Chieftain No. 34

[Phil Woollard]

Your are doing a great job Charles! It's a tricky model to get right but we'll worth the effort for a most impressive beast! I had a plug wired incorrectly which took a very long time to find, most frustrating, I also had a couple of important parts missing to which were soon sent out but I did have to pay for some of them. I'm sure my second commission Chieftain build will go well.
Keep at it Charles she is looking lovely!
Maybe we will get a Challenger 2 soon, now that will be fantastic!

[John Clarke]

Charles sorry to hear your uninspired with the LED flash, Centurion came with 3x LED's which isn't too bad. You could experiment with a multi LED system but you may need to use the trigger circuit to control an output circuit for something brighter.

In the past I've built a flash unit from a disposable flash camera which works very well and was triggered by the Armortek sound card via a home built relay circuit.

On ebay a flash unit for the 1/16 tanks can be purchased for around £10 which could be used, I've got one waiting, just needing a small extra battery and figuring out the trigger circuit. YouTube describes connections on 1/16 tanks and from this information it should possible to make it work.
Keep up the great work.

[Charles A Stewart]

hi All.

Thank you for the positive comments and encouragement.

I adjusted recoil this morning after yesterdays work and have a bit more movement and this functions well with the shorter barrel. However, when we put the other half of the barrel on today, the servo didn't like it, pulled barrel back but not forward, you could hear it straining. By supporting the barrel with my hand it worked fine, I tried some dry lub, still the same result.

Elevation works ok but was a bit sluggish with the extra weight. Other than that the tracks are back on and we ran it along the work bench, almost took it outside but the heavens opened up again, ho um.

Cheers all
Charles

[Dave Nadin]

I had the same problem with my Chieftain, Had to take down the barrel recoil, The white nylon bush had moved in the barrel pivot block, The nylon bush needs to be fixed in position so it is flush with the end of the pivot block, ( at the breach end). the barrel needs to be clean for the length of the recoil stroke. Any lubs will act as a fiction break.

It be well worth all your hard work, cheers Dave N

[Charles A Stewart]

Many thanks Dave
Surgery carried out this morning, refit amd test this afternoon .

Cheers Charles

[Charles A Stewart]

Recoil worked a lot better, thanks again Dave. I think a further mod maybe add a stronger servo and some lead to help the counter weight. Beautiful though it is that barrel is a heavyweight .
Cheers Charles

[Mark Russell]

Recoil worked a lot better, thanks again Dave. I think a further mod maybe add a stronger servo and some lead to help the counter weight. Beautiful though it is that barrel is a heavyweight .
Cheers Charles

I fitted a 35kg servo as I found that the supplied 25kg was very borderline on recoil operation...

[Charles A Stewart]

Spot on Mark, you must be a mind reader. I ordered one about 4o'clock, after testing, many thanks for the conformation. found it on ebay from a British model shop even though it will be of Chinese origin no doubt .

While we are on the subject of barrel movements etc. Is there anyone out there who could allow me to purchase a rifled Chieftain barrel insert please?

Thanks again gentlemen for the help and suggestions.

Cheers Charles

[Richard Goodwin]

Nice work Charles.........so glad I can program my sound card with anything I want and not what someone else thinks I want

Phil may be able to help with the rifled insert, excellent quality and very reasonably priced, although he may have run out of those nice pink boxes

[Charles A Stewart]

Good evening all.

Hope everybody has had a pleasant and productive weekend.

No.34 has been out of the garage under its own power for about 45mins yesterday, video to follow at some point.

It has been raining again, so out came the numbers:-

This is becoming addictive!!

Cheers Charles

[Charles A Stewart]

As I promised folks, here's the movie

If some of the movements are questionable, it is because I/we are not used to the single stick control (our Panther is two stick). At some point we may move in that direction. We also found that one side seemed to operate quicker than the other, although this could be finger trouble by operator, most likely.



Enjoy.

Cheers Charles

PS comments welcome.

[John Clarke]

Thank-you, Charles a most enjoyable clip.
Pretty good driving too
Couldn't resist the tunes of glory either, though I think getting a troop synchronised will be a challenge.
Whimsical

[Stephen White]

If some of the movements are questionable, it is because I/we are not used to the single stick control (our Panther is two stick). At some point we may move in that direction. We also found that one side seemed to operate quicker than the other, although this could be finger trouble by operator, most likely.

The motor-gearbox-running gear interactions will vary from side to side. It's also possible that the radio setup has an imbalance, which would contribute to the model not running straight when there is no steering input.

Charles, with single stick it's a simple matter to get the model to run straight. Jack it up so that the tracks can run free, move the stick forward and see which track moves first. Then advance the physical trim in the direction of the slower track. Once you're happy with the direction and amount of trim required, go to the Sub-Trim menu (I'm assuming you're using Spektrum) and apply a similar trim. Then centre the physical trim and check the input. If not satisfactory, make incremental adjustments to sub trim until satisfactory. On OpenTX, there is a measure to capture the sub-trim required automatically.

You may well find that having set it up to run straight forwards, it isn't satisfactory in reverse. That would again be the result of a variation in the physical behaviour of the motor-gearbox-running gear interaction on each side. In that case, you'd have to find a happy medium. Since reverse is used less often than forward, it makes sense to optimise forward.

In practice, with single stick operation, it becomes instinctive to adjust input to run straight, something which is greatly more challenging with two stick setup. Furthermore, single stick allows traverse and elevation to be put onto the other stick, making it easier to control the turret simultaneously with driving. That's a much more realistic representation of real life.

[Richard Goodwin]

Great clip Charles.....thank you

[Charles A Stewart]

Good morning all.

Many thanks for the advice Stephen, though not wishing to get a hernia, we broke the tracks. The adjustment was simple enough using a laser rev. counter to balance both sides. The hand book isn't too clear, to me at least, but do you need to "bind" after all adjustments to the TX?

We are looking at the sub trim, just need to work which bit.

Many thanks for the help

Charles