Cat Excavator Updated With Boom And Arm!!!
 

Well there have been several people that have been hounding me to show the start of my build so I decided to take a few photo's of my progress so far today and let you all see where I'm coming from. I don't have any before photo's but of course we all have seen a stock Bruder by now. Anyways I'll let a few of the pics do the talking. :D

The start of the drive tracks.

http://i90.photobucket.com/albums/k2...s/100_2070.jpg

New drive hubs that will be capped off with the center acting as a wheel nut.

http://i90.photobucket.com/albums/k2...s/100_2071.jpg

Back of the drive hubs.

http://i90.photobucket.com/albums/k2...s/100_2072.jpg

Now we all know what the back of the excavator looks like right?

http://i90.photobucket.com/albums/k2...s/100_2073.jpg

But once it's filled with lead it becomes a great counter weight for the boom.

http://i90.photobucket.com/albums/k2...s/100_2074.jpg

Did anyone say they needed to dig at night? If so I should be able to help lol.

http://i90.photobucket.com/albums/k2...s/100_2075.jpg

Now the start of my new rams on the arm.

http://i90.photobucket.com/albums/k2...s/100_2069.jpg

And a quick video of the first testing.

http://i90.photobucket.com/albums/k2...h_100_2068.jpg

Thanks for looking and hope to be able to make some progress on it this week and possibly get it rolling.:rolleyes:

Re: Bruder Cat Excavator Conversion
 

Awesome start!!! Looks like a very clean build.

Re: Bruder Cat Excavator Conversion
 

Awsome start! Can't wait to see more.

Re: Bruder Cat Excavator Conversion
 

That looks like a great start. Can't wait to see more.

Re: Bruder Cat Excavator Conversion
 

Well just thought I'd post a quick update of my progress this evening. Got the second bucket ram mocked up and functioning. I still have to find the best pivot point but it is getting closer. Next project to tackle with be the main boom drives to support this whole contraption. Here are the pics to show you my recent progress, hope you enjoy. :D

http://i90.photobucket.com/albums/k2...s/100_2076.jpg

http://i90.photobucket.com/albums/k2...s/100_2077.jpg

http://i90.photobucket.com/albums/k2...s/100_2078.jpg

http://i90.photobucket.com/albums/k2...s/100_2079.jpg

Thanks for lookin. :rolleyes:

Re: Bruder Cat Excavator Conversion
 

Very cool ,looking good:D

Re: Bruder Cat Excavator Conversion
 

Nice and clean looking. It will be cool to see it dig.

Re: Bruder Cat Excavator Conversion
 

nice work on the excavator

Re: Bruder Cat Excavator Conversion
 

nice work ....

Re: Bruder Cat Excavator Conversion
 

Great looking build! Can't wait to see more.

Re: Bruder Cat Excavator Conversion
 

Thanks guys. I hope to have some more progress done this evening and get atleast one boom cylinder done so I can have the whole thing working. I'm waiting on some parts for the rest of it but I should be able to finish up the drive wheels also. :D

Re: Bruder Cat Excavator Conversion
 

Well just to post an update. I've found out that he drives that I'm using are just too much force for the plastic boom and arm so out went the idea of staying cheap and stock and in with the new over built project. I decided to put an order in for some brass from McMaster and build my own boom that will hold up to the abuse these drives are throwing at it. I was wanting to stay cheap on this but as everything else that didn't last long. I hope to get the brass here in the next few days and get it all layed out and brazed up. The stock boom weighs less than a pound and I have a feel the new one will be atleast a minimum of 2lbs to begin with and only go up from there. I should be getting my new radio for it today so I will try and post a vid up later of the rams in action. :D

Long Time Update
 

Well it's been several weeks since I updated this thread so I thought I'd show a little bit of my progress as of recent. I have been waiting for some parts to come in and working on the new boom design and decided I had enough to start today. :rolleyes: Here are some pics of the new drive style hubs and the start to the boom. I hope to start brazing it up tomorrow and have the arm started this week sometime.

Here is the inner part of my drive hub I've started. I have to get a new tap tommorow from work as I broke mine today in one of the holes but it shouldn't take long on the other hub.

http://i90.photobucket.com/albums/k2...r/100_2100.jpg

Here is the stock arm next to one of the sides of my new arm of brass.

http://i90.photobucket.com/albums/k2...r/100_2099.jpg

Here is the arm starting to go together with bracing and hollow rods for the pivots and screws.

http://i90.photobucket.com/albums/k2...r/100_2101.jpg

http://i90.photobucket.com/albums/k2...r/100_2102.jpg

http://i90.photobucket.com/albums/k2...r/100_2103.jpg

Thanks for looking and hope you all enjoy. I really hope this boom will hold up to these rams this time without breaking on the third load pull.:confused:

Re: Bruder Cat Excavator Conversion
 

Looking good!
The brass boom is going to be a really nice addition to the model. I don't think there will be any problem with it breaking.
Are you going to use servos for the track drives?

Re: Bruder Cat Excavator Conversion
 

:confused:I was wondering how you were going to build the boom. These pics answered my question. Thanks for the tips.

Nice work so far:cool:

Re: Bruder Cat Excavator Conversion
 

Thanks to both of you and to answer your questions, yes I am going to be using hi-torque servo's for the drive wheels. They will be housed in a custom brass housing and be completely protected from the elements.:D

Re: Bruder Cat Excavator Conversion
 

Well the boom was going to be soldered up today but I've decided that I want some more bracing and am going to be running some parallel bars through it that I'll drill the sides for so it can all be soldered solid. I'm looking at making this boom operatable so if I want in the future I can run full hydraulics if I want. Time for another order from mcm.

Re: Bruder Cat Excavator Conversion
 

looking good

Re: Bruder Cat Excavator Conversion
 

Tyler. Don't know if you thought about this, but you might try to fill the Bruder boom with expandable foam. Make sure you leave relief holes or it may overfill it. That stuff when it dries is fairly rigid and might do the trick. RC Logger built his boom from blue foam and laminated aluminum side plates and it's incredibly strong.
Rob

Re: Bruder Cat Excavator Conversion
 

Re: Bruder Cat Excavator Conversion
 

Thanks for the compliment.

Hey Rob. I have seen your idea that you are talking about done before but that just will not sufice to my likings. I have to build this excavator over kill because I just don't want to have any weak spots. I will have some pics of my boom up soon from my afternoon progress.:rolleyes:

Thanks for the compliment bud. I know you can build your's up and have it operatable in no time. The worst part of the build is the beginning of tearing apart an $80 toy. :eek: After you get that out of the way thats when things definitely start to change. Just don't look back and take a whack at it.

Re: Bruder Cat Excavator Conversion
 

Well I have some progress from this weekend. I still have some time left to work so I will be working like a mad man to get some things started on the arm but thought I'd take a break and post up some progress for you guys to look at. Hope you enjoy the pics and I should have another update later this evening if possible. Now onto the pics.

First was the start of mocking up my drives. Here are a couple quick shots.

http://i90.photobucket.com/albums/k2...r/100_2105.jpg

http://i90.photobucket.com/albums/k2...r/100_2106.jpg

Now onto the boom.

Swiss cheese sides.

http://i90.photobucket.com/albums/k2...r/100_2107.jpg

Starting on the supports.

http://i90.photobucket.com/albums/k2...r/100_2108.jpg

Sides and bottom brazed up.

http://i90.photobucket.com/albums/k2...r/100_2110.jpg

http://i90.photobucket.com/albums/k2...r/100_2111.jpg

How the ram will sit.

http://i90.photobucket.com/albums/k2...r/100_2112.jpg

http://i90.photobucket.com/albums/k2...r/100_2113.jpg

Some comparisons with the stock and my newly designed boom.

http://i90.photobucket.com/albums/k2...r/100_2114.jpg

http://i90.photobucket.com/albums/k2...r/100_2115.jpg

http://i90.photobucket.com/albums/k2...r/100_2116.jpg

http://i90.photobucket.com/albums/k2...r/100_2117.jpg

Final stages of the upper and lower supports of the boom on with the ram.

http://i90.photobucket.com/albums/k2...r/100_2118.jpg

http://i90.photobucket.com/albums/k2...r/100_2119.jpg

http://i90.photobucket.com/albums/k2...r/100_2121.jpg

http://i90.photobucket.com/albums/k2...r/100_2120.jpg

And a final look down the front of the boom.

http://i90.photobucket.com/albums/k2...r/100_2122.jpg

That is all the progress I have from today and hope to get the arm close to this stage this evening if all goes well. :D

Thanks for looking.

Re: Bruder Cat Excavator Conversion
 

Well I have a little more progress for this afternoon so far. I got the sides cut out and drilled for the arm so I can start brazing it up tomorrow after work. I am in the process of turning down all the cross braces and getting it aligned and it will be operatable hopefully soon.

Here's some more pics.

http://i90.photobucket.com/albums/k2...r/100_2124.jpg

http://i90.photobucket.com/albums/k2...r/100_2125.jpg

http://i90.photobucket.com/albums/k2...r/100_2126.jpg

Thanks for looking. :D

Re: Bruder Cat Excavator Conversion
 

Looks good Tyler:cool:

Re: Bruder Cat Excavator Conversion
 

SWEET!!! I'm liking this build!

Re: Bruder Cat Excavator Conversion
 

Thanks for the compliments guys. Here are just a couple shots to see what it will kinda look like once it's together.

http://i90.photobucket.com/albums/k2...r/100_2127.jpg

http://i90.photobucket.com/albums/k2...r/100_2128.jpg

Re: Bruder Cat Excavator Conversion
 

Re: Bruder Cat Excavator Conversion
 

Looks fantastic. Are you using soft solder or silver solder on the arms. Look like you'll be digging in no time.
Rob

Re: Bruder Cat Excavator Conversion
 

Hey Paul. Nothing special here that I am doing that I'm sure you couldn't accomplish. Thanks for the compliment. I'm still thinking I need to see a build for your's though. I'm sure I could rummage some help up for you if ya needed it lol. :rolleyes:

Thanks for the compliment Rob. I am using silver solder as it is a little better flowing and stronger I've come to realize than simple solder. I hope if all keeps going well that I will be digging by the end of June. I still have a ways to go and this thing is moving slowly.

Re: Bruder Cat Excavator Conversion
 

Boy it's really coming along!
I have a question. I see that the bolt holding the servo in place seems to go right through the case. Is there room in side the servo for it to clear all the electronics or have you moved stuff to make it work?

Re: Bruder Cat Excavator Conversion
 

The servo is only drilled through just behind the pot on it where the casing is hollow. I chose it directly center of the ram and just behind there for the best center pivot point to the actual ram. There is no modification other than what I have done for full rotation to the electronics. I will be using a piece of brass tubing running through with a wrist pin to pivot on like a normal cylinder would so everything will be encased. The screws are just temporary holders and work great. :rolleyes:

Re: Bruder Cat Excavator Conversion
 

Thanks
I'll have to make note of that modification to be able to use it on some upcoming projects.
The excavator is really coming along and looking good doing it:cool:
Jordy

Re: Bruder Cat Excavator Conversion
 

Wow, i'm very impressed with your fabrication, simply amazing.

I bet Bruder never thought their toys would transform into "working" models such as this ;)

Big John

Re: Bruder Cat Excavator Conversion
 

Thanks John, I apriciate the compliment and I would assume that Bruder had no idea that us "big kids" would be turning their products into working machines meant to do work. I think it would be kinda interesting to take a video and some pictures of it when it's done and send to them to show what all can be accomplished by their work..... Hmm now I have got myself to thinking. :D

Re: Bruder Cat Excavator Conversion
 

Very nice - your servo-cylinders look really great!

BTW, Bruder know quite well that their toys are used by big boys ;) (they told me when I submitted a product suggestion).

Re: Bruder Cat Excavator Conversion
 

Tyler, that is looking great! What an ambitious build!

Brian

Re: Bruder Cat Excavator Conversion
 

Well time for an update on this little guy. I got some work done the last couple days to with the weekend off so I thought I'd show some progress. Not a whole lot but its starting to take shape and I can see that this thing is going to need some more power I believe. I was running it back and forth on the arm yesterday with a 10lb weight attatched to it and "SNAP" goes the pot in the servo for the arm. I couldn't believe it but the pot actually snapped apart and the servo went crazy. I shut it down and checked it out and low and behold the tiny fingers inside were all mangled and crossed contacts. So now I'm going to be ordering a stronger servo for the bucket movement seeings as how the 645 didn't really wanna take all the abuse.

Any ways here are some pics of my weekend progress. Hope you like.

http://i90.photobucket.com/albums/k2...r/100_2137.jpg

http://i90.photobucket.com/albums/k2...r/100_2136.jpg

http://i90.photobucket.com/albums/k2...r/100_2135.jpg

http://i90.photobucket.com/albums/k2...r/100_2134.jpg

http://i90.photobucket.com/albums/k2...r/100_2132.jpg

http://i90.photobucket.com/albums/k2...r/100_2133.jpg

Thanks for looking guys. :D

Re: Bruder Cat Excavator Conversion
 

Looking really good!
I like the way the servos are hidden inside the boom.
Are you putting the brass booms back inside the plastic ones for looks?

Re: Bruder Cat Excavator Conversion
 

No, the brass boom will get some more detail and will be all that is seen. I hope to scale it as close the the full size as possible. :D

Re: Bruder Cat Excavator Conversion
 

nice stuff....really nice stuff... being new and poor to this hobby and lurking for a few weeks on this forum i was trying to find another way of moving the arms of an excavator and what you seem to have seems to be the ticket... hydraulics seem out of the question.... way out of my range of know how and cost.... my question is where did you pick up those screw type cylinders, if thats what they even are, and how do they work radio wise, do you need a speed control or just reciever.... and while i'm asking questions, how do you make a servo go around and around acting like a drill, i thought they had limits to how far they could turn...

thanks Joe ...i'm really green to all this stuff