March into April into May 2024
Final pieces………??? :
The second mix of rubber for the tracks was ordered and arrived in a few days.
I poured the remaining tracks and then it came time to join the first complete track together.
Because of the flex, I had to hold the joining ends in place with two metal ‘V’ blocks, above picture.
Teeth moulding attempt No1:
I tested the loctite 480 glue again and although it held, it didn’t last long though.
Then I remembered Sikoflex! This is similar to silicon sealant, but is stronger for bonding. I bought some to test on a sample piece of track.
Before I used the Sikoflex, I attempted to bond the ‘teeth’ onto the track using some of the rubber mix. This time I didn’t press down too hard, just held it gently in place. Two test pieces later and they were on solid….. but again it didn’t last long. Tried to fix in place with a pop rivet, but that didn't work.
NOTE: I think the main problem is that the 85 shore hardness is too hard when poured to the thickness required. It's ok (flexible) when poured at the track thickness. May need to look at using the softer shore hardness that I had a sample mix of previously.
Ordered some 60 shore rubber (sample bottles I had previously purchased and tested) to test in the newer mould. These should be a lot softer but still retain some rigidity due to the height.
As for fixing them onto the track, think this will require a definite mechanical process.
Teeth moulding attempt No2:
Here is the second attempt at moulding the tread teeth. The mould was dimensioned to the unofficial blueprints, they are longer than my mould version 1.
** pic **
These came out great, though some of the mix did leak out of the bottom of the mould. They will flex, but still have rigidity.
After more YouTube research, I noticed that the surface needed to be 'roughed up' before bonding to help give the glue something better to 'key' with. On the first test 'tooth', using loctite 480 glue, this worked to help bond it to the track!
Track Fitting:
Next up, test fit of the assembled track No1, onto the wheels.
Track mouldings No2:
Here are pictures of the last section of track being moulded.
Still managed to have some problems with bonding these together. Patience is definitely a requirement lol.
May
Saw the completion of the tracks.
I found that the faces of the track and teeth, needed to be really roughed up! So dug out a wire wheel and attached it to a drill.
Once done the teeth bonded much better to the track. Wire wheel on drill.
Track one was complete,[May 7th], time to fit it onto the wheels.
🛞🛞🛞🛞
Front Wheels location:
Before I could work out the length for the last section of track. I needed to fix a few things. The exterior plate needed to be modified slightly, to allow locking nuts and washers to be used.
The plate was increased in thickness to locate the nylock nuts in place (along with a recess for a washer).
This worked great and made locking the front wheels in place even easier. This upgrade did through up a slight hole alignment issue, requiring two to be drilled slightly larger and straighter lol.
[April]: The next issue though was that there wasn't enough movement to pull the track tight. So after measuring the possible distance needed, I modified the inner and outer locking and location plates to be able to accommodate.
These were re-printed again and helped with keeping the track 'tight'……but the next issue was…..
Wheel alignment: [April]
When tightening the track on the front wheel, the axil would 'bend' (not actually). I would that the 'washers' I had 3D printed were flexing under the tension of the wheel. I swapped them over so the metal washer was next to the bodywork and then the 'plastic washer' between it and the wheel hub. This improved the alignment.
**pics of new brackets**
Speaker:
Didn’t get this far….
Battery brackets: [April/May]
Was thinking about repositioning the battery and combining the brackets into the mast base bracket. Didn’t get much further done either lol.
Servo leads: [May]
New servo wires were made to connect the Sabertooth speed controller to the RC receiver. Then the servo leads from the mast socket were connected to the receiver.
Additional arms:
As I mentioned in Blog post (part no.) I had painted up left over arms that I was thinking about using. I then had a thought about actuating the gripper tool, which led on to actuating the whole arm, like the claw one.
This I completed, and will share the files on my Prusa account, but for actually using it on WED, it wasn’t till I’d made a new bracket that I realised that there wouldn’t be enough room for the servos etc.
**picture**
April/May:
After being paid I was able to purchase the (hopefully) last mix for the rubber tracks.
I made tracks to gets these finished as I NEED to get him ready for the South West Droid Builder’s day here in Bristol, Sunday July 7th 2024.
Last few pieces to fit together for WED to be done.
Powering everything up…..
Testing of the motors, servos etc and the transmitter….. in next post!
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