Treadwell Droid Build
- Thread starter Paul6700
- Start date
Broilermaker
Sr Member
Wow, thank you for all of the info,, and the pics this is a great build! I also like the r2in the back ground!
Yes I am very close to the 29 inch wheel base. The plans specify that there is 7.25 inches between the center of each axle. Which mine has, however the rear axle hole is a slot to allow the belt to be tightened or to add tension. Here is a picture of my base:
I did shorten the over all length of my base by 3 inches, so that it better matched the pictures. However I still kept the axles 7.25 inches on center. The belt will stretch with time and you need the slot to keep adding tension.
Also note, my base is 6.25 inches tall so that the axles would have more material around them. The plans call for the height to be 5.875 inches, so my axles are 5.875 inches on center from the top edge of the base.
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I took the droid to an R/C show in Long Beach with the R2 Builders. This was the first time he was on display and my first time really testing everything out. As these things go Treadwell had a rough weekend. However, I learned a lot. First there is a lot of torque on the long PVC and ABS body. At the very base is a 1 inch PVC pipe and it is starting to get loose from the sudden stop and go.
At the show I burned through about 12 30amp fuses. Every time I would turn Treadwell, without moving forward, I would blow a fuse. The rubber treads are creating a lot of resistance and my speed controller can only handle peak 40amps for short periods of time. I am also thinking these motors and using tank treads is putting more stress on this little speed controller than it can handle. Which leads to another problem, I am using one 12 volt battery for the whole operation and I notice under certain situations that the voltage drops considerably and my sound system and Bluetooth disconnect from the transmitter. I also notice intermittent control of the speed controller. There would be moments when he wouldn’t move at all or worse take off in one direction at full speed.
In addition, I have replaced the servo for the eye movement and the motor for the neck movement once already. Both could not handle the stresses this little robot is putting on them. Both ended up stripping the gears, so that area will need either a beefier set of gears or a redo.
I really want Treadwell to reliably move around and have strength up through the body. I know as I add arms there will be more weight at the top of the body. I also want the neck and eye to move reliably and be able to interact with people. So I am going to do a bottom up rework of his mechanical systems and strengthen all weak points.
At the show I burned through about 12 30amp fuses. Every time I would turn Treadwell, without moving forward, I would blow a fuse. The rubber treads are creating a lot of resistance and my speed controller can only handle peak 40amps for short periods of time. I am also thinking these motors and using tank treads is putting more stress on this little speed controller than it can handle. Which leads to another problem, I am using one 12 volt battery for the whole operation and I notice under certain situations that the voltage drops considerably and my sound system and Bluetooth disconnect from the transmitter. I also notice intermittent control of the speed controller. There would be moments when he wouldn’t move at all or worse take off in one direction at full speed.
In addition, I have replaced the servo for the eye movement and the motor for the neck movement once already. Both could not handle the stresses this little robot is putting on them. Both ended up stripping the gears, so that area will need either a beefier set of gears or a redo.
I really want Treadwell to reliably move around and have strength up through the body. I know as I add arms there will be more weight at the top of the body. I also want the neck and eye to move reliably and be able to interact with people. So I am going to do a bottom up rework of his mechanical systems and strengthen all weak points.
It has been a couple of weeks since my last post. I have disassembled Treadwell into four basic sections; the base 
, the body 
, the neck 
and the head 
. I am reworking each area and my goal is to have Treadwell finished for Wondercon in April. I am starting with the base because I want a reliable drive train to build up from. I started by gutting the old speed controller out of the droid and replacing it with a dual channel Roboteq AX2550 speed controller.
I ended up moving the audio system forward, which made space for the two new batteries. I am using one battery to maintain control of the speed controller, one battery for the motors to draw from and the last battery is for all other electrical systems. The new ESC can handle a lot more amps and allows for finer control over the treads. I will post a video soon to show the base in action. I also relocated the fuse block and installed a new 100 amp fuse to protect the speed controller. This much power almost instantly fried my relay. So I also added a 200 amp relay to the system. The two new switches control power to the electronics in the ESC and the main 200 amp relay.
, the body , the neck and the head . I am reworking each area and my goal is to have Treadwell finished for Wondercon in April. I am starting with the base because I want a reliable drive train to build up from. I started by gutting the old speed controller out of the droid and replacing it with a dual channel Roboteq AX2550 speed controller. I ended up moving the audio system forward, which made space for the two new batteries. I am using one battery to maintain control of the speed controller, one battery for the motors to draw from and the last battery is for all other electrical systems. The new ESC can handle a lot more amps and allows for finer control over the treads. I will post a video soon to show the base in action. I also relocated the fuse block and installed a new 100 amp fuse to protect the speed controller. This much power almost instantly fried my relay. So I also added a 200 amp relay to the system. The two new switches control power to the electronics in the ESC and the main 200 amp relay.
xingshen
Well-Known Member
Thanks for the update and pics. Looking forward to the video. I'm interested in how you will reinforce the body to the base.
I've been researching my own build for a while now and the thing that has me stumped are the wheels. I haven't found an economical way to machine these. Any thoughts?
I've been researching my own build for a while now and the thing that has me stumped are the wheels. I haven't found an economical way to machine these. Any thoughts?
Xingshen,
I am looking at a couple of options for strengthening the base to the body, stay tuned for that. I believe the originals where machined aluminum, but you could get a very similar look with a hard wood like oak. Another builder posted pictures of wood wheels. You could cut the wheels using a 4 inch hole saw for the 8 end wheels and a 4 1/2 hole saw for all of the idler wheels.
It is good to know there is another treadwell builder out there!
Sent from my iPad using Tapatalk
I am looking at a couple of options for strengthening the base to the body, stay tuned for that. I believe the originals where machined aluminum, but you could get a very similar look with a hard wood like oak. Another builder posted pictures of wood wheels. You could cut the wheels using a 4 inch hole saw for the 8 end wheels and a 4 1/2 hole saw for all of the idler wheels.
It is good to know there is another treadwell builder out there!
Sent from my iPad using Tapatalk
That would be fantastic Leach145, I appreciate any help I can get.
Wonderful build! I've been dying to see somebody tackle this for ages!
The first test run allowed Treadwell to move around, however there was a lot of slip in the tracks. So this area needs to be beefed up and I also thought this would be a good time to show how I handled the tension system. To access the tension system I need to remove the speed controller and the deck everything is mounted to. Here is how I originally built it. Basically a block of wood that is trapped inside a pocket with a single bolt applying the tension.
What I discovered is the right hand side block had completely come apart.
What I discovered is the right hand side block had completely come apart.
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The right side needed to be completely rebuilt, so first I removed the block, the wheel and the axle.
I glued the four pieces of wood back together and used thin aluminum to skin both sides. I also used glue and screws to secure the aluminum to the wood.
I drilled a single hole to pass a screw through that attaches to the back side of the block. This acts as a pivot point and allows me to tighten the system by adjusting the bolt on the opposite side.
This is what it looks like with the block installed. I am using a shaft color to keep the axle from sliding out. With the system under tension the block wants to lift out of the pocket. The deck is screwed down and is used to keep both blocks level.
I thought I would throw this picture in so you can see the cut up fan belt riveted inside the blower belt.
I glued the four pieces of wood back together and used thin aluminum to skin both sides. I also used glue and screws to secure the aluminum to the wood.
I drilled a single hole to pass a screw through that attaches to the back side of the block. This acts as a pivot point and allows me to tighten the system by adjusting the bolt on the opposite side.
This is what it looks like with the block installed. I am using a shaft color to keep the axle from sliding out. With the system under tension the block wants to lift out of the pocket. The deck is screwed down and is used to keep both blocks level.
I thought I would throw this picture in so you can see the cut up fan belt riveted inside the blower belt.
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With the base completed and working reliably, I have moved on to the body. I temporarily zip tied the arms to the body to avoid accidently ripping one off. I also pulled out the old wiring harness because I am going to replace it with a newer harness.
Upon closer inspection it looks like the pipe I am using is still strong and rigid and the problem lies with the screws and weak glue.
I used my super strong Zap-A-Dap-A-Goo II glue (great name) around the base, where the plastic pipe meets the metal flange. I also used four 5/64's metal rod for additional support. After the glue dried, I used larger screws to secure the body to the base.
There is considerably less movement at the top of the body.
Upon closer inspection it looks like the pipe I am using is still strong and rigid and the problem lies with the screws and weak glue.
I used my super strong Zap-A-Dap-A-Goo II glue (great name) around the base, where the plastic pipe meets the metal flange. I also used four 5/64's metal rod for additional support. After the glue dried, I used larger screws to secure the body to the base.
There is considerably less movement at the top of the body.
xingshen
Well-Known Member
Cool videos ( nice jeep )
Glad to see you got the drive train working good.
What motors are you using?
I'm wondering about the horsepower to weight ratios.
I think leach145 is talking about this:
http://www.elstreeprops.com/page20.php
You'll have to scroll down to find the Treadwell Stuff.
I've thought about using wood for the wheels, but I think I have that aluminum-itis from another build I've been working on for a while.
Happy New Year!
Glad to see you got the drive train working good.
What motors are you using?
I'm wondering about the horsepower to weight ratios.
I think leach145 is talking about this:
http://www.elstreeprops.com/page20.php
You'll have to scroll down to find the Treadwell Stuff.
I've thought about using wood for the wheels, but I think I have that aluminum-itis from another build I've been working on for a while.
Happy New Year!
Happy New Year!
The motors I am running are two AmpFlow E30-400 brushed DC Motor. I tend to build heavy monstrosities that require a lot of power, the base weighs in at around 100 pounds. The peak horsepower on these motors is 2.1.
Thank you so much for the link, I have not seen this information before. I have most of those pictures from other sources, but this is the first time I have seen info on the tension system they used.
The neck area of the droid is being changed out completely. About a month ago I tried Google Sketchup for the first time to see if I could make something that better matched the plans and what was originally used.
This is my current neck
This is what I was able to do using Sketchup. It will need to be modified as I could not figure out how to remove some areas.
I ended up printing the part with Shapeways and this is what I got.
I have marked the prototype with the areas I need to remove. Once I have this prototype looking the way I need it to look, I will mold it. I am a little nervous this one will not be strong enough without reinforcement.
This is my current neck
This is what I was able to do using Sketchup. It will need to be modified as I could not figure out how to remove some areas.
I ended up printing the part with Shapeways and this is what I got.
I have marked the prototype with the areas I need to remove. Once I have this prototype looking the way I need it to look, I will mold it. I am a little nervous this one will not be strong enough without reinforcement.
Moving on with the body, it is now time to build the three remaining arms. The reference pictures just do not show a tremendous amount of detail of the dummy arms. However from what I can see, I believe most of the arms are made up of different tools. My first two arms follow that logic, one is a magnetic tool and the other is the heat sensor from a multi-meter. I am going to make one dummy arm from a soldering iron and the other will be a scratch built saw. I got the saw idea from one of R2's tools. However this one will look like it is an earlier model.
Here are the parts I plan to use:
Most of these things are left over bits I have laying around.
I created a couple of sprockets for the chain to rest on with bushings and styrene tube.
This is going to be the motor for the saw. Any of the R2 Builders out there will notice it is a cut down resin Knurled Hose Fitting with a washer and a heat sink glued to it.
I am using a piece of rectangular brass stock as the main base for the saw.
Simply drilled some holes in the brass stock and used screws and glue to hold everything together. The saw is a plastic cap with the threaded lip removed.
This is what it looks like with the chain attached. It is not glued on because I want to paint it separately.
Glued on two more pieces of styrene tube as hold downs for the wire.
Ran a braided wire to the mock motor, the wire will feed into the body.
Test fitting the saw arm to the body.
Here are the parts I plan to use:
Most of these things are left over bits I have laying around.
I created a couple of sprockets for the chain to rest on with bushings and styrene tube. This is going to be the motor for the saw. Any of the R2 Builders out there will notice it is a cut down resin Knurled Hose Fitting with a washer and a heat sink glued to it. I am using a piece of rectangular brass stock as the main base for the saw. Simply drilled some holes in the brass stock and used screws and glue to hold everything together. The saw is a plastic cap with the threaded lip removed. This is what it looks like with the chain attached. It is not glued on because I want to paint it separately. Glued on two more pieces of styrene tube as hold downs for the wire. Ran a braided wire to the mock motor, the wire will feed into the body. Test fitting the saw arm to the body.
xingshen
Well-Known Member
Thanks for the info on the motors
Been wondering about the Shapeways material myself. Looks like you went with the nylon based stuff. Seems like it would be durable since it won't be under a lot of stress or weight. Another option might be to skin it with aluminum since most of the areas are flat.
Agreed that there doesn't seem to be any really good detail pics of the arms. I like the saw idea. Seems like something that would actually be on the droid.
This is the clearest pic I've been able to find
View attachment 270453
I'm also noticing some differences between The ANH and Clones versions.
View attachment 270454
Been wondering about the Shapeways material myself. Looks like you went with the nylon based stuff. Seems like it would be durable since it won't be under a lot of stress or weight. Another option might be to skin it with aluminum since most of the areas are flat.
Agreed that there doesn't seem to be any really good detail pics of the arms. I like the saw idea. Seems like something that would actually be on the droid.
This is the clearest pic I've been able to find
View attachment 270453
I'm also noticing some differences between The ANH and Clones versions.
View attachment 270454
