Cat 777D Mining Truck - Page 11

modelman · #**201** 06-29-2011, 11:26 AM

Thanks for the comments guys-I decided to make the hinge pins since I could not find shoulder bolts with long threads. Some of the pins are going into aluminum so I need lots of thread engagement. I am making these now and I have a few other small parts to make. Some of the small detail work I have been putting off has to be done before painting. I need to get a radio and ESC to check out the operation of all systems and I need to put limit switches on the dump bed and that is going to be a major pain because there is no room left. I have not decided what type of battery to use so I am open to suggestions.

JensR · #**202** 06-29-2011, 01:01 PM

I have used Tamiya shoulder bolts for their kingpins with some success.
Their thread is M4 and about 5mm long - maybe not enough for you?
If interested, check parts# Tamiya 50100 and 84175.

For the limit switches, maybe keep in mind that you can have the switch either actuated by the sliding "nut" or the dump box.

Battery: Sorry, cannot really help. I'm still using my old NiMH packs and have neither made the switch to LiPos nor bought new packs in ages.

Cheers
Jens

modelman · #**203** 07-25-2011, 05:51 PM

I had some small parts that needed to be made and I kept putting it off til later and now it had to be done so I can get this project finished. First I made this plate for the bottom of the radio box and it also serves as a shield to protect the steering servo linkages-

Next I made the front wheel hub covers-

I got the correct wire for the grille. This will have to be painted. They had this in stainless but the smallest pc. I could buy was $70+shipping and I only needed a pc. 2-1/4"X3" so I felt that was a bit high so I decided to paint the brass-

Next I put the springs in the rear suspension and put these chains on to limit the travel-

I put the limit switches on the dump mechanism-

I won't route the wires until it's painted. I think that's about all the building on this model. It will be awhile before I paint it . I am waiting on the ESC now and I have a radio to test everything. I still have to decide which radio to get. I need a switch to run the dump box so I am open to suggestions on a radio. That's all for now.

9W Monighan · #**204** 07-26-2011, 08:17 AM

Maybe a DX3 is all you'll need for it? You know, Put it a box and send it up here so we can give it a endurance test at Brownsville in 2 weeks

I would love to test it to see what grade the haul roads need to be in our miniature pit

tc1cat · #**205** 07-26-2011, 08:47 AM

Traxxas has a 4 channel pistol grip 2.4GHZ radio TQ 4 that has a 2 position switch and a 3 position switch for channels 3 & 4. This should work very well for your truck. I have 1 in one of my trucks that I am going to use with one of Izzy's bottom dump trailers. It runs the Firgelli with no problem. Tower Hobby has them for $103. Not a bad price for what you get.

Truck needs some paint!! Still looks nice as it is!

modelman · #**206** 07-27-2011, 12:17 PM

Steve-I wish it was finished-that would be a good test. While I am making a wish list I wish I wasn't 720 miles away. I would really like to go to some of these shows. tc1cat-thanks-that may be just the radio I need-I could use the on-off switch for lights and the 3-pos. switch for the dump box. I agree the truck needs some paint. I am sick of chasing rust!! But I have to get everything working with a radio before paint. There is probably holes to drill for wires and who knows what else. Maybe it won't be too much longer.

td9clyde · #**207** 07-27-2011, 06:18 PM

i would put a lil primer on it since your that close primer is easyer to fix

Slick · #**208** 07-31-2011, 07:32 PM

I can't wait to see it painted.

modelman · #**209** 08-11-2011, 03:16 PM

Just a small update-I got my esc and used my Airtronics M8 radio to test the truck. To my disappointment the truck is really slow

and I mean crawl speed slow. It is running .385-MPH and the correct scale speed is 1.5-MPH. I guess I had brain-fade when I calculated the speed of the truck and ordered the motors and now I am limited to the motors I can use because they have to fit inside the rear wheels. I have located some motors that will work but they will be about 30-35 RPM slower than I need but that is as close as I can find so I guess they will have to work. That's it for now.

9W Monighan · #**210** 08-11-2011, 04:36 PM

Sorry to hear it's not working as planned. Luckily a quick motor change should do the trick. At least with a slower final drive it'll have power to pull hills.

Smokin Joe · #**211** 08-11-2011, 05:16 PM

I build 1/24 scale models for clients from pictures of "the one they
wish they still had" Right now I am building a Pro Street 2006 Camaro Station
Wagon! Chevy made one up to the clay stage and then dropped the prototype program for it. A engineer asked me if I could build him one. I found a resin s/w body on ebay. $9.99 My point is I have a guy who casts tires for me when I need. I would be more than happy to ask him for tires anyone needs. You have the buck built which is the most difficult part. He also can use different compounds to fit the application.
MicroMark sells a good rubber mold compound for use in silicone molds. You
would be able to make a 2 part mold using the correct mold release spray.
Any questions, please ask. Joe
Experience is what you get right after you needed it.

Smokin Joe · #**212** 08-11-2011, 05:21 PM

Very nice craftmanship!

Smokin Joe · #**213** 08-11-2011, 06:21 PM

Quote:

Originally Posted by modelman

Thanks TD9-but factories are not supposed to make mistakes. I messed up on the angle of the front bumper and I really don't know how I am gonna fix it.

If you don't make mistakes, it only means you are not doing anything! You a true artist.

modelman · #**214** 08-12-2011, 10:25 AM

Steve-the motors do not have as much power as I would like because of the size and speed but I filled the box and the motors I have worked just fine and the new faster motors have more torque so I think it will all work out okay. Smokin Joe-I'm not sure what your thought process is here but the tires were the first thing I made on this project and they are the correct size but thanks for the offer and for your comments.

Smokin Joe · #**215** 08-12-2011, 03:36 PM

Quote:

Originally Posted by modelman

Steve-the motors do not have as much power as I would like because of the size and speed but I filled the box and the motors I have worked just fine and the new faster motors have more torque so I think it will all work out okay. Smokin Joe-I'm not sure what your thought process is here but the tires were the first thing I made on this project and they are the correct size but thanks for the offer and for your comments.

I leaped before I looked. I was not aware you had cast your tires previous
to my post. An attempt to help. I admire your skills.
Joe

Lil Giants · #**216** 08-14-2011, 04:23 PM

Looking better with every update Tom...

modelman · #**217** 08-23-2011, 11:57 AM

Lil Giants joe-thanks a lot! I am slowly getting there!

modelman · #**218** 09-15-2011, 08:27 PM

UPDATE!! BAD NEWS-I got the truck painted and thought it turned out great

But,that was a week ago and the paint is not dry

So now I get to strip it down and start all over

I think the idiot at the paint store gave me the wrong paint. Maybe I should just put it out in the drive-way and run over it a few dozen times with my truck!!! Then see if the paint is dry!! OH WELL!!

Trucker47 · #**219** 09-15-2011, 11:39 PM

hey sorry to hear about the bad news,hopefully you can get rollin again soon.

Chris

Lil Giants · #**220** 09-16-2011, 12:57 AM

I'm no paint mixing expert by any means, but could it be as simple as no or not enough harder added to the mix?

Would it help to try and bake the parts in the oven at 100 to 200F degrees or more to quicken the drying time?

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