An Advanced Friction Drive System

I guess my thinking about friction drive is that people that will buy one want cheap or they want to be able to hide the drive. Does it really need to be anodized if it's aluminum? I imagine most of these being covered by panniers. If someone is really into bling I don't see them being that attracted to friction drive anyway. I would tumble polish the parts and skip the anodizing. They would look like chrome for very little cost.

I doubt it would matter how much I bling my drive out. When I tell someone it's friction drive, even people that don't know much about e-bikes, they just kind of roll their eyes.

And I just want to be clear about my comments. I don't mean to be overly critical but I think you need to really know who you're selling these to. You're going to spend a lot of money to get this going. Make sure you get it right.
 
Thanks for the feed back guys. I dont have any experience in plastics and as such need to draw on other people's experience here. I was really keen on Acrylic and loved the professional finish it gave. However, quality and reliability are paramont and there is no way I want to compromize this. I will do a bit more research but I think for now, I will stick with aluminium as the standard material with perhaps carbon fibre offered at a later date, perhaps as an upgrade kit.
 
My vote is for alloy.
I too have seen both acrylic and lexan crack around holes and screw threads.
If cost of anodising is a factor then offer the kits as plain alloy. I think it would be easy enough to paint or get anodised yourself.
Great build by the way!
 
If you want to go with a plastic Polyoxymethylene or polyethylene are two that offer more strength than acrylic. Polyethylene is commonly seen in kitchen cutting boards. It is available in many thicknessess it is softer than plexi and doesn't 'shatter' like plexi.
Polyoxymethylene or Delerin as it is more commonly known is harder and more plexi like but IMO stronger. Plexi supplier i buy from carries the polethelyene but not Polyoxymethylene its order in and more costly.

I think sticking with Ali would please the massess better though Kepler.

KiM
 
Why not just do ALY but with a tumbled/vibra-sonic de-burred finish? It looks very modern and is likely very cheap. Plus it de-burrs the pieces for you at the same time so they are not sharp. I too agree it needs to be made of metal, or people will not see it as a quality kit..
 
Whiplash said:
Why not just do ALY but with a tumbled/vibra-sonic de-burred finish? It looks very modern and is likely very cheap. Plus it de-burrs the pieces for you at the same time so they are not sharp. I too agree it needs to be made of metal, or people will not see it as a quality kit..
Click to expand...
Agreed. If your kit cost is lower than expected, for example close to $200, and it's only 10% more to anodize, then go for it. :wink:
AussieJester said:
If you want to go with a plastic Polyoxymethylene or polyethylene are two that offer more strength than acrylic. Polyethylene is commonly seen in kitchen cutting boards. It is available in many thicknessess it is softer than plexi and doesn't 'shatter' like plexi.
Polyoxymethylene or Delerin as it is more commonly known is harder and more plexi like but IMO stronger. Plexi supplier i buy from carries the polethelyene but not Polyoxymethylene its order in and more costly.

I think sticking with Ali would please the massess better though Kepler.
Click to expand...
Agreed. Metal perception on the whole is considered higher quality than "plastic" for breakage and durability. 8)

Though KiM's two suggestions are excellent for using a polymer material, I think the Delrin is best, but its cost is probably too expensive?


:mrgreen:
 
I recently started working with delrin and have done a lot of research about it. Again, uv isn't good for Delrin at all. They have uv stabilized versions but none of it would be as strong as 6061 in this application.
 
If you are actually trying to make a buck at this, the last thing you want to do is use plastic.

If you do, you had better have a ROCK SOLID reason for doing so. A reason that is so obvious that people go, "oh, I see why he used plastic."

Otherwise, you lose major cool factor and believability on the reliability claims.

My first reaction on receiving a drive that used plastic (and worse, acrylic) as a load-bearing element would be, "WTF?!"

I want you to do well.

If you must do plastic, you must only use POLYCARBONATE. Why? Because it's bulletproof, which you will demonstrate with a video on the website, thereby reassuring everyone, and, it's waterproof. This isn't just a real objection, but also what the public will believe. They will not believe that your plastic is as good as aluminum, even if it is.

Polycarb is the only way to go for building with bolts and such.

Acrylic is brittle, doesn't like stress risers, work hardens, then fractures, UV unstable, hazes and clouds, and, yellows over time. Can you get material that avoids these problems, yes of course. But will other people believe that you have done so? Probably not.

Use Aluminum.

Paint it black for the base level.
Sell your aluminum sanded nicely with a clear coat - people like shiny - upgrade level 1.
Sell anodized - upgrade level 2.
Sell engraved and anodized - upgrade level 3

I want you to do well, you have an excellent product as far as I can see.

When will units be available for testing? I would suggest that you send out units for testing simultaneous with starting to take orders.

Go kick ass.

Katou
 
EVTodd said:
I recently started working with delrin and have done a lot of research about it. Again, uv isn't good for Delrin at all. They have uv stabilized versions but none of it would be as strong as 6061 in this application.
Click to expand...
Excellent point on the UV issue.
katou said:
When will units be available for testing? I would suggest that you send out units for testing simultaneous with starting to take orders.
Click to expand...
Excellent idea. :idea: You should have some beta-testers (sell kit "at cost" for feedback) to begin with. :twisted:

I'm game. :mrgreen:
 
Well it’s a resounding no for plastic. So no plastic it is then. Looks like I need to work on aesthetics using aluminium as the primary material. Thanks for the suggestions guys. :D

Some might be surprised to learn that although the drive may look very simple, there are in fact 27 individual parts that need to be either laser cut or CNC machined. In addition to this there are around 50 high quality Unbrako fasteners used throughout the drive. Then you have some miscellaneous parts and anodizing. All these parts add up and although I am doing everything I can to keep costs to a minimum, people should be under no allusion that a drive like this can be sold for $200 when manufactured in relatively small quantities. The reality is that I am doing my best to keep the cost under $350. Hopefully I will have final pricing tied down in the next few days.

In relation to beta testing, I won’t release the drive unless I am satisfied with its performance and durability. With the drive built in Aluminium, I am quite satisfied that it is ready for market so thankyou for the kind offers but beta testing has already been covered :) .
 
Kepler said:
In addition to this there are around 50 high quality Unbrako fasteners used throughout the drive.
Click to expand...

And boy don't the price add up when your using high quality fastners Kepler! The Guys at Coventrys fastners smiled when i rolled through the door LoL
my crusier would easily have 300 bucks worth of stainless steel caps screws and nylocs invested in it :-S

Anodized alumnium should be offered like Recumpense offers for his drives, at an additional cost...If buyers
want annodized unit they need to pay extra for it IMHO... And on the other end of the spectrum
perhaps you could offer a 'raw' unit starait from the cnc machine no polishing etc? for lil cheaper not
talking much cheaper maybe 20-30 bucks over the polished units?

Staying with metal is a good choice...If you made a full carbon fiber unit though Kepler even i could
be swayed....:: druuuuel :: caaarbon fiiiiber mmmmmmm hehe

KiM
 
Do they ever. Still you cant beat Unbrako quality.

I will be looking at Carbon fibre for sure. Just need to find it at the right price. There is also the option Fibreglass sheet with a final carbon layer to consider. Need to find suppliers for this also. Any ideas?
 
Kepler said:
Do they ever. Still you cant beat Unbrako quality.

I will be looking at Carbon fibre for sure. Just need to find it at the right price. There is also the option Fibreglass sheet with a final carbon layer to consider. Need to find suppliers for this also. Any ideas?
Click to expand...


No not for already laid up carbon fiber ina thickness you would prolly need no... Luke might be the person to ask i know he has bought a heap of CF
I only know of 2-3mm max thickness sheets in smaller sizes like foot by foot, useful for smaller parts in rc helis and planes etc Hobby City
have a range of it also might want to see if any of their stuff is suitable?

Fibreglass Sales is my local distributor of glass and carbon fiber and they only sell it on a roll not
already made up in sheets. Its frightfully expensive too....my next cruiser frame i hope to make entirely of CF...

KiM
 
Kepler, you must do what you believe to be best. A designers passion and enthusiasm covers over a myriad of choices. Once you start asking you will get dozens of odd requests (Can I have mine anodized lime green, with SAE threads on all the connectors, and weight reduction holes in the shape of a copper molecule?)

If you truly end up having to order 50 units to get this started, I'd suggest keeping it simple. For what its worth, I agree with others, make all the first batch aluminum (serial stamped with #03--#53?), no plastic or carbon fiber (you could still explore those options later). You might consider spraying a clear-coat on half of them to preserve the shiney tumble-deburr finish, and leave the other half raw so the customer can anodize to what ever color they can specify from a local shop.

If you really want to have some of them anodized from the start (50%?, 20%?) black is a very safe color (very professional-looking), but just about any other color is a gamble. The buying public is very fickle. They'll SAY they'd love one thing, but once its made they don't lay their money down.

Your choice of high-grade connectors and solid aluminum plate is (IMHO) money well-spent. The entire presentation fits perfectly into an upscale demographic. Wealthy early adopters will pay extra for a product they can be proud of, and then a reasonable price (such as the price range you've mentioned) will made them sell even faster.
 
Hi Kepler,

Good range of thicknesses here: http://www.s271082832.e-shop.info/shop/category_3/Plates.html?shop_param=cid%3D%26 Not sure how the price compares.....

I'm not that keen on using CFC just for the bling factor, though.....
 
Kepler said:
I will be looking at Carbon fibre for sure. Just need to find it at the right price. There is also the option Fibreglass sheet with a final carbon layer to consider. Need to find suppliers for this also. Any ideas?
Click to expand...

I've been looking at this company with their birch core composite sheets:
http://dragonplate.com/ecart/categories.asp?cID=3

I'm building my battery boxes in a similar fashion and I have no experience with this company other than looking at their website.

You might be able to give them the specs for the pieces you want in CF and have them build a run of sheets. They also have straight up CF sheet if you want that route.

Triton

PS I still plan on buying two kits. While the black looks good a natural aluminum would match my bike better and be more stealth than black. The other could be purple for all I care because it will be a present for my father. M2C as you mull over the final offered finishes.

PPS As I monkey with my own friction drive I wonder how you fit a bearing on your Hyperion 4045. The shaft I have is like a 16 penny nail and if shifted the circlip slot is no longer available to secure the shaft. Did you use a different shaft? Where did you source a 6mm ID router bearing?
 
Hello!

Very nice Drive System you made!

I have just one question, if you take this Motor, and use it like other RC Motors with a chain or a belt to drive the wheel, how much more speed and efficiency would this bring?

Thanks in advance

ATB
Manuel
 
Kepler said:
Well it’s a resounding no for plastic.
Click to expand...

I'm no plastics expert and even though you'll probably forgo plastic for this round, I wouldn't give up on the idea.

Looking at all the pictures of the drive, it seems the basic frame is nothing more than a modified C channel. Even though the sides, as designed, are removable, I can't see why you couldn't substitute a C channel and load all the other components from the rear.

Although the mold would cost quite a bit, I could certainly see a thermoplastic substituting for aluminum... or for that matter, simply replace the sides and top with a suitable section of aluminum C channel, if one could be sourced, thereby lowering component count.
 
Sorry if I came out a bit negative on my last post there. As I said, I want you to succeed. I would help you put a friction drive on every bike if I could.

So, it seems like cost to manufacture is a bit of a problem.

Fasteners specifically are driving up the cost. Even when bought in bulk. Hmmm.

How good are the fasteners you are spec'ing? Here in Canada, for bolts (just an example) I can get:

1. No Grade - from the local hardware store, made of compressed tinfoil I believe. But good enough for many things. - about 10c
2. Grade 3 - pretty good for most things that I build, but on occasion, especially for critical parts, I wonder... - about 20c
3. Grade 5 - dead solid bolt. Situations where the bolt will be quite stressed, in critical parts where bolt count is low. - about 30c
4. Grade 8 - holycrapitstrong. Situations where bolt is stressed, in critical parts, where I can't just use a larger bolt - about 50c

I wonder if you are over spec'ing some of your parts? Ideally I'd use Gr. 8 for everything, but we all know that would restrict my choices in fasteners, and pentuple my fastener budget.

When making a part for production, the question becomes "what is the appropriate strength for this part" rather than, "how can I get the MOST strength in this part"

Once again, probably obvious, but perhaps still worth mentioning, if only for the lurkers.

Katou

I'm sure you've thought about all this, so sorry if I'm saying stuff that's obvious.

It would be difficult for us here to make really detailed suggestions, we would have to be very knowledgeable about the specific design, which would take a lot of explanation from you - time consuming - for perhaps very little benefit.

I wonder what would happen if you asked for a price from a manufacturer to build it "their way". Might be a good idea
 
No, fasteners specifically are not driving up the price, just trying to point out that the parts count is higher then what most people would expect with the sum of the parts being the driving factor in regards to cost. :)

In regards to manufacturer's advice, well and truly been down that path before this stage was reached. The input received helped me reduce the parts count already. Also one of the important manufacturing strategies was to design the dimensions of the drive around off the self bar stock sizes rather then every face requiring machining. C channel sections have been considered together with cheaper fasteners and of course different materials.

The advise from forum members has been invaluable in regards to this project and has been much appreciated but katou, you are completely correct when you say its difficult for you guys to make detailed suggestions not knowing the real specifics of the design. The Acrylic side plates are a good example of this. Feed back was a resounding no mainly due to stress issues but the full picture is that the side plates are in effect only covers and not under stress at all. I know this as the designer but there is no way you guys are going to know this. Still very useful advice though as my experience with plastics is next to zero and I now have a better understanding on where plastics could fit in the future.

Spinningmagnets, thanks for this guidance: Kepler, you must do what you believe to be best. A designers passion and enthusiasm covers over a myriad of choices. Once you start asking you will get dozens of odd requests (Can I have mine anodized lime green, with SAE threads on all the connectors, and weight reduction holes in the shape of a copper molecule?)

I hope this response doesn’t come across as sounding negative to the input from forum members, that certainly isn’t the intent. Just felt it was important to relay that I am doing everything I can to provide a refined design that is of high quality throughout but still at a price that makes buying one of these units an easy decision.
 
I see. That the acrylic pieces were to be *covers* alone, that certainly was my misunderstanding.

I find that the best way to use the fora is for specific questions. General questions whose answer is wide in scope do not fare well, very few will take the time to do a bunch of educating. The other big thing fora are useful for is to get marketing information, so to that end, you were getting good information on the acrylic/aluminum debate.

I would love to help out more, but the difficulty is endemic.

I still would love to see the construction drawings though.

Katou
 
Kepler,
I truly believe your excellent engineering will carry this friction drive to wild success and appreciate your soliciting opinions.
No one is doubting your efforts to create rock bottom value for exceptional engineering. A suggestion - feel free to ignore.
Many of us at ES are of limitless enthusiasm while of limited funds. Yet, many a friend often solicit our opinions on best of breed.

Should you decide to accelerate your marketing volume at any point in your business, please consider this limited Ponzi like scheme.
For every say 10-20 referenced purchases, allow a 'refund/kickback' to the referrer of say 5-10% discount on their original order.
No doubt such a scheme is not necessary given the demand, but it may nevertheless advance your interests while spreading
the ES Friction Drive Goodness Gospel to a wider community.

Best of luck,
Kevo
 
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