My First Diamond Dust
 

I have just recently got me a DD and am now in the process of building it. When i was in middle of deciding to buy it i noticed they had a combo for it. The combo came with a MVVS .40 GRRT. I was going to go with this set up but seen they had another engine MVVS GRRT.40 FIA, with same specs and it had round exhaust setup with it. I liked the idea of being able to attach the pipe directly to the engine.

Somthing i didn't realize was it has rear intake and there is no throttle, its just straight wide open full time. I noticed this after i had done bought the Darn thing.

Now my question is does anybody else have a the same set up here or similar with rear intake? I'll be honest i seen the DD fly before and I and pretty intimidated by not having throttle control. Does anyone have any ideas how to fix this? Or how to set this up so i can have a throttle or something to slow it down some at command.

I know my first flights I'm going to use a OS. 46 FX to get the trim set up and get the feel for the plane. If anyone has any idea please let me know.

I now for a fact i cant tell my wife that the engine i spent my money on cant be used in the plane i just bought. Wives just don't understand .

GRRT
 

MVVS does offer a throttle carb for the GRRT. PN 3226.

RR

My First Diamond Dust
 

great! I'll have to check it out. Hopefully it is for the rear intake setup and bolts right in.

only problem i have now is the intake is in the way of the engine mount. I think I'm going to have to cut away from the ply mount. Only thing is i dont want to loose its strength. I'm going to see if i still have some fiberglass left to maybe reinforce this section some.

RI engine mounting...
 

Here is a pic of mine...I had to take quite a bit out of the firewall, but I ran some beams under the ply mount to stiffen things back up..

http://www.pan-tex.net/usr/w/jwillia...s/Dusttank.jpg

The front ended up looking like this..sorry it is not a close up, and I busted my digital camera, so I can't get a better pic just now.

http://www.pan-tex.net/usr/w/jwillia...ond%20Dust%201

My First Diamond Dust
 

ChuckAuger,

Thanks for the pic. that was exactly what i was looking for. I tried posting a pic of my set up but it says my pic size is to large to be poseted. Anyways i got a good idea how to set this up now.

FlooredCobra
 

Change the pic size to 640 on your camera...

That's the right size for here, and for E-mailing.

Chuck....looks hot, man.. :eek:

Dave.

Cool Dust!
 

Chuck,

Gotta tell ya, that is one seriously cool looking machine!

Gene

My First Diamond Dust
 

Chuck, how much fuel can you carry in those three tanks? That's quite a set-up. What brand pipe are you using?

I must be missing a tank!
 

There are just 2 tanks, Dave...as low as the carb centerline is, I didn't want to have a 6oz sticking up (plus getting it under the pipe) so I have a 4oz main and 2oz hopper. I get 4 minutes of WOT, then a little to land with. It is an absolutely reliable set up,but if I'm not careful and run out of fuel at WOT I usually blow a plug.

The pipe is a Nelson something. I asked Dave Shadel what prop I should run, and bought some 7.4 X 8.25 CF props, Q40 practice props, I think. But I was getting brutal plug failures, so I called Dave again. He asked what pipe I was running, and I told him Macs 7.5 un-muffled. Right off he told me my pipe was too small volume for the RPMs I was getting (about 21K then).

So he sends me this pipe, and I can get 22K on the ground and use a plug for 4 or 5 flights if I don't run out of fuel. The engine looks pretty dirty in that pic..that's because it has a lot of runs...I run Powermaster 10%, and it just keeps on turning. It feels new right now.

The pic shows a hole in the header flange..it had a screw in that hole, but it came out, went lean, died, and blew a plug!

So even though I was running a OS DF engine, ol' Dave took the time to help me get set up. He could have sent me on down the road, but he knows a thing or two about trning R's.

My First Diamond Dust
 

Thanks for the info Chuck, that's an awesome set-up, and a great looking DD. Good thinking on the tanks, I dislike how a 6oz. sticks up on mine, looks like I have a little plumbing work to do, LOL. I have a K&B 6.5 FIRE with Macs 8.5 pipe on mine.

My First Diamond Dust
 

WOW, the time of this thread is perfect!

I got my DD yesterday and am putting a Picco .45 DF in it which also has a rear carb, didn't know if it could be done. I like the smaller tanks, I bought a Perry pump, figured I'd use two 4oz. tanks at the CG and a 2oz. at the carb, will this work?

I like Chuck's color scheme, without looking you know it's from Texas. Pretty plane, what kind of speed are you getting?

My First Diamond Dust
 

Has anyone tried closing in the pipe and tank area to streamline it? Was it worth it?

Hey soarrich...
 

I don't know about the Picco, but the shaft on the OS was too short to go thru a D1 hub APC. The fan adapter nut is a spitting image of a Tru Turn spinner nut, so I just turned the OD of the fan nut shoulder down, made the shoulder a little longer, and drill the prop hub out a tad so the nut actually goes thru the prop hub. Then got a 6mm allen head screw and a 1.5" Tru Turn, and it looks like it was made that way. The drawback is I can only run props that are .550" thick at the hub, but I like the one I am running, just wish they made them with a little more pitch.

On the engine mounts, I ran a piece of 1/4" X 3/8" spruce under the ply mount back to the fire wall. Then layed another piece on that that goes back and hits the bottom of the plane a couple of inches back. Then ran a piece of 1/16" ply between these beams and back to where it hits the bottom of the plane. Tied everything together and made a skid pan to boot.

I wouldn't worry about running two 4oz and a 2oz, I think 6oz will give you a pretty good flight, and keep the weight down. I don't know if you can tell, but my throttle servo is not where the plans call for, it is right behind the front spar, turned sideways. The 4oz tank is where the throttle servo would be.

As far as speed, I quit guessing about that long ago. Some guys were extremely interested in it and went to great lengths to figure it. I really just like engines. I love the sound of this engine..the Dust is just something to carry the engine IMHO. I can tell you it will do vertical rolls out of sight in just a very short time even with the 7.4" diameter prop, so I figure I have plenty of diameter.

I have seen a Dust with the tank covered over with covering, and a pilot named Carl E has built a full engine/tank/pipe shroud to cover everything. He is running a MVVS GRRT.

Shoot me an e mail if you want to talk over any of these mods...I'm anxious to see what the Picco will do!

My First Diamond Dust
 

Chuck
I just bought a Jett .40 Q500 engine, which do you think would be the better choice for the DD, the Jett or my Picco .45DF? I want to go VERY VERY FAST.

HHhhhhmmmm.....
 

Tough call...The way I see it (and I am probably wrong) I would go with the DF engine, and put the Jett on a Q500 plane. Because...

The Q500 props are typically in the 8.75" diameter range, with about 7.5" ~ 8.75" of pitch. This is just ballpark. And they turn in the 18~19K RPM range (again, I'm not a Q500 racer, these are just what I seem to recollect), maybe 20K.

The 45 DF engine is timed to run probably in the mid 20's, making it closer in performance to a Q40 engine. That's why the CF Q40 practice props work so well on mine. I know..a true Q40 engine turns 26, 28, 30K, but that's on a wood race prop. Shadel seemed to think the RPM's I'm getting are pretty good for the practice prop. I know nothing about Q40 engines or their set-up, just going by what was passed on to me.

I think the Jett Q500 would sure haul the mail, and it is front intake, so it would be easier to mount. But I think to get the fastest Dust on a 40, you will need to go to a Jett or Nelson Q40 engine (or the GRRT like I mentioned) with a carb fitted. And they ain't cheap.

But a 45 sized DF engine is very cheap, comparatively speaking, and will almost get you to the realm of the poor man's Q40.

These are just my personal feelings, I might be wrong. I do know that the guys who are running Jetts seem to really like the 50...it will turn the Q500 props better than a Q500 engine.

If it was mine, I'd slap the Picco on it.

My First Diamond Dust
 

Thanks. The Picco it is then.

Does the guy that makes the CF props have a website?

Yeah...
 

http://www.pspec.com/

Just ask for Dave and tell him what you want..they aren't listed on the website, but you can get the phone # there. Seems like they had a 7.4 X 8, 7.5 X 8, and 7.4 X 8.25..not a wide selection, these are APC props, just CF props never became legal for Q40 so they didn't develop a very large selection. Funny thing..seems like these prop sizes don't match the ones on the APC website, but I have had all of them....

Some guys are using regular gray APC props like the 8X8, but I like the CF props..again just my personal preference. Sticker shock is $7.50 each.....

My First Diamond Dust
 

Well I just got down flying my DD for the first time.

I ended up putting a OS .46 FX for now until i can get a throttle for my GRRT. And glad i did! When wife let it go it went up and to the right hard. And pretty quik to. Think with the GRRT it would of been in the grass as mulch by then.

I trimmed it out and flew it around 1/2 throttle for a bit. It fly nice but very different. I cant seem to get used to the delta wing loook in the air. When i go to make a turn my nose was down almost everytime. I need to get used to the way it looks in the air change my angle when turnning.

One thing i notced is that i couldnt set carb on the engine as i can on my other planes. Seems i am going to have to set it a bit more rich than i usually would. It leaned out on its own fairly quik on me and I wasnt used to this. So once in air i could not go full throttle, it just gobbled up air and bogged down. So my flights ended up beeing 1/2 to a bogging down 3/4 throttle.

All and all i liked the plane, flew straight and tracked well. I did notice that my pushrods were vibrating and sounded a bit cheap in air. But i have some C-clamps for that problem. All i need now is to find a carb or some way to control throttle for my GRRT and I'll be in business! :D ....

My First Diamond Dust
 

Congratulations on your first flight, the hard pull right is a typical launch. Get used to the speed with the .46, then mount your GRRT. I had an OS Max-H .40 on mine at first, now have a K&B 6.5 F.I.R.E. with tuned pipe. Hope you fly it for a long time.

My First Diamond Dust
 

had two dd's with st 51's with a macs mufflers and let me tell you i still remember the first launch, i think i am still shaking! sold one after my stroke and am working back into the other. my a-4 propjet is the perfect tune up! flys about 130 with os-46fx and macs pipe, and is damn near axial on rolls four feet off the deck! my dream now is to try a whiplash!---henry

My First Diamond Dust
 

well i now have a few more flights on my DD now. I am now getting used to it and it is a blast. The roll rate is awsome!

One thing though is I am already wanting more speed out of it. I got adjusted to it already and have the urge for more. Heck guess thats how it goes. As of now all i have on it is my OS .46FX and 9x7 prop.

After a few flights and a little bit of fiddling with the engine i got it running right. Sounds great pulling them R's. Even with this Mild engine its alot of fun flying. The guys that seen it fly for first time were amazed at the speed. I had to keep telling them that what they seen wasnt nothing compared to a real engine installed in the DD. Was trying to explain it looks like the plane is in fast forward the whole time.

I do have a question though, what servos are you guys using with the higher powered engines?as of now I am just using the standered JR 507. I had a few people say that I may need to upgrade when I install the more powerful engine.

Also what batteries do y'all think seem to work better 4.6 or 6.0 volts? Just curious.

My First Diamond Dust
 

Good coreless servos will do when you upgrade your engine. The key is great centering. 4 or 5 cells really shouldn't matter if you get strong servos. Check out the Hitec digitals, you can't go wrong for thr price.

Mark M.

My First Diamond Dust
 

I will check them out. I had my eye on the high torque hitecs but never crossed my mind on coreless.

Thanks for your help!

getting used to it
 

well i have got alot more time in my DD. Its a blast!!! Even with my OS .46 FX . I changed a few markings on it so I can see it better, flouresent goes a long ways!

Its kind of funny, I get to the field and pull out the DD and the guys say to thier buddies " you aint seen nuttin till you see one of them fly" I have to keep reminding them that its just a .46 on it. Yet they still in aww when it flies. Its really hard to explain how much difference a real engine is compare to what i have in there now. I tellem way over 100+ and they look at my like an idiot....

As for my GRRT i called up Morris Hobbies and they are going to send me that adapter plate i need to mount the carb on. After that I'll be in a whole new league of speed. Theres nothing like the sound of a screamming piped engine.