Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Getting new investment castings made from old lugs?

Notices
Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

Getting new investment castings made from old lugs?

Old 07-31-23, 11:15 AM
  #1  
Newbie
Thread Starter
 
Join Date: Jan 2023
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Getting new investment castings made from old lugs?

Hey guys, I知 having a frame built for me using some lugs that the company no longer has casts for.

I知 wondering how hard/expensive it would be to get moulds made from existing lugs so they could potentially keep making these in the future. They only have one road and one track set left, and I知 taking the track dropouts.


In case anyone is wondering, the company is cherubim, and they池e making me a 3rensho (same family, they own the rights) using 3rensho modeulo lugs. And it値l be pink with rainbow flake.

Thanks
Maurice
Mauricemonge is offline  
Old 07-31-23, 01:16 PM
  #2  
Banned.
 
Join Date: Mar 2021
Posts: 1,183
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Liked 345 Times in 263 Posts
What the fellow did for my custom bike was to take lugs and cut them in half and then make the necessary adjustments and braze them back together. Talk to a couple frame builders as this is a situation they encounter and have already solved.
Calsun is offline  
Likes For Calsun:
Old 07-31-23, 01:54 PM
  #3  
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,047
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,391 Times in 2,323 Posts
It's very expensive to have the tooling for investment casting made. I'm designing a lug to be 3d printed. That's about the same price as buying cast ones. Probably can 3d print for investment casting patterns, at least I have seen talk of people doing that.

I suppose they could get those lugs scanned now before they use them. But I think I could copy almost any lug pretty closely just by looking at a completed bike
unterhausen is offline  
Old 07-31-23, 02:41 PM
  #4  
blahblahblah chrome moly
 
bulgie's Avatar
 
Join Date: Apr 2009
Location: Seattle
Posts: 1,709
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
Quoted: 1012 Post(s)
Liked 2,101 Times in 901 Posts
Consider making lugs out of steel tubing, mitered and welded (or brazed) together then smoothed to look like one piece. Time-consuming, bit still probably cheaper than IC, for a one-off.

For example see the perfect clone of a 1961 Masi Special, made by Rob Roberson, commissioned by Richard Byrne (of Speedplay pedals fame). The Flickr album shows in-process shots of the lugs being made. Some of the photos have terrible focus, Roberson is a better framebuilder than he is a photographer, oh well.

Once, for Davidson, I made a complete lug set including BB shell that way, that was sent to Takahashi Japan to be used as master models for a new line of IC parts. I think I spent most of a week just on the BB shell, but I am slow. I never took pictures of anything back then, sorry. The parts I made could have been used to make a frame rather than sending them away to be copied as castings, if it were a one-off frame. The bastards never sent the masters back, claimed they "lost" them. Of course we had the cast parts, but those hand-made masters had sentimental value to me, and they were actually better than the cast parts in a couple ways they screwed up a bit. That's always a risk with IC parts, you never know how they're going to fit until they're done, and if they're terrible, you have to just use them anyway because of all the sunk cost.

Mark B
bulgie is offline  
Likes For bulgie:
Old 07-31-23, 03:08 PM
  #5  
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,047
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,391 Times in 2,323 Posts
I think OP is more thinking of the future of those lugs, not for their bike. Unless I misunderstood that Cherebum wanted to keep them. Anyway, in the future we will all be using 3d printed lugs and wondering where we're going to get tubing. I found some companies that will use a 3d printed model for investment casting. I'm not sure if that's superior in anyway to just having them printed directly.
unterhausen is offline  
Old 07-31-23, 06:14 PM
  #6  
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 17,686

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4026 Post(s)
Liked 3,444 Times in 2,092 Posts
I have read that when casting lugs there's a shrinkage on cooling that has to be accounted for when making the master. So a lug that is the correct to braze up dimension would not be the right size for the mold master.

For a one off I agree with just making one's own lugs with thinned down tubing and a lot of cutting and filing after the filets are done. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 08-01-23, 04:39 AM
  #7  
Senior Member
 
Join Date: Jan 2013
Location: South Jersey
Posts: 2,235
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 701 Post(s)
Liked 760 Times in 455 Posts
I agree with Unterhausen that 3d printing is the way to go for small batch items like that. I know people that love lugged frames think that there is a huge market for them, but the reality is that it is a very niche thing and not profitable to continue to produce them with investment casting.
dsaul is offline  
Old 08-01-23, 10:19 AM
  #8  
Newbie
Thread Starter
 
Join Date: Jan 2023
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks for all the replies. Looks like the builder probably came to the same conclusions when getting more of these made.

As far as making one off lugs that look like these. there is some cool webbing that would take some time to braze, and there are 3 spikes (don稚 know the technical name) that attach to the tubes, instead of just a top and bottom.

I値l just be happy I知 getting the last track bike made with these old lugs, and leave it at that

thanks again!
Mauricemonge is offline  
Old 08-01-23, 07:56 PM
  #9  
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,047
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,391 Times in 2,323 Posts
I found this thread from someone who had those lugs 3Rensho Reproduction / Frame building Diary
They would be easily 3d printed. It's not that big of a deal to braze or weld some up either.

Last edited by unterhausen; 08-01-23 at 08:01 PM.
unterhausen is offline  

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 Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.