Letting the cat out of the bag...........

[Kin]

Hey, I know you are probably overwhelmed with various PMs and other details. And, you know, working on the system. I just wanted to make a plug for a surprisingly affordable waterjet cutting company, since you said part of the high cost comes in the small parts and custom designs for them and that's kind of frustrating. bigbluesaw.com, they do waterjet and laser cutting in various materials. I'm just curious if certain parts can be made cheaper from them either through lamination construction or when the piece is thin. I've heard of people 2D cutting a chainring and then filing down the teeth profile for high count chainring at a lower price (actually when I finally get to it I was planning that for my 20" bike unless I can snag a high count ring at a more reasonable price elsewhere). Anyway, these are just some side points. I have not used the company yet, but it was recommended by a trustworthy acquaintance as a good place. My main thing is that I've gotten automated quotes on several different projects/ideas that were *much* cheaper than local shops [they calculate the cost on price with a formula like ponoko and the other type of on-demand sites]. -End plug. not affiliated at all. By the way, by 'lamination method', I mean, building up a 1.5" part with 3 0.5" lasercut pieces that are then epoxied together.

[deVries]

#4 The freewheeling crank. This is one thing I am really excited about! It will use a second support bearing to eliminate the overloaded freewheel bearing issue that is so common with freewheeling cranks. It will also use standard 130mm BCD chainrings for multiple ratio options. I am very excited to have come up with a solution to the FW crank bearing issue. I am not the first to do this, but I think it is the first to be readily available. My system will come with this new FW crank system and a new lengthened bottom bracket.

freewheeling crank is crank arms, bottom bracket, spindle, retainer, spacer, bearing, sprocket adaptor, White Industries freewheel, two chainrings, bolts, etc.

Matt, can you fill-in some more info here... as your pics aren't showing the freewheeling crank bearing setup w/2nd support bearing??? Give us some drawings or pics when you have a chance. Thanks.

Looking good.

[etard]

Very nice Matt, I was beginning to wonder about that motor until I read your post.

Devries are you planning on buying one of these?

[johnrobholmes]

What a trick way to incorporate the mounting foot into a tensioning device!


Looking great, can't wait to see how you finalize it!

[deVries]

What a trick way to incorporate the mounting foot into a tensioning device!

Even more trick is how to get chain alignment?

Do you see and understand how it can move laterally to get chain-line alignment?

Use spacers or is there a tracking slot to move it?

[recumpence]

What a trick way to incorporate the mounting foot into a tensioning device!

Even more trick is how to get chain alignment?

Do you see and understand how it can move laterally to get chain-line alignment?

Use spacers or is there a tracking slot to move it?

Lateral adjustment for sprocket alignment is accomplished by loostening the mount foot clamping screws and sliding the whole jackshaft bearing tube left or right in the assembly. In my mock-up, you cannot see what I mean. But, the bearing tube will be about an inch longer than what is in the mock-up. For chain alignment, the whole jackshaft is moved side to side to make infinate alignment adjustments.

Thanks for pointing out something that could be easily overlooked in something like this. Do not be afraid to make suggestions or ask questions. It is not out of the realm of possibility that I could ovelook something or not thing of something that would be a good addition to a given design.

Also, yes, I have looked into lazer cutting and water cutting. Those are great options for 2D work.

The freewheeling crank has been boiled down to one machined part ------ the sprocket adaptor. I, ironically, looks much like my disc brake/chainring adaptor. I do not have any CAD drawings to show. I will wait to show the finished part.

Matt

[johnrobholmes]

Lateral adjustment for sprocket alignment is accomplished by loostening the mount foot clamping screws and sliding the whole jackshaft bearing tube left or right in the assembly.... the bearing tube will be about an inch longer than (the drive foot and motor plate). For chain alignment, the whole jackshaft is moved side to side to make infinate alignment adjustments.
Matt

This is an extremely easy job too, it does not take but mere minutes on the initial installation.

[MitchJi]

Hi Matt,

Do not be afraid to make suggestions or ask questions.

You might want to either include or offer as an option a CA set to force pedaling at startup as described here:
http://endless-sphere.com/forums/viewtopic.php?f=9&t=34331&p=514207#p513941

The slipper clutch is set to prevent too much wheelie action and the acceleration is brutal.

The bike must be pedaled up to 4 mph to engage the drive to make life easier on the motor controller.

I'd like to know how your drive forces 4 mph pedaling to engage the drive and how that works in conjunction with the slipper clutch.

The CA-LRC has a minimum speed setting that allows the motor to sync up and avoid the super high amp surges from attempting to start the motor from a dead stop. The slipper clutch is just a mechanical torque spike limiter and I usually set it tight enough that it doesn't slip unless the throttle is totally pegged or I land the bike with the throttle engaged.
------
It's a pretty cool setting. On this bike, I have to make two pedal cranks to get to 4mph and then the throttle comes in. It lets the motor sync up before there's a load on it.

[Sharkboat]

I think the price is reasonable and the quality is amazing, as always. Can't wait to see more pictures.
-Pat

[recumpence]

I have more to show, but no time right now. You will just have to wait.

Matt

[farmkid4]

I have more to show, but no time right now. You will just have to wait.

Matt

What!! Hold us in suspense how could you!!

[veloman]

It's good to see your progression after these last few years. I think $1500 is not out of the question for what you are offering, though I won't be buyer at that price. I've built crank drives and they are a lot of work, and compromises are always made. If someone wants a $500 system, there are options, but they won't come close to the attributes of what you seem to be offering.


Edit: for those looking for a cheap mid drive, they are out there, very cheap on ebay. I'm sure quality, power and function is considerably below Matt's however.

[recumpence]

Thanks for the votes of confidence, Guys. However, do not be afraid to give suggestions, recommendations, or outright complaints. I understand. The biggest complaint is bound to be price. That is something I am working on. My problem is (as I have gone through this with my RC helicopters and upgrades as well), I never seem to work the development cost and time into the final product. That never seemed like a big deal when I was spending $100 on materials and 2 hours of time developing a heli product. With bike stuff, I may spend $1,000 in fixturing, programming, and a couple prototypes. Hmm, well, if I make $100 on each drive, I can make up for that in 10 sales. Then there is $100 profit for me in further sales. But, I tend to update things in a regular basis. So, any profit tends to get eaten up by further development. See how that goes? With this crank drive, there are far more individual parts than any other bicycle related kit I have ever produced. In fact, this setup rivals my complete RC helicopter in parts count! I have a motor manufacturer, a crank manufacturer, a bottom bracket manufacturer, a sprocket manufacturer, controllers, two manchine shops for pulleys, two separate suppliers for various clutch parts, belts, CNC machined mounts and drive parts, freewheels come from two manufacturers, freewheel adaptors come from another machine shop, etc, etc, etc. And, I have to pay for programming, fixturing and prototyping for every individual part (machined part). It is mind boggling. It looks like I will be out of pocket upwards of $7,000 for innitial design, fixturing, debugging, testing, and other design work. Then I have somewhere in the neighborhood of 50 hours of time from my own schedule doing design work. Next I have to do testing and spend around 20 hours making instructions. On top of all that, I need to part with around $10,000 in manufacturing for these various parts. See how difficult this is? And, the only reason this is even within the realm of possibility is because I already developed (or at least have accumulated knowledge that I can apply) my other drives and can use that knowledge here. There is a huge risk in this, still, however.

Anyway, I am not looking for sympathy, just understanding and patience.

Oh, the freewheeling crank programming and prototyping is ordered. That is my next hurdle. I think I have all the bugs figured out, though.

Matt

[Steven57]

Matt,
Will this bolt to a triple ring crankset? Or a Schlumpf drive? What do you anticipate weight being minus batteries?

[ultima]

Hi Matt,
I have been lurking here for a while, and this may be the system to finally switch me from my gas-assist bike Like Steven57, I am curious whether this kit will utilize a 3 chainring front derailer as per my current Bimoto crank system? Also, since I already have a 10S LiFePO4 A123 20Ah waiting to be hooked up to something, will the controller you have in mind be suitable?
Sorry for the newbie questions, and please keep up the impressive work!

[recumpence]

The crank will have a standard 130mm BCD bolt patern. So, the smallest chainring would be 39 tooth. I could add holes for 110mm BCD as well if I get requests for that. 3 chainrings can fit (remember, one chainring is for the electric drive). With freewheeling cranks, most people use one chainring for the rear drive and one for the motor. So, a dual drive hub system is best for more than 9 speeds. But, again, 3 chainrings is possible. As for Schlumpf drive, no, that uses its own crank. My system requires a freewheeling crank. Of course, you could choose not to use a freewheeling crank. But, then the cranks will be driven when the motor is running.

Matt

[Steven57]

So one chainring for electric freewheeling and 2 left for pedaling at 39+ and bigger ring?

[j3tch1u]

The crank will have a standard 130mm BCD bolt patern. So, the smallest chainring would be 39 tooth. I could add holes for 110mm BCD as well if I get requests for that.

Matt

yes, 110mm BCD plleeeasse (i need to run a 32T)!

[veloman]

My system requires a freewheeling crank. Of course, you could choose not to use a freewheeling crank. But, then the cranks will be driven when the motor is running.

Matt

And I've done a build like that. It takes some getting use to, but eventually you remember to let off the throttle 2 seconds before you might need to stop pedaling. It certainly can and will knock you off the bike if you aren't careful though. I'd highly recommend the freewheel cranks because coasting is one of the beauties of ebikes.

[recumpence]

The crank will have a standard 130mm BCD bolt patern. So, the smallest chainring would be 39 tooth. I could add holes for 110mm BCD as well if I get requests for that.

Matt

yes, 110mm BCD plleeeasse (i need to run a 32T)!

I will see what I can do.........

There is room on the adaptor for it.

Matt

[johnrobholmes]

Another vote for 110 bcd, I want to offroad!

[Steven57]

I'll ask a different way. With this setup will there only be one sprocket for electric and one for pedal?

[johnrobholmes]

That was matt's original plan I gather, but it sounds like there may be a way to have two pedal sprockets.

[recumpence]

Yes, at this point, I am looking at changing the drawings to accomodate two 130mm BCD chainrings and one 110mm ring. That would allow two pedal and one electric ring. I think this would be perfect. The larger pedal ring would be good for road riding and the smaller ring for lower ratio off-roading.

Matt

[johnrobholmes]

If this adapter is 3d already, you could machine the 110bcd on another plane to avoid using spacers for the other rings. Thoughts?