Alignment table alternatives?

[David Tollefson]

I've heard of some of the hobby builders using things other than a foot-thick certified granite table for alignment checks and building frames. I'm in the "research" phase of setting up my shop. Thanks to Doug in the acetylene vs propane thread for helping me wrap my head around the things needed for the gas/flame portion.

My wife and I spent some time in a few Seattle construction recycle stores (Habitat for Humanity, 2nd Use, and one other that the name escapes me), and I had my head swiveling looking for things to use as jigging and such. Didn't come up with much, but there were some thick glass plates 3'x4' (about a half-inch thick), and several sections of granite countertop, some up to 1" thick. I would wonder about how robust glass would be, heat-wise, especially if it's used as a base for tacking up a frame... Even using V-blocks.

What are some of the alternative surfaces you've all used, or seen used to good effect, for alignment checks and tacking?

TIA.

[Andrew R Stewart]

I would be warry of glass. Thin stone (counter tops) will sag under it's weight if under supported.

Tomb stones, milling machine tables, table saw tops, plates or channels of steel with grinding are all possible alternitives. You want flatness to a degree but stability and consistency are more important. Will you be using a torch close to the surface? If not then wood/laminate products might even work if thick enough. Not mentioned is the base for whatever surface you end up with. For makeshift surfaces the base is maybe more important.

But the cost of "real" stone flat surfaces are so low that it's easy to stop there. Andy.

[JLP]

Not sure what time constraint you are under, but it only took me a couple of weeks to find a surface plate with a stand at a great price on the Seattle Craigslist. Then the issue became one of moving it.

[shiggy]

I've heard of some of the hobby builders using things other than a foot-thick certified granite table for alignment checks and building frames. I'm in the "research" phase of setting up my shop. Thanks to Doug in the acetylene vs propane thread for helping me wrap my head around the things needed for the gas/flame portion.

My wife and I spent some time in a few Seattle construction recycle stores (Habitat for Humanity, 2nd Use, and one other that the name escapes me), and I had my head swiveling looking for things to use as jigging and such. Didn't come up with much, but there were some thick glass plates 3'x4' (about a half-inch thick), and several sections of granite countertop, some up to 1" thick. I would wonder about how robust glass would be, heat-wise, especially if it's used as a base for tacking up a frame... Even using V-blocks.

What are some of the alternative surfaces you've all used, or seen used to good effect, for alignment checks and tacking?

TIA.

Not needed to build a frame.

I have built a couple of frames on the "almost a jig" in this thread:
To go with the free tubes: some almost jigless tooling - Mtbr Forums

[Jonathan]

I'm almost done with an epoxy over steel surface plate. Central Florida is pretty devoid of industrial equipment compared to other parts of the country and hauling a 800lb slab of rock to my barn was not an option. In a earlier thread here, there was a link to a guy in GA who builds large car sized plates for NASCAR and IMSA teams and the inspectors for those bodies. He recommended I pour 1/4" of his epoxy over a well supported steel or Al plate. I picked up a piece of 1" plate from the scrap yard and will pour the epoxy in a week or two. This stuff is supposedly 9x harder than concrete once cured and if you need or want to resurface you just do a light sand and pour a new surface. The key though is to have your plate well supported. I'll report how it goes but people with a lot more money and prestige than framebuilders use them.

[-HvA-]

I'm almost done with an epoxy over steel surface plate. Central Florida is pretty devoid of industrial equipment compared to other parts of the country and hauling a 800lb slab of rock to my barn was not an option. In a earlier thread here, there was a link to a guy in GA who builds large car sized plates for NASCAR and IMSA teams and the inspectors for those bodies. He recommended I pour 1/4" of his epoxy over a well supported steel or Al plate. I picked up a piece of 1" plate from the scrap yard and will pour the epoxy in a week or two. This stuff is supposedly 9x harder than concrete once cured and if you need or want to resurface you just do a light sand and pour a new surface. The key though is to have your plate well supported. I'll report how it goes but people with a lot more money and prestige than framebuilders use them.

Jonathan, I remember you mentioning this some time ago, really interested in a write up of the details if you'd ever have time for something along those lines and this ends up working out.

[Doug Fattic]

photo[2].jpg

Jonathan, certainly one of the biggest contributions you could make to the budget minded or weight and mobility challenged framebuilding community is see if an epoxy poured full sized table will work. Many of my students are not settled enough or have the ability to truck in an 800 pound granite or cast iron table when they are setting up their own shop. Of course beams or milling machines tables and even a straight edge with an adjustable screw can check alignment but there is nothing like a full sized table for convenience and accuracy.

For those not on a tight budget but still need to be able to move a table without hiring a crane and want a full size table, I can suggest a cast aluminum table from the Wolverine Bronze company near Detroit. I bought one for my classes and few years ago and it works just fine. It is 48" X 34" and weighs under 200lbs so it is easy for 2 guys to carry or one guy to move with a dolly. The legs (with level adjuster screws on the bottom) unbolt from the top. The WB company bored a 1" hole where I wanted the post. It is webbed so it can support itself and won't sag in the middle. There are pads on the underside of the table where the legs and bb post are attached. Both the pads and top were Blanchard ground. Aluminum is softer than cast iron so it needs to be used with some moderate care. It cost around $1500. I'll attach a picture.

Just so everyone knows, a 2' X 3' table is big enough for a front triangle if the post is in the very southeast corner. With this size the rear triangle hangs off of the table. Around 3' X 4' is ideal – unless more work space for other things is desired or one is making tandems. That gets the entire frame on the table. By the way I place my post hole 8cm up from the bottom and 66cm over from the left edge. That gives me room around the post to place the picture frame pieces of my fixture on the table.

[seankanary]

Not needed to build a frame.

I have built a couple of frames on the "almost a jig" in this thread:
To go with the free tubes: some almost jigless tooling - Mtbr Forums

Shiggy, I stumbled across that thread not long ago and am interested in doing this myself. Do you have more of a detailed write up on this? The link you posted to frameforum is corrupted...any chance you can detail some of that here?

[jerk]

you could use an alignment window if you are building historical re-enactment frames.

[Jonathan]

photo[2].jpg

Jonathan, certainly one of the biggest contributions you could make to the budget minded or weight and mobility challenged framebuilding community is see if an epoxy poured full sized table will work. Many of my students are not settled enough or have the ability to truck in an 800 pound granite or cast iron table when they are setting up their own shop. Of course beams or milling machines tables and even a straight edge with an adjustable screw can check alignment but there is nothing like a full sized table for convenience and accuracy.

.

I'm not doing this out of budget and only partially out of weight. I'd have found a way to bring in a granite plate. Like your aluminum plate I was reallytrying to challenge conventional wisdom. I really do like the Al table you have. All things being equal I have not found a nagative yet with an expoxy table for how I am building frames. Like your table above I don't think Epoxy has to be a compromise consideing the othe industries where they reside.

[randonneur]

I took a tig-welding seminar, and one of guys in the class had built up a couple of frames using an old flat panel door as a work surface. I've also heard of people using several sheets of MDF glued together. Maybe for a hobbyist, either of those solutions could be straight enough.

[shiggy]

Shiggy, I stumbled across that thread not long ago and am interested in doing this myself. Do you have more of a detailed write up on this? The link you posted to frameforum is corrupted...any chance you can detail some of that here?

Frame forum is gone (and one of the reasons this forum exists). I do not have records of that thread.

[seankanary]

You had mentioned here that you were detailing your first frame using that fixture. I'm just curious as to your process using the almost-a-jig.

[Mike Mcdermid]

I'm not doing this out of budget and only partially out of weight. I'd have found a way to bring in a granite plate. Like your aluminum plate I was reallytrying to challenge conventional wisdom. I really do like the Al table you have. All things being equal I have not found a nagative yet with an expoxy table for how I am building frames. Like your table above I don't think Epoxy has to be a compromise consideing the othe industries where they reside.

Jonothan I have been trying to keep out of this having used epoxy surfaces for jigs etc before

but if you wish to challenge conventional wisdom why do you need a table, there are 4 points on a frame which need to be in some form of alignment why would you need an entire table, you could pour 3-4 sub plates and align them on a master

If you look at machine tools ,very accurate grinders etc they are made by replicating a master and grouting the slides or ways into place one reason they use epoxy granite because its thermally stable and you can replicate the surface you are casting to a couple of microns

before i left my job we had worked on such a system which could be pushed and pulled using a metal frame (the metal frame was the weak point and you had to allow for its movement but you are talking less than 10 micron over the temperature range ) I have no idea if your intention is to
braze or weld on this thing or if its for purely for checking alignment

in industry those massive chunks of large jigs ,fixtures and flat metal plates are becoming an expense that companies are trying hard to move away from

[David Tollefson]

So to add in the "why" for the question: For space and budget reasons, I'd be looking to do a true alignment table at some later date, maybe a few dozen frames into this venture. My plan is to use the table for set-up with V-blocks, tacking, and then checking alignment post-brazing. It was suggested to get a Bringhelli BB post (the expensive part) and add it to whatever base I was planning to use. I'd seen some rather decent-sized chunks of granite countertop at the construction-recycling places ($65-90, about 1" thick), and was wondering if these might suffice for an interim measure before committing my half of the garage to frame building...

My intention is to use a propane/oxygen concentrator set-up for welding, and fillet-brazing the tubes together. With lots of practice before joining up an actual frame.

[shiggy]

You had mentioned here that you were detailing your first frame using that fixture. I'm just curious as to your process using the almost-a-jig.

The pics in that thread show part of it. Did it just the way that I drew in the frame.
The instructables link may give you a better idea of the steps, though I made the T- version rather than the single beam.

Main triangle just tacked in the jig. Brazed in a Park stand.

Rearend brazed mostly in the jig.

[prolix21]

Jonathan, I remember you mentioning this some time ago, really interested in a write up of the details if you'd ever have time for something along those lines and this ends up working out.

Curious to hear more about this too, sounds interesting

[beardydave]

I'm also trying to get set up on a budget, and have been meaning to ask the forum for advice on this. The idea I've been toying with is mounting a laser pointer rotating around a bottom bracket post, with some sort of v-block based measuring stick to measure back to the frame. Perpendicularity of the stick to the frame not an issue - just rotate the v-block slowly roud the tube and read the lowest measurement! Seems simple, cheap and potentially quite effective so I'm guessing there's a very good reason why it's not already a documented method...

[Mark Kelly]

I use laser pointers, but I just use two of them, one on each tube, and aim them at the opposite wall. When the two lines are parallel, so are the tubes. For the rear triangle I turn one of the pointer's beams to 90 degrees and mount it on a dummy axle and put the other pointer on the seat tube.

Don't cross the beams!

[PJN]

Any use cases from one of these yet? Good or bad?

-James Nelson