Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesSRM EngineeringLucas Classic MotorcycleIndustrial tec supplyHepolite PistonsThe Bonneville Shop

Upgrade your membership to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Welcome to BritBike Forum!
Britbike forum logo
Member Spotlight
Bry
Bry
Scotland
Posts: 363
Joined: May 2006
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Top Posters(30 Days)
Allan G 80
quinten 52
Top Likes Received (30 Days)
Cyborg 19
Newest Members
Steve W 1959, Bobpin, VWK740, Alloy Clipper, DonB
11,757 Registered Users
Who's Online Now
4 members (OriginalScott, Stuart, Hugh Jörgen, L.A.B.), 35 guests, and 73 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Page 121 of 133 1 2 119 120 121 122 123 132 133
Joined: Feb 2008
Posts: 5,676
Likes: 271
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,676
Likes: 271
If you have ever been in a foundry sand casting large aluminum parts you will realize that it is hardly a precision environment.
It was quite a common practice "back in the day" for large aluminum sand castings to be vacuum impregnated with a liquid epoxy to eliminate the effects of porosity.
This was normally done on 100% of production to reduce rejects at a later stage of manufacture.
Just another piece of useless information from my vast repository!

1 member likes this: Magnetoman
Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Tridentman
It was quite a common practice "back in the day" for large aluminum sand castings to be vacuum impregnated with a liquid epoxy to eliminate the effects of porosity.
There are two approaches to this problem: repair all the castings that come from the foundry, or fix the casting process. We might call these 'the JB Weld Approach" and "The Japanese Approach."

Joined: Feb 2008
Posts: 5,676
Likes: 271
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,676
Likes: 271
If you are a relatively small customer of a relatively large foundry your leverage is strictly limited i.e. zero.
But you still need usable leak free castings to make and sell your product.
So it may seem to be the JB Weld approach but unless you sold product you couldn't pay the wages---including your own!
Needs must when the devil drives!

1 member likes this: Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Tridentman
If you are a relatively small customer of a relatively large foundry
But BSA wasn't a relatively small customer, and they owned the foundry. The JB Weld approach was their management choice.

Joined: Feb 2008
Posts: 5,676
Likes: 271
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,676
Likes: 271
I thought that you were referring to my namesake motorcycle manufacturer.

1 member likes this: Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Tridentman
I thought that you were referring to my namesake motorcycle manufacturer.
I was. Apparently, even though nearly 50 years have passed, you still haven't come to terms with the fact it was made by BSA.

Joined: Oct 2001
Posts: 1,810
Likes: 187
S
Britbike forum member
Offline
Britbike forum member
S
Joined: Oct 2001
Posts: 1,810
Likes: 187
Originally Posted by Magnetoman
Originally Posted by Tridentman
If you are a relatively small customer of a relatively large foundry
But BSA wasn't a relatively small customer, and they owned the foundry. The JB Weld approach was their management choice.
BSA had a foundry, but quite a few of the aluminium alloy castings were bought in from at least A&M.

1 member likes this: Magnetoman
Joined: Feb 2008
Posts: 5,676
Likes: 271
Britbike forum member
Offline
Britbike forum member
Joined: Feb 2008
Posts: 5,676
Likes: 271
The Trident engine was designed by Triumph and many if not all the aluminum castings were out sourced.
For example the heads were cast by either AMAC (Aeroplane and Motor Aluminum Castings of Smethwick, Birmingham, part of the Associated Engineering Group---a very big group of companies and where incidentally I had my first job as a development engineer in their Group R&D Center) or HDA (High Duty Alloys--a member of the Hawker Siddeley group of companies which became part of British Aerospace--now BAE and a 10% partner in the US F-35 fighter jet).
So probably best to consider BSA as a sub contract engine assembler for Triumph.

1 member likes this: Magnetoman
Joined: Mar 2019
Posts: 845
Likes: 182
Member
Online Content
Member
Joined: Mar 2019
Posts: 845
Likes: 182
Originally Posted by Tridentman
So probably best to consider BSA as a sub contract engine assembler for Triumph.
Step 1. Insert dowel "A" into hole "C".


1970 T120R - 'Anton'
1970 Commando - 'Bruno'
1967 T120R - 'Caesar'
1968 Lightning - 'Dora'
1 member likes this: Magnetoman
Joined: Sep 2008
Posts: 1,685
Likes: 39
S
Britbike forum member
Offline
Britbike forum member
S
Joined: Sep 2008
Posts: 1,685
Likes: 39
I find great comfort in the fact that the current Triumphs aren't owned by BSA anymore. And they're made East of Birmingham by a good few miles...

SR

2 members like this: NYBSAGUY, Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Returning to matters Ariel, the two layshaft and one mainshaft bushes will exhaust my supply of C544 bronze so I ordered another 1 ft. of 1¼ OD to have on hand if ever I rebuild another Burman gearbox, which I won't. Or, if I screw up making one of the present bushes, which I might... It will be delivered tomorrow along with CCMT carbide inserts profiled for Al for a set of boring bars that presently have inserts profiled for steel.

In case the information is useful for someone else, I used "Al" inserts for machining the OD and ID of the bush I made yesterday and they worked really well on the C544 bronze, which is why I ordered the CCMT inserts (the tools I used yesterday have TCMT inserts so they aren't interchangeable). Lathe and mill tools needing inserts with different shapes and in different sizes, and each in different profiles for various materials, and it doesn't take long before implementing a computerized inventory system for the inserts wouldn't be a bad idea.

Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
I only had a small window of opportunity to work in the garage today, but it was enough time to make the second layshaft bush. The diameter of the shaft this will have to fit is 0.6200" so, as can be seen, I left ~0.0015" to be honed after I press it in the gear, plus whatever clearance I decide on.

[Linked Image]

The mainshaft has a spiral oil/grease groove cut in it so the bush in the sleeve gear doesn't need one. However, the layshaft doesn't turn so a groove in it would be less effective for moving fluid than one in the bush. Since Burman felt a groove was necessary to lubricate the sleeve gear, I'll speculate that the bushes originally installed in the layshaft gear cluster had grooves. The fact the ones I removed lacked such a feature may have been a contributing factor in their demise.

I don't have quite enough C544 left to make the sleeve gear bush, but more is due to be delivered before I have my next garage time on Friday. I'll probably make it first, then reconfigure the lathe with the accessory head to cut the grease/oil grooves in the two layshaft bushes.

Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Idle hands, plus the internet, are the devil's playground. Thanks to access to the university library, which has agreements with a large number of publishers, I was able to spend several hours reading 'Engineering Tribology' by G. Stachowiak and A.W. Batchelor (Elsevier, 2013) to learn way more about journal bearings (AKA bushes) than I knew before, and yet not enough.

For present purposes, the equation for load carrying capacity of such a bearing derived from the Reynolds equation suffices to illustrate what is involved.

[Linked Image]

Without describing this equation in detail, it shows that the load W that can be carried by such a bush increases linearly with rotation rate U and lubricant viscosity η, but decreases as the square of the clearance c. However, the derivation of this equation assumes the viscosity is a constant, which even for simple oil isn't a good approximation (the viscosity of 30W decreases by 20× between 70 ℉ and 180 ℉). Worse, when dealing with a non-Newtonian fluid like semi-fluid grease, equations like the following have to be solved.

[Linked Image]

Further, cavitation and hydrodynamic instability set in if the parameters are too far off. However, all is not lost in making use of this information. Even not knowing the viscosity of the semi-fluid grease, nor how it varies with temperature, the equations show that as far as clearance c is concerned, bigger isn't better. As long as the semi-fluid grease can make its way into the gap between the shaft and bush, smaller is better.

Repeating something I wrote a few days ago:

The most authoritative paper I've found so far, taking into account rotation speed, viscosity, hydrodynamic force, temperature, etc., recommends a clearance of

0.0015"/inch (=0.00094" for a 5/8" shaft), or alternatively 0.001"/inch plus 0.001" (=0.0016") with a maximum of 0.002"

Given that both bushes will have grooves in them to help with grease/oil flow, I'm strongly leaning toward splitting the difference and giving them a clearance of 0.0013". Because clearance enters as a square, the difference between 0.0013" and 0.002" is a factor of 2.4× in load capacity.

Last edited by Magnetoman; 05/13/21 10:53 pm. Reason: fixed typo
Joined: Oct 2001
Posts: 1,810
Likes: 187
S
Britbike forum member
Offline
Britbike forum member
S
Joined: Oct 2001
Posts: 1,810
Likes: 187
Originally Posted by Magnetoman
Without describing this equation in detail, it shows that the load W that can be carried by such a bush increases linearly with rotation rate U and lubricant viscosity η, but decreases as the square of the clearance c.
As I understand it, lubricity is more likely to be the limiting factor on the bushes rather than load capacity. Oil wets metal surfaces quite readily and works well in a thin film, but greases tend not to share these properties.

Greases tend to be used in high load, low speed applications (e.g. king pins), and/or where a crease film can be pressure fed between the metal surfaces (e.g. universal joints)

1 member likes this: Magnetoman
Joined: May 2019
Posts: 915
Likes: 336
C
Britbike forum member
Offline
Britbike forum member
C
Joined: May 2019
Posts: 915
Likes: 336
Well what a coincidence! I was also exploring the world of Tribology today. Scraping spuge off the bottom of that honing fluid tank.

The magnetic pickup still works.

[Linked Image from live.staticflickr.com]8EF611BB-4FF6-4E5D-A301-5A657E51D5F8 by First Last, on Flickr

1 member likes this: Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Shane in Oz
Oil wets metal surfaces quite readily and works well in a thin film, but greases tend not to share these properties.
When I get interested in a topic I tend to get "reasonably" into it. Twenty or so years ago I became interested in the topic of oil and gasoline and the photograph shows the ~1000+ pages of SAE papers on the topic I still have from that time.

[Linked Image]

However, I didn't have the same level of interest in grease at that time, so none of the papers deal with it, and I'm going to do my best to avoid developing that interest now. That said, Grade 00 semi-liquid grease has more in common with oil than it does with the grease used on a tractor kingpin.

Originally Posted by Cyborg
The magnetic pickup still works.
How those small particles align themselves with the field lines from the magnet is the most fascinating image I've seen in this thread for quite a while. Thanks for posting it.

Joined: Oct 2001
Posts: 1,810
Likes: 187
S
Britbike forum member
Offline
Britbike forum member
S
Joined: Oct 2001
Posts: 1,810
Likes: 187
Originally Posted by Magnetoman
I didn't have the same level of interest in grease at that time, so none of the papers deal with it, and I'm going to do my best to avoid developing that interest now. That said, Grade 00 semi-liquid grease has more in common with oil than it does with the grease used on a tractor kingpin.
You know you want to exercise the minds of your current students by running a series of experiments to compare the wetting properties, film thickness and viscosity of engine oil, gear oil, 00 grease and 0 grease smile

For extra credit, try this at various temperatures.

1 member likes this: Magnetoman
Joined: May 2019
Posts: 915
Likes: 336
C
Britbike forum member
Offline
Britbike forum member
C
Joined: May 2019
Posts: 915
Likes: 336
Originally Posted by Magnetoman
How those small particles align themselves with the field lines from the magnet is the most fascinating image I've seen in this thread for quite a while. Thanks for posting it.

Not that it would have taken much, given the circumstances, but it was the highlight of my day. I wished there was some way to preserve it, but in order to bring it inside, it would have to be hermetically sealed. The bride isn’t a big fan of things that smell like funky tallow. I’d estimate that 98% of the iron came through Stevenage which would have added some interesting provenance. Anyway.... if the honing fluid was replaced with saturating epoxy, one might be able to make something similar. I seem to have both the epoxy (in sufficient quantities) and half a bushel of rare earth magnets.

Can you guess what object is creating that pattern?

1 member likes this: Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Cyborg
Can you guess what object is creating that pattern?
A Lucas rotor?

Joined: May 2019
Posts: 915
Likes: 336
C
Britbike forum member
Offline
Britbike forum member
C
Joined: May 2019
Posts: 915
Likes: 336

1 member likes this: Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
My plans for the day fell apart (but for a very happy reason), significantly reducing garage time, but I did manage to make a little progress. I machined a length of 1" Al to press the bush out of the sleeve gear.

[Linked Image]

I then used that piece in the hydraulic press to remove the bush.

[Linked Image]

The bush came out without extraordinary effort.

[Linked Image]

Measurements I then made found the OD of the bush to be 1.0011"–1.0012" and the ID of the gear to be 1.000", so the interference fit was a little over a thou. at 0.0011"–0.0012". That fit seems to have been fine, so when I'm in the garage tomorrow 'll make the new bush with it in mind.

Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Proving once again that idle hands, plus the internet, are the devil's playground, this weekend I filled in the gap in my 3-point internal micrometers, so I now have all holes and bores covered from 0.15" (the smallest such micrometer made) to 3.6". Because they got to 600 cc by increasing its stroke as well as bore, even the 89 mm (3.504") cylinder of a 600 cc Matchless Typhoon falls within range, should I ever give in to the temptation to own one. Although the 92 mm (3.622") and 94 mm (3.701") of my Ducatis are out of range (which easily could be remedied...), I now can measure the cylinders of every old bike I have, or am ever likely to have, to 0.0001" with both 2 and 3-point instruments.

OK, it's not as if I need to measure a cylinder bore to 0.0001", but 3-point micrometers have the advantage of being much faster to use than 2-point. The photograph shows the components of a 2-point bore gage.

[Linked Image]

To get this ready to use requires finding the right extension and installing it (which usually take a couple of tries, and often requires one or two of the shims to get it within range), inserting the dial indicator, setting the micrometer to the desired value after first checking its calibration at one or other extreme of its measurement range (e.g. either 3" or 4" for the nominal 81.8 mm of the Ariel), rocking the instrument back and forth in the jaws of the micrometer to find the minimum value while simultaneously pushing or pulling the dial indicator into position so the needle is on scale, and doing the final fine tuning to 0.0001" with the dial on the dial indicator while again rocking the instrument in the micrometer.

Basically, the same process is required for split-ball instruments.

[Linked Image]

All of the above steps only take a few minutes, and is no big deal when it might be done maybe once in a year when boring a cylinder. However, it's time-consuming and annoying when measuring smaller holes, such as for a bush, where the ID of the bush needs one setup and the ID of the hole it will go into another, requiring repeatedly going through the process.

In contrast, a 3-point micrometer just requires a quick check in a ring gage to be sure no one has sneaked in the garage and readjusted it since the last use, and then using it.

[Linked Image]

Only one calibration check is needed for the full range of any one of these micrometers, and if a second measurement is outside the range of one of them, a second micrometer is simply used rather than having to repeatedly go through the process of swapping components and recalibrating. Because a 3-point gage is nearly as fast to use as a caliper, and a lot more accurate, there's no incentive to skip making measurements that really should be made.

What set me down this 3-point path was needing to measure the ID of the hole required for the exhaust valve seat in the Ariel. What I needed was a gauge that measured the diameter of a shallow hole of diameter 1¾" to an accuracy of no worse than a few tenths. The construction of a 2-point gage, like that in the first photograph, places the measuring probe too far above the bottom of a hole to be useful for this purpose. A split-ball gage, as shown in the second photograph, would have worked, but the largest anvil made for them is too small at 1.6". As can be seen in the third photograph, the measuring pins of a Mitutoyo Holtest micrometer extend to nearly the bottom of the instrument, so it's perfect. Of course, these micrometers aren't only useful for shallow holes.

After having "discovered" how much faster such micrometers were to use than their 2-point equivalents, I decided I "needed" them even for smaller holes already covered by my split ball gages. One thing then led to another and I decided I "needed" them for larger holes (bores) as well so in for a penny, in for, well, somewhat more than a penny. The final gap I filled this weekend covers the 75 mm of my A65, which I'll never rebuild, and the 77 mm of my Matchless G15/45, which somehow always seems to find itself in 3rd position on my rebuild list. But, someday it will make it to the top and I'll need this latest micrometer. Really...

p.s. I decided to shed some light on these various types of hole/bore gages because today is:

[Linked Image]

Last edited by Magnetoman; 05/16/21 9:08 pm. Reason: p.s.
1 member likes this: gunner
Joined: May 2019
Posts: 915
Likes: 336
C
Britbike forum member
Offline
Britbike forum member
C
Joined: May 2019
Posts: 915
Likes: 336
You really need to get a grip man..... here’s a tool for you http://www.smartrecovery.org/abc-of-urges/


Although.... let he who has not.....

In the latest pile that I dragged home, there was a Sunnen AN600 !! Had no idea it was in there. How’s that for good fortune.

Last edited by Cyborg; 05/17/21 3:49 pm.
2 members like this: chaterlea25, Magnetoman
Joined: Nov 2011
Posts: 7,193
Likes: 401
Britbike forum member
OP Offline
Britbike forum member
Joined: Nov 2011
Posts: 7,193
Likes: 401
Originally Posted by Cyborg
here’s a tool for you
That site isn't useful since it's about reducing urges, not compulsions. It should be clear that more than a simple urge is involved. Besides, I can see right through your trick to try to throw me off my game and gain advantage in the Tooling Wars®. Telling me about that site is like "helpfully" telling a race competitor to watch out for a slick spot in turn 3 in order to gain an advantage over them.

Originally Posted by Cyborg
In the latest pile that I dragged home, there was a Sunnen AN600
Congratulations on that. It's a major score.

Joined: Feb 2019
Posts: 520
Likes: 216
S
Britbike forum member
Offline
Britbike forum member
S
Joined: Feb 2019
Posts: 520
Likes: 216
Originally Posted by Magnetoman
p.s. I decided to shed some light on these various types of hole/bore gages because today is:
[Linked Image]
https://imgix.bustle.com/uploads/im...0&fit=crop&crop=faces&fm=jpg

2 members like this: Gordon Gray, Magnetoman
Page 121 of 133 1 2 119 120 121 122 123 132 133

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5