Fizzit's RC freeride build log - now with videos

[wildharemtbkr]

Hi sorry to tell you after the fact. The cranks appear to be for an american bottom bracket, the frame has an english one which is smaller and threaded, they will not work. The same seller has some that will fit, but they are cottered cranks and are heavy and weak!! On the plus side your bike is decent, way better then most of the others you were looking at!!

[fizzit]

Darn. Well, thanks for telling me anyways. I knew my n00b-ness would screw me over at some point, but I wasn't expecting it to happen so early

I learned a lot today about cranks and bottom brackets from research that I should have done before. I think I'm still gonna go out and look at or attempt to disassemble the cranks to wrap my head around this whole trials crank/freewheel setup that people are using, because its really confusing to me

The only next step I can think of without having to redesign my drive is to get the Eno 2-speed freewheel and the cyclone cranks. Which adds up to over $150
So obviously, any other ideas appreciated

[Hillhater]

I'll try to get the motor apart soon to look at it. It does, in fact, still turn. I think I have the same problem as swbluto did with his 63-74, which is why I don't think the shaft is bent, instead the bearing is just messed up (rotated out of the seats, as you said). That and the fact that the motor still revs up fine without vibration.!

The bearing is in the stator, and must be still in position or the motor would not turn.
The 4mm bolts fixing the end bell to the stator must have broken or stripped the thread. check carefully.

[fizzit]

I took it all apart, and in fact they were just loose. I suppose I should have checked that
It appears that HXT has not discovered threadlocker yet
Thanks for letting me know about that!

Also, I did more research and found out that those eno dos don't allow two chains. And they're crazy expensive anyways. The freewheel on my scooter appears to use the standard freewheel threading. It has a 5-bolt pattern to attach to the sprocket. So my new plan is to get the cyclone cranks and two big #40 flat machinable sprockets from mcmaster. I will then cut out large holes in each and bolt them onto the freewheel, with some washers to space them from each other to prevent chain interference.

What would be really cool (read: cheap) though is if I could take 2 of the sprockets off of the spider on the bike and get some sort of adapter to attach them to the freewheel. Then I wouldn't even need to buy sprockets. So I am currently hunting for an adapter for that

Edit: hmm never mind the fw uses 4 bolts. Which is really annoying because the cool sickbikeparts chainrings I just found use 5 bolts

[fizzit]

Slight update. I got a bunch of stuff in the mail. These are a couple of problems/things I'm working on currently, just putting them out there for the record and in case anyone has any ideas.

A) freewheel on my scooter is stuck
I placed the remover on the freewheel and clamped it in a 12" or so wrench and then clamped the scooter wheel vertically in my vice (so it was actually clamping on the tire, with soft rubber shoes on the jaws of course) and pounded pretty dang hard on the end of the wrench with a mallet. The wheel just started turning. The problem is, I don't think I have a stronger way to clamp the wheel than the vice (which turned also).

B) bicycle chain is not #40 chain
Yeah I'm an idiot. My 11t #40 .5" bore sprocket's teeth are way too wide, I immediately discovered. I started grinding on them with my dremel to thin them down to the right width, and it's taking forever, but I think it might work! I'm also trying to make a sprocket out of sheet steel that I can just attach to the old one, but lets just say it's not pretty

And thats it, only two problems so far, thats surprising with my level of incompetence

[recumpence]

Fizzit,

Please do not get discouraged. You are going through the typical groing pains. This is still a relatively rare/exotic hobby.

#40 sprocket will work fine if narrowed. I have one on my work bench right now that I am setting up the same way. However, in my case, I am using a large grinder while spinning the sprocket on the lathe to narrow it.

You are actually doing quite well considering you jumped into the deep end of the pool!

Matt

[fizzit]

Thanks, recumpence
I'm pretty sure I'll run out of money way before I get discouraged, as it stands I'm deciding whether I want a bike with a controller or with batteries Time to start ebaying random crap I have laying around!

Thats good that thinning the sprocket works. I might have to get another and redo it, when I started I didn't think it over too well and didn't mark the teeth so they arent in the best line

Also, in other news, I got the freewheel off with some help from google. My new problem is that the freewheel threads halfway onto the cranks, and then starts to resist threading on. From the appearance of the threads, it looks like the freewheel started shaving off the threads on the cranks. I thought all freewheel threads were 24 tpi? Oh well, I don't plan on pedaling too much, maybe it'll work fine threaded only halfway on

[AussieJester]

I am using a large grinder while spinning the sprocket on the lathe to narrow it.

ah ba ya whaaat!?! Recumpence goes "ghetto" well i never

Time to start ebaying random crap I have laying around!

I am sorry to be the one to tell you fizzit, but you are showing all the signs of e-bike addiction :: nods head::
Soon you will buying e-bike components instead of food, which is, incidentally ...the real reason behind weight lose in e-bike owners ;-P

Seriously best of luck with the build and as Matt says it is "its still a relatively rare/exotic hobby." and
you have dived straight in, kudos to you and best of luck with getting it all together

KiM

[fizzit]

I am using a large grinder while spinning the sprocket on the lathe to narrow it.

ah ba ya whaaat!?! Recumpence goes "ghetto" well i never

Time to start ebaying random crap I have laying around!

I am sorry to be the one to tell you fizzit, but you are showing all the signs of e-bike addiction :: nods head::
Soon you will buying e-bike components instead of food, which is, incidentally ...the real reason behind weight lose in e-bike owners ;-P

Seriously best of luck with the build and as Matt says it is "its still a relatively rare/exotic hobby." and
you have dived straight in, kudos to you and best of luck with getting it all together

KiM

Hmmm would this "addiction" also be characterized by attempting to convince one's parents to convert one's "College fund" to an "ebike fund"? Because I would never do that.
Thanks AJ, doing this is already a lot of fun.
BTW, your work is amazing, I can only dream of someday making an e-bike 1/50th as cool as yours


Stuff I've done:
I ordered the sickbikeparts freewheel, it literally shipped half an hour later, and because I live in the same state as them, it shouldn't take too long to arrive
This is my wooden mockup that I made of the reduction layout while waiting for my ebay aluminum to come.




As you can see, about the complexity and beauty of a cardboard box, but lets hope that somehow it doesn't explode. I'll be sure to take video.

And here, hopefully you can see how it's all going to work out. I haven't replaced the cranks yet, but I managed to convince the guy that lives across the street from my friend to let me use his crank remover this weekend. Probably should have asked for a bb-tool also if I'm gonna use my extended spindle...



The layout marked on my shiny new 16"x8"x3/8" block of 6061


Any comments, criticism, or insults are appreciated, but extra-appreciated if they are soon because I hope to start working on the aluminum tomorrow!

[dequinox]

Hi fizzit, you're using some seriously heavy plate there for a motor mount! Are you going to sandwich it around the tubing or are you going to just let it hang from one side (sorry doing homework and don't have time to look through the whole thread on my short break from it)? I recommend thinner plate and a sandwiching configuration that hangs below. It would be a little lighter I think. You could always drill a bunch of the weight out also. Take any large swath of the plate you don't need and drill a large pattern of holes in a rectangle so that it falls out...or if you have a jigsaw you can just drill 4 large holes (large enough to fit the blade) at the corners and get-a-cuttin'.

If you want to take a look, my build used a sandwich-style motor mount: http://endless-sphere.com/forums/viewto ... =6&t=14038

I'm a total dork in the videos...you'll get the idea if you just see the first few seconds of the first vid.

[Hillhater]

Its not clear exactly how you are mounting those bearings on the jackshaft, but simply spacing them out is not a good solution.
I assume you have another bearing on the sprocket side of the main plate ?, but you should fab up a second support structure for that outer bearing as it will have to withstand a lot of chain tension force.
You could do as dequinox suggested and "sandwich" the frame tube with another plate which could also act as a support for that bearing.

[fizzit]

Thanks for the responses!

Dequinox, I watched your video. Thats very cool how you did that, I wish my frame had a triangle that I could do something like that in.
Yeah I guess the plate is a little thick. It just seemed like that was about the size that other people were using on their reduction drives. I will make sure to drill it out for maximum weight-saving (no jigsaw )

I was planning to sandwich the tubing by clamping it with bolts. The other "slice of bread" on the other side of the tubing wouldn't extend all the way down to the motor jackshaft area, so the reduction basically would be hanging off. I was hoping that clamping the bearings would support the jackshaft sufficiently, because I am not sure I have the resources to construct a better bearing support (I would need some even thicker aluminum, I think). If I were to use a plate on the other side of the tube, it seemed to me that it would be hard to keep the bearings lined up with no another tube on the other side of the jackshaft that I could sandwich for stability. Would it work fine to do it like that?

Right now, the bearings are just bolted tightly together and onto the plate with the pieces of wood in between, as shown in the first photo. So in a way, they are sort of just spaced out, but the wood is also acting as a lateral support. I will replace those two wood spacers with aluminum pieces about .75"x.75"x1.5". Would that not be strong enough?

[AussieJester]

"I will replace those two wood spacers with aluminum pieces about .75"x.75"x1.5". Would that not be strong enough"

I reckon that would be fine, clamped down with decent bolts those bearing plates look like they are made of decent thickness material...
That big fat down tube is just too easy to get a mount happening with its large flat surface!... Coming along well Fizzit

KiM

[Hillhater]

sorry, I have to disagree .
Spacing the bearings on the mounting bolt holes is not very rigid, alloy spacers or not. You will bend that shaft in no time.
Use another plate on the other side of the frame tube with a couple of spacer posts bolted at the bottom.
You should be able to get the shaft alignment close enough if you drill all the holes with the plates clamped together.
Since you intend to make a plate for the side of the frame tube anyway, this would be an easy fix and 10X more rigid.

[fizzit]

Hmmm... what to do???

Hillhater, are you saying that the bearing flange will bend between the bearing and the bolt or the bolt threads will strip? Because that's the only way I can really see it flexing, barring the spacers deforming. The chain loads will be completely pulling towards one of the bolts on one side and away from that bolt on the other, the only reason the bearings are rotated 45 degrees on the mockup is because I countersunk the wrong side the first time I drilled the bolt holes

AJ, I wish it were that easy! The pictures don't show it, but the tube is oval shaped

[Hillhater]

Sure the position of the bolts will support the shaft to a certain extent , but mainly only in the one direction, and only back to the single mount plate hung from the frame tube.
The sprocket is going to try to twist itself in any direction it can find movement so its better to secure it as much as possible..
Why are you reluctant to fit the second support plate,? its a simple addition and a much more rigid support for the whole drive assy & sprocket shaft.

[dequinox]

Hmmm... what to do???

Hillhater, are you saying that the bearing flange will bend between the bearing and the bolt or the bolt threads will strip? Because that's the only way I can really see it flexing, barring the spacers deforming. The chain loads will be completely pulling towards one of the bolts on one side and away from that bolt on the other, the only reason the bearings are rotated 45 degrees on the mockup is because I countersunk the wrong side the first time I drilled the bolt holes

AJ, I wish it were that easy! The pictures don't show it, but the tube is oval shaped

The bolts will hold everything together fairly secure, but you may need to adjust from time to time. Below is an image I conjured up of the idea I was talking about as applied to your bike. Let me know if any part of it is confusing. KEEP IN MIND: You need to make some part of this thing adjustable for chain tension, or be prepared to add a chain tensioner wheel or drag tensioner like in my video. Its fairly difficult to plate the motor mount with the exact right distance between sprocket centers. Besides, its nice to have some adjust-ability in case things aren't working quite right. Good luck cutting up that aluminum tomorrow. PS the image on the right is a view similar to the last photo you posted...and also the top 5 bolt locations I suggested are wrong...they should be centered on the oval tube which is the black outline in that picture.

Fizzits motor mount.jpg

(187.54 KiB) Downloaded 3 times

For some reason this dirty rat-bastard of a picture isn't showing up directly...I'm not sure why. Sometimes they show up right in the thread and sometimes they don't

[fizzit]

Thanks for that picture! Took me a little while to understand the one on the left though
I think I get what you guys are saying. Hillhater, I was a little reluctant because it seems like the other plate could move around since the tube is rounded, but if I do a spacer-type thing like dequinox shows, that problem should go away. I just wasn't sure about the whole application of it, but now I see more clearly how it could go together.

[dequinox]

Yeah just food for though fizzit. Heck you could even add the second plate later if you felt you needed to, thats the beauty of this type of build is that it's not set in stone, and you can always play with it a little.

[fizzit]

More progress

I cut through the aluminum. 8" of 3/8" aluminum with a dull hack saw, that was fun

And below, you see the n00bish results of my handiwork. Along with a prototype sandwich plate on the other side, made of wood, just to get the hole spacing down. The bolts on either side of the tube aren't installed in the picture, it's being held on by two bolts through the tube. I need more bolts
Any opinions on what I've done so far are appreciated!





Hopefully you can see my hacked-together chain tensioning system for the small chain. It better hold up . As far as chains go, I've been informed that my hacked #40 sprocket needs work. I agree But still, I lack the skills/tools to make one that I'm truly comfortable using regularly. So I'm wondering. Does anyone have any idea how I can get a 11-or-so-tooth bike chain sprocket onto a .5" shaft? I'm open for any ideas, even for having someone machine another #40 sprocket for me. however, I want to keep it under $25 if I can, and with that budget I think machining is out

PS. My freewheel finally got here, guess what, it doesn't clear my bottom bracket. Luckily, I anticipated this problem and bought a 158mm spindle to replace my short one with! Unluckily, I assumed that if you could buy replacement spindles, its possible to replace your spindle, which it apparently isn't. Also, 158mm is really way too long. So it looks like I'll be spending another $25 on a SBP bottom bracket and a few more $ to get the current one replaced. Oh well!

[dequinox]

Lol not bad looking for a dull hack saw. I think it will work! The idea behind the sandwich plate, though, is that you bring it down far enough to mount the other bearing to. Cut a hole in it for the motor...or just leave a corner off or something like that.

Does anyone have any idea how I can get a 11-or-so-tooth bike chain sprocket onto a .5" shaft? I'm open for any ideas, even for having someone machine another #40 sprocket for me. however, I want to keep it under $25 if I can, and with that budget I think machining is out

$9.60 at McMaster-Carr: http://www.mcmaster.com/#drive-sprockets/=9jxfxz
or $13.44 if you want hardened teeth. I don't know what shipping is... but they even have 9 tooth sprockets for a 1/2" shaft.

[fizzit]

Lol not bad looking for a dull hack saw. I think it will work! The idea behind the sandwich plate, though, is that you bring it down far enough to mount the other bearing to. Cut a hole in it for the motor...or just leave a corner off or something like that.

I'm glad you think it will work ! Yeah I may do that with the plate, the wooden one is definitely not permanent, so for right now I'm just seeing where things go.

$9.60 at McMaster-Carr: http://www.mcmaster.com/#drive-sprockets/=9jxfxz
or $13.44 if you want hardened teeth. I don't know what shipping is... but they even have 9 tooth sprockets for a 1/2" shaft.

Correct me if I'm wrong, but it doesn't look to me like Mcmaster stocks sprockets with teeth that are bicycle-chain thickness

[dequinox]

I'm not sure what the thickness of the teeth is on those sprockets. If bicycle chain is in fact #40 (I've never researched that ironically) they have the right pitch available. What width of chain are you using? 1/8" or 3/32"? Their detail drawing doesn't provide the thickness of the teeth.

[Miles]

#40 chain has the same pitch & roller dia. as bicycle chain but it is much wider.
Dimensions here: http://www.gizmology.net/sprockets.htm

[fizzit]

#40 chain has the same pitch & roller dia. as bicycle chain but it is much wider.
Dimensions here: http://www.gizmology.net/sprockets.htm

Yup. So what I did before, is I bought a 11T #40 1/2" bore sprocket from mcmaster and dremeled the teeth down to be bicycle-chain thickness. However, I don't have a lathe so I couldn't do it particularly well and I am looking to replace my sprocket with a better-made one. I think I may just buy another and take it to the metal shop at school and see if they'll let me use their lathe.