| Author |
Message |
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
 Posted: Sat Jun 07, 2014 9:24 pm Post subject: |
 |
|
Nothing like a bit of Sunday morning modelling.
Refining the lower outer bush to have a grease seal and a flange but not so thick as to become a thrust face for the lower control arm due to reasons I stated in my previous post.
The lip contains a simple o'ring like the original top thrust washer does.
Top outer bush with thrust face to replace the old thrust washer.
Inner bush outside edge. Chamfer collects grease as original. All bearing are now approx 5mm wider than original. This is aprox 25% additional bearing area.
All that is left to do really is prototype the measurements to test my allowances for squish and press fitting creep control. As the bush is pushed in if the diamter is say .2mm oversize to create a nice tight press fit the 0.2mm reduces the internal hole by approximately the same amount. That was my understanding as explained by the material salesperson. So you then also have to give a small amount for clearance for the shaft to spin. I think this is the main problem with the urethane bushes. The measurements weren't allowing for squish. Plus they also had to accommodate for shrinkage out of the mold so there is even more reasons for the sizing to be incorrect. Most people I've heard using cast urethane almost always have to ream out the centre bore. I'm hoping with an accurately machined piece that no additional work has to be done.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 5:41 am; edited 1 time in total |
|
| Back to top |
|
 |
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sun Jun 08, 2014 7:14 pm Post subject: |
|
|
If you've been looking at this thread thinking, "Yeah that's great but I got no lathes, equipment or know-how to make those tools" then you may find some on eBay but there's no guarantee.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 5:45 am; edited 1 time in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Tue Jun 10, 2014 6:19 pm Post subject: |
|
|
Anyway since I had a bit of time last night I decided to see if I could make my own deep reach bush extractor on the lathe with a few bits I had lying around.
It's like a really big Dynabolt.
You can see me use it in the videos
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 5:49 am; edited 1 time in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Fri Jun 13, 2014 11:34 am Post subject: |
|
|
Ok so it does work. Home made tool actually works pretty good.
Here's a video.
http://youtu.be/QJEN7W1bnNE
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Wed Jun 18, 2014 9:59 pm; edited 1 time in total |
|
| Back to top |
|
|
Brent
Samba Member
Joined: April 28, 2010
Posts: 1614
Location: San Tan Valley, AZ
|
| Posted: Tue Jun 17, 2014 4:53 am Post subject: |
|
|
Congratulations! That's pretty awesome.
No turning back now.
_________________
69 Fastback Build
Berg5 Build |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Wed Jun 18, 2014 10:16 pm Post subject: |
|
|
| Brent wrote: |
Congratulations! That's pretty awesome.
No turning back now. |
Too right.
The other day I actually got a top and bottom beam cut sections of the inside bearing locations from the owner of Vintage Veedub. The owner had these two small sections set aside for possibly the same project I'm undertaking here. He gladly loaned them to me. Will make it easy to double check my diameter measurements and make a prototype now. I have some Delrin here so I might turn some inner bushes when I get the chance to help decide the right oversize diameter for interference fit. At first I though 0.2mm would be enough interference but I can't be sure till I try it. Also need to know how much the bearing will squish once it is press fit so I can allow some clearance for the shaft to spin.
If anyone out there has experience with that let me know. I'd like to get a nice press fit with material that has hardness of high density polyethylene and nylon. What oversize measurement would you use?
.1, .2, .5mm,????
_________________
Sydney, Australia.
66 Type 3 Fastback |
|
| Back to top |
|
|
eyetzr 
Samba Member
Joined: October 09, 2013
Posts: 1425
Location: Toronto, Ontario. Canada
|
| Posted: Thu Jun 19, 2014 10:28 am Post subject: |
|
|
| So where do we send our money for these bushings? Looking good. |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Thu Jun 19, 2014 5:54 pm Post subject: |
|
|
| eyetzr wrote: |
| So where do we send our money for these bushings? Looking good. |
Once I'm happy with the fit I'll make a few sets for the lads that want em. After that I'll work something out to keep them available. There's another thing I might need to get sorted before making them is an installation tool.
_________________
Sydney, Australia.
66 Type 3 Fastback |
|
| Back to top |
|
|
ataraxia
Samba Member
Joined: March 19, 2010
Posts: 4504
Location: Illinois
|
| Posted: Thu Jun 19, 2014 5:57 pm Post subject: |
|
|
| I'd buy 2 or 3 sets once you're happy with them. |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Thu Jun 19, 2014 7:01 pm Post subject: |
|
|
| ataraxia wrote: |
| I'd buy 2 or 3 sets once you're happy with them. |
Sure, that would good. If I know I can shift a few the machining cost would work out better.
I am also thinking of a solution for scored shafts on the inner bush. It involves making a beam bush with an oversized inner diameter and finding a steel sleeve that fits tight over the end of the shaft that can be brazed in position. The score marks all tend to gouge out one side but they also tend to leave a few mm at the end untouched so a sleeve would still be able to centre itself if the gouges were filled somehow. Using the braze as filler/weld like a bike frame builder would connect steel or chromoly frame tube with braze-on connectors or like a plumber brazing copper pipe.
_________________
Sydney, Australia.
66 Type 3 Fastback |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sun Jun 22, 2014 9:36 pm Post subject: |
|
|
Haven't got around to making the bushes yet. Been too busy.
Thought I might show you what I picked up off a classified ad recently.
A reproduction set of lower beam rubbers cast from original by the looks of it. Looks to be a urethane type of rubber. It has the proper castor compensation built into the rubber with its asymmetric design thickness. Interested to see how durable they are. Certainly better than cracked and crushed old originals.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 5:50 am; edited 1 time in total |
|
| Back to top |
|
|
vlad01
Samba Member
Joined: October 27, 2010
Posts: 3069
Location: Australia
|
| Posted: Sun Jun 22, 2014 9:52 pm Post subject: |
|
|
oh how cool!
are they firmer that the originals?
_________________
The best of VW engine development!
https://www.youtube.com/watch?v=BROWqjuTM0g
71 Aussie notchback, the money pit
92 VP vacationer, old faithful never die
95 VR executive, Restored beyond factory
92 VP S Pack, bought it new old |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sun Jun 22, 2014 10:06 pm Post subject: |
|
|
| vlad01 wrote: |
oh how cool!
are they firmer that the originals? |
I don't really have a 'new' set of originals to compare with but they seem firm. Pushing my ball point pen into them to the point that the pen will probably break and the tip only digs in about 2mm. I'd say they will do the job fine.
I don't know who made them though, there is some letters scratched into the mold. 'VVDS'. May be my local parts supplier Vintage Veedub Supplies did a small run of them a few years back. Might bring them next time I go there.
_________________
Sydney, Australia.
66 Type 3 Fastback |
|
| Back to top |
|
|
vlad01
Samba Member
Joined: October 27, 2010
Posts: 3069
Location: Australia
|
| Posted: Sun Jun 22, 2014 10:16 pm Post subject: |
|
|
That does sound firm, good originals are very soft.
I have one side only in NOS, hard as rock. Not sure it will even compress to fit in place.
These sound like good alternatives. Maybe possibility for further camber increase too.
_________________
The best of VW engine development!
https://www.youtube.com/watch?v=BROWqjuTM0g
71 Aussie notchback, the money pit
92 VP vacationer, old faithful never die
95 VR executive, Restored beyond factory
92 VP S Pack, bought it new old |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Wed Jun 25, 2014 5:59 am Post subject: |
|
|
I got my hands on some beam cuts to measure up and see what exactly was going on inside. Here's some pics for reference. It's really helpful to understand what's going on inside. You can clearly see why I had so much trouble getting the lower fibre bushes out.
Top bush is straight forward. Round inside tube.
The back side of the top bush has three locating bumps to locate it.
Bottom bush locates differently. This one looks like it had a hard life.
You can see the back sheet metal that the pulling tool was getting hung up on. That's how I bent the first one.
Cutting the fibre bush out with the Dremel tool. You'll probably need to use the smaller diameter flexible extension on the Dremel to fit it in the beam. Or you could just go ape with a cold chisel.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 5:57 am; edited 1 time in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Wed Jun 25, 2014 7:35 am Post subject: |
|
|
Also, I noticed just now, if you're going to cut it and chisel out you definitely should try to make 3 cuts, I tried with just two cuts but it just wouldn't lift but after the third cut the pieces lifted relatively easy.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 6:00 am; edited 1 time in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sat Jun 28, 2014 3:49 am Post subject: |
|
|
Working out the press fit interference required a prototype.
I had some Delrin which is fine for working out the tolerance.
Really happy with the fit now. This is the inner top bush and I'm currently working on one of the lower flanged bushes to ensure I have the flange thickness right.
Some progress pics.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 6:05 am; edited 1 time in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sat Jun 28, 2014 8:20 am Post subject: |
|
|
Just finished the lower outer bush.
The flange style bush gives you about 7mm extra width for the bearing. That's 35% wider than stock roller bearing and might help if your shafts have a little bit of fretting.
Adding the o-ring has been a bit of a pain to be honest but I finally got the right fit. There's not really much room for the o-ring but I don't like the idea of not having a dust seal like other plastic style bushes I've seen.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 6:07 am; edited 2 times in total |
|
| Back to top |
|
|
Yabbadubbadoo
Samba Member
Joined: May 21, 2012
Posts: 914
|
| Posted: Sat Jun 28, 2014 9:38 pm Post subject: |
|
|
The moment of truth.
Fits like a glove. I guess I expected the worst but the calculations worked out spot on. Having the beam cut sections really helped and doing the prototype was an absolute must to understand how much over size it all needs to be.
Some clearancing in one spot is required but doesn't affect the o-ring seating even though it looks like it might.
I will use a slightly thinner o-ring. 2 1/4" x 3/16
You can see the gap I left to ensure the flange does not act like a thrust face like the top outer bush does. Also you can see how much seat the o-ring has.
_________________
Sydney, Australia.
66 Type 3 Fastback
Last edited by Yabbadubbadoo on Mon Jul 29, 2019 6:09 am; edited 1 time in total |
|
| Back to top |
|
|
Brent
Samba Member
Joined: April 28, 2010
Posts: 1614
Location: San Tan Valley, AZ
|
| Posted: Sun Jun 29, 2014 4:12 am Post subject: |
|
|
As usual, great job Paolo.
Please don't think I'm knocking on your design here, but why the o-ring on the lower torsions? OEM VW lower seals are available new for about $15; the good ones with the metal ring inside the flange. Seems not worth the extra machining and material costs IMO.
_________________
69 Fastback Build
Berg5 Build |
|
| Back to top |
|
|
|
