Doin it with V-Blocks

[Tom T]

Hey-o,

Somewhere between reading one of e-ritchie blogs and Dave Kirk's 10-year summary I got the idea of trying my hand at a frame with minimal tooling (e.g. life size drawings, flat surface and some v-blocks)  

The question is this, how big of a v-block would you recommend?  

My sense is that I could get away with 4"  on its side but maybe 5" or 6" would be better. 

Thanks

T

[Andrew R Stewart]

Tom- The challenge using Vee blocks on a surface is to get all the blocks of the same (meaning matched) sizes. I have never seen more than a pair offered as a matched set. Will you use a "real" flat surface plate? if so then the frame can be set up and tacked with Vee blocks that are 'almost" the same size then aligned before full brazing. The big issue with using blocks on a surface is the access for tacking, getting the blocks high enough with parallels or other shim like things and protecting the surface from the flame/flux. Don't assume that the tubes will be straight... I'd use two blocks a tube positioned as close the the tubes' ends as possible. Andy.

 

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Andrew R Stewart
Rochester, NY

[OBCA]

My thought is secure the bottom bracket with a screw adjustment and provide threaded supports on center (500mm. is good) for seat tube and head tube then take your vee blocks for the top tube and secure to ground posts on which they can float.  This is actually on the market.  www.marchettispa.it.  Or get some fireplace andirons and have a go!

Cheers,

Andy N.

www.strawberrybicycle.com

www.oregonframebuilders.org

[OBCA]

Here is word from Mr. G.V. O'Donovan, Executive Director, TI Carlton Cycles Ltd., 4th. August, 1971:

(c)  Jigs & Tools - A bench vice (sp.), a surface table and a collection of vee blocks have produced more than one championship winning frame.  When you want fancy jigs design them yourself to suit your own methods."

Strawberry heeded this advice for awhile.  The jig we designed was a piece of junk.  My thinking is even if you are a mechanical engineer/tool designer, leave the jig production to the folks who do it for a living whether it is Marchetti, Henry James, Anvil or whomever.  You will be money ahead and you can get on with the day-to-day framebuilding.  Just a consideration.

Cheers,

Andy N.

www.strawberrybicycle.com

www.oregonframebuilders.org

On Jun 4, 2013, at 7:51 PM, Andrew R Stewart wrote:

[Richard Sachs]

Equipment is nice, but it’s not a substitute for a procedure. I am not suggesting a monastic/framebuilder path, but strongly against getting four tons of steel and then listing it for sale in two seasons when the dream expires.

http://www.richardsachs.com/site/2012/01/20/downsize-the-fantasy/

e-RICHIE
http://www.richardsachs.com/site/category/atmo-bis/

[jon norstog]

To the list:

Using V-blocks is inviting an out-of-plane main triangle. Think about the geometry: different diameter round sections settling into the same V profile. I guess you could shim up the different pairs of blocks to compensate.  Sounds like some openings there for Murphy's Law. 

If you must use blocks, IMHO get a set of HJ blocks and caps.  They will hold multiple tube sizes to a center 2" above the surface table.  And they can be fastened to the backing plate of the HJ jig ... hmm!

Good luck!

jn

"Thursday"

[Eric Keller]

Even a crummy set of vee blocks are square and equidistant to the
sides to within bicycle frame tolerances. Just set the blocks
sideways and clamp the frame together that way.

[Andrew R Stewart]

http://alexmeade.com/fixtures.htm

Once again I'll plug Alex's stuff. This link shows some tube fixturing for
flat surfaces. I have found Alex very easy to work with and very cost
effective. Andy.

[Todd Mosley]

If you turn the v-block on it side so that the V points sideways instead of up, different tube diameters will still be on the same plane.

[Tom T]

Wow, ya'll thanks for the input!

Lemme start from the top:

@ Andrew Stewart: I understand that good alignment is necessary but I'm thinking refining my skill/technique would lead to straighter frames. In other words, if the blocks are within 1/10" of each other, and the frame comes out wonky, its probably not the v-blocks I need to worry about.  

What say you?

@ Andy: Maybe I'm misunderstanding what you're writing.... I don't wanna buy or make a jig. Even a 8020 homemade job seems like overkill on frame 1 . . . and paying for a few parts to get machined seems . . . costly.

@ Richard: Yeah, this is what I'm trying to channel. 

@ Todd: Bingo!  It's easy enough to find myself a 36x48" granite remnant (and that seems cheaper + more durable than gluing 3-4 sheets of MDF together). I recognize that persuading the frame into alignment can't happen on a 3/4" - 1.5" thick piece of rock though. In terms of the V-Blocks, do you wish you had used something taller instead of putting the v-blocks on top of 123 Blocks?

@ Thursday: Yeah, shimming would be a bad idea but I'm thinking about placing the V on its side so that it looks like this >. If I have all the same size blocks and the tubes are clamped in, I'm thinking the alignment will be pretty close (yeah maybe not Anvil Jig close, but close enough for build #1)

@ Andy. Yeah, I saw Alex's stuff but $800 - $1300 seems like a lotta scratch to drop. Don't that this as me undervaluing the materials/machining I'm just not that flush. 

[Brandon Ives]

I'm no professional builder nor a particularly good amateur, but I've built quite a few frames (@50), and pretty much always on a budget. I know the desire to try this stuff cheaply and with as few tools as possible, so take this information from that perspective.

Let me add a few things.  First granite remnants aren't very strong and crack pretty easily.  If you're using it just to check the alignment it's OK, but steel is really what you're going to want if you plan to put any pressure on the frame or braze it while it's on the granite. I sheet of MDF cut in half and folded over on itself is a better way IMHO.  Find Talbot's book online and see what he did.

Here's my list of lo-fi set-ups:

1. Bench vice 4"-5" bolted down firm (soft jaws a bonus)

2. Yard/ meter stick aluminum 2"-3" wide or other straight edge

3. Perfectly dished rear wheel of the dropout spacing you desire

4. Park FAG-2, or something similar

5. Torch, files, calipers, etc as you'd expect

 

Here's the build sequence (pinning at each stage might be best):

1. Braze the ST the BB shell. Check alignment by having the ST protrude horizontally from the vise with the midline of the BB shell exposed.  Now lay the straight edge against the shell and check the distance from the ST on both sides.

2. Braze the dropouts into the CSs, and then the right CS into the BB.  Once that's set do the left making sure to check the alignment with the wheel at each stage.

3. Build the hockeystick, and then braze it into the BB shell. Check this alignment the same as you did with the ST.

4. You've got the keel done and if this is all straight and right the rest will fall into place.

5. For the TT do the front end first.  When you do the TT/ST add most of the heat and filler at the bottom as that's the direction it'll want to pull and this will tighten everything up.  Whereas if you heat and feed from the top you might leave gaps in the joint.

6.  Now just slap in the SSs as you would usually using the wheel as your guide to placement and alignment.

Now that I've typed that all out I'd really say just go take a framebuilding class. The classes might seem expensive, but the time, frustration, and money saved is well worth it. I built 30+ frames before taking a class and still learned a ton. If you're going to build 1-5 frames just take the classes, but if you honestly think you'll build more buy real framebuilding equipment and don't waste your money on things like granite countertops. Check the archives as this is a question we beat to death regularly.

Good luck,

Brandon Ives

Springfield, MO

[Ken Cline]

Lots of ways to skin a cat. Nothing wrong with shimming. MDF (3/4") can be used to build fine fames. Even freehand assembly (e.g. brazing with lugs and pins).

Precision surfaces, V-blocks, even professional jigs are basically either time savers or substitutes for ingenuity/skill. There's no need to be accurate to 0.001".

My idea of a minimal set up was scrap lumber L-blocks screwed onto a small-ish (2'x2') piece of melamine coated particle board (plus and outrigger to hold a dummy axle). Shims cut (with care) on a chop saw were certainly adequate. Just be doubly sure to have your fire extinguisher handy when operating a torch near wood.

Investing in tools makes more sense as you expected number of frames increases. At least that's how I see it.

Back to lurking...

[Mark Bulgier]

One nice advantage of a steel surface is you can use magnets to hold your v-blocks in place.  Little right-angle magnets designed for welding steel structures are super cheap – $3 each at Harbor Fright for example.  At that price I don’t mind getting two of them for each v-block.  $43 including shipping for 12 of ‘em.

 

Lay your full-size drawing on the steel plate, center your tubes in v-blocks over the drawing, and lock the blocks down with magnets. Insta-jig!

 

The idea is to hold the tubes just firmly enough for drilling/pinning.  You probably don’t want to actually braze an inch away from your paper drawing.   For lugless construction, if you’re a TIG welder then this method still works, but for braze-tacking with oxy-fuel torch, you’ll probably have to get the drawing out of there, and lay out your angles with direct measurements.

 

Yes steel can warp, and a plate thick enough to not warp (much) is heavy and not always cheap.  If you get a cheap cut-off remnant or scrap, you need to inspect it for warping, but even cheap hot-rolled plate I’ve looked at has generally been flat enough for bike frames.  Mine is ½” thick but I’m pretty sure 3/8” would be fine.  Any dents or burrs need to be filed flat.  Try to find a piece that was sawed to size, not flame-cut.

 

I was given, for free, the steel base plate for a Park two-bike professional stand. (That’s the rectangular one, not the square one which is for the one-bike stand.)   It’s 23 x 35”, a good size, and not being over large means I can lift it and move it around by myself (about 150 lb).  It’s nicely deburred with rounded corners.  It’s a flat as my straight-edge methods can detect, definitely good enough for bikes.  Leaned against a wall it takes up little space when not in use. 

 

New Park baseplates appear to be powdercoated.  That would sorta suck for a jig, you’d probably want to strip it.  Mine is old, and bare steel.  New ones are slightly thinner too, 7/16”, which is fine, maybe better since it’s lighter.   They’re pretty expensive to buy new, when it’s really just a piece of steel.  I just looked, $280 from Amazon (yuck, but shipping is free).  I’m just saying, look for a sorta thick steel plate that’s not too big in the plan dimensions, ideally just barely big enough for bike frames.  Even joints sticking out over the edge is OK with me as long as the v-blocks are supported fairly far out towards the ends of the tubes.

 

This only works for front triangles of course.  You need something else for tacking the rears.  This can be a false axle (3/8” all-thread is dirt cheap and will do, with a bushing to bring nominal  3/8” (actually under that) up to 10 mm at the dropout).  Bolt or weld that to a piece of square steel tube long enough to reach the head tube. Clamp it to HT and ST with shim at the ST to make up the diameter difference with the HT.  Also you need to spread the load out over a large enough handful of ST, because that’s thinwall tubing and it’ll flex out of the way when you clamp it. 

 

There are many sources of slop and inaccuracy with a method like this, so tack (or pin), check, adjust, tack some more and check some more before fully brazing up.

 

You can also use two pieces of square tube, going up both sides of HT and ST, to take some of the potential sources of error out or at least reduce them.  But I like the one-sided method because it’s cheaper (less of the square tubing to buy), quicker to assemble, and good enough if you’re careful.

 

Mark Bulgier

Seattle

[Owen Lloyd]

  I would suggest tube blocks.  Bicycle research has individual ones that are handy in the vise, and on the surface plate.  Probably not as cheap as v blocks, but their utility makes up for it.

Owen

Blue City Cycles

Chicago

--

[Alex Wetmore]

I think that the Paragon tube blocks are even nicer than Bicycle Research.  They have clamping bolts (which is also helpful when mitering to keep miters in phase).

I also like the Alex Meade tube blocks, I don't know if he is still making them.

alex

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From: frameb...@googlegroups.com [frameb...@googlegroups.com] on behalf of Owen Lloyd [oll...@gmail.com]
Sent: Wednesday, June 05, 2013 5:50 PM
Cc: frameb...@googlegroups.com
Subject: Re: [Frame] Re: Doin it with V-Blocks

[Tom T]

Yeah I emailed with Alex Meade today.

Do all the sizes of the paragon blocks line up or do they need to be shimmed?

[Owen Lloyd]

Those Paragon blocks look very nice.  If they line up they are a steal at that price.

Owen

[Doug Fattic]

First of all a good flat table is one of the smartest tools a hobbyist or beginner can buy.  It can compensate for other less precise home-made fixturing.  It also makes the perfect foundation for some kind of tube holding system.

Somehow, some way there needs to be accuracy to spot or pin tubes in alignment before brazing and then check to see how much it moved and correct afterward.  A flat table with a surface gauge makes these tasks easier to do.  Of course one can use some kind of straight edge with an adjustable pointer off of the face of the bb shell (or some another method) but these less accurate and more time consuming ways add frustration to the job.  

If I was going to MacGyver something together (named after the guy on the TV show that could repair a helicopter with whatever was in his pocket) I would buy Paragon's aluminum 2" X 2" tubing blocks at under $15 apiece.  Two 1 1/8" ones to hold the seat tube and two 1 1/4" one to hold the ends of the head tube (obviously extended) on the flat table.  The top tube and down tube would be held by the lugs.  Of course it is just spotted together on the table and brazed free.  The shell would be brazed to the seat tube 1st.  And I would put the back end on with a true wheel and a straight edge.        

Keep in mind that if V blocks are not on their side but laying on their back on the flat table, it takes some complicated shimming to get the tubes to all line up in a single plane.  Because the tubes are touching the V blocks somewhere along their sides it takes some serous mathematics to know how thick the shims should be holding the blocks off of the table.  I'm going by memory here so don't quote me but a 90º angled V block requires something like .088" per 1/8" rise.  In other words a V block holding a 1" tube off of the table needs to be .088" thicker below the V than a V block holding a 1 1/8" tube for them both to center at the same height (or something like that :).

A couple of things I'll mention having taught lots to build frames (next week will be the 37th anniversary of my 1st framebuilding class) is that the less experienced can benefit from better tooling.  It is easy to get frustrated (the root of mistakes or just quitting) when it is difficult to hold and measure things right.  Many can't get a good start when they are experimenting with methods that justifiably earn them a bad reputation that is difficult to correct.  If someone wants to be good they are going to learn from a master first.  Trial and error is not an effective teacher and poor results can have a long life.   

Doug Fattic

Niles, Michigan

[Mark Bulgier]

Doug Fattic wrote:

First of all a good flat table is one of the smartest tools a hobbyist or beginner can buy.  

 

Me: Maybe, but it can also be too large for those of us with a small house or apartment and no dedicated framebuilding work space.  I might question the wisdom of a hobbyist spending more than the minimum to get going, since many hobbyists build one frame only and then they’re done.  That doesn’t make them failed framebuilders – if their goal was to build one frame, there’s nothing wrong with that.  I know a guy who built two frames 20 years apart.  Should he have gotten  “a good flat table” big enough for framebuilding and let it take up all the space in his basement for 2 decades between frames?  I think the first-timer who doesn’t really know if he’ll ever make frame #2 is a pretty common scenario.

 

Doug:

Keep in mind that if V blocks are not on their side but laying on their back on the flat table, it takes some complicated shimming to get the tubes to all line up in a single plane.

 

Me: My simple fix for that, which requires no shimming, is to use the v-blocks only for tubes of the same diameter.  As Doug points out, for lugged frames, you only need to hold the seat tube and the extensions of the head tube.  My head tube extension is ~2 feet long and 1-1/8” diameter, same as my seat tube.  I use sliding adapters that go over that 1-1/8” tube and inside the head tube ID.  These pretty much have to be made on a lathe, but it takes under 10 minutes to make ‘em from a piece of 1-1/4 x .058 tube. Bribe your friend with a lathe with a 6-pack maybe.  I recommend making them with a slight taper so they snug up on head tubes of slightly different inside diameters. Optional: Slit the part of the slider that goes inside the HT, so the taper wedges them down, locking them onto the 1-1/8” tube

 

If you like OS seat tubes, you’re probably using a larger head tube  too, so upsize your HT extension tube and sliders to match.  If you build frames with 2 or 3 diameters of seat tube from time to time, it’s not too hard to have 2-3 matching HT extension tubes, and sliders to make them fit the HT diameters you use.

 

This method also allows you to use a normal-length head tube, rather than starting with a ~2 foot long HT for each bike and cutting the extensions off later, leaving you with chunks too short to use on the next frame.

 

Mark Bulgier

Seattle 

[Andrew R Stewart]

Mark's tip to use sleeves of the same OD to center tubes (of differing sizes) within Vee blocks is a great one. I have a framebuilding email folder that gets really good posts. This tip is going into it for future reference. Andy.

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[Todd Mosley]

I dind't have a problem using 123 blocks as spacers.  Ideally, larger v-blocks would have been better but cost went up significantly if I went larger than that size.  Also, a 31.8 tube is about the max those blocks would hold - I only held the seat tube and top tube in the blocks and the down tube hung free.  I used a scratch height gauge to make sure all the tubes were still straight.

[jon norstog]

On 6/5/13, Mark Bulgier <Ma...@bulgier.net> wrote:
> Doug Fattic wrote:
> First of all a good flat table is one of the smartest tools a hobbyist or
> beginner can buy.

A solid core door works pretty well, especially for one or two frames.
Cheap used, and disposable.

jn

"Thursday"

[Alex Meade]

Alex W,

 

Yes, I still make and sell tube blocks.  I try to keep all standard sizes in stock, and I can also make other sizes.  If there's a need for high precision on the standoff heights, I can do that as well.

 

Thanks

 

Alex M.

http://www.alexmeade.com/Tools.htm