ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-01-2010, 02:57 PM   #76
x3300 OP
geoff
 
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Swingarm Fixture

rediRrakaD, whether or not we have realized it yet, I think we are all heading there.

I took a trip over to the scrap yard to look around for some stock I'll need while working on the monolever arm.

Here's what I found from the left; two 3/4" hardened bolts for the shaft, one of which I hoped would work, a section of 2"x1/16" tube for a cross brace, a rusty piece of 1" square tube for a fixture brace, and a section of 3"x2"x3/16" rectangular tube to make up the main part of the fixture.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/fixture-stock.jpg

My idea was to have a T-shaped fixture made of heavy gauge rectangular tube that would clamp the front of the swingarm at the swingarm pivot bearings, and then to have an indexable end plate that duplicates the final drive mounting pattern to hold the rear of the arm. The indexing of the end plate would allow it to hold swingarms of differing lengths.

I made up these swingarm fixture drawings to work with:
bearing plug drawing
angle plate drawing
main arm drawing
The main arm acts as a stable base for the other parts and allows indexing of the angle plate at 25mm increments. Arms of 0, 50, 75, 100, and 125mm. I don't think 25mm worth the effort, and the two index holes at 50mm were actually an error in my drawing that I didn't catch until after I got the machining done.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/main-arm-drawing.jpg

The angle plate duplicates the mounting pattern of the final drive and holds the rear of the swingarm in position. The lower section of the plate has two 10mm chromed pins pressed in that allow precision positioning of the plate on the main arm. The pins provide the alignment, and two 13mm bolts provide the attachment force.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/angle-plate-drawing.jpg

The bearing plugs fit into the bores of the swingarm pivot bearings and clamp the front of the swingarm in position. Two bolts with 15mm of the diameter turned down fit into the center hole of the plugs. These bolts then thread into nuts welded on the front risers of the fixture.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/bearing-plug-drawing.jpg

I found these concrete anchor bolts are a handy way to pull the swingarm bearing out of the race.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/bearing-puller.jpg

I decided to make the angle plate out of aluminum because aluminum is easy to work with, but I think now it would be better made of steel since it seems as it will wear fast. I bored out the big hole in the angle plate and drilled the holes with this setup.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/boring.jpg

Here's a detail of the main arm and angle plate. This gives a good view of the angle plate's alignment pins. The bolts fix the plate to the arm and are 1/2-20 UNF grade 8. The hole in the far end of the arm is to accept a bolt that will act as a jack screw to keeps the swingarm from rotating on the front bearing plugs. I found I needed to reposition this hole outward as seen in other photos.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/main-arm.jpg

Anyway, after a while I had this collection of fixture parts assembled and ready for welding.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/fixture-parts.jpg

To get the arms aligned for welding I clamped them down to this piece of 3/8" aluminum plate.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/welding-fixture.jpg

I welded nuts onto the fixture at the bearing plugs and the jack screw. After welding I needed to chase the threads. This photo also shows the jack screw bolt and how I put a rounded profile on the top to get a constant contact area between the bolt and the swingarm when the bolt is turned.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/chasing.jpg

And the finished fixture, its relly a heavy beast.

http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/fixture-done.jpg

Here's another view with the arm installed. The idea for use is to set the angle plate at the 0 index, bolt an unmodified arm to the angle plate, then close up the bearing plugs, jack screw and top clamp such that the arm is held in place without any bending force, then cut the arm with a hacksaw and move the index plate to a new position.


http://stuff.gotdns.org/bike/orgs-build-up/28-swingarm-fixture/arm-mounted.jpg

After having the actual fixture and with some fitting of the arm to it I think the bearing plug method of holding the arm will be difficult to control accurately. I think it will be enough with some careful setup, but I think something with fixed alignment stops welded to the fixture may work better.

-x3300
x3300 is offline   Reply With Quote
Old 10-01-2010, 03:03 PM   #77
fishkens
Further...
 
Joined: Nov 2009
Location: Seattle, WA
Oddometer: 5,147
Fancy! Keep up the great work.
__________________
Forging ahead, down a false trail.
fishkens is offline   Reply With Quote
Old 10-08-2010, 11:34 PM   #78
x3300 OP
geoff
 
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Monolever Extension

I did some hunting around the Internet and took a few trips to local MC dealers with a tape measure in my pocket to collect some info on rear suspensions. I'm not sure of how wheelbase is measured, but I put down what I measured with the bike supported and the suspension topped out, plus an adjustment for the longer swingarm. Here's the tally; wheelbase, travel front and rear, swingarm length, final drive ratio:

Code:
bike       wbase   front  rear   salen  final

R80G/S     1465    200    170    410    3.36
CRF250R    1478    315    315    ?      -
R100GS     1514    225    180    455    3.09
R1200GS    1520    190    200    533    -
F800GS     1577    230    215    622    -
HP2        1610    270    250    575    -
HPN-Adv    1620    295    240    510    -
ORGS       1622    280    280    535    2.91
It seems 100mm is a common monolever swingarm extension. I wanted to get some more travel and figured I'd try 125mm, so 80mm more than the max of the R100GS paralever swingarm.

I marked the cut with a Sharpie pen, put the arm in the fixture, then went at it with a hacksaw. I put the cut where the swingarm tube runs exactly parallel to the centerline of the bike so that both swingarm tube and the extension tube ends would need 90 degree cuts.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/cut-arm.jpg

Here's a view of the section.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/section-view.jpg

The 2"x1/16" tube I mentioned in the previous post was intended for the cross brace. I bolted the back end of the arm at the 125mm index of the fixture then measured the angles the cross brace would need. I set the brace to give the maximum support and have just enough clearance to fit an 18" wheel.

I used this hole saw and a vertical mill to cut the tube ends. I set the head at the needed angle then made the cut.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/hole-saw.jpg

The hole saw wasn't long enough to cut straight through the tube, so I needed to cut until the saw bottomed, remove the tube from the vise and cut off the scrap, and then remount the tube and continue with the cut.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/hole-saw-finish.jpg

I drilled this small hole in the bottom of the brace to vent the tube while welding.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/cross-vent.jpg

Here's the arm and additions cleaned up and ready for welding.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/arm-parts.jpg

I used masking tape to hold the extension in place for tack welding. I cut out small sections of tape and made the tack welds.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/tack-welds.jpg

I used this big C-clamp to hold the brace in position for tacking.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/tacked-cross.jpg

There wasn't much room between the bottom of the arm and the fixture so I needed to use this short tungsten cap to get in there.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/short-cap.jpg

Welding in progress.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/cross-welded.jpg

And the finished arm out of the fixture.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/cross-done.jpg

I measured the arm before and after welding with this height gage to check the alignment.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/measure-length.jpg

Here's the arm installed with a fender and shock mock-up.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/right-view.jpg

I really like the look of the triangle the arm and big cross brace make just in front of the wheel.

http://stuff.gotdns.org/bike/orgs-build-up/29-monolever-extension/left-view.jpg

I'll need to look into and decide on a shock before setting up the shock mounts.

-x3300

x3300 screwed with this post 10-09-2010 at 09:13 AM Reason: Update URLs.
x3300 is offline   Reply With Quote
Old 10-09-2010, 12:41 AM   #79
fishkens
Further...
 
Joined: Nov 2009
Location: Seattle, WA
Oddometer: 5,147
Quote:
Originally Posted by x3300

I marked the cut with a Sharpie pen, put the arm in the fixture, then went at it with a hacksaw. I put the cut where the swingarm tube runs exactly parallel to the centerline of the bike so that both swingarm tube and the extension tube ends would need 90 degree cuts.

-x3300
Still my favorite thread.

But a hacksaw? Is that because you don't have a cutoff saw or band saw where you could set a jig to cut at a 90 degree angle or because you felt you could cut an equally square cut in the same time with a hacksaw or for some other reason. Just curious.

Thanks.
__________________
Forging ahead, down a false trail.
fishkens is offline   Reply With Quote
Old 10-09-2010, 10:38 AM   #80
x3300 OP
geoff
 
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Quote:
Originally Posted by fishkens
But a hacksaw?
Hi fishkens,

I used a hacksaw because I wanted to make a cut that was relatively narrow and also precise. I didn't want to have a big gap to weld up, nor to mess around with grinding and fitting the pieces. I think it would be difficult to get that fixture into a bandsaw at the correct orientation. With the arm cut accurately I could just cut the extension tube to 125mm (on a horizontal bandsaw) and weld it in.

The swingarm tube is thin and made of mild steel, so easy enough to cut by hand with a sharp blade. I made an accurate mark around the circumference of the tube with the marker and just made sure the cut was always progressing along that mark.

-x3300

x3300 screwed with this post 10-09-2010 at 10:40 AM Reason: Fix format.
x3300 is offline   Reply With Quote
Old 10-09-2010, 10:44 AM   #81
fishkens
Further...
 
Joined: Nov 2009
Location: Seattle, WA
Oddometer: 5,147
I knew you had considered the options so thanks for the explanation.

Keep up the good work.
__________________
Forging ahead, down a false trail.
fishkens is offline   Reply With Quote
Old 10-10-2010, 05:22 PM   #82
rediRrakaD
Whoopdie do
 
rediRrakaD's Avatar
 
Joined: Jan 2006
Location: Deep in the Redwoods near the Pacific
Oddometer: 716
X3300 (got it right this time),

I think the 100mm extension idea stems from the folks @ HPN.

I'm currently working with Phil @ Aftershocks (Palo Alto) on the proper shock for my rig (Wilbers custom). He may be able to add some insight to your project as well... smart guy, when it comes to suspension/geometry.

Really enjoying your thread.
Thanks for taking the time to post.
Cheers,
S.
__________________
"Death in the pursuit of happiness is triumphant!"
rediRrakaD is offline   Reply With Quote
Old 10-14-2010, 10:48 AM   #83
Beater
Mighty Unclean
 
Beater's Avatar
 
Joined: Sep 2009
Location: Atlanta, GA, USA
Oddometer: 3,158
Holy Crap. This is the first I've read this ...

I have an '83 r80 looking for just this kind of treatment.

Sub-freakin-scribed.

__________________
Fred
'85 R80RT G/Sified <|> '91 R100GS Bumblebee (103K miles and climbing) <|> '73 R75/5 LWB
Airhead Zen: Ride - Repair - Ride - Maintain - Ride - Repeat
Beater is offline   Reply With Quote
Old 10-15-2010, 11:43 PM   #84
x3300 OP
geoff
 
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Shaft Extension

The long swingarm will need an extended drive shaft to match.

As a start I measured the stock shaft to get a kind of baseline. I used this height gage and a ground pin to measure the length. I zeroed the gage with the pin under it, then put the pin in the yoke bores and took the reading at the top of the pin as the length of the shaft to the bores. It measured 284.27mm.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/length-zero.jpg

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/shaft-length.jpg

The stock shaft is center drilled on both ends, so I put the shaft on a lathe between two centers and setup a dial indicator to check the runout at the center of the shaft. I measured .064mm max.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/runout.jpg

My plan for the extension was to cut the shaft at its center, drill a 5mm hole in the end of each of the resulting sections, then make an insert that had a section on each end turned down to 5mm. The turned down sections would press into the holes to hold the insert in alignment for welding.

Here's the machining of one end of the insert. I turned the end down to 5.1mm, and on this end I put a very small center hole to use when aligning the first weld joint.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/center-drill.jpg

After I got the shaft and insert ready I pressed the insert into the shaft with this arbor press. The shaft plus insert was too long to fit into the press so I used these C-clamps and a piece of steel plate to make a base to press against.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/pressing-shaft.jpg

After I got the insert and one shaft section pressed together I mounted them in the lathe and checked the runout. To adjust the alignment I supported the shaft with blocks on each end and tapped on it with a plastic mallet. After a few iterations of checking and tapping then checking I could get the runout to about .015mm.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/first-check.jpg

With the insert aligned I tack welded the joint then put a bead all the way around the shaft.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/first-tack.jpg

I let the shaft cool slowly and then ground away the excess bead.

The stock shaft was heat treated, but I decided it would be better to leave the shaft soft at the weld points than to try a heat treatment and have it too brittle. If I have trouble with it when I put it into use I'll consider having it done by a heat treating service. After welding I found the runout was close to 1mm.

I used this setup to get the shaft aligned. It took a few trips between the lathe and press to get the shaft back to about .060mm runout.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/first-align.jpg

After the first joint was finished I repeated the process on the second joint. Here's the shaft just after finishing the second bead.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/second-weld.jpg

After the insert was fully welded in I did a final alignment of both weld joints to get the final shaft runout to about .060mm.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/final-check.jpg

With the shaft aligned I could then turn down the weld beads to the diameter of the shaft. I mounted the shaft in this four-jaw chuck and used a dial indicator to get it precisely centered for machining.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/turning.jpg

I saw a monolever arm and shaft up for a reasonable price, so figured it wouldn't be a bad idea to have a spare on hand. Here's how the extended parts compare.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/arms.jpg

After finishing the extension work, I can say that I don't think my method of a press fit alignment was a good one. I think a better way would be to make a fixture that holds the shaft ends and the insert in position for welding.

Here's a shaft fixture drawing of what I'm thinking about. It can handle +100mm and +125mm shafts. I have some 3"x2"x3/16" rectangular tube left over from the swingarm fixture I can use for the base and I'm thinking I'll pickup some rectangular bar stock for the V-blocks next time I'm at the scrap yard.

http://stuff.gotdns.org/bike/orgs-build-up/30-shaft-extension/shaft-fixture.jpg

-x3300
x3300 is offline   Reply With Quote
Old 10-16-2010, 12:42 AM   #85
fishkens
Further...
 
Joined: Nov 2009
Location: Seattle, WA
Oddometer: 5,147
Quote:
Originally Posted by x3300
After finishing the extension work, I can say that I don't think my method of a press fit alignment was a good one. -x3300
Why don't you think the press fit was good? I was going to ask why you didn't drill both the shaft ends and the insert ends and use dowels (v. turning down the ends of the insert) but it sounds like you'd perfer a butt joint welded in a jig.

Any clues are welcomed.

Lovin' your work.
__________________
Forging ahead, down a false trail.
fishkens is offline   Reply With Quote
Old 10-16-2010, 01:41 AM   #86
Caddy82rats
Beastly Adventurer
 
Caddy82rats's Avatar
 
Joined: Mar 2007
Location: South France
Oddometer: 1,164
your work is incredible, thanks for sharing this art
Caddy82rats is offline   Reply With Quote
Old 10-16-2010, 02:58 PM   #87
Airhead Wrangler
Adios Mexico
 
Airhead Wrangler's Avatar
 
Joined: Mar 2008
Location: Back in Seattle, FINALLY
Oddometer: 6,428
Quote:
Originally Posted by x3300
I think a better way would be to make a fixture that holds the shaft ends and the insert in position for welding.
Inertial friction welding is the way to go for solid driveshafts. It welds the whole cross section. I'm guessing you probably aren't set up for that though. You might be able to make it work on your lathe though.

__________________
R80ST Gets The HPN Treatment
Seattle to TDF on an airhead

Current rides: HPN #834, '93 R100GSPD "red rocket", '73 R75/5 Toaster mongrel, '80 Ducati Pantah 500SL, '92 DR350, '67 Honda SS50, '80 Honda Chaly.
Airhead Wrangler is offline   Reply With Quote
Old 10-16-2010, 03:16 PM   #88
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,734
I always wondered if it was better to just use two shafts, and only make one splice. You know, cut each one off center, and use the longer of the two sections.
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 10-16-2010, 03:16 PM   #89
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,734
Quote:
Originally Posted by Airhead Wrangler
Inertial friction welding is the way to go for solid driveshafts. It welds the whole cross section. I'm guessing you probably aren't set up for that though. You might be able to make it work on your lathe though.

wow that is pretty cool-

and yeah, agreed, this is great work. Fun to watch, too.
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 10-16-2010, 06:18 PM   #90
fishkens
Further...
 
Joined: Nov 2009
Location: Seattle, WA
Oddometer: 5,147
Quote:
Originally Posted by Airhead Wrangler
Inertial friction welding is the way to go for solid driveshafts. It welds the whole cross section. I'm guessing you probably aren't set up for that though. You might be able to make it work on your lathe though.
Wow. Simple as that.

Thanks.
__________________
Forging ahead, down a false trail.
fishkens is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 01:20 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014