2008 Kawasaki KLR456 Diesel Dualsport Project

[SamM]

At this point, I'd just like to finish the bike. Getting the parts together to have a rolling chassis are first on the agenda. If propane injection could be worked out later, I'd be interested IF the power improvement would make the bike significantly faster. I'd like to see what is possible with the stock engine first.

RICOR will be rebuilding my rear shock next week. I'll be sending the shock to them tomorrow. Next, I'll need a new front wheel. My rear wheel needs a new rim and spokes to make it compatible to the 21/18" Heidenau K60 tires that I bought for this project.

The problem with these bikes has always been having enough room to fit the Diesel engine and transmission. I plan to power the final drive on this bike with a jack shaft. If it is required, I can power the rear wheel from either side. I just purchased a bracket to add a rear caliper to left side of the bike. The KLR normally uses a caliper that is located on the right. The driven side of the jack shaft will use a small 14T or 15T sprocket. The final drive will use a smaller 11T or 12T sprocket and the smallest sprocket that I can find to fit the KLR cushdrive. Also, I'm not convinced that a CVT is required on this bike. The engine only makes 13hp.

[dieseltech]

If propane injection could be worked out later, I'd be interested IF the power improvement would make the bike significantly faster. I'd like to see what is possible with the stock engine first.

If you're feeling lucky you can raise the max RPMs quite a bit - the stock 3000/3600RPM (nominal) value is extremely conservative, as it is intended for continuous duty operation. They should be able to take up to 4500 full load RPM (~5000-5500 redline) no problem, and maybe up to 5k (around 6k redline) if you are feeling lucky.
The power will increase roughly proportionally with the max RPM setting, as the torque depends only slightly on RPMs in NA diesels. You will need to advance the injection though, to compensate for the constant injection delay time decreasing the effective advance at high RPMs.

I would imagine using a turbo would give somewhat disappointing gains - the engine is simply too small for even the smallest turbo to work well across the normal RPM range, so low- and mid-range torque would be seriously lacking. Also you would need an ALDA setup to prevent heavy smoke emission and take full advantage of the available boost. An intercooler would also help a lot, but placement could be a serious problem.
Using a boost control valve (instead of hooking up the turbo actuator straight to the intake manifold) would also increase the midrange boost significantly, and such a valve can be easily made from (mostly) common household parts and can be indeed quite tiny. If you do go that route I can help you with that.

EDIT: Also, while not exactly a performance modification, you can significantly improve driveability by replacing the stock all-speed governor arrangement on the engine with a min-max governor.
To clarify: for driveability reasons, diesel cars have min-max governors - at least they used to, while they were still non-electronic - while FARM TRACTORS, combine harvesters and other industrial equipment have all-speed governors, these are excellent for maintaining a steady speed under load but cause serious jerking when the "throttle" position is changed.
Since the governor on the yanclones is external to the engine IIRC, the modification is quite trivial - it does involve a bit of DIY fabrication and a lot of tinkering with the min and max springs, but the working principle is extremely simple. Again you can ask me for help here if you need it.

As for the propane - after the bike is rolling you can try jury-rigging a cheap test setup in a similar way to my starting aid. In Poland LPG powered cars are extremely popular, so you can get a proper LPG solenoid valve at a scrapyard for chump change. For the tank you can use some old propane blowtorch. A metering valve (adjustable) can be salvaged from an old kitchen stove.
This way you could try it out with minimal costs, and then if you decide to make it more permanent, at the very least the solenoid valve can be reused.

The problem with these bikes has always been having enough room to fit the Diesel engine and transmission.

Well, I would go ahead and say that it is a problem with any bike. These engines are designed for power generators and industrial machinery, not bikes. For one, the cylinder is dead-on vertical, which sucks monkey balls in a bike. On the twins the cylinder arrangement is also quite unfavorable.
Enfield got it right in this respect - their engines were engineered to fit the bikes right from the start.
Sadly, until someone will be willing to start a company and "mass-produce" diesel bikes, so that the gigantic NRE costs will be easily covered by the scale of production, not much can be done about it.

Also, I'm not convinced that a CVT is required on this bike. The engine only makes 13hp.

That is exactly why a CVT is pretty much required. Unless you are using a bike gearbox - which I understand you're not - you will need the CVT if you want the bike to be able to outperform an overloaded semi truck (or a freight train) from a dead stop.
You've got it pretty much backwards: you don't need a CVT if the bike is ridiculously overpowered. Just look at those gearless car-engined ratbikes. All that power and still rather poor performance.
The CVT, when properly chosen and adjusted, allows the engine to work near its max power RPM at virtually all times when needed, which helps A LOT. Instead of a constant torque characteristic at the wheel, you get a good approximation to a constant power characteristic, which is awesome.
Have you ever driven a CVT-equipped vehicle? (which includes pretty much 100% of cheap chinese scooters) Because then you would know what I'm talking about, without a doubt.

Seriously, the CVT is worth its weight in gold on such a bike. The benefits FAR exceed the extra weight - the top speed might decrease a tiny bit due to the weight, CVT losses and possibly extra aero drag, but the 0-max acceleration will improve drastically. Also it makes the resulting performance far less sensitive to the choice of final drive gearing (if present) - it doesn't have to be exact, just reasonably close to optimum, just to keep the CVT working within its operational limits.

EDIT 2: Also in terms of weight reduction, if you are feeling adventurous you can drop the electric starter - I can't see it in your photos but I presume there is one - and use the smallest possible battery, starting the engine with the pull start and compression release instead. Definitely far less convenient, but at least 3-5kgs can be saved due to the smaller battery and lack of heavy wires for the starter, and the lack of the starter itself.
If using a CVT you can also try lightening the flywheel a bit also, since the engine will never be under any load at low RPMs. As much as 2-3kg can be saved, possibly even more. But without the electric starter this could cause serious starting issues.

IIRC these engines have internal balance shafts - you could also try deleting it to save some weight, but good luck if the engine is bolted directly to the frame - you can kiss the mounts goodbye.

Really the question is, how far are you willing to go in the pursuit of performance. And in any case you are better off increasing power than decreasing the weight, because ultimately the former has a larger effect on the top speed than the latter.

[SamM]

Great information dieseltech. I really need to get the rolling chassis going first before thinking about too much more. I believe the frame will need to be stretched a couple of inches in order to fit the engine. That will give me more room to fit the fuel tank and inverted forks.

My plan to eliminate the CVT is because I have decided to purchase a Hillard extreme-duty centrifugal clutch to use on the bike. The Hillard is rated for a 13hp engine. My engine makes 28 ft/lbs of torque. I'm hoping it's enough to get a decent top speed out of it. I'm well aware that none of this may work. If it doesn't I'll find a nice mini bike frame to stick it into.

I'll get with you about increasing the power. Thanks for the offer to help!

SamM

[coachgeo]

....
I would imagine using a turbo would give somewhat disappointing gains - the engine is simply too small for even the smallest turbo to work well across the normal RPM range, so low- and mid-range torque would be seriously lacking. Also you would need an ALDA setup to prevent heavy smoke emission and take full advantage of the available boost. An intercooler would also help a lot, but placement could be a serious problem.
Using a boost control valve (instead of hooking up the turbo actuator straight to the intake manifold) would also increase the midrange boost significantly, and such a valve can be easily made from (mostly) common household parts and can be indeed quite tiny. If you do go that route I can help you with that....

Your knowledge is going to be most helpful around here. Thank you for offering assistance.

Here is a thread about turbo's on single engines. Maybe you can enlighten us more there?

viewtopic.php?f=32&t=962

Other threads in that forum on the topic as well.


BTW We also have a CVT forum in here to you might review and see if you can pipe in some thoughts when you get a chance.

[dieseltech]

Great information dieseltech. I really need to get the rolling chassis going first before thinking about too much more. I believe the frame will need to be stretched a couple of inches in order to fit the engine. That will give me more room to fit the fuel tank and inverted forks.

My plan to eliminate the CVT is because I have decided to purchase a Hillard extreme-duty centrifugal clutch to use on the bike. The Hillard is rated for a 13hp engine. My engine makes 28 ft/lbs of torque. I'm hoping it's enough to get a decent top speed out of it. I'm well aware that none of this may work. If it doesn't I'll find a nice mini bike frame to stick it into.

I'll get with you about increasing the power. Thanks for the offer to help!

SamM

You will soon find out that the centrifugal clutch setup gives you quite abysmal acceleration - unless you are willing to gear it low, but then you lose out on the top speed. Gear it too high, and you'll be unable to climb even the gentlest hill. With fixed gear it's always a huge compromise. And no amount of weight saving or power gains will help you with that.
A CVT allows the gear ratio to vary according to vehicle speed. It's always low geared when going slow, and high geared when going fast, so you get the most out of the little engine power you have.

Let's try something else: I presume you have at least some experience with mountain "bikes" (bicycles). But have you ever ridden a fixed gear bicycle? Here in Poland there are still many of them remaining from the bygone times, owned mostly by elderly people. In fact when I was a kid, the first bicycle I had was fixed gear - that was quite the workout! It was geared to go about 18-20km/h with normal pedalling RPMs, and it was an absolute hell to drive it up even the slightest incline. And to get any acceleration out of it you had to really stand on the pedals. Later I got a proper mountain bike, and the difference was like heaven and hell.

Do you know why ALL the chinese 50cc scooters have CVTs? If they weren't needed the chinese would NEVER put them in there. The engine is simply far too weak for any usable performance without a CVT. But with the CVT it can climb hills with relative ease, accelerate like a speed demon from a dead stop, and still achieve a really respectable top speed - as much as 80 or more km/h on flat ground, out of a 50cc engine!

EDIT: Coachgeo, I'd like to be able to offer some advice regarding CVTs in general, but unfortunately I don't have much hands-on experience with CVTs. I work almost entirely on cars, don't deal with bikes too often. Let alone scooters - I avoid those like the plague. Especially the chinese ones, which are totally flooding the market.

The general attitude of Polish bikers is that "scooters are not motorbikes" - and I wholeheartedly agree. Especially since in order to drive 50cc scooters you don't even need a driver's license at all (although that may be changed eventually). You can probably imagine what happens on the roads. Yeah, it ain't pretty. Most motorists perceive scooter riders as complete, unrepentant douchebags, and there are good reasons for that.
The big issue is that in Poland, most roads outside city limits are very narrow - usually only 2 lanes (one each way), and each lane is barely wide enough to fit a semi or a bus. And there is usually NO margin - usually you get a lovely roadside ditch instead. So ANYTHING that moves more than slightly slower than the normal traffic speed is a serious hazard in and of itself. Scooters, bicycles... oh no just don't get me started on the bicycles.

I do have a bit of experience with industrial hydraulic CVTs used on metalworking lathes - these allowed smooth speed control from -100...0...+100% speed, and were widely prevalent in the olden days before VFDs became the norm for motor speed control. Also they were cast iron and weighed tons - a heavy lathe is a good lathe, so yeah. In other words, these CVTs are useless for bikes.

In fact I'm not even aware of anything else than the Comet-style CVT with a rubber belt and 2 split pulleys, that would be feasible to use on a single or two cylinder bike. And I never really bothered to research the CVT subject any further - in Poland, any Comet-style CVT that's not a replacement part for a scooter is roughly as expensive as a whole new scooter (or worse) - there just isn't really any market for non-scooter CVTs here.
And since my own build uses a car gearbox and a decently powerful car engine, there was never really any reason to bother with CVTs.

I did at one point contemplate employing a CVT using a variable displacement hydraulic pump driving a hydraulic motor, instead of the fiesta gearbox - the weight would be roughly similar to a car gearbox anyway - but such a hydraulic pump is exorbitantly expensive for the average person, to the tune of $6000+. So that idea was also very short-lived.

[SamM]

I think I'll just sell everything and buy a new Rokon Trailbreaker!

Thanks!

[gilburton]

Most single cylinder diesel bikes achieve around 50/55 mph in (80kph) using both manual and CVT transmission.
There are plenty of threads on here re CVT transmission so if it was useless people wouldn't be using them irrespective of theory.
My own reason for using one was lack of room to fit a gearbox.
It was easy to fit,just a 3/4" jackshaft mounted on 2 pillow block bearings which allowed a sliding adjustment to get everything in to alignment and then it was easy to purchase a few standard industrial sprockets to experiment with acceleration/top speed.
I used one from an Aixam microcar. It was a bit bulky compared to the Comet types but performed well.
In the UK these jackshaft kits are hard to find but you should have no problem in the US either with Comet CVT or the jackshaft kits.
My own personal theory is that a CVT keeps the engine revs/powerband constant bearing in mind these small industrial engines are designed for a constant speed and not the continuous changes that a manual box demands.
I found that you had to almost twist the throttle or pre anticipate before you actually wanted to to allow the small 9hp engine to gain power.
Once on the open road you just held it open and the engine revs stay the same and the CVT does all the work.
Engine lag probably wouldn't be a problem on 2/3 cylinder engines.
I'm surprised no one appears to have tried a cvt from one of the larger scooters yet??

[dieseltech]

My own personal theory is that a CVT keeps the engine revs/powerband constant bearing in mind these small industrial engines are designed for a constant speed and not the continuous changes that a manual box demands.

That is essentially correct. The whole purpose of these CVTs is to keep the engine RPMs close to its max power point when the thottle is maxed out.

I'm surprised no one appears to have tried a cvt from one of the larger scooters yet??

Now this is purely speculation on my part, but it could be related to the wildly mismatched engine RPM ranges. Our diesels generally max out at 4-5k RPM tops, while at such RPMs most bike/scooter gas engines are barely beginning to enter their powerband.
So a scooter CVT is designed to keep the engine RPMs very high, way in excess of the diesel's capability. You would then need a primary drive or some serious CVT modifications to manage this.

[pietenpol2002]

My plan to eliminate the CVT is because I have decided to purchase a Hillard extreme-duty centrifugal clutch to use on the bike.

As if we haven't discouraged you enough, be aware that to drive directly from a centrifugal clutch to the rear wheel would require off-setting the engine a good deal to the right. In the interest of balance, you might yet be compelled to utilize a jackshaft. In fact, I think Hilliard only offers the 1" bore on the pulley version of that clutch. The sprocket version only goes to 3/4" and wouldn't have the option of a #50 sprocket that could be used with a 530 rear sprocket. You could however drive a jackshaft with a belt and then choose whatever drive sprocket you wished for the final drive. Additionally, the belt version engages at 1800 RPMs instead of the sprocket version's 2300 RPM. I fear you'd be disappointed with the limitations of a single speed bike.

[coachgeo]

one of my favourite little set ups that looked like it fit well in smaller dirt type bikes was the one fellow who took an engine and spun a generator (56v?) which fed power into diodes? These fed a pair of 24v? electric motors which drove the back wheel via chain.

Basically a two wheeled locomotive. I have ZERO clue on it's performance though. Just liked the concept and the compactness. Would think two 24v motors would make it move pretty damn quick.

http://www.dieselbike.net/privateconver ... onsI-R.htm

The Suzuki Kubota Diesel Electric Bike.

[dieseltech]

one of my favourite little set ups that looked like it fit well in smaller dirt type bikes was the one fellow who took an engine and spun a generator (56v?) which fed power into diodes? These fed a pair of 24v? electric motors which drove the back wheel via chain.

Basically a two wheeled locomotive. I have ZERO clue on it's performance though. Just liked the concept and the compactness. Would think two 24v motors would make it move pretty damn quick.

http://www.dieselbike.net/privateconver ... onsI-R.htm

The Suzuki Kubota Diesel Electric Bike.

While it might look cool, there are no doubt enormous losses involved with such a setup.

I know much more than I willl ever need about electric motors/generators and transformers, so I will give you something to think about:
Industrial motors and generators are VERY efficient - over 95% at the multi-kW power levels and over 99% at multi-megawatt power levels - but they are very large and extremely heavy.
Car alternators are extremely small and lightweight for their power level - and their efficiency is around 50% at its best. Yes, for each unit of mechanical energy converted to electricity, another unit of mechanical energy is lost as heat.
If you used a car alternator to power a similarly inefficient motor that's an efficiency of 0.5*0.5=0.25 (25%) - 75% of power gets wasted as heat.

Electric machines (that's the "technical" collective term for motors, generators and transformers) simply MUST use a lot of iron and copper to get a good efficiency. Unless you can repeal the laws of physics there is no way whatsoever to change that.

In locomotives the massive weight is actually a good thing - they need all the weight they can get in order to get the most out of the relatively low friction between the wheels and rails. Many locos even use huge slabs of concrete to further increase the weight.

In bikes... not so much. You are either wasting most of the little engine power available, or adding a huge dead load, and both are really just as bad.
So unless someone invents room-temperature superconductors and ultra-low-loss transformer steel, that just ain't gonna be feasible.

EDIT: Just to further my point - do you know the hub motors used in electric bicycles? They have less than 70% efficiency... the cheap ones, 50-60%.
An electric motor is actually not much unlike an internal combustion engine in that it has a "powerband" in which it's most efficient. Operate it far from its optimal operating point and the efficiency suffers. A lot.
In fact, electric motors outright hate running at low RPMs and high torques - this makes them overheat rapidly due to insufficient cooling. And at very high RPMs the aerodynamic windage losses in the air gap become a very significant source of internal losses.
In locomotives the low speed overloading/overheating problem has been solved by vastly oversizing the motors, so that they can handle both the very demanding high-load, low-speed operation (ie. shunting), and also the relatively undemanding low-load, high-speed operation (cruising). In bikes, again not feasible.

[coachgeo]

..........
In locomotives the low speed overloading/overheating problem has been solved by vastly oversizing the motors, so that they can handle both the very demanding high-load, low-speed operation (ie. shunting), and also the relatively undemanding low-load, high-speed operation (cruising). In bikes, again not feasible.

Maybe that is why this builder used two 24motors instead of one?

But this is best discussed in another thread. Don't want to cloud up this fella's thread. If folk want to discuss this concept more maybe moderator will move it

[dieseltech]

But this is best discussed in another thread. Don't want to cloud up this fella's thread. If folk want to discuss this concept more maybe moderator will move it

Yes, I fully agree.

Back on topic - SamM, I think your best bet is really to get a Comet-style CVT and put that between your engine and jackshaft, like what dieselbikin has done. Since you have shown us another KLR456 with such a setup, it's a relatively simple process to recreate it - at least, unlike me, you don't have to design and build everything from scratch.

Failing that, you could try using a standard bike gearbox. It doesn't seem like you would be able to reuse the KLR box though, as it appears to me that the primary is on the wrong side.
But this might involve some serious frame hacking, to be able to fit both the engine and gearbox in the available space. And then you still need to rig up a new primary.

So in the end the CVT does seem like a very attractive option after all - both in terms of performance and ease of installation.

EDIT: and as for weight reduction, it just occured to me that once you run out of areas where you can save any further weight, you can then resort to converting the exhaust system to thin-walled stainless steel - since it will essentially never corrode, it can be very thin-walled and lighweight, easily twice as light as the stock exhaust. And then there's the appearance bonus. But such an approach would not be exactly cheap.

Also, depending on your local exhaust noise laws, maybe you can even delete the muffler altogether and use a short open pipe running from the engine and ending underneath the bike, for even greater weight savings? That will be seriously loud though, so not everyone might like it.

Remember that in these diesel engines, there is no real gain from any sort of "tuned" exhaust, at least not with the available space - the required length would be way too long, considering the diesel's relatively low RPMs. So the best way to minimize the power loss is to just minimize the exhaust restriction. A short open pipe is the best.
If you do need to use a muffler, the stock KLR one should be more than adequate for your diesel, so you don't need to worry about that.

[SamM]

It's all for sale. I'm going to part out the rest of my KTM 950 Adv and sell all my KLR parts. A 2x2 Rokon Trailbreaker would serve my purpose much better anyway. It seems pointless to make something just to sell it, as in the Diesel KLR. The problems associated with this project are very hard to overcome anyway. After a nasty crash last year, I no longer plan to ride street bikes anymore. The Rokon will serve me well and go places that an ATV could never go.

Thanks for all the good advice though!

[dieseltech]

Are you by any chance considering converting the Rokon to diesel power? Looking at the design, such a conversion seems relatively uncomplicated, seeing as the Trailbreaker is already factory-designed to use an industrial engine.

The lower-displacement yanclones (not the ~400cc ones) would most likely fit with relatively minimal effort, there is no need to worry about redoing the whole drivetrain (since it's already there), and the power would be still quite reasonable - I don't remember what displacement the smaller yanclones are, 250cc? If so, then 8hp is realistically achievable out of that without investing much time and money - and that's actually an improvement over the stock 7hp, so it would cancel out at least some of the extra weight of a diesel.

In fact, just by looking at the Trailbreaker, it seems to me that the gas engine was a really poor design decision - since they chose an industrial engine, why not an industrial diesel? Sure it would be a little heavier, but that can be worked around by using more power.
In fact, if using more power doesn't help in solving the problem, it means you aren't using nearly enough of it.

I guess it boils down to 2 real issues in the end: one is the extra cost of a diesel - although probably not significant anyway, given the bike's price tag - and the other issue, probably the main one, is the general absence of OEM diesel bikes on the market and on the streets. I would imagine that the average non-diesel biker would perceive a diesel bike as an oddity equivalent to a gasoline-engined semi truck or locomotive, or a cat-powered hamster wheel generator (good luck getting THAT one to work!).

[coachgeo]

It's all for sale. I'm going to part out the rest of my KTM 950 Adv and sell all my KLR parts. A 2x2 Rokon Trailbreaker would serve my purpose much better anyway. It seems pointless to make something just to sell it, as in the Diesel KLR. The problems associated with this project are very hard to overcome anyway. After a nasty crash last year, I no longer plan to ride street bikes anymore. The Rokon will serve me well and go places that an ATV could never go.

Thanks for all the good advice though!

Keep your eye out for an Echorider!!! Will probably have to import it. It is a 2wd Rocon-ish DIESEL bike.

http://www.ebay.co.uk/itm/Rare-Ecorider ... 417af6e1ab



or get an old TW200 yamaha fat tire enduro and put a diesel in it. You have much of the parts already.


Another option is build a Raccoon. But they seem to have gone out of biz. BUTTTTTTTTTT there is a way still

http://sumacmt.com/index.html Buy one engine-less and put a diesel in it


Their are several diesel ATV's. Here's on on craigslist new

http://danville.craigslist.org/snd/4247614362.html

[coachgeo]

Are you by any chance considering converting the Rokon to diesel power? ...).

Rokon made them with a diesel for a short while. Used a Hatz. It didn't go over well cause the size of the engine just does not work in there they said. Rokon is built around a tilted engine allowing for the short in height engine bay. Ground clearance dropped literally to fit the diesel in there. BUTTT...... dont think it was well thought out.

You cant modify the frame's neck under the tank thus allowing for engine to sit higher up UP because the neck running under the tank contains the shaft that drives the front wheel drive components. IMHO the whole bike should have been enlarged a tad. Taller front forks and rear frame heightened as well to keep the ground clearance. Maybe even taller fatter tires?

[gilburton]

The Ecorider isn't 2 wheel drive Coach. I think he is just trying to describe it as a 2 wheel tractor and they are no longer in business!

[SamM]

I have no plans to convert the Rokon to diesel. A vertical cylinder will not fit into the Rokon frame. A new frame would need to be fabricated.

[coachgeo]

The Ecorider isn't 2 wheel drive Coach. I think he is just trying to describe it as a 2 wheel tractor and they are no longer in business!

ahhhhhhhhhh..... yes your right I had forgotten that they were not 2wd....... just tractorish lol. Yeah I know they went out of biz unfortunately. You can still find them occasionally though like the ebay link points too. Except frame and body work........ the parts Im sure are pretty off the shelf stuff.


So not to hijack this thread......... see viewtopic.php?f=3&t=2797 if you have interest in 2wd bikes to convert/build as a diesel model

[dieseltech]

Rokon made them with a diesel for a short while. Used a Hatz. It didn't go over well cause the size of the engine just does not work in there they said. Rokon is built around a tilted engine allowing for the short in height engine bay. Ground clearance dropped literally to fit the diesel in there.

I have no plans to convert the Rokon to diesel. A vertical cylinder will not fit into the Rokon frame. A new frame would need to be fabricated.

It would be possible with a bit of effort to convert the yanclone to operate in an inclined position, instead of massively hacking up the frame to make it fit vertically "as is":

IIRC even the small yanclones use an oil pump - so the oil pump intake would have to be repositioned in the crankcase, or possibly to use a suction hose connecting to the outside of the crankcase rather than the internal pipe. Obviously the engine mounts would require some alterations.

Also the engine would need to be positioned such that the camshaft and valve lifters are facing down, or otherwise an external pipe/hose added to give the oil a return path from the head to the sump.

No other modifications would be needed, since other than the oil there are no parts on the engine that would be affected by its orientation, at least as long as the fuel tank is above the engine's fuel line connection - which is pretty much guaranteed to be the case here.

As a bit of an aside, I wonder when will 3D printing metals finally become affordable (it is already possible, just way WAY too expensive). Then it would be economically feasible to design and print our own engines - or at least just the crankcases to keep things simple - with customized cylinder angles and mounting arrangements. And also bigger cooling fins so we can ditch the ugly cooling blower and shroud.

[tappy]

We use quite a lot of 3D metal printing at work - and several other novel manufacturing methods for rapid prototyping. It'll be a little while before anyone uses them to make crank cases directly

[dieseltech]

We use quite a lot of 3D metal printing at work - and several other novel manufacturing methods for rapid prototyping. It'll be a little while before anyone uses them to make crank cases directly

Just for reference, how expensive is it? And in what material?
I don't know the pricing here in Poland, since I have never been involved with metal printing in any way. But I know that it's very expensive.
I do know that it IS still significantly cheaper than making certain "difficult" parts on an one-off basis with normal methods. Totally out of reach for the average individual though.

Somewhat unusually, it's the opposite of subtractive machining price-wise: the metal powder constitutes the majority of the cost, apparently - while in subtractive machining, when dealing with short production runs or one-off parts, the cost of the material is usually chump change compared to the actual machining costs.

I'm considering the possibility of building a generic 3-axis CNC platform someday, if/when I have the $$$ to spare and the space to keep it. Probably belt drives on the X and Y axes (steppers of course), for fairly high max feeds and low cost. Don't need great accuracy here - it would be used for 3D printing plastics, plasma cutting (fairly high feeds needed here, >10mm/s in thin materials), PCB hole drilling and maybe some light milling in soft nonmetals. One issue is that this causes some conflicting requirements though.

As for 2WD bikes, an interesting approach would be to use a hydraulic pump - driven by the rear wheel's drive chain or directly from the PTO shaft - which would drive a hydraulic motor at the front wheel. Either a stock hydraulic motor driving the wheel via a chain or belt, or some specialized integral hub motor.

That would require no complicated drive shafts, universal joints and bevel gears, and has the advantage that with some valve wizardry (hydraulic "freewheel") and careful part selection you can easily make it so that the front wheel will only start to pull when the rear starts to slip slightly (ie. a few % slip), which seriously improves handling as opposed to powering both wheels equally. Also then there are very few parts to break or require any maintenance, and industrial hydraulics are extremely reliable when applied properly.

It would be also feasible to use engine oil (from the sump) as the working fluid, negating the need for an external hydraulic oil reservoir. Incidentally that's what I plan to do on my Fiesta bike for the "power clutch" hydraulics.

[tappy]

I do know that it IS still significantly cheaper than making certain "difficult" parts on an one-off basis with normal methods.

It is generally not cheaper, unless the parts are extremely small. There are some types of components that are very small and a very complicated shape that can even be cheaper for production runs if they're designed carefully. Its use for "one-off" stuff however is generally to make stuff very quickly but at very high cost - there's little post-processing and less pre-processing so you can keep changing the design in CAD up to the last minute.

In future if the equipment and material stock get cheaper by a factor of 100 then it might be cheaper than conventional methods for one-offs.
In my experience the cheapest way to make one-offs is to carefully design parts using "machine from solid" from relatively cheap shapes that can then bolt together. That is pretty tricky for crank-cases tho'..

[Stuart]

Guys, just a heads up to say that 3D printing is a subject that deserves a thread all of its own so later (when I'm not reading this via Tapatalk on the phone) I will perhaps copy some of this info over.

[gearhead1951]

If you want to make yer own cases , take a look at www.backyardmetalcasting.com and thier forum www.alloyavenue.com ! Not as high tech as 3d printing but fairly cheap !