words from Gerhard Michel in Nuremberg echo in my head that the tracks are expensive and sprocket rings are cheap. I understand he can cut his own, but I found that the mere material would be quite costly for me, as it would have to be cut down to manageable size, even if I could cut the rings myself. I suspect having them professionally waterjetted could be a viable solution, or simply order new ones from A-tek? Anyway, my eleven years old alu sprocket rings were left in place and have worked very well with the steel tracks for three years now. The tracks were just drop-in and go.
The alu tracks performed very well and there is no performance difference with the steel tracks. However, due to the weight, they hang down better under strain, so look visually better.
The steel tracks don't require any modifications. However, the tracks are expensive. If overstrained, the aluminum track will stretch beyond its tensile limit and the weakest link will break. But the whole track will be damaged/elongated. With steel tracks, something else is going to break instead. The question is what. The idler shaft bending, the sprocket shaft bending, the final drive housing screws breaking are a few suspects. This is the reason I put soft aluminum safety pins in the idler levers instead of the original high tensile screws, as you can see above. They will snap like the safety pin of an outboard propeller to protect its gearbox.... ...is the plan...
The load on the motor shaft will be essentially unchanged with the steel track. Or is for me with the smooth track. You both have late tigers that now will have chevrons that will have a better grip and thus more strain on the gears... But my bet is that the chevrons will be very non-aggressive, because I know Liam is scared to death of HonKong-Vincent's panther track disaster. People filed them down to half and still had problems. Some even filed them flat and not even that seem to have solved it.
Put them on and enjoy!

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[RC_BobM]

Chris,
Good to know and thanks for information. I am handy with CAD and have a really good laser/waterjet cutter here (in US) - I can get rings made if need be. there is still a lot of machining to do on the cut rings.

I have Liams awesome links for the Panther as well. Yes they are very spendy, but I started machining The late tiger links to add the cleats - what a job! I think I am 1/4 done with one track. Ugh.

The Late T1 does not look right with early tracks so this will be welcome upgrade.

[cahlfors]

MrTyko and I had a chat on the phone today and I realize that our vintages were very close. I think his late issue is 2007/2008-ish and mine 2010 . There were lots of artefacts from the previous T1 issue, like the wrong loader's hatch, fan etc. If yours is the same range, there is a problem with the idler cranks that puts the idlers 4mm too far out from the hull. This makes the tracks bend on their journey over the idlers. I machined my cranks when I got Liam's idlers and realized that the problem was the cranks, not the idlers. You might have the same issue and might want to correct the idler cranks first. You will see it easily if you remove the idler fastening screw. If the shaft is about 4mm too short (likely compensated for with washers), then you have the problem.

I spent hours and hours to center the crank in a four jaw chuck to machine the 4mm off the inner edge. A ten minute job. I now realize that you could just pin it up using a dead (or live) center in the tailstock. Actually, I did ask a pro on how to do this best and he assured me that there are no shortcuts. I now know better, ha ha!

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[RC_BobM]

Thanks Chris,
Seems like building these tanks is sometimes like walking into a mine field. I think I can machine the idler cranks if need be. Thanks for the heads up. My tiger is 2010-ish, first batch of Late T1.
B

[cahlfors]

I am waiting for new wheel screws, so have a bit of time to write here before work commences again.

You remember the mess in the wheels:

The plan now is to prevent that in the future and that's where the new parts come in. They are flanges to sit on the rear of the wheels:

A rubber "V-ring" and the flange will work together:

The V-ring will sit on the shaft:

The wheel with its new flange installed on the shaft and moved toward the V-ring:

The wheel in its proper position and the V-ring sealing against the flange:

This ought to protect the inner bearings well. The outer ones are still vulnerable, but experience shows that the far biggest problem is on the inside.

All I need to do now is to give the wheels a final cleaning, a clear coat and start assembling!

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P.S. I am unable to remove this last picture. It shouldn't be there. D.S.

[mrTyko]

Looking good

[RC_BobM]

That's cool Christopher. I think it will help.

Looks like just adding the metal part without the seal wouldl help keep out debris due to tighter fit on axle. With seal even better.

[cahlfors]

I am currently struggling with the size of wheel screws and nuts. Every other wheel has screw heads and the other nuts visible and it appears that they are supposed to be different size. I didn't see that coming...

I assumed the screw heads would be the same size:

Markering_264.png (149.37 KiB) Viewed 2218 times

It seems that they are around 27mm, resulting in a s/w of 4,5mm on the model. The ones I bought are 5,3mm, which matches the 32mm on the real thing. I have been unable to find suitable replacements, especially since I have already tapped M3. BA could have been an option, but now I need to invent some.

After gradual development, I came up with the one on the far right. In chronological order: 1) 4,27mm first try, 3) 4,5mm with hexagonal chamfer 2) 4,5mm with circular chamfer, and 4) 4,5mm thinned and circular chamfer.

It's a reasonably quick process. 48 plus spares to do.


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[cahlfors]

Half of the visible wheels have screw heads. The other will have nuts like this:

There is no room for screw heads on the inside. The rubber ring on the adjacent wheel will rub against anything that sticks out:

MrTyko suggested to use grub screws instead. The nifty thing with that, is that the length can be adjusted so that they stick out just the right amount from the nuts:

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