D7E RC 1:7,5
 

Hello guy’s,
This is my very first tread ever started on a forum. I’ve been reading almost every RC earth moving build tread that I could find.
I always loved the D7E, by design and because the technology of the machine. Two years ago I came across an old CNC mill, and started machining with it. When I managed to connect it to my computer and machine the designs without manually programming them, it started to become clear I would build a RC dozer.
My background is mechanical engineering, and I was already familiar with 3D drawings. The CAM part of the building process is new for me, and I’m learning by trial and error.
After designing, building and reading for more 1,5 year, I decided to start a tread about the build of my radio controlled D7E.
The first few parts are machined and ready. I started with the undercarriage. The link assemblies are the first to be completed.
I plan to design and build at the same time. The drawings are a little further than the parts.
With this tread, I’ll show the progress as it goes. Hopefully the machine will ride next year summer.
I hope you enjoy reading my posts, feel free to ask any question.

Attachment 3413
Attachment 3414
Attachment 3415

Best regards, Bob.

Re: D7E RC 1:7,5
 

Welcome Bob

nice job on the sprocket

Re: D7E RC 1:7,5
 

Welcome aboard! I've spent time on the military version, of the D7E.
Cheer's, Neil.

Re: D7E RC 1:7,5
 

Thanks for the replies.

I've machined the track links:

http://i803.photobucket.com/albums/y...psef02d7c5.jpg

They will be assembled to be the track at the end;

http://i803.photobucket.com/albums/y...ps9aad8b2e.jpg
http://i803.photobucket.com/albums/y...ps18df315b.jpg
http://i803.photobucket.com/albums/y...psb64f6f28.jpg
http://i803.photobucket.com/albums/y...psca00a0c4.jpg

Regards, Bob

Re: D7E RC 1:7,5
 

Neil, did you work with the modern version? The electrical driven one.
Regards, Bob.

Re: D7E RC 1:7,5
 

****, bearings in the links, that's serious! :)

Looks like an awesome start, nice parts!

Re: D7E RC 1:7,5
 

RC Dozer-you are doing some nice machine work here. Is this going to be a shelf queen are will you be using it in the dirt. I have found that these very small bearings will fail under high-loads. Keep us updated and good luck. Nice job so far!!

Re: D7E RC 1:7,5
 

Nice work, Did you weld the cleat on the pad or are they machined? I really like the rails, lots of time invested there.

Re: D7E RC 1:7,5
 

Hats off to you. Very nice start. By any chance; are those links cast?

Re: D7E RC 1:7,5
 

Lol!, No the 60's version. I liked the 4 cylinder engine a lot better, than the F's and G's with the 6 cylinder. I left the Military after "Desert Storm".

I remember talking to the Cat guy at Con Expo Con Ag show, when the "new"
D7E came out. The conversation was hilarious when somebody asked if it was going to start on fire once a week, like the Letourneau machine's did.
My comment was, Oh you copied Terex on the blade lift cylinder. Well he did have a sense of humor. I've sat in one, no demo time at the dealer's open house yet.

Look's like you have a great start!
Cheer's, Neil.

P.S. Have you tried Google for picture's, to help with detail's?

Re: D7E RC 1:7,5
 

Great start. I'd recommend bushing instead of bearings due to the potential for dirt and grit getting into the bearings over time, bushings are much less expensive too.

I demoed a D7E about 2-3 years ago right as they came out. I thought it was a nice machine, good power, smooth operation.

Re: D7E RC 1:7,5
 

Hello modelman, it will not be a shelf queen, the goal is to push dirt. Hopefully the bearings will last, and if not, I can always replace them with bushings.

Re: D7E RC 1:7,5
 

The pads are welded on the other side, and machined flat again before bending.

Re: D7E RC 1:7,5
 

Thanks for the nice comments.
The links started as waterjet cuts, and are machined to the current shape.
It was a **** of a job, but the result is what I hoped for.

Re: D7E RC 1:7,5
 

Some pretty nice detailed parts!! I'll be watching!!

D7E RC 1:7,5
 

I've been working on the drive.
The gears that I'll use are bought.
At the moment I'm machining the final drive parts that hold the gears and the bearings.
Hereby some scerrenprint from how it will be made.

The gears
http://i803.photobucket.com/albums/y...ps1393efea.jpg

The design
http://i803.photobucket.com/albums/y...psd125ed66.jpg

http://i803.photobucket.com/albums/y...pse370daa2.jpg

http://i803.photobucket.com/albums/y...ps3213b64b.jpg

Re: D7E RC 1:7,5
 

Today I've been machining the gearboxes that will hold the gears.

http://i803.photobucket.com/albums/y...psfe7b2aef.jpg

http://i803.photobucket.com/albums/y...ps90739966.jpg

http://i803.photobucket.com/albums/y...psffe8c74d.jpg

http://i803.photobucket.com/albums/y...psbd56f9aa.jpg

Still needs some machining.
Thanks for reading, regards Bob.

Re: D7E RC 1:7,5
 

Great job on the dozer!!! Hope to see more soon.....keep up the great work!!

KP

Re: D7E RC 1:7,5
 

Very nice parts. High quality build. Will be following you.

Stefan

Re: D7E RC 1:7,5
 

The last few weeks, I've been machining one of the frame plates.
That was a lot of work due to all the different shapes and heights.

http://i803.photobucket.com/albums/y...ps72ff5910.jpg

http://i803.photobucket.com/albums/y...ps7ca09bff.jpg

http://i803.photobucket.com/albums/y...ps14b6f96d.jpg

The rest of the final drive parts are machined at the moment.

Re: D7E RC 1:7,5
 

Bob you are doing an excellent job. I am just starting to learn CNC and it is not easy for me but I guess it will happen some day. Ed

Re: D7E RC 1:7,5
 

It has been silent for a while on the thread. The where some issues with my mill, which are sorted out now.
In the mean while I have been working om the electronics and the drawings. I recently finished one side of the tractor and I am now working on the other side.

http://i803.photobucket.com/albums/y...pslv9alixw.jpg
http://i803.photobucket.com/albums/y...ps3zt60a33.jpg
http://i803.photobucket.com/albums/y...psebd2lq0n.jpg

The first run, still without the recoil tensioned. But the overall performance is not bad at all.

https://youtu.be/BhSus3TSL9w

Thanks for watching!

Re: D7E RC 1:7,5
 

Glad that you are back, this is looking very good, can't wait to see what else you have in-store.

Re: D7E RC 1:7,5
 

Thanks rc farmer,

I hope to have the tractor part driving soon.

http://i803.photobucket.com/albums/y...pstmt6ifwf.jpg

The other roller frame is close to be finished.

Thank you for watching!

Re: D7E RC 1:7,5
 

Looks very good, will follow progress closely.
Dan

Re: D7E RC 1:7,5
 

Thanks for the complements, still al long way to go.
Hereby the status as it is now.

http://i803.photobucket.com/albums/y...pssfpsop0k.jpg
http://i803.photobucket.com/albums/y...psbhvceh5o.jpg
http://i803.photobucket.com/albums/y...psqytxo6al.jpg

Re: D7E RC 1:7,5
 

Wow!! Love what you did with the motors!! I'm sure you will be happy with them. I used similar in my dozer (big wiper motors) and they have never stalled, worn out, or given any problems, two+ years now and still good. May want to make sure before I say that :) lol!! This is really looking good!! Heavy!!

Re: D7E RC 1:7,5
 

Thanks for your feedback Cooper, I hope the motors will do as good as yours. They actually come from a Cat 740 ATD. Regulating the speed is still a challenge, and hopefully the power consumption is not too much.

Re: D7E RC 1:7,5
 

I got to hand it to you working with steel is a lot harder than aluminum but it will last a lot longer. Ed

Re: D7E RC 1:7,5
 

Nice!!! Really like what you have done....looking forward to seeing this build take shape....

Re: D7E RC 1:7,5
 

Nice, love the wide tracks...

Re: D7E RC 1:7,5
 

I managed to get the D7E running.
The project will be silent for a year, I'll be building a house first.

At least the power train is done.
Still enough to finish, but I'm glad it is moving.

A little video.
https://youtu.be/ezx7_X_h47w

Thanks for watching!

Re: D7E RC 1:7,5
 

Wow!! Very smooth. I guess you are on the list of places to visit, take you out for a late night of partying, then I can quickly slip away with your dozer!!! I know Ed complimented you on working with steel, I also agree, tuff to work with on these small parts but doing an excellent job. Looking forward to your next steps. Good luck with the house, I too am prepping for a summertime move.

Re: D7E RC 1:7,5
 

That's what is was saying while watching the vid o "wow and smooth"!

I can't get over how big that thing is, going to seem even more so when you get it finished!

Jim

Re: D7E RC 1:7,5
 

Thanks for all the comments guys!

Making the small pasts is a challenge, but I am fortuned to have a CNC mill. The components are drawn in 3D first, after which I can create the CNC program directly in the same software. That makes life easy.

Yes, it is rather big. Building scale 1:8 has that consequence. The machine will be up to 1000mm long, once the blade and ripper are installed. My guess is that the weight will be around 10kg. The size has the advantage that I can use normal components, and the machine will also actually be able to move some dirt.

Regards, Bob.

Re: D7E RC 1:7,5
 

Very impressive Bob. That´s the advantage with such beefy motors - almost silent, probably torque without end. Evidently that´s 100kg. I´m only a bit confused about the scale: Title says 1:7,5 but you just wrote 1:8???

Stefan

Re: D7E RC 1:7,5
 

Very nice work so far look forward to more.

Re: D7E RC 1:7,5
 

Stefan, The overall scale is 1:8, however some parts are slightly bigger. In the beginning when I was only building undercarriage parts, the overall scale was 1:7. If you count the links in the link assemblies, you will find one less than the real machine has. It came out like that, using the bearings I found.

Thanks for watching.