High power RC motor and drive unit production

MitchJi said:
The perfect FW adaptor for this application would be for a 1/2" shaft. The reason 5/8" is mentioned is that Matt has some sleeve material that can be put on the 1/2" shaft to bring it up to 5/8".

Did you mean freewheel bearings with a ~1/2" inside diameter? How about these from VXB: http://tinyurl.com/6mru6w
 
Hi,

Are bolts with this tread and and appropriate strength available?

If so isn't this as simple as boring a 1/2" hole in center of the bolt and drilling and tapping one or two holes in the head for set screws?

If a slot for a key is desired that would be more difficult but given that someone had a 100 made for about $12 the slot cutting portion of the job should be affordable.
 
Not wise or brilliant :oops: :oops:
 
recumpence said:
Wise but not so brilliant? :wink: :mrgreen:

Matt

Hi Matt,

Smart but not wise might be a better description (how Ishi described us):

http://www.jedriffefilms.com/ishi.htm
Ishi, The Last Yahi
(1994) The year 1911 was a low point in history for Native Americans. Contact with white men's diseases and violence had reduced their numbers from over 10 million to less than 300,000. In California, there were only 50,000 Indians alive. Most were living on reservations or had been assimilated into the general population. It was into this world that Ishi, The Last Yahi walked. Ishi came to be known as the "last wild Indian in North America," and his sudden appearance stunned the country. He had been in hiding for forty years. His tribe was considered extinct, destroyed in bloody massacres during the 1860s and 70s.

For Alfred Kroeber, an ambitious young anthropologist at UC Berkeley, Ishi's appearance was great news. He had been searching for years to find unacculturated Indians so that he could document true aboriginal life in America. He arranged for Ishi to come to the Museum of Anthropology in San Francisco, where he lived for the rest of his life.

Ishi lived only four more years, but during his brief stay he transformed the people around him. His dignity and sense of self, his tireless dedication to telling his stories and showing his way of life, and his lack of bitterness towards the people who had destroyed his own, amazed and impressed everyone who met him.
 
There is alot of truth to that.

I know a number of missionaries. When an unreached people group is finally found, quite often disease from the missionaries raveges that people. Alot of vaccinations are pushed for missionaries these days because of that.

Good intentions, bad action trying to implement those good intentions.

The older I get, the more foolish many people seem. Oh, well, I am no better than anyone else. One person has one skill set, while someone else has another. My accountant hires me to fix things for him, while I pay him to do my tax paperwork.

I am good for mechanical design and problem solving. If you have a tax question, go to someone else!

Its all good. :wink:

Matt
 
Hi,

So I guess the 1/8th scale rc trans. isn't a good idea; however I think I might buy one just to see what's in it and how they make the shiftpoints work. I'd really like two speeds in my new project, one that takes me to around 15mph with tons of torque and one to cruise around town at 30-35mph.

I like your bike Mitch, infact it's what I was looking for on my next bike, but since I saw the Haro X3 extreme frame on ebay for $100.00 I had to pick it up. The frames are similar so hopefully we can share some ideas on a drivetrain. Oh and if you haven't picked up a fork yet I happened to find the fork I'm using(a 100mm Manitou Stance for $89.99) on Cambria bikes.
 
Jason said:
Has anyone considered the use of a 1/8 nitro truck transmission. The motors now are pushing up to three horsepower and $25.00 would be pretty sweet for a two speed if it could handle the torque.

http://cgi.ebay.com/NEW-4-6-SAVAGE-...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318

I don't think anyone's done it yet, but I think it's worth a try for sure!
Something to keep in mind though is that these gearboxes are designed to spin at 20-30,000 rpm on the input to handle 3 HP. So mating one of these to a high power brushless inrunner that spins at those speeds might be better than using a slower outrunner to get that kind of power output.

But holy crap, is there anything these buggies can't survive? http://www.youtube.com/watch?v=WDMSCmdLs6E :shock: :twisted:
 
I'm going to have to see what's available in a high kv brushless motor that can handle 26 volts at somewhere around 3000 Watts which is what I'm aiming for. That would also solve the shifting issue since from what I've been told these 2-speeds rely on a centrifugal shifting system within the gears and judging by listening to these motors whine I don't believe they are shifting till the motors get up toward peak rpm.
 
Hi,

recumpence said:
Here is a quick sketch of the drive unit.

You can see how it can be layed out or folded up, or any position in between.

The shaft centers are 3 and 1/2 inches apart for the secondary drive and the motor is mounted on a slotted plate for belt tension adjustment.

Any questions?

Matt

The motor plate looks a little thin. It doesn't look like there is much stress on it but are you sure its strong enough (would steel be better)?

Jason said:
Hi,

So I guess the 1/8th scale rc trans. isn't a good idea; however I think I might buy one just to see what's in it and how they make the shiftpoints work. I'd really like two speeds in my new project, one that takes me to around 15mph with tons of torque and one to cruise around town at 30-35mph.

I like your bike Mitch, infact it's what I was looking for on my next bike, but since I saw the Haro X3 extreme frame on ebay for $100.00 I had to pick it up. The frames are similar so hopefully we can share some ideas on a drivetrain. Oh and if you haven't picked up a fork yet I happened to find the fork I'm using(a 100mm Manitou Stance for $89.99) on Cambria bikes.

I could be way off here but don't think that GB of 1/8th scale RC gets nearly the load of a 50 lb bike with a 150 lb rider.

Another way to go would be a Nexus 3 speed hub driven on the right.

The reason I picked the Sonix frame is that the bottom bracket is on the swingarm so there is zero chain growth between the crank and the rear hub. I plan to connect the crank to the GB output shaft and the GB output shaft to the rear hub (Serial Drive). I was specifically looking for a FS frame with zero chain growth between the crank and the rear hub to accommodate this design. There are very few modern FS bikes with zero chain growth. The Sonix is one of them and the X3 extreme isn't. But $100 sounds like a great deal. I paid $430 for mine :( although it is almost new :).
 
The front plate is programmed as 3/8 inch thick for production. The reduction unit on my recumbent is 1/4 inch thick and it adequate. I agree the drawing looks thin, I know. :wink:

The RC gearboxes are good and bad. The shift point is set for high RPM. If you run a very high RPM motor, there will be alot of noise. Also, those drives are designed for very occasional high load with much less sustained load. For example, a typical RC car acellerates less than 4 seconds before reaching its top speed or reaching the next corner. They are not designed for sustained high power handling. I am not saying it is a bad idea, I am merely pointing out the short life span you can expect from the gearbox should you go that route.

There are a few reduction units designed for large scale planes and RC boats that may work, though. Those are designed for high duration and high load useage.

Matt
 
Jason said:
Has anyone considered the use of a 1/8 nitro truck transmission. The motors now are pushing up to three horsepower and $25.00 would be pretty sweet for a two speed if it could handle the torque.

http://cgi.ebay.com/NEW-4-6-SAVAGE-...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318
Remember these transmissions are connected to differentials (that increase torque further) which turn tiny little RC wheels. I like the idea though, if there was some sort of super high torque RC transmission It could be good...
 
So, I was thinking and thinking the other night that there must be a better way to get a multispeed transmission going while maintianing build strength and compact/stealth nature. I kept looking at the cyclone system and thought to myself, why not change that just a bit to keep the chain from cutting off your leg along while making it more stealthy.

What I thought up was changing it to a geared system. Instead of mounting the large chainring on your crankset, why not mount a large 4-5in 1/2 in face 20pitch gear to the inside of your chain rings. From there you could build a small two stage reduction using gears that an rcmotor could bolt up to easilly with a profile that would be no larger than your biggest chain ring itself.
 
Dave finished the motor plates today. :D

I will pics them up tomorrow and take a few pics of them. I will try to roughly set one up for you to see. It will not be totally complete. But, it will be together enough to get an idea of what it will look like.

Keep an eye open tomorrow for pics! :mrgreen:

Matt
 
..."if there was some sort of super high torque RC transmission It could be good"...

Close but not RC...Dewalt, and I'm sure others, multi-speed hammer drill transmissions. They can definitely handle the rpms and torque. The only questions are durability under continuous use and their efficiency. Actually the real question is who will be the first to try other than the company selling the silly priced gearboxes you just plug your hammer drill directly into. It's on my list with lots of other stuff to try. Here's info from the robot war guys. http://www.robotmarketplace.com/products/dewalt_gearboxes.html

John
 
John in CR said:
..."if there was some sort of super high torque RC transmission It could be good"...

Close but not RC...Dewalt, and I'm sure others, multi-speed hammer drill transmissions. They can definitely handle the rpms and torque. The only questions are durability under continuous use and their efficiency. Actually the real question is who will be the first to try other than the company selling the silly priced gearboxes you just plug your hammer drill directly into. It's on my list with lots of other stuff to try. Here's info from the robot war guys. http://www.robotmarketplace.com/products/dewalt_gearboxes.html

John
The first question that comes to my mind is what sort of gearing ratio do these transmissions have. Would it really get the RPMs don to where we want them?
 
The Stig said:
John in CR said:
..."if there was some sort of super high torque RC transmission It could be good"...

Close but not RC...Dewalt, and I'm sure others, multi-speed hammer drill transmissions. They can definitely handle the rpms and torque. The only questions are durability under continuous use and their efficiency. Actually the real question is who will be the first to try other than the company selling the silly priced gearboxes you just plug your hammer drill directly into. It's on my list with lots of other stuff to try. Here's info from the robot war guys. http://www.robotmarketplace.com/products/dewalt_gearboxes.html

John
The first question that comes to my mind is what sort of gearing ratio do these transmissions have. Would it really get the RPMs don to where we want them?

Stig,

I'd be more concerned about possible efficiency loss in too much step down in the gearing. Looking at the specs on the 2 speed transmission for the 24v motor (which both have the most shared data for alternative uses) it seems the high speed gearing is a step down of about 10:1, and 45:1 in low gear. Like RC motors those small power tool motors are very high rpm to develop the kind of power they do in such a small size. Given how cheap the hammerdrills can be from those who bought package deals just to obtain the Dewalt batteries.

If I swing the Bosch sponsor deal I'm working on then I should be able to get full specs on the motors and transmissions in their cordless power tool line. I'm primarily after their batteries, but I'll include the possibility of using their motors too for my Caribbean to Pacific on a single charge ride, but I'd need data that has been elusive about power tool motors especially with regard to efficiency and durability testing they've already done. I'll be sure to share anything I can.

John
 
Here are some nearly finished pics of the drive unit.

You can see the final dimentions are 9 inches long for the dual stage drive and 6 inches long for the single stage (single stage is the motor plate and one mechanical tube withe bearings.

The mount plates are not shown in these pics. But, those are next to be machined.

The drive is relatively light weight (haven't weighed it yet).

You can see who it looks layed out or folded up. It can be adjusted to an infinate number of positions.

The front plate has no slot for motor mount holes yet. Those will be added per order based on specs required.

Oh, the drive is very compact when folded up. It pretty much fits in my hand. It is only a tiny bit larger than my recumbent drive.

Matt
 

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Great work. Can I get mine with that used AXI already attached? Oh, and while I'm begging, a cheap controller that runs it?

John
 
I figured you might part with it, and thought I'd be the first to ask. Just PM me a price, including anything else you think I might need that you can part with. Assume that I have nothing and know nothing. Blown controllers is a concern. Won't they just blow again, or will some caps in front sufficiently protect them?

John
 
If you don't push them past the rated specs like Matt did, they won't blow. 6500w or more on a 5500w controller usually spells disaster when wires are too long on the battery side.
 
there looking very nice matt 8), great work although we knew it would be :)
just for maths again how many teeth on both the motor pulley and the drive pulley in the first pic?
Also, would you do a custom unit for me please? pretty please? i will draw what im after and thats partly why i've asked for the sizes of the pulleys - are they the smallest and largest available too??
Once again, fine work matt, have you thought of any name for your creation yet???

Cheers,


D
 
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