Chieftain kit arrival

[Youngjae Bae]

For about two days, I temporarily installed it in the turret for the installation of the actuator support and the main gun inner part.
And I found an unexpected problem.
It was the fact that interference occurred between the actuator hinge point and the ceiling connection of the turret.
So I modified the design and moved the hinge points to the center of the turret.
To match the length of the arc accordingly, the design was completed based on a new length of actuators available on the market and the steel plate was ordered to be cut and bent with laser beams.
Two actuators are designed and can be expanded to four if necessary.
If I extend it to four, I'll have the over power to control the up and down of the main gun.

Youngjae

[Youngjae Bae]

In the evening, I found the parts that changed the design, assembled them, and verified the validity of the design.
Everything is in line with my intentions. A new battery arrived and installed in Chieftain.
The capacity will grow and the size will be reduced, making the renovation easier.
It's a small change, but progress must continue.

Youngjae

[David Battson]

Hi Youngjae,
Really enjoying the excellent work on your Chieftain modifications. The three motor idea seems a great way to increase turret traverse speed and torque and the barrel elevation proposals look really robust. It will make a great test bed for any gun stabilisation plans.

Do you (or anyone else reading) know what the actual Chieftain tank turret rotation and barrel elevation rates (degrees/second) are for the real thing ?

One query, if I have understood your calculation table correctly, moments appear to have been taken by multiplying mass by total length either side of the elevation pivot. I believe this should actually be mass by distance to centre of gravity either side. I would guess CoG of the barrel is at just over half of it's length which should significantly reduce the torque bias and add a good factor of safety to your design.
Keep up the innovating,
David

[John Clarke]

Whooosh
Flipping heck David, I'd love to say I was thinking the same, but I'm not clever enough.
Most manufactures I know would just cut a slot to shift the weight to the correct position and use the "Eeee that's about reeght" technique.
This whole thing is fascinating.
I know whats going to happen, but just can't wait for the next episode.
A bit like the "Curse of Oak Island" where they can't get enough of buried wood

[Youngjae Bae]

The final bill will be released soon.
The stroke of the actuator is designed with a reference of 75 mm and can also be used 50 mm.
Of course, I can't use two lengths at the same time.
Let's wait and see what happens.

Youngjae

[Youngjae Bae]

This is the time required for some interim verification.

- I saw the angle of Main Gun in Chieftain MBT in wikipedia is -10degrees and 20degrees.
- I designed to use the electric actuators on the market to up and down Main Gun.
- The specifications of the electric actuators I ordered during the initial design are 50 mm stroke, 90 mm/s speed, and 100 N force.
- I found an unexpected interference between the turret ceiling and the hinge point. So I had to move the hinge point to the center of the turret.
- I had to re-select the market electric actuators to control the up and down of the Main Gun.
- The specifications of the electric actuators I ordered during the final design are 75 mm stroke, 150 mm/s speed, and 60 N force.
- The arrival of actuators and some parts has been delayed.
- I made some modifications to the Actuator Guide so that both 50mm or 75mm actuators can be selected for use,
and when I have tried the temporary motion test, I have confirmed that there is no problem.
- I made a guide to control 30 degrees with a 75mm actuator, but only 27 degrees.
- In the calculation for torque, 50 mm case and 70 mm case were obtained after finding the center of gravity point.
- I found out that the weight added by Kian was the best. Thus, his product value was applied to the final output.
- This weekend I'm going to make a bolt hole to hold the Actuator Guide on the turret ceiling and install a slip ring in a new location.
- Between the bottom end of the Actuator and the bottom of the Chieftain, there will be 12mm of space between the lines so that no wires can be caught.
- I am thinking of moving the receiver to the turret to install, and the GYRO to install next to the receiver has arrived and is waiting.
- I prepared a 24-channel slip ring for a new wiring. So I'm going to finish the wiring this week.

Youngjae

[Youngjae Bae]

I made six bolt holes on the turret ceiling to fix the guide.
And I did the hand motion and checked for interference.
It also raised the turret to the body and rotated the turret to check for interference again.
In particular, the interference between the turret gear and the main gun connection was checked meticulously by rotating the turret 360 degrees at maximum angle.
The results of today's work are satisfactory.

Youngjae

[Vince Cutajar]

NICE.
Can't wait to see what gyro and control system you will be using.

Vince

[Youngjae Bae]

NICE.
Can't wait to see what gyro and control system you will be using.

Vince

I, a Korean who takes care of everything quickly, am also waiting hard.
The Gyro and the slip rings are ready and the 50mm linear actuators are shipping, and the 75mm actuator is likely to ship next week.
In addition to the stabilization, the small tanks that make up the Recoil system and the ultra-small air compressor to be installed on board are expected to arrive sometime in March.
Whatever it may be, I will first assemble the items that arrive and share the results.
Let's wait a little longer together.
I'm sure there will be good results for us.

Youngjae

[Youngjae Bae]

Today, I completed the P&ID related to recoil and stabilization to save time while still waiting for the arrival of the actuators and put the connection points and terminals on 24 channels of the slip rings.
Finally, the receiver will be installed on the main body as previously, and the Gyro will be installed in the middle of the turret.
I'm going to draw the base where mount the Gyro.

Youngjae

[Youngjae Bae]

Today, I reduced the strength of the spring to return to the Recoil and increased the number of the final eight, and finished the recoil movement with a 6mm diameter rod.
I also measured the center of gravity when I installed the heavy weights I made and found the center of gravity when I put on the original light weights.
The impact analysis of this value will be determined using the worksheet tomorrow morning.

Youngjae

[Youngjae Bae]

I did some renovations waiting for the arrival of the actuator to stabilize the Main Gun, and I calculated the optimization of the weights to reduce the burden on the actuators and concluded that 1500 grams is the best for me.
If the turret and the main gun were rotated and stopped, the clearances of the root of the main gun were clearly visible at the end of the main gun. This time, I installed a 0.25mm synthetic resin washer on the left and right to minimize the shaking of this part.
Later, additional ring blocks will be installed in the Actuator Guide to prevent swaying.

I just received an EMS tracking number for the delivery of the actuators.

Youngjae

[Youngjae Bae]

I compared the drawings and the bill just before leaving work and found that the center of gravity in the Main gun direction differed from the drawing, so I re-verified it.
So my Chieftain's best weight is 968 grams.
My original weight of 1640g is 80mm in diameter and 41.35mm in height.
I have to reduce this weight by 17mm in the direction of length.
I will work on reducing to lathe next Monday.
Have a nice weekend, everyone.

Youngjae

[Youngjae Bae]

I finished processing weights according to the bill.
It also draws a layout diagram of the air compressor, air storage tank, pressure gauge and fitting for the inside of the turret.
Twice a day is to confirm the arrival of the parts, a tedious but interesting process of patience.

Youngjae

[Youngjae Bae]

I checked the effects of weights at home.
If I slightly let go of my hand in any position, it will stop.
The center of gravity fits so well.
The Main Gun has a range of +20 degrees and -10 degrees.
It was easy to go up and down with the little finger.
Of course it's inside Turret.
Although confirmed by hand, the shrinkage and expansion of the recoil are also very good.

Youngjae