MCD Comp V4 Monster Truck-Assembly Thread

[macboss]

I just joined the LSF and posted an intro in Introduction Thread.

I became interested in RC cars a few months ago. My main hobby is RC planes; have several 50cc size gas planes and one 1/5th scale P-47 with a 5kw electric motor. The wind has been very bad this spring and a friend purchased a E-REVO and it really interested me. I just did not want to have to work with lipo batteries and did not want to go back to nitro engines. When I saw the 1/5th scale gas cars on the market, I knew that would be how I would go. I'm going to be more of hobby driver and hope to not have a lot of crashes.

I ordered the MCD V4 Monster from IHP and was very pleased with the service. I called them (did not write down the name) and was informed that they were out of stock of Zenoahs so I went with the CY 28.5cc in chrome. I figured it is really like this, I'll probably want to buy one of the custom engines later.

Basic kit:
MCD Competition V4 Monster
CY 28.5 Engine/chrome
Upgrading to IHP filter set/with outerwear
HS-5755MG Servos (using both throttle and steering)
DX3S radio: will us SR300T receiver for at least receiver battery voltage
Will have a 6v 4600 battery but may use A123 batteries ( I have several from my planes)

Just a couple of pictures;more tomorrow night, I hope. Pictures show a big box; everything was in good shape in box; chrome engine. No instructions but this thread has already helped me. Please fell free to send suggestions.

 

[CSR260]

looks very nice bud that engine looked huge!! in the 3rd pic but its how the pic
turned out :lol:

keep us posted

 

[macboss]

I'll post a few shots of the frame to show how the engine lays out tomorrow night. The engine is huge when compared to the engines used in aircraft.

Your up early,

Even old guys like me can see this truck. That is why I went to 50cc size planes. Big flys better and is easier to see. Hope same applies to cars. What I really like is gas engines are low cost on fuel and you just set on the ground and pull the cord.

Ed

 

[macboss]

Just a couple of comments on my build plans:

I'm going to use a spring loaded control horn on the brake: saw this in a post but can not remember where.

I used the big servos and will open them up and re-seal the bodies and shaft exit.

Will make my own wire bundle to have all servos draw power directly from the battery. Saw in a thread on this forum. Set this up with Y-harness and works great.

Put a new vent port in the gas cap: saw on this forum.

Will install a kill switch: either one from my plane inventory or I'll buy a Killer-B.

Will probably get a header and pipe later but using standard muffler now.

My hold up is waiting for delivery of the HiTec grease from Horizon Hobby-will be here on Tuesday.

I'm going to attempt to paint a nice color scheme. I may break out my air brush but rattle cans are OK too.

Good night for now.

 

[Bigger the Better]

I love seeing boxes that big full of toys!!!!!!!!!!!!!!!!!

 

[atom3624]

+1 BtB - love big boxes full of bits!!
I'm not a fan of the 'new MCD MT tyres' as they just don't look like MT tyres - they have the dimensions and I'm told they're better made, more consistent, etc., .... but they're not MT tyres for me.

Definitely looks an interesting build.

Do you have an idea of the paint scheme yet?

Al.

 

[CSR260]

Your up early.



Ed

Dude i never even went to bed :lol:

 

[BiggaJ]

High Macboss, on your servo's 5755mg why are you opening them up? they already come dust and water proof!!

Might be worth looking at the CPI Side pipe from Large Scale RC, very good power made from this pipe on the larger engines and fits the car perfectly unlike many so called yuned piipes that say they fit but burn your body and radio box!!!

Good upgrade is the MCD metal gear carrier, strengths things up, gets rid of heat better, smooths out the drive train.

MCD plastics are very tough. Good decision on the car.

 

[macboss]

BiggaJ-thanks for comments.

About the servos: There is a post in the electrics sections about problems with HiTec sealing rings on the servo bodies. Also, improving water resistance by putting a large bead of grease inside the servo cap around the output shaft. I probably will not be running in real wet areas but I'll have to think about this.
One servo issue that is bothersome is how the servo arms line up on the shafts. I attached a picture below showing the 3 servos with arms attached. One of my three servos has the arm almost perpendicular to the long axis of the case. The other two were off in almost the same direction by a few degrees. I used these 2 on the steering and as luck would have it, the are evenly off so I will have symmetrical alignment of the steering arms. I removed the cover of one of the steering servos to see if I could rotate the gears to get the arm to be straight but could not seem to make the arm change alignment. I did notice that there is no grease around the output shaft to keep water out: if that is needed.
I also attached pic of the standard muffler with a hose attached. I'll use this for a while. LS RC is out of stock on pipes so I'll get that later.

 

[macboss]

Just a few more pictures of the body and chassis. You can see the size comparison to my controller. I also attached a picture of the wire harness I made up. The two steering servos are on a Y; the throttle servo is on a Y; I have a battery Y that goes to two JR male terminals. The steering Y is then connected to a second Y which is connected in parallel with the throttle Y to the battery and receiver. Note my battery will use the EC3 type connector ( I have a lot of these on planes).
Set up the servos, wheels, etc, and drove the truck around the yard today. Now that I know it all works, I start hard wiring everything in. Then on to body painting.

 

[BiggaJ]

Just a few more pictures of the body and chassis. You can see the size comparison to my controller. I also attached a picture of the wire harness I made up. The two steering servos are on a Y; the throttle servo is on a Y; I have a battery Y that goes to two JR male terminals. The steering Y is then connected to a second Y which is connected in parallel with the throttle Y to the battery and receiver. Note my battery will use the EC3 type connector ( I have a lot of these on planes).
Set up the servos, wheels, etc, and drove the truck around the yard today. Now that I know it all works, I start hard wiring everything in. Then on to body painting.

Lots of 'Y' leads used......my only question is Y?

Servo arms look normal to me.

 

[macboss]

There is a good disscussion about this in the ELECTRONICS section on the topic of Servo Wiring. Using a Y with battery and servo on the female connectors and the male connector going to the proper channel on the receiver prevents the receiver form seeing the high current draw if the servo should get stalled. This looks like a good idea with the steering servos on a monster truck. The HS5755 servo pulls almost 5 amps at stall.

On the large scale airplanes, a power box that separates the servos from the receivers is used for this: in some cases 3 or 4 servos can be grouped together to get very high torque so current draw can be high in normal loading.

I would like to rebuild the servo and Y leads but I am out of crimp-on connectors so I'll probably build using all this wire and then assemble a new wire system later.

 

[macboss]

PROBLEMS:

Well....I don't want to complain, but.......this truck sure could use a larger battery, receiver box. Very minimal space. Not enough room for my Y connectors, a small engine kill switch, the switch body, and then a 4600 mah battery.

I'm thinking about making a 1/2" spaceer out of wood to provide more volume. Even if I put the Y connectors outside the box, it is a tight fit.

If I could find a small receiver box from another type car, I may attach it to the top of this box to get more room.

Off to the local car shop to see if they have a suitable box.

 

[macboss]

Finished for now:

I finally gave up trying to stuff everything in the one box. I bought a Traxxax receiver box and mounted it to the top of the existing box. Drilled a 1/2" hole between them and glued the boxes together with RTV. Used three small bolts and nuts to hold them together.

I drilled a 1/16" hole in the top of the Traxxax box and let the antenna poke straight up. I'll dab a little sealer on this later.

 

[macboss]

A few more pictures: The three servo lead and the charge lead route nicely out the slot in the battery box. I used my dremal tool and opened the slot a little.

I used a aircraft engine shut off I had and am not sure where I'll mount it. I attached it to the spade connectors on the engine kill switch. Needed a soft place to mount it so I velcroed it to the air filter.

 

[macboss]

A few shots of the assembly. I put two fuel lines on the tank cap: one for vent and one for filling. I'll use my aircraft gas system for filling.

Put a hose on the exhaust and will get a header later.

Now on to painting. I'm going to use red, gold, some white, and black.

 

[Elk]

Macboss,

You've obviously done some very nice and thorough work so far, and your experience from airplanes clearly translates. I think you'll have a lot of fun with the MCD platform and find it more than durable enough if you take care of it and drive sensibly.

Would you be able to post some clarification about your servo and battery wiring. I've seen this referred to several times on various forums, but I have a difficult time following it without a diagram. Would you have a link handy?

-Elk

 

[macboss]

Elk,

Thanks for posting.

I attached a picture showing the method of using Y servo leads to allow the servo to draw power directly from the battery. This is like mine but I have two steering servos so there is an additional Y to link them. I down loaded this from another thread.
(Posted by "Bigger the Better" on 4-3-09: https://www.largescaleforums.com/showthread.php?t=4889&highlight=direct+servo+wire

 

[CSR260]

Ed how you getting on? its looking really sweet..

 

[macboss]

Had one of the nicest days today. Did not work on the truck to go fly my new 85" wingspan Yak 54. Has a 55cc gas engine. Weather is supposed to get bad later this week so I'll start painting then.