Newbie ROSSA project

[m1tch_87]

I have now finally got a set of hex adaptors that actually fit the car, here are the 1/8 on road wheels fitted - I will be looking to get some 1/8 off road wheel as soon soon:

 

 

Here is the car with the basher/original body on it to give some idea of the design, the good news is that I should be able to fit 190mm or 200mm bodies between the wheels which should open up a lot of other options with regards to bodies:

 

 

 

I am actually quite tempted to use the stock body and add one some mods, its actually quite a low slung body without that much frontal area.

Edited March 13, 2016 by m1tch_87

[m1tch_87]

Quick update, I have got around my issues with the 2 speed threaded clutch and bought a HPI one which fits much better, its correctly shimmed and everything is looking good.

 

I have geared up the stock .18 engine with the 2 speed gears I have plus the 2 speed FTX box that is the optional upgrade for this model which uses a 50t first and a 45t second (stock it has a single 50t gear). I have used the threaded gears I have with an 18t 1st gear and a 23t second gear - this will give me a 18/50 first and a 23/45 second gear eg a 43mph first gear and a 61mph second gear @ 30k rpm.

 

It would seem that the HSP models have the same if not identical parts as the FTX cars (probably from the same factory!) but I know there is a 44t/39t 2 speed setup which has an upgrade to have metal gears. I am going to see how well this setup runs just to try out the gearing etc, when I swap in the larger .28 engine I will be using a 14/50 single speed setup again for engine break in.

[m1tch_87]

The Mod1 gears have arrived along with the 12x0.5 tap, I have an 11.5mm drill on order which won't take long to arrive, I will then hopefully be able to then drill and tap the gears to fit to the clutchbell. I do however need to check the thickness of the gears as they are slightly thicker and heavier than I expected, might have to look at getting a different set of gears - not ideal as the usused parts are starting to mount up.

 

I have also ordered a new FTX Carnage body to replace the current cracked one, need to have a look into where I need to drill a hole for the heat sink on the new engine once that is mounted up.

 

I plan to run the original engine with the taller gears this weekend to see what its like although doubt I will have enough space for it to change gear @ 43mph lol.

 

I am also looking at other bodies that might fit and also be more aerodynamic, it seems that the 190mm bodies fit fine as they give space for the front wheels to steer - will perhaps look into using one of the 190mm touring car bodies but I am initially going to run the stock body as its not too bad in terms of aerodynamics as well as fitting and sealing on the chassis plate.

[m1tch_87]

Still having real issues with the gearing at the moment, I have the tap and have a 11.5mm drill bit coming, the mod1 gears have arrived but they are way too thick meaning I am back to square 1 again, might still try and make a spur gear adaptor to screw onto the threaded clutch - that way I can simply bolt on different spur gears onto the hub adaptor from off the shelf part - really struggling at the moment!

[ajlovering]

Are the gears hardened? If not I can cut them down to 6mm or less so they fit on the clutch bell. Let me know if you want them done

 

Cheers

Edited March 28, 2016 by ajlovering

[m1tch_87]

17 hours ago, ajlovering said:

Are the gears hardened? If not I can cut them down to 6mm or less so they fit on the clutch bell. Let me know if you want them done

 

Cheers

 

They aren't hardened but are steel, I am going to get some Delrin 500 gears as well to have a play with the gearing etc, the hop up 2 speed box on the FTX I believe is mod 1 as standard (the electric version is mod 0.6 I believe) - will get some gears on order to try out, didn't take a note of the thickness before I ordered the metal ones!

 

The threaded part of the clutch bell is around 9mm so I would need to thin down the gears slightly anyway - found some Delrin 500 gears at 6mm width.

Edited March 28, 2016 by m1tch_87

[m1tch_87]

Quick update, the drill bit has now arrived, just waiting for the Delrin gears to turn up and I will then drill and tap those out for the clutch bell, they are 6mm wide so I might need to sand them slightly but that shouldn't be an issue. I have also taken delivery of a new FTX Carnage stock body, the plan is to use this as the speed run body by only cutting out part of the wheel arches to accommodate only the drive shafts and the threaded bar which will act as the 'suspension' - should be more streamlined. I will also then look into how best to cool the engine, the shell has no holes cut at all as the body is used on both nitro and electric models.

 

I have also taken delivery of some off road 1/8 buggy wheels, these are 115mm diameter rather than the 100mm diameter on road wheels, the tread on the tyres might actually be suitable for the speed runs as they might work on the unprepped/dusty surface, will be bringing a few sets of wheels for speed runs anyway.

 

A steering gyro has also turned up which I will add to the car soon, should help in keeping the car straight when doing speed runs, its all coming together it seems, just need to get that other engine broken in and the starter box set up so I can actually start the thing!

[m1tch_87]

Quick update, I have now got a rotostart for the back of the .28 engine, I had to mod it to fit due to the 32mm spacing between the mounting holes not actually matching up with the 32mm spacing on the engine, its all fitted now though.

 

I did try and start the .18 engine again but it looks like my glowstarter has given up the ghost, I have another on order but rather annoying as I wanted to run the engine with the 2 speed gears.

 

Plan now is to mount up the larger engine onto the chassis and run the stock 50T gear with the 14t clutch bell as I need to break the engine in still, hopefully the starter is up to the task, still have issues with using the starter box, it spins up but just leaves rubber on the flywheel.

 

Really finding nitro quite a faff with very little payoff still but will carry on, its just costing a fair amount to be able to get things to work as nothing seems to fit and I am having to mod most things to work, nothing just bolts up.

 

Anyway, the 45 and 50 tooth gears have arrived finally, will be drilling and tapping them out so I can thread them onto the clutch bell when the time comes, getting there slowly as I have hardly any tools at my disposal.

[m1tch_87]

Ok, making a bit more progress now, I have found that with the easystart back I need to raise the engine up slightly, originally it was fine simply flat mounted to the chassis plate but I now need to raise it slightly. I have therefore now found a use for the m4 wheel nuts I no longer use on the car - I am going to use them as spacers between the chassis plate and engine mounts, they seem perfect. Just need to get some m3x12 or m3x16 bolts to ensure that everything is tight, everything seems to mesh ok with the standard 14t clutch and 50t single gear so will be good for break in.

 

Here is the nut spacer solution as an example (will be doing all 4):

 

 

Here is the car mocked up to get a general idea of the space etc:

 

 

 

Bodywork test (original broken body!)

 

 

 

The larger heatsink on the .28 engine still fits under the stock body:

 

 

Update on the suspension as well, here is the stock suspension (90mm shocks)

 

 

Here is the replacement suspension - will be 70mm to lower it to where I want it:

 

 

I have also got some 2mm lexan on order so that I can add on some additional wings down the side of the body, I will be running a stock FTX Carnage body, however will try to not cut out all of the wheel arches to keep it as aero as possible.

 

The setup is current 4wd for testing, however I might look to remove the front dogbone and mod the front CVD half shafts to run 2WD - still deciding but quite impressed that the engine fits up ok so far and has clearance for everything. The stock gearing is already Mod1, I will be drilling and tapping the gears to test fit them soon, will probably need to cut some clearance slots in the chassis plate but might get away with it, I do have a feeling that I might need to change or mod the fuel tank though.

 

 

[m1tch_87]

Hmm I just snapped one of the Delrin gears so will now be looking for some alternatives, might need to ask for help with modding the mod1 metal gears I already have to work, luckily I still need to break in the new engine first on stock gearing.

[m1tch_87]

I have now got some m3x12 button bolts and I have test fitted the engine using the nut spacers, all seems to line up great so seems like I am onto a winner, will be running the stock 14/50 gearing initially for engine break in.

 

I have also ordered some very bright orange florescent paint to paint the body so I can see the car at a distance (and to get out of the way of it!) will probably paint the bonnet black or something to tell which way is which, I also have some clear lexan sheet coming so I can add on some fins down the sides of the body to keep it stable at speed.

[m1tch_87]

I have now had some gears cut and sorted so that I now have the gears I will be using for the speed record.

 

I have just tried to start work on the body, started using a scapal to cut out the wheel arches - just managed to crack part of the body trying to tear the arches out! I still have curved scissors on order, really really want to get this body sorted, just waiting on scissors to arrive!

 

I have mounted up the larger engine but its not meshed with the gears, will be breaking that in over the next few weeks hopefully.

[m1tch_87]

Some new suspension parts arrived today, took a while to arrive, they are smaller than ordered and I have also managed to snap the top hole of the first 1 I tried to fit - back to the drawing board and yet more wasted money!

Edited April 26, 2016 by m1tch_87

[locky]

1 hour ago, m1tch_87 said:

yet more wasted money!

 

To err is human to learn, think of it as money invested.

[m1tch_87]

12 hours ago, locky said:

 

To err is human to learn, think of it as money invested.

 

Indeed - was a bit frustrated last night when the dampers finally arrived after a fair while of waiting, only for the first one to not fit/break when trying to attach the top mount.

 

I will probably go back to making solid suspension instead, better aero - issue being is that it will take me quite a while to cut through the threaded bar with just a hacksaw but will crack on with it over this week.

[m1tch_87]

I have now started up the new engine, it wasn't connected to the drivetrain but was in the chassis, used a drill to start it up, kept all the settings stock to start with, new glow plug igniter and the thing fired up right away.

 

I have now run around 2 tanks through the engine so far, first tank was basically idling with a few slightly higher idle speeds, I could see that the engine was running rich due to the fuel that came out the exhaust every now and again - which is fine as I wanted to make sure that there is plenty of oil and fuel for a few more tanks yet.

 

The engine does sound much beefier than the .18 engine the car had originally, it idles well but did sometimes die if a blipped the throttle slightly and then closed it - probably just the throttle trim on the transmitter.

 

The drill stater works perfectly and I did use it a far few times as it did cut out every now and then, I do also have a laser thermometer and I pointed it at the head, the fins are around 80c after a fair period of idling and very light throttle. I know that this would be well within specs but as it was the first tank and I had no way to move the engine through the air I thought it best to play it safe.

 

Next step is to continue with the engine mounts and to get the drivetrain meshed up to then take it steady for the first tank or so with quite easy gearing (14/50 single speed), from there I will gradually bump up the gearing as the number of tanks used increases.

 

From now on its more about the build up of the engine break up, gearing and my driving experience - will still need to build the solid shock replacements which I will probably do next week, next thing is the aero bodywork which is starting to come along.

[locky]

Usually I measure engine temp by pointing down at the glow plug, cooling head maybe be a bit lower in temp.  It dies as loading up with fuel as is very rich. 

 

Keep going.

[m1tch_87]

9 hours ago, locky said:

Usually I measure engine temp by pointing down at the glow plug, cooling head maybe be a bit lower in temp.  It dies as loading up with fuel as is very rich. 

 

Keep going.

 

Thanks for the advice, I figured that a more accurate reading would be from the glow plug - will do that next time in the next tank of fuel to see what temp its getting to.

 

I can tell that its running very rich which is fine for what I am after, I have also put in some after run oil and stored the engine at BDC, I am running it on 20% at the moment and have around 3/4 gallon of it - will probably use half of that whilst breaking the engine in.

 

I think for the next tank I will run the same setup but start to run 1/4 throttle for a few seconds at a time, then the tank after that perhaps half throttle, I think after that tank I will look to mesh up the transmission and take it around the back garden lightly so there is some load on the engine.

 

I am running 100% stock settings at the moment, will be a while before I start to tweak the tuning, will make sure that when I do run it with everything meshed up that there is plenty of smoke.

[ajlovering]

Dont try to run the car around with the high speed gearing it will destroy the clutch. Change it over to low speed until you are ready to do speed runs then only use the high speed gears when running in a straight line

 

Cheers

 

 

[m1tch_87]

13 hours ago, ajlovering said:

Dont try to run the car around with the high speed gearing it will destroy the clutch. Change it over to low speed until you are ready to do speed runs then only use the high speed gears when running in a straight line

 

Cheers

 

 

 

Thats the plan, its currently going to be running the stock 14/50 single speed gearing the car had from the factory, once its all broken in I will the look to run slightly different gearing for a slight bump in top end, the gearing stages I will look to run are:

 

14/50 single speed - standard

18/50

23/50

18/23 to 45/50 - 2 speed

45/50 to 45/50 - final speed run gearing

 

I do also have some HSP parts in the post, it would seem that the HSP setup and the FTX setup have interchangable parts - the HSP have metal 2 speed upgrade which gives a 39/44 2 speed box. This will give me a slightly different gearing option of either high end with the 45/50 clutch bell gearing or indeed somewhere in between,

 

I will also be looking to get a few more clutch sets to upgrade the metal 3 shoe setup to perhaps a 4 shoe setup, the benefit I have with my car is that due to it being 1/10 scale the car isn't as heavy vs a 1/8 scale car so should hopefully be slightly lighter on the clutch but I will have spares.

 

The key thing I need to work on at the moment is to ensure that all the gearing options fit, I have extended the stock engine mount slots to accept the different gearing options, but will need to do a few more mods once I get the next few tanks run in with the engine unmeshed.

[m1tch_87]

Quick update on this, I have again tried to start the car up again but its now failed to start, the easy start on the back then failed meaning that I had no way of starting the car so wasted a few hours earlier trying to get everything running. I have now recharged the drill battery which might have been the issue - eg the engine doesn't turn over quick enough.

 

You can see here how some of the thrust bearing on the smaller input gear has worn and the hex in the centre of the main gear is slightly proud - it seems to have popped out slightly, I have now taken it apart, cleaned everything and reassembled.

 

 

I then took the opportunity to see what the mounts would need to be with regards to the larger gears, you can see here that they are quite large but still fit on the stock chassis with the extension of the slots it should fit fine - this is just sitting on the chassis, there will be some additional spacers added.

 

 

 

 

It will also mean that I can actually run the exhaust inboard which would help with the aero, I will therefore be flipping the exhaust manifold 180 degrees onto the other side, I can then look to extend the stinger slightly if needed, although I might just cut a small hole in the top of the body:

 

 

Quick mock up with the body on:

 

 

[m1tch_87]

Just had the starter system fail on my twice, really had enough of this now, it's a very stressful hobby!

 

Will take everything apart again and see whats happened to it, the engine has 1 tank of idling on it so far.

Edited May 7, 2016 by m1tch_87

[m1tch_87]

Think I have found why the easy start has just been spinning, looks like there is now a massive crack in the internal 1 way bearing for the starter, will have to get another one, might as well get a new engine at this rate!

 

 

 

[locky]

Dont know that engine so not sure of quality. Did you loosen glow plug to ease starting if new engine and preheat? What drill are you using and does it have an adjustable torque setting, perhaps been using too much.

[m1tch_87]

21 minutes ago, locky said:

Dont know that engine so not sure of quality. Did you loosen glow plug to ease starting if new engine and preheat? What drill are you using and does it have an adjustable torque setting, perhaps been using too much.

 

The engine last time started really well as in within about 2 seconds of cranking, they are fairly cheap engines but are usually pretty good, the drill is a basic 12v one and the torque setting is as low as possible.

 

I have ordered a pull starter already - the original one I took off the back of the engine to check a few things but it then immediately uncoiled and is impossible to put back together. I will spend another £15 getting a new bearing as this one will be beyond use, will just start it using the pull starter instead as it seems that this is the far far easier option.