Landracing Forum Home
November 25, 2017, 02:47:35 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News:
BACK TO LANDRACING.COM HOMEPAGE
 
   Home   Help Search Calendar Login Register  


(Note: Donations are not tax deductible)







Live Audio Streaming and Archives of Past Events
Next Live Event: TBD
Pages: [1] 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 ... 198   Go Down
  Print  
Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 521544 times)
0 Members and 2 Guests are viewing this topic.
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« on: June 14, 2009, 01:03:12 PM »

This build diary shows how we handle basic problems.  It is intended for people new to racing and low budget guys and ladies like oursevles.  Nothing fancy here.

The Triumph swingarm was extended 3 inches.  It was cut and a 3-inch lengths of rectangular tube were spliced in using butt welds.  The butt welds are probably good enough but I would be in real bad trouble if there was a fracture at or near the weld.  We added four gusset plates across the butt welds, one on each side of the swingarm, for safety's sake.  Our welder calls them "fish plates."

The modified arms are longer and the swingarm assembly will be more flexible unless strength is added.  I looked at two options.  One was to build a "C" shaped truss under or over the swingarm.  The other was to add a "C" shaped box section.  I drew up free-body diagrams showing the forces, reactions, and moments in the swingarm.  This is complicated so I looked at brake load, power load, weight load, and torsional twisting load separately.  The box added the most strength in the right places with the least amount of added metal.  The Triumph has a McCandliss style twin shock swingarm with 2-inch deep rectangular tubing.  A McCandliss swingarm made from smaller diameter round tube or a single shock cantilever arm are different animals.  The added box might not be the best option for them.

The added box was discussed with the welder.  He made some suggestions and gave me some sheet steel that is compatible with the Triumph metal.  We are a low budget operation so I cut and bent the pieces.  I work for free so this saved money.  The welder welded everything up.  A big problem that none of us anticipated was contraction during welding.  The arms pulled toward each other.  The welder spent a lot of time dealing with this issue and getting everything right.  I did not ask what he did and I do not want to know.  I do know that a lot of heat, force, cussing, and cigars were used.

I seldom get everything right the first time around so I do not invest much money in paint.  I use a paint system that is inexpensive and easily patched after future changes.  It is to clean the metal as good as I can, spray on red primer, follow with gray primer, and topcoat with satin black.  I use Rustoleum rattle can paint.  This was how my parents did it.  It can look good if the blemishes are sanded smooth between coats.   

 


* Gusset_Plate.jpg (59.73 KB, 448x299 - viewed 662 times.)

* Added_Box.jpg (82.61 KB, 448x299 - viewed 623 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #1 on: June 17, 2009, 12:14:30 AM »

The paint is drying on the swingarm.  Now it is time to start work on the triple clamps.  The aluminum billets arrived from Fastenal and they must be trimmed to size.

Aluminum can gall onto a saw blade and it can plug the teeth.  This makes it difficult to cut and some alloys are worse than others.  A lubricant helps and kerosene is a traditional choice.  Kerosene soaks into clothes and workbenches and the odor can be a problem in a home workshop.  My cutting lubricant is an odorless kerosene-like oil used in Aladdin kerosene lamps.  A coarse blade such as Milwaukee 5091 8/12T resists clogging and slower cutting speeds help prevent galling.

The billet is clamped in a vice and blue tape is used to mark the cut edge.  The tape is on the cut side that must be straight.  It is easy to control the cut by following the tape.  The backside is a different matter.  Sawzall blades are hard to control in thick metal and they wander.  A guide is clamped onto the backside.  The guide is a piece of strap and it is clamped on the cut side that must be straight.  Experience shows that the guide bar must be steel and not aluminum.

 


* Tape_on_Front_Side.jpg (82.83 KB, 349x336 - viewed 462 times.)

* Guide_on_Back_Side.jpg (87.47 KB, 448x299 - viewed 556 times.)

* Cut_Metal.jpg (75.5 KB, 448x299 - viewed 540 times.)
Logged
McRat
Guest

« Reply #2 on: June 17, 2009, 12:57:31 AM »

Hotrodding at it's finest. cheers

For aluminum gauling on blades, I like beeswax or other solid wax sticks.  Less mess, works better than liquids.

Logged
Dr Goggles
Hero Member
*****
Offline Offline

Age: 167
Location: Melbourne Australia
Posts: 2960


The Jarman-Stewart "Spirit of Sunshine" Bellytank


WWW

Ignore
« Reply #3 on: June 17, 2009, 01:46:28 AM »

Hotrodding at it's finest. cheers
For aluminum gauling on blades, I like beeswax or other solid wax sticks.  Less mess, works better than liquids.

....tapping fluid, wd40, all work ......ask Grumm441 about cutting big Al stock and he'll tell you a story about a a friend of his who uses a circular saw shocked
Logged

Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #4 on: June 19, 2009, 09:29:44 PM »

Marking the billets is today's job.  The blocks have three irregular sawed sides and one smooth as-rolled side.  The smooth side is the "true side"   Measurements will be taken from the true side and the square will be placed against this side when lines are scribed across the part.

It is important to place reference points on the part for future measurements.  At least one mark on each face should be located in a place where it will not be removed during future work.  I measure halfway across the billet and scribe a line perpendicular to the true side.  The clamps are 3.980 inches from front to back.  I punch a reference point 1.990 inches (half of 3.980) away from the true side on the scribed line.  This is the exact center of the part.  I do this on all four faces.  These points will not be disturbed and future measurments will be taken from them.  Next I measure and mark the centers of the steering stem and the fork tubes. 

My scribed reference lines and punched reference points are accurate to within 1/50 of an inch.  I use a dial caliper to measure and check distances and and I use a magnifying glass to make sure they are "spot on."  Usually I punch and scribe the reference marks on a part in the afternoon then I check the layout calculations and the reference marks the next morning.  One attached picture shows the reference points and another shows an arc being scribed around a reference point using dividers.

We installed a steering damper on Werner's woodpecker bike.


* Reference_Marks_and_True_Side.jpg (87.86 KB, 448x234 - viewed 490 times.)

* Dividers.jpg (92.6 KB, 448x318 - viewed 531 times.)

* steering_damper.jpg (75.09 KB, 448x299 - viewed 513 times.)
Logged
interested bystander
Sr. Member
****
Offline Offline

Location: so cal
Posts: 977




Ignore
« Reply #5 on: June 19, 2009, 09:52:35 PM »

Dried out dial soap is a good aluminum lubricant, but the beeswax solution - it's kinda "GREEN" too - is hard to argue against.
Logged

5 mph in pit area (clothed)
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #6 on: June 20, 2009, 07:18:46 PM »

The clamp bolts will be recessed Allen head screws.  The screw heads will project 1/16 inch out from the triple clamp face.  Eight 1/2-inch diameter by 0.25 inch deep counterbores are needed.  These are made with a 1/2 inch diameter cabinet maker's Brad Point Wood Doweling Bit.  These bits work OK in aluminum.  Harder metals will ruin them.  I set the drill press for a slow 280 rpm so I will not burn up the bit.

The drill press table is adjusted so it is square with the drill press spindle.  The billet is clamped in a machinist's vice.  The vice and part are adjusted so the face and true edge are square to the table.  All of this assures that the counterbore will be square with the part.

The initial pilot hole is 1/16 inch diameter and about 1/4 inch deep.  I softly position the little drill in the punch mark on the part.  I check to make sure everything is OK with my magnifying glass, then I turn on the motor and drill the hole.  I enlarge the initial pilot hole with a 3/32 inch drill.

Now I chuck up the doweling bit and I ink the part.  I install a magnetic dial indicator base on the drill press pillar and I position a dial indicator so it measues downward movement of the drill press spindle.

I slowly feed the doweling bit down into the part.  At first only the brad point cuts.  Then I see marks on the inked part that show that the bit is starting to cut a bore.  I look at the dial indicator while I slowly lower the bit into the part.  The dial indicator hand moves 2-1/2 revolutions then I stop boring.  The bore is now 0.25 inches deep.

The doweling bit is removed and I drill the pilot hole for the screw thread tap and the clearance hole for the screw shank. 


* Dowel_Bits.jpg (83.34 KB, 448x299 - viewed 460 times.)

* Squaring_Face.jpg (81.2 KB, 299x448 - viewed 442 times.)

* Squaring_True_Side.jpg (92.06 KB, 312x448 - viewed 433 times.)

* Counterbore_Setup.jpg (83.11 KB, 299x448 - viewed 502 times.)
Logged
manta22
Hero Member
*****
Offline Offline

Age: 79
Location: Tucson, AZ
Posts: 3011


What, me worry?




Ignore
« Reply #7 on: June 20, 2009, 08:36:57 PM »

You might consider using an aircraft counterbore (AKA spotfacer); it cuts smoothly and leaves a flat- bottom hole with a radiused corner. They are used with a pilot which centers the counterbore to the hole. There are even types that can cut a counterbore on the back side of a hole.

 Regards, Neil  Tucson, AZ


* spenro20counterbore.jpg (1.97 KB, 160x160 - viewed 8025 times.)
Logged

Regards, Neil  Tucson, AZ
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #8 on: June 22, 2009, 12:54:12 AM »

These aircraft counterbores look good.  I will try one.  Do you know about a grinding wheel that works good on aluminum?

The parts were shaped this weekend.  The sawzall with steel backing guide was used for many cuts.  Lines of drill holes were used for other cuts.  A jigsaw was used to cut between the holes.  All cuts were made 1/32 inch outside of the finished face.  The saw marks were filed and ground away and the part is close to the desired finished size.

I made a few mistakes and some aluminum will need to be welded on to the part.  This can distort the part, so I will have the welding done before the fork tube and steering stem holes are line bored.

Werner finished his mount and he put the fairing on his bike.  He sawed the center brace out of a set of motocross handlebars, then he turned them upside down and bolted them on.   

    The part was saw could not be used for some of the cuts Some cu 


* Shaping_Part.jpg (84.6 KB, 448x292 - viewed 456 times.)

* Ready_for_Machining.jpg (89.73 KB, 448x299 - viewed 472 times.)

* Werner_Fairing.jpg (30.6 KB, 160x107 - viewed 7972 times.)
Logged
manta22
Hero Member
*****
Offline Offline

Age: 79
Location: Tucson, AZ
Posts: 3011


What, me worry?




Ignore
« Reply #9 on: June 22, 2009, 06:57:23 PM »

Wobbly;

No, every grinding wheel I've tried was gummed up by the aluminum. I do use belt & disc sanders on aluminum and it works reasonably well in coarse grades.

Regards, Neil  Tucson, AZ
Logged

Regards, Neil  Tucson, AZ
Peter Jack
Hero Member
*****
Offline Offline

Age: 74
Location: Calgary, Alberta
Posts: 3445





Ignore
« Reply #10 on: June 22, 2009, 08:26:13 PM »

Sanding discs lubricated with A-9, an aluminum tapping and cutting fluid, will give a really nice matte finish which can then be polished if desired. I'm sure Alumitap would give a similar result.

Pete
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #11 on: June 23, 2009, 11:25:01 PM »

The belt sander idea worked good.  This winter when I get some $ I will try the aluminum cutting fluid.  During lunch I saw the post about Jessie Jame's instantaneous speed attempt.  The exact opposite is Werner.  He is making his parts from scrap and mowing lawns and cleaning storm gutters to buy what he cannot make.  I help with a few things like the steering damper.

He bought a plastic fairing for around $50.  It is an EMGO.  It is made to mount on a headlight, so he made a headlight shaped mount for his Honda.  He beat a piece of scrap into a dish for a "lens."  The fairing slides onto the mount and two aluminum straps hold it in place.  The 15-year old fits perfect in behind the fairing with the low bars.  Kids are so flexible. 

He calls the woodpeckers on the fairing "Honda Birds."  Neither of us know Honda got involved with birds.  If anyone knows, please tell us.  Tomorrow he is going to cover his fuel lines with fireproof tubing.   


* Fairing_Mount.jpg (81.44 KB, 448x299 - viewed 509 times.)

* Fairing_on_Mount.jpg (81.42 KB, 448x299 - viewed 495 times.)

* Woodpecker.jpg (82.18 KB, 448x299 - viewed 458 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #12 on: June 26, 2009, 12:53:02 AM »

Fire sleeve insulation is required on fuel lines by AMA/BUB regulations.  We use XRP Performance Products XRP-4.  There are many other suitable brands.  Our local speed shop sells the sleeve by the foot.  The hose has a teflon impregnated cover and fiberglass insulation.

My trick to install this sleeve is to push a large pencil through the sleeve and follow it with the fuel line.  It is hard to push the hose through the sleeve by itself.
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #13 on: June 26, 2009, 12:56:43 AM »

I forgot the pictures.  Here they are.


* Fire_Shield_Tube.jpg (83.29 KB, 448x276 - viewed 472 times.)

* Pencil_in_Tube.jpg (103.99 KB, 448x299 - viewed 426 times.)

* Pulling_hose_behind_pencil.jpg (30.54 KB, 160x107 - viewed 7531 times.)

* Fuel_Line_Shielded.jpg (89.58 KB, 448x299 - viewed 479 times.)
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4451





Ignore
« Reply #14 on: July 15, 2009, 12:53:01 AM »

A lot of internet research went into this attempt to cure the speed wobble.  Typing "BMW Speed Wobble" into a search engine provided all sorts of info.  One item mentioned was the importance of having the holes in the triple clamps in proper alignment.  The dimensions between the hole centerlines in each clamp should be within a couple of thousands of an inch, ideally, according to the posted advice.

The fork hole centers were specified to be 3.376 inches from the part centerline with a plus or minus .001 inch tolerance.  The steering stem center was specified to be on the part centerline with a tolerance of  plus or minus .001 inches to the right or left.  There were similar tolerances for the distances from the true faces on the front of the clamps.  This meant that the holes in the upper and lower clamps would not be more than .002 inches different.  These were tight tolerances.

The machinist stacked the clamps one on top of the other and line bored the fork tube and steering stem holes through both parts at the same time.  This assured that the holes in the top and bottom clamps would be within the specified tolerances.



* Holes_in_Clamps.jpg (84.61 KB, 448x273 - viewed 469 times.)
Logged
Pages: [1] 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 ... 198   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!


Google visited last this page November 24, 2017, 05:06:59 AM