Landracing Forum
Tech Information => Technical Discussion => Topic started by: javajoe79 on April 01, 2013, 09:21:37 PM
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We are nearing completion on our own chassis jig or frame table if you prefer and I thought that a discussion on the subject might help us and others. I have built a number of cars but never to this level of needing a chassis jig. A few months back we had a little talk on the chat line about this and it helped us move in the direction that we did.
What I am after is any suggestions, ideas, comments etc.. that will help make our jig better and or help others build a nice solid chassis jig.
I will share some pics and details and I hope some other folks will too. I know that there is some serious know how and experience on this site and I would love to hear anything you folks have to say.
So for starters, my jig is basically on long I beam (20') with outriggers at the wheelbase of our car(1993 Firebird). We have removable casters at all four corners so we can move it around as needed and we have leveling screws along the length of it. At this point we are planning on adding leveling feet to the outriggers, connecting the outriggers and end beams with square tubing that we can adjust in and out and eventually make removable plates to fill in the spaces in between the outriggers and center beam. So far we have about $500 in materials. We got the caster on craigslist for $200 and the I beams at an auction for a few hundred.
Here are some pics to get things started and please let me know what you think or anything that you think can make it better.
Pics coming shortly :cheers:
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(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1445_zps637a6e7e.jpg)
(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1444_zps57cffc7f.jpg)
(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1443_zpsb9642330.jpg)
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(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1442_zpsb3249b1f.jpg)
(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1441_zps25047033.jpg)
(http://i27.photobucket.com/albums/c179/javajoe79/DSCN1440_zps5f842422.jpg)
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Good thread idea, I would like to know if a table made with 2 main rails like a rectangular box would be more ridged?
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Great timing for this sort of thread
i am just about to build a jig for a partially built motorcycle streamliner i want to make some changes on .
Was thinking of a square frame like 4x2 rhs with risers to the suspension pivot points
I like the rotisserie idea
Javajoe do you get much flex from the i beam or is the floor true enough to rely on the wheels on the ground
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I have a jig table for car chassis and a purpose built jig for rigid bike frames. The car deal is for one off stuff so it's flat, level and square, the bike jig is for "production" not that 1000's of frames were built but it is adjustable. It rotates. I built it from square and rectangular tubing and has a few machined components that clamp the pipes. I build frames for custom Sporty based bikes and I can go from a Bobber to Pro Street to a long chopper frame all off this one jig. The best tools I have for getting things spot on are a Bosch tripod mounted laser level, tube notcher and white marking pens. I think the trick is not to get the welding wrong. Have all the frame components in the jig and move around when welding. I think of cylinder head torque when I'm welding, going from one area to another but not trying to weld the whole frame in one go. The same thing goes for the car chassis. I'm not chassis builder of the decade but if you take your time building the jig and keep it flat all else built on it should be the same. Good clamps and patience. I modified some G clamps by tacking half round pieces of tubing onto the threaded ends. Clamping round tubing with a normal clamp sucks especially when you work alone. I've marked the pic where my bike jig swivels off a bushing. Clamping pressure comes from the bolt that threads into it but I prop it up with a pipe for insurance.
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Great timing for this sort of thread
i am just about to build a jig for a partially built motorcycle streamliner i want to make some changes on .
Was thinking of a square frame like 4x2 rhs with risers to the suspension pivot points
I like the rotisserie idea
Javajoe do you get much flex from the i beam or is the floor true enough to rely on the wheels on the ground
As it sits right now, the central I beam will twist easily if you lever on one of the outriggers. The wheels are only to move it around. Once we are using it, we will unbolt the wheels and sit it on the ground. We are adding leveling screws to the outriggers too, so once it's set on the ground we can adjust all the leveling screws to make it sit level and solid.
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Do you need to bolt it down so it can't pull diagonally ?
and would a raised platform make it easier to work on ?
MTA i agree it has to be stiff or there is not much point in building the frame
your c channel looks much more solid than i was originally thinking i needed , time to recalibrate the thought process ;)
the liner bottom half is like 1/2 an octagon and i find it tapers too fast, my shoulders are too tight , Kim fits fine
and the motor has the same problem at the crank centreline
so i intend putting a new bar pretty much from the feet area all the way to the back about 4" lower than the current wide point
this will mean all the vertical and angle braces on the sides will be cut and replaced over a ~8 ft length
and i think he jig should have the capability of alternate suspension mount points as i am rapidly running out of room
working with Jon on an overdrive has just eaten up another foot of engine bay
so now as i want good access without the jig blocking anything but still very stiff , in the air on a rotisserie
i am picturing a perimeter box frame braced , with adjustable supports along the sides to secure the position of the upper and lower frame rails when i release them
sometimes wonder if i should start again and sell the existing frame to someone smaller with a narrower motor
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We are adding braces across the outriggers and at an angle from the outriggers to the I beams on the ends. We decided on the height it is, planning on having the car floating maybe 18" above it. That way it's not too tall to get to the top of the car and we will be able to access everything on the bottom side too.
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Joe:
Looks like a good platform to start with. It is hard to tell how high it is off the ground. But some heavy wall nesting pipe with holes and pins like the old round jack stands. Then some big 1" bolts to use as leveling feet welded to the bottom of the nested tubes. I would add some tube gussets to X brace the out riggers.
BR
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Notice that the Bloodhound jig is built out of rectangular tubing and the top was machined flat.
(http://farm9.staticflickr.com/8240/8471463396_c902b01ec9_c.jpg)
The ultimate in jig fixturing is to use a granite surface plate.
I found a 240" x 72" x 30" on Ebay for only $12,500!!! 52,000 pounds. How strong did you say your garage floor was?
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Only $12,500??? Seriously though we have joked about having this one ground flat on the top. It's pretty flat and square but not perfect. Would love to know who has a surface grinder that big and how much that would cost though. No doubt it's ALOT!
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I have used perimeter jigs made out of rectangular tubing as well as one with a long Ibeam down the center. I prefer them to be waist high and we tack smaller Ibeams to the top in an outrigger fashion.
Here is one a pal of mine built, different style
http://www.jalopyjournal.com/forum/showthread.php?t=577892&highlight=frame+table
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How much sag do you get in the center of the 20' I beam? We used a 26' tapered ex steel sq.tube light pole and had to put a jack in the center to take out about 1/2" sag.
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I have used perimeter jigs made out of rectangular tubing as well as one with a long Ibeam down the center. I prefer them to be waist high and we tack smaller Ibeams to the top in an outrigger fashion.
Here is one a pal of mine built, different style
http://www.jalopyjournal.com/forum/showthread.php?t=577892&highlight=frame+table
That is frickin beautiful!!
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How much sag do you get in the center of the 20' I beam? We used a 26' tapered ex steel sq.tube light pole and had to put a jack in the center to take out about 1/2" sag.
Very little at this point. The beam itself is 12" tall and 3/8" thick. We planned for some though so we have leveling screw along it's length to support the middle once it's on the ground.
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I have only built a bike jig, which didn't require the same degree of resistance to twisting that a car jig would require. But I beams or the more commonly used wide flange H beams are not good at resisting torque (twisting). Hollow structural square, rectangular, or even round would be a better starting point. However, you have a start, so you may be able to box in the beam to make it much better in resisting twisting, if the welding doesn't warp it. Whatever you use, you still need to constantly check it and the frame you are building for level and square. You can always shim to level, but if your jig is not stiff in torsion, welding up your frame could pull it.
FYI, I met an ex machinist who built an absolutely beautiful Triumph powered special build bike. He said he built it on a piece of 3/4" plywood, reinforced to keep it from twisting.
Tom
Tom
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This is the "ultimate" build jig: a floor mill floor plate. This one is 6ft x x22 ft 15 inches thick, cast iron with tee slots. This is what most of the NASCAR guys use. They are amazingly reasonable, usually the price of steel/pound. Probably cost more to have it moved plus once you put it some place it isn't going to be moved.
Rex
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This is the "ultimate" build jig: a floor mill floor plate. This one is 6ft x x22 ft 15 inches thick, cast iron with tee slots. This is what most of the NASCAR guys use. They are amazingly reasonable, usually the price of steel/pound. Probably cost more to have it moved plus once you put it some place it isn't going to be moved.
Rex
That is cool Rex. Our problem in my area is that we have NEVER had any manufacturing so this type of stuff is unobtanium. :-(
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No more progress yet. We are moving shops soon so we mainly wanted to get this thing mobile. We will be adding braces to stiffen the setup as well as connect the outriggers and add leveling screws to the outriggers.
Keep up with the pics and suggestions. I will have more pics when we make more progress.
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I use 2 x 4 3/16 tube with a 2x3 spaced under as in a space frame chassis, rectangular shape.
There is no sagging.
I use a Starrett square .0005 in a foot increments on the bubble.new app. 600 dollars.
You cannot use a carpenter square they are not accurate enough.
If it is not ridged and square and you have to use leveling screws to jack it into shape it is not going to be satisfactory.
If you put a high precision square and level on what you have I think you are going to be unhappy with what you have.
I have been building machines and fixtures for 40 years, you cannot do good work without good tools.
J Y/B
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I said Starrett square, I meant level, you also need a good machinist square.
J Y/B
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Howdy, Peckerwood. I burn lots of your namesake fuel in our wood boiler. But that's beside the point. I don't see your location in your avatar spot. Would you please be so kind -- and let us know where you're located? Thanks.
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Slim, I meet you at B Ville a few years back, I was with Courtney Hizers group, Buick C/BFA car no. 80.
I am in NW. Ga. Adairsville not far from Courtney,s place Rome ga.
I knew Hizer for 45 years there will not be another like him.
Additional info on jig.You can have a steel plate Blanchard ground at a reasonable cost.
In Atlanta Withers Machine can do a 12 foot plate, the will furnish the steel if you want.
It does not take long to Blanchard a large plate, is not perfect but normally within .010 on a
10 foot plate.
I used them for machine bases in the past.You can get same day service, these are monster machines.
Even a 3/4 inch plate needs some reinforcing on the back to keep it from sagging.
Jim Youngblood aka Peckerwood
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I think I've put your location in place for you. As for meeting you a few years ago -- gee, I think I remember -- but the years do sorta add up and the memory gets fuller and fuller, too. Best wishes and thanks for signing up for the forum.
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In So Cal Shaffer Grinding can blanchard really big stuff. If you happen to have something done be sure to do both sides as if you only do one side it can cause the plate to bow from the inducing and relieving of stresses. Try not to do cold rolled plate on one side only as it will look like a potato chip when you're done.
Rex
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As much fun as it would be to have a jig that cost more than my house..................I build on a shop -made table. 16 ft. long, 40 in. wide and 36 inches in height , 2X4 3/16 tube with cross tubes spaced evenly . Around the periphery are 1 1/2 angles placed ( you guessed it) 1 1/2 " down from the top w/ leg facing inboard. 1 1/2 sq. tubes drop in place from above and can be located anywhere along the length. Large steel casters on the corners ( do yourself a favor and make it steer from one end) and leveling jacks in the legs. Voila`..Made many a hot rod frame on it .
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"( do yourself a favor and make it steer from one end)". Right, mine still doesn't but I don't move it much. Mine is sort of similar to what you describe and the cool thing is that you can build all sorts of other cool projects on it as well.
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"( do yourself a favor and make it steer from one end)". Right, mine still doesn't but I don't move it much.
I find swivels on all the corners is sometimes a really good thing... two of those should have swivel locks to you can make it steer from one end when you want as well.
The cart I built for the little car has these
http://www.northerntool.com/shop/tools/product_363217_363217
:cheers:
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We got our casters on craigslist for a killer deal. They all swivel and lock. So far it rolls real nice.
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Or call these fine people www.bluco.com
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Floydjer
My local steel dealer allows me to dumpster dive in his drops, small towns have some upside.
On my all rectangular tube jig I bought one 20 ft 2/4 by 3/16 stick cut in half,jig is 10 ft by 4 ft, plus out riggers , the rest is made from drops,
I have hundreds of of bits and pieces of steel,cost zero. Total cost of jig around 100 bucks.
I go by the old adage measure 4 times cut once,then measure 5 times weld once.
The jig is dead nuts in every plane and dimension plus or minus ten thousands and and virtually zero flex.
I would also like to have a NASCAR style surface plate jig but .010 is close enough on a frame for us Georgia peckerwoods.
J Y/B
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Ok so I have decided that I might as well go all out with this chassis table and build the table of my dreams. The guy who I am building the chassis of the firebird for will be buying me a piece of plate in exchange for building the chassis.
From my research I have found alot of folks using A36 steel plate in 1/2". This is what I am planning on doing. Any suggestions otherwise or in general? I am using the frame I have so far shown in the pics, adding bracing then laying the plate on top, shimming as needed. Then I will be laying out a grid of threaded holes.
Once it's done, I plan on making legs to put the table up to normal table height for use as a large fab table when there is not a car on it.
The frame is currently about 19' long just because that is how long the I beam was that we got for real cheap. How long and how wide do you guys think is good? Keep in mind we are buidling a somewhat stretched version of this firebird and have plans for something along the lines of a lakester in the future.
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And be d*mn sure that any bracing between the legs is higher than your engine hoist legs. Yes, I learned that the hard way. :cheers:
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And be d*mn sure that any bracing between the legs is higher than your engine hoist legs. Yes, I learned that the hard way. :cheers:
That is an awesome point and something I have dealt with many times. Thanks for reminding me.
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So..... Much progress has been made on the chassis table. It even has a car on it now.
(https://scontent-a-atl.xx.fbcdn.net/hphotos-ash3/t1.0-9/1972502_511125108997388_435894146_n.jpg)
(https://scontent-a-atl.xx.fbcdn.net/hphotos-prn1/t1.0-9/1970703_511125055664060_399529400_n.jpg)
(https://scontent-a-atl.xx.fbcdn.net/hphotos-frc1/t1.0-9/1902846_511124928997406_2056891949_n.jpg)
(https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn1/t1/10015076_512236488886250_1482820686_n.jpg)
(https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-ash3/t1.0-9/1098064_512236548886244_1726775119_n.jpg)
(https://scontent-a-atl.xx.fbcdn.net/hphotos-frc3/t1.0-9/1920046_512236618886237_774832716_n.jpg)
(https://scontent-a-atl.xx.fbcdn.net/hphotos-frc3/t1.0-9/1514238_512236665552899_1894245616_n.jpg)
(https://scontent-a-atl.xx.fbcdn.net/hphotos-ash3/t1.0-9/1797598_512236852219547_1569432568_n.jpg)
(https://scontent-b-atl.xx.fbcdn.net/hphotos-ash3/t1.0-9/1794775_512236905552875_633149161_n.jpg)
(https://scontent-b-atl.xx.fbcdn.net/hphotos-prn1/t1.0-9/1977397_512237308886168_116568299_n.jpg)
(https://scontent-b-atl.xx.fbcdn.net/hphotos-frc1/t1.0-9/1965038_512237282219504_448609437_n.jpg)
I ended up with a 6'x20' piece of half inch plate. Large I beam down the center and at the ends and 2"x4" tubing for the outer frame rails. It has levelling feet every few feet as well.
I bought a magnetic base drill press just for the job of drilling 490+ holes and tapping them to 3/8 coarse thread. Funny fact... a friend of mine ran the numbers on how much the material weighed that we drilled and tapped out of the plate and it came to 100lbs.
The first candidate is shown in the pics. The owner also just started a build diary as well. Should be one hell of a car.
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Joe, that's awesome.
Man, that's a lot of work there.
I hope it brings in lots of bucks for you. :cheers:
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:-)
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Joe, that's awesome.
Man, that's a lot of work there.
I hope it brings in lots of bucks for you. :cheers:
Thanks man. I hope so too but for now I am happy having what I have always wanted. Once this firebird is off of the table I will be building legs to put it up to normal working height so I can use it as a huge fab table when there is no car on it. Then after that my Triuimph TR8 will go under the knife to begin it's transformation.
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Chris:
I covet your chassis jig. I like the idea to make it convert to a large fab table.
BR
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Having the veh elevated is a great idea. The 111 & 444 cars are on 18" rolling platforms at the shop, on the salt we work on them from the trailers,much easier on the back and/or with the cars on the ground. :cheers:
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Having the veh elevated is a great idea. The 111 & 444 cars are on 18" rolling platforms at the shop, on the salt we work on them from the trailers,much easier on the back and/or with the cars on the ground. :cheers:
Yeah for the jig I wanted to be able to get under the car at all times during the build.
I am with you on taking it easy on the back. :cheers:
Chris:
I covet your chassis jig. I like the idea to make it convert to a large fab table.
BR
Thanks Bill. I also have some really large casters that I will use so that I can move it around easily. This thing weighs over 4000lbs easy.
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So, is the TR-8 going to become the next Black Salt front drive car?
Doug :cheers: :cheers: :cheers:
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No the TR8 will be a road course car. I may take it to the Ohio Mile but not the salt. It will be all C5 suspension and cradles, dry sumped LS6, T101A dog box, ford 8.8 diff etc... Just a project for me that will be fun on the track. The body will look something like the Group44 car in my avatar.