Treadwell WED-15-77: Part 27 - Testing

Well…… A few hiccups before the finale.

• The tracks need shortening (both).
• The mast base support needed a slot in it (think i did this as a second version on the model but didn’t reprint it.

May 9th

Connected up the battery and plugged in the fuses and plugs into the receiver, and powered up.

After dipping the Sabertooth into tank mode, right transmitter stick in full control.

I added WED-15 to the transmitter, and colour coded the LED’s to match.

Might also have to invest in some blue sticks.

May 10th

Today was the mast and head install.

This was there I realised I hadn’t but a slot in the mast base plate for the servo leads. I decided NOT to bother with the servo block plug, as it would of been difficult to reach once the mast was fitted. I just extended the servo leads.

I first connected up the head pivot servo.

Then the eye/head servo for the up down action.

Once happy with this, I connected up the main claw arm lift servo to a switch on the transmitter. Again, all good.

Next was the claw servo…. It worked but not for long??

Its been a while since testing it so don’t know if I hadn’t done something right, as on closer inspection, the case looked warped.

Took it out of the forward servo casing and, yes, the gears had jammed and one had melted, over heating the motor and melting the servos housing.

I did take a test video, you can watch it in the next post.

May 13

I trimmed the neck servo to increase it’s turning range. I also adjusted the head servo to increase it’s looking up position.

May 15

I got round to pinning the head/eye supports to the pivot bar. I had to fit an additional cross bar back in, for rigidity.

The ‘piston’ and the two ‘clamp’ rings got a respray, to a more brass look.

The eye/head servo lead I decided to modify by adding an additional plug on the outside of the neck. This allows the eye/head unit to be fully removable, found it so much easier to work on this way.

Added a spacer to reduce the clearance between the neck and mounting plate.

This fits under the bearing shim.

May 21st:

Tested out the track on the ground.

It works, but the teeth are still a problem, also the front brackets are flexing under the tension and there’s not enough torque on the axle nuts.

3D printing some beefier versions out of ABS.

I’ll also be printing new motor brackets in ABS too as these were flexing slightly.

Ordered a new nano servo.

Treadwell WED-15-77: Part 26 - The last pieces

 

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 printed a larger version of this mould (above picture) with more recesses, so one mix could do loads in one go. I didn’t use it though.

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.

Not in correct slots yet!

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!

Treadwell WED-15-77: Part 25

 March 2024

I started this build back in November 2021:

Link to part 1 and now it’s coming to be completed this year 2024.

I will be creating a page viewable via the top tabs (PC) or via the drop down menu on your phones which will have links and photos to these posts.

This month:

• Spray Painting
• 3D printing
• Rubber track moulding (YouTube)
• Re-assembling
• Electrical installation and testing

Painting the base:

I stripped the base of everything not made of wood lol, a pain, but it means I don't have extra weight and also I don't have to worry about something getting knocked by accident.

I then masked off the paint I wanted to keep and sprayed the bare wood with primer.

Some of the area's not sprayed are because these are going to have panels covering them, as painting neatly wouldn't of been easy. Here’s the masked off areas, spray primer work.

Once happy with the primer, I applied the blue paint.

A clear coat was going to be applied once dried, but the order didn't arrive, so this will have to be done at a later date.

Painting extras:

The one remaining wheel, plus the front wheel brackets and the lid supports, all got a coat of silver (not Plasti-kote) paint.

Also sprayed up were these missed wheel bushes and the mast base support.

Servo connections: block plug or just loose.

(Planned work, now next month’s schedule)

Tracks:

Ordered a single batch of two part mix of the mould mixture, to create the tracks with. I thought, if I need more, I can buy more.

The new track mould I printed last month didn’t print out very good (lifted off bed so not flat). Later, after a few failed prints, I found that the nozzle wasn’t as clean inside as I had thought, even with hot and cold pulls. So I didn’t reprint it as I already had two moulds anyway.

I used my original moulds (green filament) ones. Dusted with talcum powder as a release agent. I had seen this done, but don't think it works too well in this application lol. Read on for what I eventually used.

Here are the track moulding in progress. I made a video of this now up on my YouTube channel.

In the video, the track that couldn’t come out of the end of the mould was due to the filament that didn’t have support and had sagged, so the fluid mix was absorbed into it, bonding it together.

This part of the mould has been removed (cut out) and sealed with superglue.

Only one of the two mouldings poured, cured, bit disappointing really and don’t know why?? = after a few more attempts, I figured out that the mixture wasn't mixed properly and so hadn't cured properly.

Here is the joining plate with two ends, of already moulded track in position. Mixing up and pouring into this, joining plate, joins these together.

The poured join. Inside doesn't look great, but that's not important.

This was another poured moulded section.

Here is all the track made so far, these will all be joined when the second delivery of mix arrives.

The mixing and moulding process improved as I went along. I now have enough moulded to complete one full set of tracks, but will have to order a second batch of mixture.

Guide teeth:

I did have a go at moulding a ‘guide tooth’ onto a piece of track.

This first attempt, didn't work. The rubber didn't bond to the back of the track like it does with the joining sections, as I had expected. Once released from it's mould, the thickness (height) effected it's ability to flex with the thinner track when moving over (around) the drive wheels at both ends. So am going to have to look at something else or another mould idea.

Glue:

I did find and test out some special loctite glue which can be used on rubber.

This seems to work, still testing, but this could be what I need.

Mould Release:

Here’s the mould release agent I used, found a can in work:

The following picture was the last of the mix I had to bond together two pieces of the track. The rest went into one and a half track mould.

Video of the track coming out of the mould on my YouTube channel.

Test laying the track on the wheels:

Re-assembly:

As the build progressed, little snags appeared. One being my choice to use nylock nuts and washers to secure the front wheel brackets. The protrusion restricted the required clearance and they would catch on the inside face of the wheel.

Plus i needed to trim the bolts down in length, and use normal nuts with thread lock.

Not to waste the nylock’s, these were swapped over on the mast base support bracket.

Electrical:

I needed to move the power switch to the outside panel for ease access. This meant unsoldering the switch on the panel, adding a new plug connection and fitting the switch into its new location.

I drilled a dia 20 hole and fitted the switch just behind the mesh panel.

I finished off adding the power cable from the battery to the board, via the switch. And (test) connected up to the battery……

…..we have lights on the components.

Will the next Blog post be the final one…..????