Some custom work going on in the "Matt-Cave" :~)

[liveforphysics]

I'm very glad to hear you're looking to try out just RWD first. I think you will find that suits your needs much better.

It's funny how FWD can be setup to work extremely well, and RWD can be setup to work extremely well, and AWD pretty much always sucks for everything but gravel/mud/snow conditions.

And for the Subaru/Evo/Skyline/DSM fans of AWD out there, note that all the fastest on-road racecars that started out AWD always get converted to just RWD when they get serious about winning.

 

[liveforphysics]

My Pitts will do 0 - 140mph in 1/4 mile, but I'm sure you would definitely have me in the first hundred yards or so.
My fun begins after that 1/4 mile...! 8)

Damn! Trapping 140mph means you're accelerating pretty damn hard! That's trapping faster than my civic in the quarter!

 

[AussieJester]

Yeah, not your granny trike.

You might need electronic traction control...

3 guesses who he will be coming to design it too Mr Fechter ...best get a head
start there now you have all the power requirements etc SiR hehee

Fechters Throttle interface & Traction Control Unit
'

So ..Matt...you will be using 2.4ghz radio gear and drift gyros to "test" this insane piece of
machinery before you sit in it yourself i assume? Maybe take it down to the local RC on road track and
show the 1/8th scale boyz how itz done

Your an inspiration mate...

KiM

 

[recumpence]

I was one of the first to run a heli gyro on an RC car years back. Now they are called "Drift boxes". I was laughed at when I tried it with a heli gyro. But, now it is commonplace. I am still the only person I know of who has run a heading hold gyro in an RC car. They memorize position. So, if the car spins, it will do an EXTREMELY quick 360 and regain position, then continue on. It looks really cool!

Anyway, I am looking forward to seeing just what I can get out of these two 3220s. They are 2 and 1/2 turn running 12S. That should be about the maximum RPM they can take. Bob from Astro assured me they would hold together. It should really scream! I will probably make a primary chain enclosure to reduce the DB level of chain noise. That way you will hear the motors screaming instead!

Anyway, the overall build should look really slick. I am adding side bolsters to the seat for cornering. I am also adding a good quality steering damper.

Oh, hey, there is a speed shop here that make $100,000+ street rods (I have a pic of a $115,000 orange 65 Chevelle they built) down the road from me. That is where it was sand blasted. Great guys there. A friend of mine is best friends with the owner of that shop. His son races 4 wheelers and karts. They may have an interest in a fire-breathing trike. Maybe another line on some wealthy customers for my wares.

I will post more pics as I have them. I will be at the shop tomorrow working on it. Oh, my rims are due in tomorrow or Friday. Also, my $4,000+ all carbon fiber Velokraft VK3 recumbent frame arrived yesterday.

I am broke............ :wink:

My wife cannot keep track of all my stuff arriving lately. But, as long as projects are selling and cash is showing up, she is happy.

Matt

 

[flyinut]

Luke,
It's the first few feet that kill me - lots of cavitation at lower speed (even with a constant speed prop), but once it gets going...
A quick pull on the stick will get 1000ft vertical, more on a cool day (especially at sea level) :lol:

My money says that Matt's first few seconds off the line beats my 1500ft climb...

Mark

 

[MitchJi]

Hi Matt,

First, I will build the entire trike as RWD only to do some testing. Then I can work on the front wheel drive. This is for two reasons;

I spent some time talking with some RC guys today. We went over this design and the expected performance and a few things came to light. First of all, I will be running a far wider rear rim than my previous trikes (wider rims all around). Second, the higher RPM motors along with far higher pack capacity will give my A LOT more power. Third, this trike will have much more weight on the rear wheel than my previous trikes. It looks like it may accelerate so hard just on the rear wheel, that the front end will lighten up enough to negate the added traction benefit of the front wheel drive.

So, here is the plan, it will be built (finished off beautifully) with rear wheel drive. Then I will do some performance and handling testing. If the front end is getting light under hard accelleration, and it pulls like a Vette, I may leave it rear wheel drive only. Basically, if it is already pulling so hard and I will not gain anything, I will not do the front wheel drive. If it is obviously losing a ton of traction, I will work on the FWD.

What would you guys do?

Matt

I'd consider either RWD only (with an even wider rear rim if necessary) or FWD only (maybe shift some weight towards the front).

I wouldn't finish it off "beautifully" until you have done enough testing to be sure there won't be any major changes.

 

[recumpence]

Wether I add FDW or not, the frame will require no changes. That is why it will be finished off very nice first even RWD.

The only difference to go to AWD is modded front spindles.

Matt

 

[northernmike]

Matt, what are you going to do for rubber?

 

[gestalt]

I'm diggin this build with a frikin back hoe! Are you planning on keeping the pedals? with a monster like that you would have a hard time convincing the motorcycle cop who you almost got away from that you were running legal power settings.
About how many amps do you use on that thin of steel and about how fast do you set the feed? I know every machine is different but a god place to start would be helpfull. Although after just learning to tig I think I did an allright job of slapping together a controller box I'm more comforatable doing structural work with a mig.
I think you're going to need a special canopy on that thing to help keep you from flying away, maybe a stabilizing airfoil in the front like a canard wing. Whoooohoooo! Hold onto your butts folks!

 

[amberwolf]

What would you guys do?

Regarding the problem of rear wheel lifting the front enough to lose traction there:
1) work out how long it takes for the FWD to pick up the speed for startup; put a fixed delay in to the rear throttle from the main throttle equal to that.

or

2) use the speedo sensors or a torque sensor on the front wheels vs rear wheel to see when the fronts grab and are spinning as slow as the rear is (which will just be rolling along at this point), which then triggers roll up of the rear wheel (not suddenly but ramped very very quickly to keep traction, monitoring it's sensor compared to the front wheels so that they stay the same relative speed vs wheel size).

3) put two separate throttles on there, one front and one rear, and modulate them yourself as you get a feel for them.

 

[liteCycles]

Matt, you have a knack for coming up with really interesting builds. I have a few questions/comments since I would like to tackle a tadpole build in the near future. This is NOT a critique and you don't have to answer these – but on second thought if you don’t my feelings will most certainly be hurt.

1. What will the front reduction units look like and how will they be mounted? (It seems challenging to get a large sprocket on the front wheels and have a rigid reduction unit assembly mounted to such a small area. Two stage reduction? I think spanning the reduction chain across the wheel axel could be beneficial. [i.e. Jackshaft below the frame, motor above the frame. Or vice versa.] And what will your mod of the front spindle involve?)

2. As I'm sure you know, if the distance between the geometric center of the seat and the rear axle is increased the force of the rear tire on the ground will be slightly less. Did you experience under steer during acceleration on previous builds - so your hoping the larger tire and extended frame will offset this effect?

3. How are the bumps at speed with a tadpole? Have you considered an elastomer mounted seat to provide a plusher ride?


I really like the FWD option. Keep it. It's just really cool. 8)

 

[recumpence]

The seat is now a stressed member of the frame. So, no suspension I'm afraid. No matter, it will not see any bumps anyway.

The FWD would be a two stage from motor to wheel. As I mentioned, for now, I am building it RWD. If I sense the need, it will become AWD.

I spent 3 hours at the shop today working on the handlebar tillers. I have a pretty cool setup figured out.

I like Tadpoles. They handle closer to a kart than anything else. I also like them really low. The seat hight on this trike is 5 inches.

So, my battery boxes are being CNCed tomorrow. Saturday I am at the shop doing some more welding. I also have more Astro motors that came in. Those need to be boxed up and I have 3 twin 3220 drives for customers to build up.

It will be a busy next week or so.

Matt

 

[Ypedal]

holy geezus... Matt, dude !!..

That rear tire better be wide ! traction is going to be the issue here i think. Bone dry, clean, hot pavement will be the only way to get this to grip hard enough lol.. Double rear rim maybe ? double wide hookworms .. hmm..

Test ride no.1 with heavy throttle hand on AWD i'd be looking for full body armor :lol:

Bear Suit ?
http://www.break.com/usercontent/2007/11/Anti-Bear-suit-404022.html

 

[Thud]

http://www.gamaniak.com/video-3625-descente-cote-buggyrollin.html

How far are we from putting 6 motors on this guy?
srry, for the Hijack.....Thud Out.

 

[recumpence]

I spent quite a bit of time at the shop today and got a large amount of work done.

#1 I lengthened the tierod.
#2 I replaced a couple frame gussets.
#3 I reversed a frame bracket (it is a long story).
#4 I added the last couple seat braces.
#5 I modded the front spindles for the 203mm Hope hydraulic brakes and the new tillers.
#6 I mocked it up to see how it sits and how it feels as well as looking for any mechanical interfereances.

It all looks really good! This this takes some getting used to being 5 inches wider and 3 inches longer. The front of the frame looks really wide. But, the battery boxes will make the front end look more "Full", thus reducing some of the wide look. Plus, the new rims and everything else need to be mounted. That will help the look too.

The seat height is only 5 inches! It looks very well proportioned, overall. Oh, with all the frame welding, the rear fork opened up about 5 or 6mm. So, I will have to persuade it back those few mm. I could leave it alone, though. The rear skewer pulled it right in. No problem.

Tomorrow the battery boxes will be CNCed. Then I can weld the box mount tabs on the frame, install the drive unit to check for interfereances, then strip it and take it to the powder-coater.

Oh, my custom rims came in from Tiawan today too! These things are the cats! I love them!

Anyway, I will try to get some pics for you tomorrow.

Matt

 

[AussieJester]

Matt ... ever thought of the possibility of popping a front bumper on the
trike, i was wondering how a sprint kart bumper would look

http://www.karts.com.au/index.php?main_page=product_info&cPath=193_275&products_id=1826

They are very lightweight not sure how it would look or if it would foul with pedals/wheels etc...just a
thought...

Look forward to piccies ...:: makes sure tissue box is full ::

KiM

EDIT: BWAHAHA Ypedal man...LMFAO at that bear suit video, i snorted milk out
my nose when the first baseball bat to the head happened too funny...

 

[dragonfire]

as for safe antilock braking a pedelec sensor disc may be usable ( or replicable more fitting your wheels hub), a similarly simple routine that allows the abs to work ( release brake by hydraulic valve with an electromechanical switch/ gate as connector, should be available in the bmw motorbike spare parts an on honda motorbikes) on locked wheel if others still spin) can be used to set a variable at which a singular wheels rpm´s are allowed to differ from the others before the motor is cut of by the dedicated controller of that motor.

great project !

 

[recumpence]

The fron brakes are separate levers mounted to one handlebar. The left front wheel will brake by my middle finger (left hand) and the right front wheel will brake by my index finger (same hand).

It is hard to explain. You will see soon enough.

I hope it works well. If not, I will go to ao single lever setup. I think this will be good for differential braking in corners.

Matt

 

[amberwolf]

That braking sounds a little like how I planned mine for the cargo trike; no idea how well it will actually work since the frame isn't even past the design stage.

 

[liveforphysics]

The fron brakes are separate levers mounted to one handlebar. The left front wheel will brake by my middle finger (left hand) and the right front wheel will brake by my index finger (same hand).

It is hard to explain. You will see soon enough.

I hope it works well. If not, I will go to ao single lever setup. I think this will be good for differential braking in corners.

Matt

On a shifter kart, or most serious roadrace cars, the brakes run through a simple linkage with a threaded rod to adjust brake bias on the fly as needed. For example, when you start out on cold tires, you can't brake as hard, so you can't shift weight as effectively to the front tires, so you dial in more rear brake. After 1-2 laps, the tires are smokeing hot, and you dial the brakes in to be about 90% front, otherwise the rear axle locks up too soon. If it start raining, you dial it way back, maybe 60/40 because you don't have enough traction to get much weight shift at all.

There are a zillion different ways to do it, but you can get the idea from this picture:

The same sort of arrangement could easily be accomplished with cables and a pair of levers with a threaded adjustable cross-beam for adjustment, or a variety of other combos.

 

[zenon]

Hey! that frame looks awesome, with the new wheel track around 37 inches and extended wheelbase to 47 inches its going to be a road huger. I like wide tracks but sadly i have to keep my design around 30 inches wide so that i can bring my trike inside my house.

Great work cant wait to see this Tadpole rip the road down.

 

[TPA]

I wonder how a high power trike would perform with two closely spaced driven rear wheels. Since it does not tilt, they would not need to be independently suspended. You could experiment with powering them together and separately. Assuming of course that traction is a problem.

Kinda like the tomahawk motorcycle.

 

[recumpence]

I did some more work today.

I removed and redid the rear frame section. This allowed for a much better equipment fit and serviceability. While I was at it, I improved the look a touch.

You can see how LOOOOOW this thing is. The seat hight is 5 inches. The top of the seat back is below the top of the rear tire. It looks too low to be useable. But, it is only a couple degrees lower than my Catrike 700 and I have always wanted that thing lower.

The drive unit has plenty of room even considering the lower seat angle.

This is only a mock-up. The new rims and tires are not on. Also, the rear disc will come off to mount the left side sprocket. I also need to clean up some of the welds (hello flap-disc!). Plus, I ran out of welding wire. So, I had to stop without the welds finished. Lastly, I need to make seat side bolsters (at the hips) and weld battery box mount tabs. After that, it is off to the powder coater to get some serious color!

Matt

 

[AussieJester]

:: fumbles around for tissues :: ...That is very slick Matt, it is now noticeably wider
with the wheels on that the stock frame but still not 'silly' wide. This will
corner like its on rails! Would liked to have seen a 20x4.25in tire on the back
pitty there are no high quality 20x4.25in rims though :: hint hint :: hehee...
Any chance of a 'Recumpence' stamped 20x4.25 heavy duty rim coming out
from the factory your getting them rimz made mate? I would like a 24in when
you have then in stock too please

Anxiously await the next update, magnificent work Matt...

KiM

 

[zenon]

Hi Matt,

I'm just wondering what technology does Kmx used for their Kingpin is it sealed bearings or combination of sealed bearings and plastic bushings like the catrike design.

Thanks,

Zenon