I’m in the process of choosing which frame fixture to upgrade to and I find it difficult to really decide which is better and for what reasons.
I’m assuming I can’t be the only one in this position.
It would be lovely to build a collection of reviews of frame fixtures you have used in this thread for people like myself in doubt of where to put my hard earned money.
Would love to hear why you bought the specific fixture, what features you love about it, what would you change or what have you changed on the fixtue, limitations on setup etc.
I thought this thread could also include a list of currently available fixtures on the market.
I’ll start the list and update if people know about different manufactures or new ones come alive:
Hi Tore, cool to see you’re in a position to make such an investment with your business!
I have used an Anvil Journeyman before and currently I’m using a home made Cobra style fixture. Both these configurations are similar to other fixtures in your list, the Anvil is similar to Engine/Sputnik and to some extend also similar to all the others except the cobra, which again is similar to some other jigs of which I forgot the names unfortunately.
The essential difference is that the cobra style jigs do not use a horizontal reference but their main beam is oriented perpendicular to the headtube. This allows you to only adjust one angle instead of two and makes for a very stiff overall layout.
This feature comes with a list of pros and cons I guess, here is my take:
The Cobra style fixture is inherently very stiff, because the super sturdy main beam runs along the middle of the frame. The Anvil style jigs can be equally stiff but need to use a lot more material/more expensive massive CNC parts to achieve that. The lighter Anvil style jigs (arctos, flume…) will probably be a little bit more flexy
In my opinion, stiffness is a very important feature in a jig, if the jig is too flexy you’ll have a hard time deciding wether a mitre is actually accurate enough or needs some more work. With a jig orders of magnitude stiffer than the tubes in a frame, that question is easier to answer.
The Anvil reference frame makes it easier to botch fitment without messing up the geometry too much, especially on the chainstays. That is because you can cut the mitre a tiny bit too short and just adjust the horizontal chainstay length without changing the bb height. Same goes for the front center length but here it is a bit more complicated…
So I would say, the Anvil style is more error tolerant in some way.
I like the adaptability of the alu extrusions. Depending on what your business model looks like (small batch or super custom everything), you’ll inevitably include some specific custom addons sooner or later. This is quite straight forward when working with the extrusions
The extrusions have sufficient (in my opinion) but not swiss watchmaker level accuracy. The 0.01mm repeatability claimed by Engin will not be achievable with extrusions
I use fixture from Konga as references to build my own. He provides the 3D model to make the parts on your own. Really recommended, solid and very affordable especially if you’re in to DIY stuff (and budget oriented like me) to make your own tools
Bit altering the orientation and some parts of mine (first picture) such as slightly lighter head tube fixture with 50x50mm aluminum extrusion beam for the head tube fixture. Bicycle Frame Buddy (BFB) frame fixture source file can be downloaded at his website
Plenty of good choices. All need careful checking and calibrating when received. Most will be good but you have to be diligent.
Also, a huge amount of value in making your own jig. It’s not about reinventing the wheel but it definitely takes you deep into understanding how you design and build bikes. I built my own window frame jig early on and still use it, with all its good and bad points. It’s not pretty but it’s super accurate and easy to set up when you understand it. I also learnt way more about my frame building than I thought.
Definitely not dismissing buying one at all. Just trying to add to the data for the purchase decision from experience. Some days I think about buying a replacement instead of spending the time building a new one.
I use their original LCFF (I have seen it made out of Alu as well) and I have to say that it works as expected, it’s not the quickest nor the easiest to setup but it does its job and from what I can tell it’s the cheapest (or was) out there
I’m still in the process of making my own jig with as many off the shelf parts as possible. No idea if it’s any good yet because I haven’t built my first frame yet
You didn’t mention Doug Fattic’s fixture. If you scroll down on the Ukraine Bicycle Project website, you’ll see pictures of it in use and a description of its features. I used one when I took his framebuilding class. It’s really quite nifty.
Some years ago, I found some pics of a frame building fixture fixing not the tubes’ ends, but clamping somewhere in the middle. Former German frame builder Holger Koch (long out of business) used it. The big pro should have been, one could braze the frame with the fixed tubes and so avoiding misaligning. Can’t find it now. HK sold all his stuff to someone else, but this guy is no help at all, won’t give anything …
As far as I remember, it was built with aluminium extrusions as a rectangular frame around the bike frame?
