If FEMA had the bicycles, would it fund Hustler's manlet bib? - Page 24 - Miata Turbo Forum -Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Insert BS here A place to discuss anything you want

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 10-09-2013, 09:20 PM   #461
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by dcamp2 View Post
injection molds made of metal and very expensive.
Question: Does not this presuppose a mold created by a traditional toolmaker? Would not a mold produced via SLS be satisfactory for the relatively low-volume production of bicycle frames (as opposed to, say, plastic forks)?
Joe Perez is online now   Reply With Quote
Old 10-09-2013, 09:22 PM   #462
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Quote:
Originally Posted by Joe Perez View Post
Question: Does not this presuppose a mold created by a traditional toolmaker? Would not a mold produced via SLS be satisfactory for the relatively low-volume production of bicycle frames (as opposed to, say, plastic forks)?
Probably joe. But I was thinking make the tooling in china and crank out a few thousand of various sizes. And sell them with the bottom end name brand components for the $500 range.
Leafy is offline   Reply With Quote
Old 10-09-2013, 09:35 PM   #463
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Hmm. I was thinking more of a small artisan shop, with "Made in the USA" stamped on it, sold for maybe 1/2 of what a comparable CF bike would cost.


Also, I am considering making this my next purchase: 2013 Schwinn Sierra 2 Comfort Bike - Bikes & Frames



This would be the bike which gets parked overnight in Manhattan (corner of 23rd & 6th) every night, and used for the crosstown leg of my commute 23 & 6 <-> 42 & 2.) Remember, I have to use the PATH subway train to get from Hoboken into Manhattan, and carrying a bike on that train is impractical. So there's really no choice but to leave it parked overnight in the bicycle-theft capitol of the world.

Thus, the criteria are:

1: Cheap.
2: Inconspicuous.
3: Comfy.
4: Does not contain high-end components which will attract strippers.
5: Won't break my heart when it's stolen outright.
6: Must survive being ridden on roads which have recently been cluster-bombed.


Opinions?
Attached Thumbnails
If FEMA had the bicycles, would it fund Hustler's manlet bib?-s13_sie2_blk_25.jpg  

Last edited by Joe Perez; 10-09-2013 at 10:38 PM.
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 09:24 AM   #464
Elite Member
iTrader: (3)
 
Join Date: Feb 2008
Location: Huntsville, AL
Posts: 1,867
Total Cats: 45
Default

Imo, spending even $100 on a bike that you'll leave outside over night in the bike theft capital of the universe is tantamount to throwing money out your bed room window. Buy $20 bikes on CL, put good tires on them and keep a spare in your laundry room.
vehicular is offline   Reply With Quote
Old 10-10-2013, 10:36 AM   #465
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by vehicular View Post
Buy $20 bikes on CL, put good tires on them and keep a spare in your laundry room.
Laundry room? Haha. No such thing here, my friend. The housing situation in this neck of the woods is a bit different from what you're probably accustomed to.

I've been searching Craigslist quite exhaustively, and there just aren't any $20 bikes around here. The absolute bottom-end of the price scale is about the same as what I'm posting here.

Were it not for the fact that I'm 6'2" and wear size 14 boots, I'd buy a $99 bike from Walmart. But having the ability to specify the frame size is important to me, and that's another thing that you're not gonna get on CL. When I ride a "normal sized" MTB, my feet hit the front wheel when I am turning.

And, to be perfectly honest, I just don't want to deal with people on Craigslist.
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 12:17 PM   #466
Senior Member
iTrader: (4)
 
Join Date: Nov 2012
Location: Colorado
Posts: 611
Total Cats: 33
Default

Quote:
Originally Posted by Joe Perez View Post
Question: Does not this presuppose a mold created by a traditional toolmaker? Would not a mold produced via SLS be satisfactory for the relatively low-volume production of bicycle frames (as opposed to, say, plastic forks)?
not familiar with SLS- what is that? I'm just thinking to get plastic to flow into thin-walled long tubes it would have to be pushed by high pressures and the mold would be hot so the plastic doesn't cure halfway through- therefore needing a metal mold.


CF bike molds are low-volume, yet still made of steel... not sure why they can't get away with aluminum or something cheaper/softer but they can't/don't. (i work for one of the big bike companies)





I think we will see 3-d printed bike frames before anything else- no need for expensive molds or skilled welders, just one machine that can print any size frame you want.
dcamp2 is offline   Reply With Quote
Old 10-10-2013, 12:20 PM   #467
Senior Member
iTrader: (4)
 
Join Date: Nov 2012
Location: Colorado
Posts: 611
Total Cats: 33
Default

Quote:
Originally Posted by Joe Perez View Post
Schwinn bike...

Opinions?
buy it, and hit it with brown spray paint (no masking allowed) so it looks like absolute **** and no one will steal it.
dcamp2 is offline   Reply With Quote
Old 10-10-2013, 12:20 PM   #468
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Quote:
Originally Posted by dcamp2 View Post
not familiar with SLS- what is that? I'm just thinking to get plastic to flow into thin-walled long tubes it would have to be pushed by high pressures and the mold would be hot so the plastic doesn't cure halfway through- therefore needing a metal mold.
Round tubes are a limitation set by metal frames, not a requirement. An IM frame would use a variable profile, probably an I beam. With metal inserts left in each molding for the head tube and crank.

SLS is a type of metal 3d printing.
Leafy is offline   Reply With Quote
Old 10-10-2013, 12:25 PM   #469
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,654
Total Cats: 209
Default

Buy $100 bike, spend $20 creating a faux rusty pile of **** finish, maybe it wont get stolen.

Full_Tilt_Boogie is offline   Reply With Quote
Old 10-10-2013, 12:26 PM   #470
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

I'd make it look gross too, like putting fake **** on the seat so someone wouldnt even steal it just to ride somewhere else and ditch.
Leafy is offline   Reply With Quote
Old 10-10-2013, 12:47 PM   #471
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by dcamp2 View Post
not familiar with SLS- what is that?
Selective laser sintering. It's basically the same as SLA, but for metal. You use a laser to melt and solidify a very fine metal power one layer at a time, enabling you to print out extremely complex shapes. It does not leave a perfect surface-finish, but you can fix that in post.

The basic idea is that you don't need to pay a tool-and-die maker to painstakingly hog out a negative from solid blocks of metal, you just design the part in Solidworks and then the let the computer print it out while you pop into Chipotle to watch Braineack fume about how incompetent the employees are.


Quote:
Originally Posted by dcamp2 View Post
shed by high pressures and the mold would be hot so the plastic doesn't cure halfway through-
You're sort of describing the blow-molding process, though I'm not sure how applicable that is to things shaped like bicycle frames.





Quote:
Originally Posted by Full_Tilt_Boogie View Post
Buy $100 bike, spend $20 creating a faux rusty pile of **** finish, maybe it wont get stolen.
If someone can tell me where to buy a $100 bike that fits me well (eg: 31" standover, 21" seat tube, > 42" wheelbase) I would be most appreciative.

There is a reason why I haven't already purchased another $99 Huffy for this, and that's because most bikes in that price range are built to accommodate someone 5 and a half feet tall with small feet.
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 01:22 PM   #472
Senior Member
iTrader: (4)
 
Join Date: Nov 2012
Location: Colorado
Posts: 611
Total Cats: 33
Default

Quote:
Originally Posted by Joe Perez View Post
Selective laser sintering. It's basically the same as SLA, but for metal. You use a laser to melt and solidify a very fine metal power one layer at a time, enabling you to print out extremely complex shapes. It does not leave a perfect surface-finish, but you can fix that in post.

The basic idea is that you don't need to pay a tool-and-die maker to painstakingly hog out a negative from solid blocks of metal, you just design the part in Solidworks and then the let the computer print it out while you pop into Chipotle to watch Braineack fume about how incompetent the employees are.


You're sort of describing the blow-molding process, though I'm not sure how applicable that is to things shaped like bicycle frames.




Got it- I have seen that, just didn't know the abbreviation. Probably could make molds with that method, just don't know if they can make SLS parts that big? And i'm not sure if it would be a whole lot cheaper than cutting at that point...



yeah i think it would be like blow molding- Leafy suggested one could make very affordable bike frames that way with some reinforced plastic or something. I'm not convinced.
dcamp2 is offline   Reply With Quote
Old 10-10-2013, 01:33 PM   #473
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Quote:
Originally Posted by dcamp2 View Post
yeah i think it would be like blow molding- Leafy suggested one could make very affordable bike frames that way with some reinforced plastic or something. I'm not convinced.
But I dont want blow molding, I dont need hollow parts or tubes. Those shapes work well for bikes make from metals or composites, because its easy for the materials to be made in that shape. But when you open up profiles that are more realistically made with molding you can make the bike stiffer with less material. We're starting to see the departure from round tubes with composite and some aluminum bikes. But obviously according to hustler thats not socially acceptable.

The other alternative to cheap light bikes is aluminum joiners with pre-made CF tubes bonded to it. Cast or machine the joiners for fairly cheap and use Chinese cf tubes, should be able to make low run (like less than 10 per size/geometry) bikes that ride like cf frames with slightly more weight for ~$700 frame including american machining and labor. And be able to change geometry and frame size at the drop of the hat for one bike with more or less no increase in cost.
Leafy is offline   Reply With Quote
Old 10-10-2013, 01:39 PM   #474
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by dcamp2 View Post
Got it- I have seen that, just didn't know the abbreviation. Probably could make molds with that method, just don't know if they can make SLS parts that big? And i'm not sure if it would be a whole lot cheaper than cutting at that point...
I'm not really sure what the true cost to beat is. I mean, you said a traditional mold is $100k, but is that all going into the toolmaker's pocket, or does that count designing the mold, buying all the fiddly bits to load it into the machine, etc?

Another option would be to sand-cast the mold based on an SLA-generated resin positive.

In the end, I'm curious as to what material would actually be used to make the finished product, though. I'm hearing talk of reinforced plastic polymers, not sure what that means. Reinforced with what? (eg: when can you squeeze through an injection or blow-molding process that works as a reinforcing material?)
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 01:42 PM   #475
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Reinforced with fibers, think unwoven short strands of CF, kevlar, or FG. Think Glock trigger frame.
Leafy is offline   Reply With Quote
Old 10-10-2013, 01:42 PM   #476
Tour de Franzia
Thread Starter
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 28,968
Total Cats: 327
Default

Attached Thumbnails
If FEMA had the bicycles, would it fund Hustler's manlet bib?-10180407984_0387856260_b.jpg  
hustler is offline   Reply With Quote
Old 10-10-2013, 02:07 PM   #477
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by Leafy View Post
Reinforced with fibers, think unwoven short strands of CF, kevlar, or FG. Think Glock trigger frame.
When I think of that, I think of fiberglass sprayed via a chopper-type applicator. Generally, these produce parts regarded as heavier, thicker, and less strong than their traditionally-laid counterparts.

If you're gonna go that way, why not just do actual CF / CK?
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 02:12 PM   #478
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Quote:
Originally Posted by Joe Perez View Post
When I think of that, I think of fiberglass sprayed via a chopper-type applicator. Generally, these produce parts regarded as heavier, thicker, and less strong than their traditionally-laid counterparts.

If you're gonna go that way, why not just do actual CF / CK?
Because you're injection molding it, not spraying it with a chopper gun.

There's also forged composite which is a similar process to injection molding with a fiber reinforced plastic but using a thermoset rather than a thermoplastic and it uses a higher amount of the fabric material.
Leafy is offline   Reply With Quote
Old 10-10-2013, 02:30 PM   #479
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago
Posts: 24,679
Total Cats: 1,576
Default

Quote:
Originally Posted by Leafy View Post
Because you're injection molding it, not spraying it with a chopper gun.
What I'm saying is- at the point where you're using actual CF and resin of the type which we might associate with chopper-gun application, could it be applied in something like a roto-casting process, wherein you could forego the cost and complexity of injection molding, huge and expensive tooling, etc?

Best yet, the resultant frame can still be called "carbon fiber."
Joe Perez is online now   Reply With Quote
Old 10-10-2013, 02:37 PM   #480
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: woosta, ma
Posts: 8,610
Total Cats: 91
Default

Quote:
Originally Posted by Joe Perez View Post
What I'm saying is- at the point where you're using actual CF and resin of the type which we might associate with chopper-gun application, could it be applied in something like a roto-casting process, wherein you could forego the cost and complexity of injection molding, huge and expensive tooling, etc?

Best yet, the resultant frame can still be called "carbon fiber."
I guess, but you can get different beam profiles and less labor per part this way. Lamborghini and Calloway kind of pioneered the carbon composite forging, but fiber reinforced plastic has been going on for a while because it can get the strength of steel parts with the lightness of plastic and slightly more money than non-reinforced plastic.

Last edited by Leafy; 10-10-2013 at 03:03 PM.
Leafy is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Generation Wuss sixshooter Current Events, News, Politics 656 Today 12:24 PM
New (4) 15x9 Gen 4 Tungsten 6UL's and (8) Black Alloy 949Racing Valve Stems $750 TurboTim Miata parts for sale/trade 4 10-05-2016 05:00 PM
15 Months & Counting - '92 Mariner Blue 1.8 Turbo Build OGWar Build Threads 53 09-14-2016 12:32 PM
WTB- 1.6L Jackson Racing Header Cxracer WTB 7 05-01-2016 10:40 AM


Tags
'gnolo > *, 3k bicycle 2k miata, beer hand up, carbonlust, crossbike > *, douche pedestrians, fenders, fit assholes, prostate cancer, sur la plaque, virgin engineers

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 09:08 PM.