Fabricating my own frame jig - 8020 questions

[EricKeller]

he's in the eastern part of PA, so Rutland would be pretty expensive on shipping. I use search tempest to search craigslist in my general area.

[Craig Ryan]

I started with nothing and took the slow road to getting better stuff. I've used mdf, and honestly, it was probably straighter than I could build at the time. Now I have a nice cast iron hand flaked surface I got for $200. I would get a good table and skip the jig until you can afford it. A good table and measuring tools will do wonders. I bet you can get that chunk of granite into your shop for under $500. It's not what you want to hear, but if you add up all that 80/20 and nuts and bolts and trips to the hardware and mistakes, it'll add up to about the same. Besides, jigs don't give you straight. Experience gives you straight.

[pruckelshaus]

you didn't catch this post? - I 2nd that. rutland tool is selling 36" x 48" x 6" black granite plates cert to .0002" for $900.00 off right now - $299.00! the thing is that it's 1,325lbs....{ mod# 9000 1467t} ..i'd like one just to roll tubes on if i could do a pick-up on it. shipping would be mucho dinero - Garro.

Yeah, I saw the post, but I'm just not sure how I'd get a 1300 pound slab of granite into my workshop, which is in my basement.

[EricKeller]

my 5500lb mill is in my basement :)

[bellman]

Yeah, I saw the post, but I'm just not sure how I'd get a 1300 pound slab of granite into my workshop, which is in my basement.

Pizza and Beer.

[EnginCycles]

my 5500lb mill is in my basement :)

What manual mill do you have that weighs 5,500 lbs? I don't even think the Cincinnati No.3 or Milwaukee No.2 weigh that much.

[steve garro]

Pizza and Beer.

Bellman shows that it's not his 1st rodeo..........get fuckin' egyptian on it's ass! - Garro.

[EricKeller]

What manual mill do you have that weighs 5,500 lbs? I don't even think the Cincinnati No.3 or Milwaukee No.2 weigh that much.

bridgeport series II cnc. I think my knee weighs as much as a manual series I

[anon.]

Whenever I get a twinge of the jig-wants I look at this picture, remind myself of the 200+ frames Dave Kirk made using this set up, and get back to work.

[EricKeller]

after I left Trek I lost confidence in my jig and converted to the string and mirrors method. I had a jig that held the bb shell perpendicular to the seat post. I would make the hockey stick, join the bb to the seat tube, and then join all of the parts of the front triangle together in a final step. It worked pretty well, but I wonder if it doesn't take a certain amount of experience before that is the case. The current state of my vision is too screwed up to let me have any confidence in that method now.

[Archibald]

bridgeport series II cnc. I think my knee weighs as much as a manual series I

They're monsters and a very nice piece of machinery. Lots of quality iron in those. What year & control does it have on it? My old Anayak weighed 6,400 & looked like a Lagun Deluxe on steroids. It was 9' tall and still the biggest turret mill I've ever seen, hell the saddle on the knee was 42" wide! I was surprised that the Tree 425 that I had in storage and shifted into the shop this weekend weighed a full 6,000 (the one in the corner).

[Dave Kirk]

Whenever I get a twinge of the jig-wants I look at this picture, remind myself of the 200+ frames Dave Kirk made using this set up, and get back to work.

I wondered if someone would dredge up an old photo of that thing. It was slow to set up but cost me about $100 as I recall for the V-blocks and tubes to make the dummy triangle (not pictured). It of course depended on the inverted T slot plate so you can't discount that.

In the end it was slow to set up but the most accurate set up I've ever used. More photos available on request.

dave

[Craig Ryan]

More photos? You bet! Throw some up on your SO next time you're bored.

What Eric said above brings up another good point. Using straight edges and vise is great for experience, a nice learning tool, but is pretty difficult to do well. I'm sure after building a thousand frames it would be a piece of cake, but until then it's pretty complicated and easy to mess up. After I got my table I put what I had left of my first frames on it to check them out. It told a lot, and it's why I cut them all up except for a couple.

[pruckelshaus]

Whenever I get a twinge of the jig-wants I look at this picture, remind myself of the 200+ frames Dave Kirk made using this set up, and get back to work.

Actually, a slotted plate like that would be perfect for my needs...low production, I wouldn't have a tool (a jig) that's only good for one thing, probably lighter than a 6" thick granite slab, etc. Where would I start to look for something like that?

Pete

[cement shoes]

google is your friend. searchtempest is also pretty nice. It lets you search a bunch of craigslists at once, basically an RSS aggregator. If you're in Eastern PA, you are surrounded by used iron.

[pruckelshaus]

I should have been more precise. What I meant was "What do I call that large plate of steel that I am looking for?" and apart from size (24x36 minimum, 36x48 ideally) what features do I look for?

Thanks,

Pete

[MDEnvEngr]

First post here. I'm a hobbiest that builds on a surface plate using fixtures that I made myself (with inspiration from Doug Fattic's plate fixture). Kind of a pain to tack on the back side but not a show stopper. Let your process drive the tools and not tools drive the process...especially for us newbies to avoid getting overwhelmed by the process. I bought my surface plate from an old pattern maker shop for $100. It's a little on the small side at 30 X 42 or so, but it works fine.

See Alex Meade's site for a setup very similar to what I use, less the surface plate: Tools

Pic of setup:


B

[Archibald]

I should have been more precise. What I meant was "What do I call that large plate of steel that I am looking for?" and apart from size (24x36 minimum, 36x48 ideally) what features do I look for?

Thanks,

Pete

You call it a cast iron surface plate, or a layout table, or a large plate of steel depending on your budget.

[Doug Fattic]

As a disclaimer to my comments, we all know that there are a variety of good ways to build a bicycle frame and that we approach these methods differently because of our personalities and prior experiences. That said it is also logical that not all ways are - and by extension the equipment we choose - equally good. And I should mention I have a dog in this race as I sell fixtures designed to build frames within my philosophy. I see it more as a service than a money maker. My real job is teaching others how to make frames.

My recommendation for those that have ambitions to build frames (defined as more than one frame a year and/or not willing to always substitute lots of time for tooling) would be to get a decently sized flat table (3'X4' if possible) as a foundation piece of equipment. This allows for accuracy in the building process that can not be obtained with a less expensive fixture (I would define as anything less than an Anvil) or something homemade. In other words it is possible to get by with a less accurate or homemade fixture if you have a good surface plate or if you don't have a surface plate you need a good fixture (and even then I wouldn’t be without a good surface plate). The third alternative is spending lots of time with rulers and straightedges checking and double checking but that method is for the only-one-a-year-or-less hobby builder. Which, by the way, only 2 out of the last 100 of my students described themselves as fitting into that category. Everyone else has more ambitious goals.

Now I know from all the feedback I get from my students that a thousand + pound hunk of cast iron or granite is completely out of the question for some of them. They don't yet have a permanent place to build and something that heavy isn't going to get or fit where they are at. One alternative I've tried is a cast aluminum table with webbing. I don't like it quite as well as my cast iron ones but the 32" X 48" table top only weighs 170lbs. That is easily movable with a couple of guys or a cart. The top is about 3/4” thick, where it is webbed it is around 3” thick and where the pads are for the legs and alignment post about 3 1/4” thick. Each leg bolts onto one of those pads on the underside of the table. They have adjustable length screw/pads on the bottom. It is accurate to less than 10 thousandths of an inch over its surface. The company I bought it from bored the 1 inch hole for the alignment post. I paid about $1100 for the top, $400 for the legs and my machinist makes posts for around $300. Aluminum is softer than steel so some care has to be exercised but it has stood up to about 2 years of abuse from my students. Type my name into flickr and somewhere pictures of it will pop up. You can tell it from my cast iron tables because it has a shiny silver top and isn’t dull brown. To review, it works fine for those that can’t get a heavier table.

I’ve often thought about designing fixtures throughout my 35 years of framebuilding. I’ll share some thoughts about what might work for those that don’t have a lot of resources in another post if I get time.

[EricKeller]

I would ask this guy how big his cast iron surface plate is and if he has pictures. There is also a 4'x4' granite plate down near the Delaware border