D8R +463 in 1/5,6

[catmack]

Too bad you couldn't put a release on the planetaries like I have on my manlift, when it breaks down, you remove covers for the release buttons, push them in to freewheel the hubs.

[doodlebug]

Too bad Warn 4wd hubs are out of scale, lol!
(they're on American 4wd pickup trucks)
Cheers, Neil.

[Espeefan]

Wow! I love the little details! In a larger scale like this, you really can see all the small touches, and they add so much to the model. I bet when it's finished, and in the proper outdoor setting, it's going to look like the fullsized machine it replicates!

[D8R]

Wow, over 50.000 views! Could never dream that there so much interest in my build

Thanks for all nice words, keeps me going. Guess I owe you a update, no pics because nothing new to show. Did work this weekend sandblasting some components, old paint was chipping (2K). With new primer and a top layer today, went back to borrowed shop to pics up att parts, only to discover that new paint didn't dry correctly like before

Since the shop I borrowed will be in business tomorrow morning, had to bring all parts back home, trying to do as little harm as possible. This is the last time I will have a limited time when painting. So much can go wrong and it did!

Was planning for a show 2 weeks ahead but guess has to cancel that now. Will not do any repainting before machine is working.

But weekend was not totaly disaster, did find a solution on the rubber cusions in bogie assemblies. Did move the steps on push arms to a correct lower position (did not have any pics with me when I welded them last week )

By the way, said earlier that I have built this during the last 10 years, that's correct but found a drawing I made, dated to 1998 on a D8N. Lucky for you that this forum was not started at that time, compared to other builds here this is a borring slowly build!

Happy eastern
/Dan

[D8R]

Last update before start up of engine

Did get most things done for this weekend show here in Stockholm, now only missing windows for cab, hydr lines to ripper tooth cylinder, lamps.
Everything else done. No, engine not started, the gray over engine is some sun reflections!


Yes, I know the ripper should be yellow but couldn't start up painting equip only for this item, will do that later


Some other pictures showing displays
Next to me was nice gentleman with a 1/6 Tiger tank, electric powered


Some RC trucks at display


Nice small scene with a Beetle bus


A 1/24(25) scale model of an UPS tractor


Old beaten Volvo F16 truck, plastic 1/24


/dan

[Lil Giants]

Originally Posted by D8R

Yes, I know the ripper should be yellow but couldn't start up painting equip only for this item, will do that later

Screw that!!! Sink it in the dirt & burn the paint off... is how it should look.

[RCLogger]

Thanks for the update Dan, great photo's... I am sure your CAT WOOOWED the people at the show...

cheers
Greg

[jack van]

This has to be the best build ever your skill is amassing do you keep a parts list and cad drawings for parts

[ptebbe]

Truly amazing work. Can't wait to see some video....

[D8R]

Hi everyone, hope you have nice holidays!
Have not been so active with this Cat, but did get it running 3 months ago.
Found out that servos did not work as well as planned, felt like not having enough power (they should).
As you can see on link to vid bellow, that day model was only doing a left turn.

http://www.youtube.com/watch?v=psCaubtK4uo

Now I have new servos, got the holder cut only to get it together. But it's winter and have no warm garage to work in so have to wait (what is a couple of months, been building for 10+ years now).

Another problem is heat, engine getting to hot. Have tested removing noice damper inside homebuilt muffler, ended up mounting original silencer instead, hood and sides can not be on model with this muffler. Have to find another solution. Will try make a exhaust system without muffler to see if temperature gets lower.

And there's still some issues in hydraulic system. Can say that I was quite close to remove engine and hydraulic drive line, replacing it with electric motors. I know now that my size of model is as small as possible to build with this, components, tubing, hoses and all oil needed to get it running is just to much. A scale 1:5 should have been useful, every bit inside is used (of course cab could been used for oil and others but that's no option for me).

Some design errors made on homebuilt hydr cylinders has to be corrected to, but I'm supriced how good cylinders for blade turned out. Still more than 3 months since model was runned, blade is in air! That's tight cylinders, and weight of blade is almost 50 lbs.

Yes Jack, have all drawing saved on the model, but there will never be another made by me, just to many other interesting models to be built.

During the last months I have been active building some railroad stuffs, will post that in a seperate tread later.

Merry Christmas and a Happy New Year to you all!
Dan

[tc1cat]

Very nice dozer, to say the least!! Your issue with the motor may be not enough air flow over the motor to keep cool. Electric may be the best way to go. With your machining abilities, it should be no problem to make a drive system for the dozer. Ripper looks OK to me. Just needs to be pulled thru the dirt a few times and nobody will know its not yellow.

[D8R]

Originally Posted by tc1cat

Very nice dozer, to say the least!! Your issue with the motor may be not enough air flow over the motor to keep cool. Electric may be the best way to go. With your machining abilities, it should be no problem to make a drive system for the dozer. Ripper looks OK to me. Just needs to be pulled thru the dirt a few times and nobody will know its not yellow.

The Honda engine has a built-in fan that should keep engine cool. Have been thinking to add extra fan to get more air in-out of engine room.
Can't so much about engine (either), but if muffler don't let exhaust out easy I guess engine will have to fight harder to get mowing. Will test with new exhaust pipe.
Yes, yes, know wrong color on ripper but a soon model is up running good, all paint will be gone

[JAMMER]

Hi Dan Merry Christmas to you. Only a suggestion but you could try some computer fans under the hood to cool it and help remove exhaust gases. This is a very nice dozer and Big hope you get the kinks worked out so you can really enjoy using it. Ed

[modelman]

D8R-dozer looks great and seems to have plenty of power. Hope you get the cooling problem worked out. This machine could do some big time pushing!!!

[D8R]

Originally Posted by JAMMER

Hi Dan Merry Christmas to you. Only a suggestion but you could try some computer fans under the hood to cool it and help remove exhaust gases. This is a very nice dozer and Big hope you get the kinks worked out so you can really enjoy using it. Ed

Yes Ed, have had same idea using such fan being powered from rc battery (have a large one and radio has voltage warning). Still think it's the homemade muffler causing the problem. A friend of mine installed a electric device that starts fan automatic when engine gets to a preset temperature.

Dan

[D8R]

Did finaly get new servos installed for hydr valves to drive motors. Did run good with full control.
Next day it was planned to put model in (warm) storage during winter, started up engine only to realize that there was something wrong with valves for blade. Cylinders was pushing the blade downwards all time, only having control when lifting blade (then back down again)

Had to remove gears in hub reduction to move it for transport to storage and knowing that machine has to be disassembled AGAIN totaly (except left track) to get valves and servos for blade/ripper function out.

Not so happy anymore, model in storage now for next 3 -4 months. Don't know what's the problem but guessing I'll have to change servos for those functions to. A little frustrating, as said before, was very happy with blade sitting in air for 3 months time.
Next model will be electric
/Dan

[D8R]

Let do like this





After a long brake (winter) I finaly had new servos installed in almost complete empty shell. The positive is that new servos are stronger, easier to "hold" centre position on valve. They are a little bigger, did check that compared to hydraulic motor diameter, it should fit.



It did NOT, the lower connector to motor, it's screw hits the servo, making it impossible to get assembly in right place. The valve hits rear end of chassis, no margin there. After another hour trying to get in place I packed up.
It looks like model has his own life, trying to make it as hard as possible for builder.
As I see it today there's 3 options
1. replace servos to same as before
2. rebuild hydraulic connectors and valve position (not much room available before hitting cab floor, maybee a complete redesign of hydaulic system.
3. rebuild machine to electric drive

My interest in this model is dropping, after 11 years and say +2000h in it, not to mention the cost, it's to much to scrap (luckely I didn't have a big hammer today).
Will let it sitt there for a couple of days, then decide what to do.
/Dan

[modelman]

D8R-sorry to hear that. This model is way to nice to give up on I can say this is one of the problems of almost finishing a model without checking all systems but you probably don't need or want to hear that . I no nothing about hyds. but I was not aware that it took a strong servo to hold valves on center. Could it be the quality of servo that you are using? I say just give it a few days and then slowly work out each problem. You have built a great model and I am sure you can figure this out.

[tracksntreadslou]

Hey dan how much room do you need ..Is it possible to turn the hex part round on your lathe then machine a hex into the backside so you could tighten with an allen wrench ..I take it thats an o-ring seal

[Cooper]

Yea don't give up, never give up,,, I am new to these things and have found many many misfortunes with build design. But after being excited to see it work to only be let down by something failing I've left it alone for a bit to come back with something that works better. I'm sure with the talent you have displayed in the building of this model that you will find a way to make it work. It's all there just have to find that final solution. Sometimes I think of breaking out the small toolbox I have in the corner, it's got a hammer and vice grips,, a big hammer!! I haven't had to use it yet,,lol!! Have you thought of low profile servos? This is a really cool model you have and how sweet will it be when you do get it running how you envisioned!!