Discussion Forums => General Discussion => Topic started by: devnill on July 06, 2017, 09:19:58 pm
Title: bikes
Post by: devnill on July 06, 2017, 09:19:58 pm
are pretty cool, especially when they are made of bamboo. http://ghanabamboobikes.org/product/bike-frame/ (http://www.un.org/climatechange/wp-content/uploads/2014/08/bamboo-bikes.jpg)
Title: Re: bikes
Post by: agweber on July 07, 2017, 04:59:00 am
Looks like something one should try to make from PVC joints instead of dropping a whopping $250 on it. My initial thought would be to 3d print the joints, but I'm not sure if they'd be strong enough.
Title: Re: bikes
Post by: devnill on July 07, 2017, 07:23:37 pm
I've been looking into bamboo a lot lately and 250 isn't actually that bad of a price. People seem to really like bamboo as an alternative to carbon fiber-- it's pretty light but extremely durable (although prone to splitting if not taken care of). A reasonable priced steel frame is about the same price and a carbon frame is easily a thousand dollars.
I don't think pvc is durable enough to work as a bike but i'd love a 3d printed bike. This bike is made from straight carbon tubing and 3d printed lugs:https://vimeo.com/78347167 (https://vimeo.com/78347167).
Title: Re: bikes
Post by: here cums the fuck truck on July 08, 2017, 05:40:33 am
I didn't know it was possible to 3d print titanium! that bike is 14500 euros. that is a lot.
Title: Re: bikes
Post by: agweber on July 08, 2017, 05:58:00 am
I'm just on the other side of the spectrum when it comes to bikes. I'm not into high quality bikes and traveling fast and all that fun stuff, despite living in a heavily bike-oriented community. I'm thinking for casual, low-income bikes.
I didn't know it was possible to 3d print titanium! that bike is 14500 euros. that is a lot.
A laser sintering printer is probably going to cost you quite a few nice bikes worth, let alone ordering the various powdered metals you're using with it.
Title: Re: bikes
Post by: here cums the fuck truck on July 08, 2017, 06:46:52 am
the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
Title: Re: bikes
Post by: h on July 08, 2017, 06:49:27 am
(http://www.motorcyclespecs.co.za/Gallery/Honda%20CG%20125%2095.jpg) does this count
Title: Re: bikes
Post by: rachel on July 08, 2017, 08:09:25 am
the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
Most bamboo bikes I've seen use bamboo poles with carbon fiber or rope wrapped around the joints which is then covered in epoxy and sanded smooth. It seems like that would be easier than needing to make custom connectors that perfectly fit bamboo which often varies in size.
Title: Re: bikes
Post by: here cums the fuck truck on July 08, 2017, 08:49:48 am
the "cool and easy" bamboo frame construction techniques i've seen involve using heavy duty shrink plastic that is heated with a blowtorch, it contracts and hardens. i don't know where you buy that stuff tho.
anyway 3d printers are PLA and ABS.. ABS can get pretty strong, I'm not sure how strong! but, you'd have to make a tapered joint for the bamboo to slide in. That's tricky. And you still have to secure it with a pin or a wedge or something. Or a clamping cutout?
PVC pipe is nowhere near strong enough.
Most bamboo bikes I've seen use bamboo poles with carbon fiber or rope wrapped around the joints which is then covered in epoxy and sanded smooth. It seems like that would be easier than needing to make custom connectors that perfectly fit bamboo which often varies in size.
that's pretty cool. I didn't know you could weld wood like that.
Title: Re: bikes
Post by: rachel on July 08, 2017, 09:31:33 am
Looks like something one should try to make from PVC joints instead of dropping a whopping $250 on it. My initial thought would be to 3d print the joints, but I'm not sure if they'd be strong enough.
Honestly $250 is pretty cheap for a quality bike, most road bikes cost hundreds if not thousands of dollars. I like the idea of trying to make super affordable bikes, but have you looked at how much just the wheels / gears / breaks would cost individually?
As for building a bike out of PVC, I couldn't find many examples, but I did find these:
Have you ever used PVC for holding weight over a long period of time? It will inevitably bend unless you use super thick tubes.
Title: Re: bikes
Post by: here cums the fuck truck on July 08, 2017, 10:18:00 am
my bike cost $800 and it was done at cost for wholesale price (10% off catalog) it's also too small for me. unfortunately there's not a very big bike community here so no way to run into random people and swap. I do wonder if I could move all the parts to a homemade frame. -- regular PVC thickness is schedule forty (SCH40) and "really thick tubes" is schedule eighty (SCH80) just in case you want to buy some at a plumbing supply house. Low pressure pipe for sewer is huge and cheap but is also very thing (SCH10 or SCH20 i think) and breaks easily.
PVC gets pretty brittle when it's cold, even when it's not full of water. and floppy when it's warm. --
Title: Re: bikes
Post by: what on July 08, 2017, 09:09:38 pm
I can pick up a decent bike at my school's surplus store for less than $20.
Ya'll are bad at money.
Title: Re: bikes
Post by: here cums the fuck truck on July 08, 2017, 09:10:58 pm
yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Title: Re: bikes
Post by: devnill on July 11, 2017, 05:22:58 pm
yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
Title: Re: bikes
Post by: rachel on July 11, 2017, 05:48:36 pm
yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
What's the difference between butted tubing and non-butted tubing? Why do you need to look for it?
Title: Re: bikes
Post by: devnill on July 11, 2017, 07:17:04 pm
Instead of a tube which has a consistent thickness, butted tubes are cut in a way where the center is very thin and the edges are thicker. A good steel frame is actually a bit lighter and much more durable than aluminum.
yardsale bikes are often really good deals, heavy fucking steel frame bikes from the 50s-80s that last forever and have bearings that can be repacked by hand. they weigh a ton, but last forever.
Its really hit or miss. Road bikes started to get really big in the 70s and a lot of manufacturers started making cheap shit to fill a gap. The trick is to look for butted steel tubing: http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/ (http://www.reynoldstechnology.biz/materials/how-butted-tubing-is-made/).
What's the difference between butted tubing and non-butted tubing? Why do you need to look for it?
Title: Re: bikes
Post by: here cums the fuck truck on July 13, 2017, 02:05:54 am
I always wondered how they made those weirdly shaped tubes of varying thickness. Now I know!
Title: Re: bikes
Post by: ThePedalMan998 on April 27, 2024, 09:49:01 pm
Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
Title: Re: bikes
Post by: here cums the fuck truck on May 06, 2024, 07:53:40 am
Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
i am so curious why you want to do this! please answer these questions, should only take a moment
- why do you want to build your own frame? - why out of steel? - is it a conventional two wheel or something more? - do you have any steel fab experience? - do you have any bike assembling/building experience?
Title: Re: bikes
Post by: ThePedalMan998 on May 07, 2024, 12:12:04 pm
Hey lads, building my own bike out of steel tubing has been a goal of mine for many years. If any of you have any experience or advice I am down to listen.
i am so curious why you want to do this! please answer these questions, should only take a moment
- why do you want to build your own frame? - why out of steel? - is it a conventional two wheel or something more? - do you have any steel fab experience? - do you have any bike assembling/building experience?
I am hoping to start building my own frames because I hope to start creating my own custom bicycles. I am hoping to eventually gain the skill to deviate from the typical bike frame design and build something more exotic, such as a velomobile. Rachel has also given me pictures of exotic pedal powered vehicles seen at Burning Man. There are also facebook pages like freakbikers Unite, which show people making highly exotic pedal powered creations. I have found these pages and resources to be extremely inspiring. I hope to create similar vehicles in the future, but I have been told I need experience building more conventional bikes first.
https://www.facebook.com/groups/freakbikersunite/
https://www.facebook.com/groups/115024628543289
As for steel fab experience, I do have some limited experience with TIG welding steel, but I am hoping to get more practice with the thin wall 4130 chromaly tubing, which is what I have been told most bikes are made out of. As for bike assembling experience, I recently built a bike from spare parts at a bike store. I also recently attended a bike frame building course held in Colorado by a lad by the name of Walt Wehner. I am very serious about making this happen because cycling incorporates a mix of mechanical aptitude and physical exercise. I am also hoping to do this to gain metaphorical "brownie points" with my friends who are also into cycling, some of which have expressed a desire to make custom tandem bicycles. I would post pictures but I am not sure how the post picture and post video options work on these forums. Anyway, I will also be the first to admit that I still have a long ways to go, but I hope through determination, grit and asking for help I will eventually be able to make custom bicycles.
Title: Re: bikes
Post by: ThePedalMan998 on May 07, 2024, 12:13:58 pm
Also, steel chromaly tubing is also relatively easy to source. More exotic materials like aluminum, titanium, carbon fiber, etc are very expensive and typically not recommended by a beginner, though learning how to make custom bikes from such materials is possible.
Title: Re: bikes
Post by: ThePedalMan998 on May 07, 2024, 12:15:58 pm
Does this answer your questions Mr.Truck?
Title: Re: bikes
Post by: here cums the fuck truck on May 09, 2024, 08:40:54 am
thank you for answering my questions!
you're not the only one who has difficulty with the images/video thing - there's an upload page somewhere where you can put pics and vids up to be hosted locally - I think its https://wiki.wetfish.net/uploader
out of all the people I've ever heard "I wanna build bikes" out of, you are easily the most prepared and most realistic. It's great you have steel fab experience and knowledge about sourcing! Esp TIG welding!
A long time ago I wanted to build my own recliner for a while but I realized i needed a LOT of skills and practice that I wasn't willing to invest for just one bike!
I don't think there's anything I can do to help you - I know just enough to know what I don't know, and my role in the past has been: buzzkill! IE informing people of the harsh realities and hours needed investing in skills to do what they imagine. This is not really creative or helpful of me.
One tip I can give; i used to volunteer at a bike co-op and we had piles of frames that just weren't worth investing in. I wanted to make art or machines out of em, but at the time I didn't have space or money. If you have a co-op near you, they probably have a similar pile. Can be great for bearings, cranks, etc
Do you have - a weld fab table (to keep your fabs in square) - a bender (for precise fab of a specific design) - a method or jig to cope round tube
of course none of these are NECESSARY and can be improvised with a workbench, a vice, and some hand made tools and a LOT of elbow grease - but I find that people tend to burn out on the elbow grease and exhaust their time before they can get to the creativity
if you're planning on dedicating all your hobby time to it, or actually gonna make money off it - thats probably the only time its sensible to invest in that equipment.
I would LOVE to see your forays into this, I hope to see more of your posts in the future! I'm so excited for you!
Title: Re: bikes
Post by: ThePedalMan998 on May 12, 2024, 05:45:34 pm
Thanks for the encouragement. I feel I have made some progress, but I still have a ways to go. I have managed to figure out how to miter tubes with a lathe and Milwaukee hole saw.
I also do have access to both TIG and MIG welding machines through the local makerspace, as well as many people with prior welding experience. I will admit though that finding the correct mandrel for bending tubes will be difficult, but can be fabricated out of wood if necessary. Overall, I do have much of what I need to manufacture a bike, with the largest obstacles right now being development of my welding skills and finding time for this endeavor. Time is an issue being that I am doing this as a hobby/side hustle. I am hoping to do this half because I think bikes are cool and half because I am desperate to impress my bicycle oriented friends.
Title: Re: bikes
Post by: ThePedalMan998 on May 12, 2024, 05:52:13 pm
Also, here is a picture of my latest TIG welding practice for coped joints. The impression I got from my friends is that this is an OK job, and more practice is required before I attempt to build a bike.
Title: Re: bikes
Post by: here cums the fuck truck on May 18, 2024, 01:33:34 pm
I'm always surprised how much those little bi-metal holesaws can cut! they're so cheap and so HANDY! i've drilled 1/2" of plate steel with a battery drill and a single holesaw (and plenty of oil)
I am sooooo glad you are practicing! I've seen so many people cut and fit material and try to weld it all on the first try!
it's really looking nice!
Title: Re: bikes
Post by: ThePedalMan998 on June 02, 2024, 12:01:39 pm
Hey lads, anyone know who posted this to the uploader? This looks fantastic.
Title: Re: bikes
Post by: ThePedalMan998 on June 07, 2024, 09:16:46 pm
Started volunteering at a local bike shop to help increase my knowledge of how bikes are put together. I learned the difference between a threaded and non threaded stem assemblies.
Title: Re: bikes
Post by: here cums the fuck truck on June 11, 2024, 07:33:09 pm
what kind of fixing table are you thinking of using for your frame welding? i'm not a great welder but it seems really difficult to keep steel in one plane without a lot of clamps and a big heavy table
Title: Re: bikes
Post by: ThePedalMan998 on June 16, 2024, 09:25:10 am
My plan so far is to use this very simple jig tutorial recommended to me by another frame builder. This will probably be more difficult than using a flat plate, but obtaining the materials will not be as difficult.
Title: Re: bikes
Post by: ThePedalMan998 on July 13, 2024, 02:00:29 am
I got a chance to ride a WAW carbon fiber shell velomobile recently, here are some photos I took of the inside and outside. I hope to be able to build something like this one day as I continue to learn about welding and bicycle design. The last photo is of a cruz bike, which was another unique type of bike that the velomobile owner I visited had. I am also still working on the design of my first bike frame, I just need to get more welding practice with thin chromoly steel.
Title: Re: bikes
Post by: ThePedalMan998 on August 03, 2024, 12:38:44 am
If anyone here is wondering about the progress I am making on the bike frame project, here is a picture of a freecad rendering of the bikeframe I am intending to build. 3d renderings are especially useful to ensure that the seat tube and the chain stays do not collide.
Title: Re: bikes
Post by: here cums the fuck truck on August 05, 2024, 06:30:59 am
if u made a wetfish wiki page on your bike project, it would easily be teh best page on the wiki
Title: Re: bikes
Post by: ThePedalMan998 on August 05, 2024, 12:22:59 pm
I think I will make a page once I get to a finished product. Is there a tutorial anywhere on how to do such a thing?
Title: Re: bikes
Post by: ThePedalMan998 on August 09, 2024, 10:07:32 am
Does anyone here like to ride unicycles? I have been learning to ride one and I am making some progress.
Title: Re: bikes
Post by: ThePedalMan998 on August 11, 2024, 09:20:15 pm
The video seems to work when you open the link in a new page. I am not sure why attached videos from google drive do not show up properly.
Title: Re: bikes
Post by: ThePedalMan998 on August 18, 2024, 05:31:26 pm
I finally got my mitering template software working in matlab. The idea behind miter templates is well summarized on this page here from the bicycle forest. In essence, miter templates are plots that can be wrapped around a tube, with the area above each curve representing material that should be removed by the mitering process.
Title: Re: bikes
Post by: ThePedalMan998 on August 18, 2024, 05:39:23 pm
Whoops, almost forgot, this miter template represents the compound miter on a down tube assembly, with the down tube being mitered twice to accept both the seat tube and bottom bracket tubes. A good example of this can be seen in the figure below, with the down tube needing to be cut twice to accept both the bottom bracket and seat tube.
Title: Re: bikes
Post by: ThePedalMan998 on August 23, 2024, 11:27:55 pm
I reached a milestone today on bike manufacturing. My friends were able to help me make a special chuck that can adapt the carbide hole saws I bought from amazon to the spindle of a mill machine. Here is a video of a test miter on some scrap tube.
This is a google drive link so you may need to copy the link into a new browser window to get the video to play.
This is the setup I will likely be using to miter real tube for the bike frame. The tube is held at the correct angle using a 3d printed tube holder, while some steel tube blocks allow the vice jaws on the mil table to grip the tube without crushing it.
My prior miters were done a lathe, a mil has the advantage though that it is easier to align the centers of the tube and hole saw. Compound miters such as seen on the down tube of most bikes are also easier to do on the mill since the four sides nature of the tube holder blocks allows the tube to be rotated exactly 90 degrees without meticulous measurement.
Title: Re: bikes
Post by: ThePedalMan998 on August 23, 2024, 11:47:26 pm
It is taking some time, but I am also making some progress on learning how to ride a unicycle. Today I was able to successfully complete a turn around pillar, which I was very pleased with.
Again this is a google drive link so it will need to be opened in a new tab to play.
Title: Re: bikes
Post by: ThePedalMan998 on August 25, 2024, 10:02:42 am
If anyone here is still into bamboo/wooden bikes, this is a bike that was recently donated to a bike store near where I live. It turns out that the wooden tubes are affixed to metal lugs, which helps hold the bike together. The bike is not purely wooden.
Title: Re: bikes
Post by: ThePedalMan998 on September 17, 2024, 12:41:58 am
I began mitering the tube for my first frame today, this is the miter for the downtube and bottom bracket shell. (https://wiki.wetfish.net/upload/7231d3bc-2eb4-8f4c-d9d2-dd863bb82f46.jpeg)
Title: Re: bikes
Post by: ThePedalMan998 on September 18, 2024, 10:05:21 pm
I was able to make one more cut on the tube. The down tube now fits well with the head tube of the bike as well as the bottom bracket. If all goes well, I should have some time this weekend to finish mitering the rest of the tubes.
Title: Re: bikes
Post by: ThePedalMan998 on September 22, 2024, 10:07:14 pm
The tubes so far line up near exactly with this 1 to 1 scale printout of my bike. This is a good sign as it indicates my procedure for cutting and mitering tube is accurate.
Title: Re: bikes
Post by: Lindstedt on September 24, 2024, 04:50:48 am
Just stopping by to make a case for bikes being one of the best modern means of transportation. I believe in subsidizing bikes to improve public health and reduce carbon emissions.
Also, love your work MrPedalMan, keep it up!
Title: Re: bikes
Post by: here cums the fuck truck on September 24, 2024, 07:07:25 am
what are you doing for the fittings ie the pedal crank, the rear wheel bracket, etc? do you just buy those off the shelf?
also how do you keep them all square in the same plane while you weld them? im super curious
Title: Re: bikes
Post by: ThePedalMan998 on September 24, 2024, 10:52:51 pm
The problem of keeping the tubes in plane is admittedly a problem I am not completely sure how to counter yet. Most of the sources I have consulted though seem to agree that strategic placing of tacks to cancel pulling forces can help, but that the ultimate solution is to use a so called cheater bar to bend any wayward tubes back into their correct position. In the case of brazing a bike together, the braze flux can be removed and tube welded once more, but this does not seem to be the case in tig welding a bike frame.
Title: Re: bikes
Post by: ThePedalMan998 on September 24, 2024, 11:03:40 pm
It is possible to make rear dropouts, but for my first bike I have been recommended to use prefabricated dropouts from framebuilder supply.
Title: Re: bikes
Post by: here cums the fuck truck on September 26, 2024, 08:47:19 am
this guy doesn't even weld - he brazes! 5yo vid. he says a fixie is an easier first bike because there's no gears or derailers to worry about
Title: Re: bikes
Post by: ThePedalMan998 on September 27, 2024, 11:16:46 pm
Yes, cobra framebuilding is indeed a great resource for building bike frames. I have utilized some of his advice on using a mil for tube mitering. I am currently planning for a my first bike to be a single speed bike, not necessarily a fixie in that a coasting mechanism will be part of the design. I agree that having to worry about a derailleur hanger and making room for a cassette on one's first frame is typically not recommended. I have also been recommended to avoid using lugs. Though lugs can be useful for holding tubes in place and reducing the likelihood of the tubes pulling to one side, lugs lock the bike into a fixed geometry. If one seeks to progress towards making an unconventional bike like a recumbent in the future learning with lugs will likely be a liability, because lug sets are near exclusive to upright bicycles.
Title: Re: bikes
Post by: ThePedalMan998 on September 28, 2024, 04:55:15 pm
This is a diagram of the bike I am hoping to make in bikecad. Is is meant to be a single speed with 700c roadbike wheels. This was made in bikecad.
I was also able to use a lathe to remove some of the sidewall on the chainstays and fit the rear dropouts. This is an essential step for getting the bike project off the ground, and I am very glad I have the tools to do this now.
Title: Re: bikes
Post by: ThePedalMan998 on October 06, 2024, 08:52:59 pm
I finally got the chainstays and seatstays complete, finding a jig and welding remain the final steps of making the frame. (https://wiki.wetfish.net/upload/28189918-a3a8-7e6c-0f9e-4468a06f50f0.jpeg)
Title: Re: bikes
Post by: here cums the fuck truck on October 07, 2024, 10:34:45 am
so cool
Title: Re: bikes
Post by: ThePedalMan998 on October 12, 2024, 02:05:06 pm
Title: Re: bikes
Post by: rachel on October 24, 2024, 01:27:33 pm
I'm really curious to know how you managed to print a giant piece of paper the size of a bike. Did you have to go to a commercial print shop? How much did it cost to print out the design?
Title: Re: bikes
Post by: ThePedalMan998 on October 24, 2024, 05:41:42 pm
The local university that I am attending for a masters degree has a poster printing service at it's library. It was about 41 dollars to get this printed, and I think it was worth it.
Title: Re: bikes
Post by: ThePedalMan998 on November 03, 2024, 09:02:50 am
Currently working on getting a jig ready to hold the tubes together. The jig I am using is based on the design seen here in this instructables tutorial. https://www.instructables.com/A-simple-bicycle-frame-jig/ (https://wiki.wetfish.net/upload/837f76b3-cfab-2130-d463-f6b799ebf9c3.jpeg)
Title: Re: bikes
Post by: ThePedalMan998 on November 03, 2024, 12:41:19 pm
Finally got the courage today to ride a 5 foot tall unicycle without holding onto a wall.
Title: Re: bikes
Post by: rachel on November 10, 2024, 12:22:09 am
Finally got the courage today to ride a 5 foot tall unicycle without holding onto a wall.
WOW!!! That's tall
Cool idea using the fence at a tennis court to keep you from falling over
Title: Re: bikes
Post by: ThePedalMan998 on November 10, 2024, 09:28:25 am
I went to a unicycle meetup yesterday and got a chance to ride this wacky custom made unicycle built around a roller skate wheel. I have no doubt this is one of the most difficult unicycles I have attempted to ride.
Title: Re: bikes
Post by: rachel on November 18, 2024, 11:21:15 pm
I went to a unicycle meetup yesterday and got a chance to ride this wacky custom made unicycle built around a roller skate wheel. I have no doubt this is one of the most difficult unicycles I have attempted to ride.
Wow I had no idea there were unicycle meetups. That's cool!
I'm surprised how smooth it rides. The gear ratio is interesting. I guess you need a lot of torque to move such a small wheel like that
Title: Re: bikes
Post by: ThePedalMan998 on November 22, 2024, 11:02:11 pm
Finally got the tubes assembled in a jig. (https://wiki.wetfish.net/upload/fa0d4e32-d075-0509-0674-14f9d22d60db.jpeg)
Title: Re: bikes
Post by: rachel on November 22, 2024, 11:44:41 pm
A nice use of aluminum t slot extrusions 😎👍
Title: Re: bikes
Post by: ThePedalMan998 on January 19, 2025, 04:49:42 pm
Hi fellas,
sorry for the long wait, life has been extremely hectic with school and work. I have managed to make some progress on the bike frame. I got some help to correct the miters on the tubes with a hand file, and the tubes now fit correctly in the jig. The chainstays have also been increased in diameter from 1/2 inch diameter to 5/8 inch diameter. This change was made because the chainstays bear more cantilever loads that the seatstays, and increasing the diameter will help ensure more power from the pedals goes into rotating the back wheel rather than bending the frame. The brake bridge for the seat stays has also been mitered with an end mill. I have also been working on improving my TIG welding skills, which are currently one of the largest remaining obstacles towards a finished product. (https://wiki.wetfish.net/upload/20565099-1815-14e2-d1ff-72e35ea2a41c.jpeg)
sorry for the long wait, life has been extremely hectic with school and work. I have managed to make some progress on the bike frame. I got some help to correct the miters on the tubes with a hand file, and the tubes now fit correctly in the jig. The chainstays have also been increased in diameter from 1/2 inch diameter to 5/8 inch diameter. This change was made because the chainstays bear more cantilever loads that the seatstays, and increasing the diameter will help ensure more power from the pedals goes into rotating the back wheel rather than bending the frame. The brake bridge for the seat stays has also been mitered with an end mill. I have also been working on improving my TIG welding skills, which are currently one of the largest remaining obstacles towards a finished product. (https://wiki.wetfish.net/upload/20565099-1815-14e2-d1ff-72e35ea2a41c.jpeg)
Title: Re: bikes
Post by: ThePedalMan998 on January 21, 2025, 09:07:47 pm
I don't get it unfortunately.
Title: Re: bikes
Post by: ThePedalMan998 on January 26, 2025, 11:20:02 pm
Drilled relief holes into tubes. These holes help prevent air from expanding inside of the tube during the welding process. This is especially important for the top tube and down tube, which are welded shut on both ends.
Title: Re: bikes
Post by: ThePedalMan998 on February 16, 2025, 11:13:12 pm
Not exactly construction related, but I recently discovered wikipedia has an article on the stability of bicycles and motorcycles, which includes a section on open loop/ no rider stability. I think the presentation of the info is fascinating. I also found this gif of an ideal bicycle in a stable weave oscillation to be very cool, especially because it demonstrates the ability of a bicycle to, atleast on paper, remain upright even without a rider placing input at the handlebars.
Title: Re: bikes
Post by: ThePedalMan998 on March 05, 2025, 08:13:55 pm
I got some unicycle bearing caps in the mail recently. I am hoping to make a unicycle soon. I have realized that a unicycle has much fewer joints to be welded than on a bike frame, and thus may potentially be a good warm up exercise for building a bike frame.