High power RC motor and drive unit production

[MitchJi]

Hi Gary,

I found places on both bikes where the clamps fit perfect. The only problem is that the bearing tube is not 1-1/8" in diameter, like I thought. It's 1-3/8".

If you know of a place in OC to get these bored out, let me know. This one is certainly beefy enough.

I'd check Craigslist for someone who does metal work. Call a couple of machine shops. Even if the holes are a little pricey it sounds like the result will be equivalent to a high quality custom mount.
http://www.google.com/#hl=en&q=mach...+ca&aq=1&oq=machine+shop+orang&fp=_rpp-4zAm3I

 

[mud2005]

you could use an adjustable hand reamer, but being such a large bore you would need 3 hand reamers to make the cut
http://www1.mscdirect.com/CGI/NNPDFF?PM ... &PMCTLG=00
1 1/16 - 1 3/16 $38
1 3/16 - 1 11/32 $45
1 11/32 - 1 1/2 $55
high initial cost but you could make many brackets.
I bought one of these and it bores out aluminum no problem by hand.

 

[ktronik]

For what its worth...

Bike stems come in these sizes:

1", 1-1/8 & on the bar side, 25.4mm, 26mm & 31.8mm

also a 'tandem stoker stem' is made to fit seatposts...



K

 

[GGoodrum]

For what its worth...

Bike stems come in these sizes:

1", 1-1/8 & on the bar side, 25.4mm, 26mm & 31.8mm

also a 'tandem stoker stem' is made to fit seatposts...



K

There is this one, which appears to have been a special one for an OE bike: http://www.jensonusa.com/store/product/ST287H01-Truvativ+Holzfeller+15+Stem+Oe+07.aspx. It has a stem diameter of 1-1/2".

Good tip on the tandem stoker stem, thanks. I'll look for those.

-- Gary

 

[oofnik]

I'm curious how many people have a working solution for mounting the drive right now. I hate to see everyone using the reduction as a shiny paperweight . I would encourage people to look in to my hose clamp solution for something that's cheap, light, and functional, perhaps using the clamps MitchJi posted links to previously.

 

[GGoodrum]

Well, I got a 1-3/8 diamond crusted hole cutter bit today at Lowes, and it did actually work, but there won't be enough material left. A wider stem needs to be used.

Not sure what to do now. Still no closer to getting this thing mounted.

 

[1clue]

I plan to make a clamp out of carbon fiber when the time comes. I have a really good place to mount it on my recumbent, and there is a Y where the rear fork comes in contact with the main tube. The carbon clamp will keep the paint from scratching and still give me firm support for the motor, without drilling or otherwise trashing my bike.

 

[MitchJi]

Hi Gary,

Well, I got a 1-3/8 diamond crusted hole cutter bit today at Lowes, and it did actually work, but there won't be enough material left. A wider stem needs to be used.

Not sure what to do now. Still no closer to getting this thing mounted.

Maybe Matt or Miles or Luke have a source for, or can suggest a simple procedure to make, 1-3/16" to 1-1/2" spacers?

How about cutting off the piece you drilled out and sending the remaining peice to Luke's welding, to weld it to the drive foot? Getting a second part and welding two to the foot, one near each end, might look better and would be really strong.

Your main objection to U-bolts was the winged look? Maybe making a similar part out of square or rectangular stock instead of angle would look better? You could grind it down to make a better looking fit.

Good Luck!

Mitch

 

[GGoodrum]

Mitch --

Thanks for the suggestions. I'll probably order a couple of the 1-1/2" stems, and see if shims can be used. I'm really not into doing a ton of fabrication to get this to work. The foot just is not useful, in my opinion, because it requires a lot of extra fabrication and/or welding. This shouldn't be this hard. Just my opinion, but I am extremely frustrated, and ready to look at something completely different.

-- Gary

 

[deecanio]

hang in there mate :wink:
i'm in exactly the same boat Gary, as you know, nothing has happened with getting my drive mounted either but i've had to wait until the crank adapter is done to measure up properly for the drives position.
Steve has been trying to find out the best method for mounting mine but everyone seems to think it's a major undertaking.
We have gotten to the point where Joz is going to try a bendy strapping to hold the foot but we'll have to see how that goes.
The foot is a little difficult to mount though, i agree.

Cheers,

D

 

[MitchJi]

Hi,

Gary:
Sorry to hear you are frustrated.

I think you will eventually figure out a way to do this that is strong, aesthetically acceptable and not too hard to do.

If you can make the 1-1/2" stems work that would probably be an elegant solution. Maybe aluminum flashing would work for spacers.

I have one more idea that I think would be very easy to implement and I think would look acceptable. Bolt some flat stock to the bottom of each end of the foot to form a small (probably rounded) extension on each side, at the ends of the feet. Probably about 1/4" thick x 3/4" wide, long enough to protrude from each foot far enough (extensions) for holes for U-bolts. Looking at it from above the extensions and each end of the foot would form a T-shape. The entire foot with the extensions would form an H-shape. Drill holes in the extensions for holes for the U-bolts.

D: Would square U-bolts help?:
http://www.dalecompany.com/custom_ubolts.html

Examples of some of the types of custom bolts or standard bolts The Dale Company will provide are:
U-Bolts

 

[Ypedal]

I think i have a fairly easy solution worked out but before i open my mouth and put both feet in it i need to test my theory.. with any luck i'll have a progress report on the weekend ! :wink:

Involves fairly thick stainless steel, an industrial spot welder, and some elbow grease..

 

[GGoodrum]

Involves fairly thick stainless steel, an industrial spot welder, and some elbow grease..,

With the exception of the elbow "grease", not many of us would have the other items available, any more than we're likely to have suitable welding equipment.

I will try the 1-1/2" stem, and may look at McMasters to find a suitable shim, but if that doesn't work, it will be time to take a big step back, and re-look at the whole problem.

-- Gary

 

[Miles]

Shimming 11/2" down to 1 3/8" shouldn't be difficult. Just get some 1/16" wall aluminium tube and slit it.

How about these http://www.doughty-usa.com/cgi-bin/trolleyed_public.cgi?action=showprod_T58887 - bolted to the bottom of the GB foot?

 

[recumpence]

Hey Guys,

Gary, I am sorry you are having such a tough time mounting your drive. One problem is the curved style frame. But, there definately needs to be a better mounting solution.

I have a couple things to mention on this.

First, I think I have a reasonable solution to this. I have been thinking about it for quite a while. I mentioned the first part of this earlier. I have a second portion (option?) to mention as well.

The easy solution is a machined plate that the mount foot would bolt to. That plate would have holes to accept U-bolts. That is relatively simple to do and can be implemented with minimal expense (maybe $30 or $35 for the plate?). The next (slightly more elegent) option is the same plate using straight bolts going to simple aluminum half moon shaped pieces that would wrap half way around the frame tube. That half clamp would have long screws going up to the previously mentioned plate. That would look more elegent and have more surface area than U-bolts, but will cost a bit more.

I am ordering aluminum plate for the new run of drives. I will go ahead and order some wider plate for these mount plates.

Also, remember, at the beginning, it was quite unclear how to mount this. At the last minute, I came up with the foot as a simple, generic base that could be worked with. I did not want to wait forever to work out mounting when I was getting many emails basically saying "I will mount it myself....." So, I went this route. That being said, we know alot more now and I think it is time to get something made that can be used for most applications.

Matt

 

[deecanio]

Hi Matt,

i hope your not thinking anyone is looking at you here?
although mounting is a pita, we asked for a custom drive and a mounting "option" , and boy did you deliver!!
we'll all get sorted soon enough, our bikes are so varied there is no "one fits all" imo.

Mitch,

thanks pal, the U bolts would be great if i were mounting higher the tube but we're going much lower than that where unfortunately it's oval
LOL my next dh'er will have round tubes dammit :wink:


Cheers,

D

 

[recumpence]

Here is a brainstorm for you............

I could make the lower curved aluminum pieces relatively thin walled (maybe 3 or 4mm) so they could curve themselves to the shape of the frame tube. The area where the bolts pass through at each end of the aluminum clamp could be much thicker and the bolt holes could be ovalled a touch to allow the bolt head area of the mount to change angle slightly with varying tube diameters.

How about that?

Matt

 

[Ypedal]

Exactly !!.. you made it totally clear that we were on our own for mounting hehe.. no apologies needed there, this is the way to an eventual goal and the road may get rough ! We'll get there however !

I sat in front of the Chaos with this thing in my hands for about an hour the other day looking at various options.... i'm entertaining the idea of a different frame! :wink:

 

[briangv99]

Just throwing out ideas that might help. I built this mounting for my BB drive system. Two U-bolts weld together to a piece of steel strip with two holes drilled to secure to the drink bottle holes to locate the drive. Gearbox affixes to the aluminium plate.

 

[MitchJi]

Hi Matt,

Mitch,

I am open to anything. My RC helicopters taught me to listen to those who buy products, but keep an eye on production cost. I have thought of a few options for downtube mounting. If this looks to be the main desire of most buyers, I can design an entirely new drive that is layed out specifically for downtube only use. That would be cheaper to make and more elegent. It will be far less universal, though.

Matt

I am aware of the following bikes (built or proposed) with your drive that don't use a downtube mount (3 bikes):
Ben's recumbent
Gary's 2 Folding Dahon's

I am aware of the following bikes (built or proposed) with your drive that do use a downtube mount (6 bikes):
Matt's PK Ripper
Oofnik
Decanio
* Gary's 2 townies
** Ypedal's RC build

* I don't know if Gary is committed to a downtube mount but if you make a drive for that purpose that is cheaper and more elegant it would probably be his first choice (particularly if its easier to mount ).

** I don't think Ypedal is committed to a downtube mount but he appears to be considering that possibility. I think he'd find a cheaper more elegant downtube drive a very attractive option.

That is 66% (with asterisks) of bikes using or open to using a downtube mount which is a sizable percent.

But its 100% (with asterisks) of bikes with conventional frames with downtubes. Since that frame type is the most popular frame type for Ebike conversions by far, I think its pretty safe to say (even considering the small sample size) that over the long run these would probably be more popular than the current configuration (no reason not to offer both).

Here is a brainstorm for you............

I could make the lower curved aluminum pieces relatively thin walled (maybe 3 or 4mm) so they could curve themselves to the shape of the frame tube. The area where the bolts pass through at each end of the aluminum clamp could be much thicker and the bolt holes could be ovalled a touch to allow the bolt head area of the mount to change angle slightly with varying tube diameters.

How about that?

Matt

That sounds like a really great idea! Is it going to be subject to flexing? If so would stainless steel be a better choice?

If provide a solution that works well for different sizes of round tubes and odd frame shapes like D's Kona it is a major accomplishment. This should do that and could probably be made to work with really odd frame shapes like Gary's Dahon's.

 

[GGoodrum]

Okay, I'm not giving up yet...

First of all, I'm now trying to use a tube-based installation for all my setups. Anything else just looks ridiculous.

I'm taking a two-pronged approach to getting this solved, at least for these first two setups. Today I ordered two $24 1.5" stems, and some aluminum tubing with a 1.5" outside diameter and a .042" wall thickness. The seat tube on the Mariner is 1-1/4" (32mm), so this should work. I will probably do something similar on the other folding bike, the Dahon Curve D3.

On my wife's Townie, I'm thinking the mount will go on the seat tube, in the area circled in red below:



For this one, I'm going to try a different approach, using some 5/8" x 2" aluminum stock. I will make two clamps that will attach to the foot. I need to do this because the Townie seat tube is closer to 1-1/2", so the stem idea won't work. I'll try and draw up what I'm going to do, if I can figure out an easy way to draw it.

-- Gary

 

[TylerDurden]

I'll try and draw up what I'm going to do, if I can figure out an easy way to draw it.

You could try Alibre... The free version has a limit of ten parts per project, so it might be adequate for something like the mount.

 

[MitchJi]

Hi Gary,

How do you plan to mount it on the 1-3/8" bearing tube?

Shimming 11/2" down to 1 3/8" shouldn't be difficult. Just get some 1/16" wall aluminium tube and slit it.

I can't find 1/16" wall tubing online. What I did find (at McMasters) is:

Wall Thickness .065"
Inside Diameter 1.37"
Outside Diameter 1-1/2"

I think, if necessary, you can remove the .025 with some emery cloth, on a shaft or stick, while rotating the tubing in a drill.
EDIT: Should be .0025

I'll try and draw up what I'm going to do, if I can figure out an easy way to draw it.

Looking forward to the drawing or better yet seeing the finished result.

Just throwing out ideas that might help. I built this mounting for my BB drive system. Two U-bolts weld together to a piece of steel strip with two holes drilled to secure to the drink bottle holes to locate the drive. Gearbox affixes to the aluminium plate.

I like it ! Very clean and strong and using the bottle mount holes to prevent rotation or slippage is an excellent idea! The plate on the bike has an "extension" which isn't on the other picture. I assumed it was for preventing rotation and slippage. What's it for?

 

[GGoodrum]

I'll try and draw up what I'm going to do, if I can figure out an easy way to draw it.

You could try Alibre... The free version has a limit of ten parts per project, so it might be adequate for something like the mount.

Thanks, TD, I'll check it out.

-- Gary

 

[briangv99]

I like it ! Very clean and strong and using the bottle mount holes to prevent rotation or slippage is an excellent idea! The plate on the bike has an "extension" which isn't on the other picture. I assumed it was for preventing rotation and slippage. What's it for?[/quote]

cheers Mich,

the extended plate on the bike was the v.2 motor mount so that I can mount the twin leg stand that is only designed for a rigid frame on my suspended bike