Leslie S Head Repairs

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Leslie S Head Repairs

Postby b2major9th » Tue May 29, 2018 4:08 pm

A set of 5 S heads showed up needing both normal machining (base only) as well as two cap center boss repairs and a cap remachine. When the diffuser plate runs loose in an S power chamber for a significant length of time, it usually beats the support rings for the diaphragm disk and to death, and the cap must be remachined to restore operation. In this rebuild, the cap with the missing diffuser boss needed to be remachined due to this damage.
Attachments
IMG_2757_55_before.JPG
#55 head on lathe, before machining
IMG_2752_55_machining.JPG
machining one of the S heads to spec
IMG_2758_55_after.JPG
#55 head on lathe, after machining

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Re: Leslie S Head Repairs

Postby b2major9th » Tue May 29, 2018 4:11 pm

Some of the cap repairs/remachining
Attachments
IMG_2590_31_no_boss_here.JPG
#31 cap, diffuser boss is gone entirely
IMG_2589_31_damaged_rings.JPG
closeup showing damage to diaphragm disk and ring supports causing the disk to be too low, and also grooving of the diaphragm ring support caused by the diffuser banging on it due to vibration and operation in this condition
IMG_2592_31_prep_for_new_boss.JPG
setting up the #31 cap to clean up the corrosion and prepare the surface for a new diffuser support to be welded in

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Re: Leslie S Head Repairs

Postby b2major9th » Tue May 29, 2018 4:15 pm

Cap repairs, continued. The cracked diffuser support bosses are caused by the power chamber being beaten on in an attempt to get it to work again. All that treatment result in is a cap with a cracked or broken boss, as well as (usually) radial cracks in the dome that need to be welded. They become evident when the new boss is welded in or the crack is welded from the inside.
Attachments
IMG_2603_31_new_boss_ready_welding.JPG
#31 cap with new diffuser support boss rigged for welding
IMG_2602_ready_for_welding.JPG
caps and other welding repairs grouped to get them done at once
IMG_2596_25_cracked_boss.JPG
#25 cap showing cracked diffuser support boss

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Re: Leslie S Head Repairs

Postby b2major9th » Tue May 29, 2018 4:18 pm

More cap repairs, continued. #31 cap remachined to spec after welding repair, and new diffuser installed
Attachments
IMG_2619_31_remachined.JPG
#31 cap remachined to spec
IMG_2620_31_remachined_finished.JPG
#31 cap finished, diffuser installed with specially machined ss screw
IMG_2621_31_cracks_repaired.JPG
Back of #31 cap after redial cracks welded up and contoured back down to the surface of the dome.

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Re: Leslie S Head Repairs

Postby b2major9th » Tue May 29, 2018 4:20 pm

#25 cap welding repair completed.
Attachments
IMG_2595_25_cracked_boss.JPG
close-up of crack in diffuser support boss
IMG_2749_crack_welded.JPG
diffuser support boss welded
IMG_2622_25_cap_repaired.JPG
#25 cap finished

Andysmith379
Posts: 27
Joined: Sun Apr 29, 2018 5:54 pm

Re: Leslie S Head Repairs

Postby Andysmith379 » Tue May 29, 2018 7:57 pm

Nice work Mike. I will be sending you 2 of mine very soon. Most likely by the end of the week

User avatar
miller49g
Posts: 377
Joined: Fri Nov 07, 2014 5:55 pm
Location: Southwestern, PA
Contact:

Re: Leslie S Head Repairs

Postby miller49g » Tue May 29, 2018 8:24 pm

Awesome work Mike as usual.

User avatar
Mafarnz
Posts: 821
Joined: Sat Oct 04, 2014 1:35 pm
Location: Moscow Idaho
Contact:

Re: Leslie S Head Repairs

Postby Mafarnz » Wed May 30, 2018 3:33 pm

Question about the feasibility of repairs. I’ll post these publicly since I’m sure I’m not the only one with these issues.

1) I have a bronze tab head with a thin nozzle, about 1/16”. Is this too thin to remachine?

2) I have a S cap with a crack along about half the length of the dome. Is this cost effective to repair?
Attachments
2C0221BC-82A1-45FC-A51B-B179B6C5B979.jpeg
Thin bronze chamber
Maddie F
Pullman WA
Long live the BN and the RS3K!

User avatar
Mafarnz
Posts: 821
Joined: Sat Oct 04, 2014 1:35 pm
Location: Moscow Idaho
Contact:

Re: Leslie S Head Repairs

Postby Mafarnz » Wed May 30, 2018 3:34 pm

Pictures of S cap.
Attachments
03563509-9313-423A-A0BD-FE02AAC33450.jpeg
S cap crack inside
36E76A46-16B2-461B-86B3-E38403E41118.jpeg
S cap crack outside
8AA71B6D-76E1-4801-8D71-4EC752579354.jpeg
Length of crack runs between my fingers.
Maddie F
Pullman WA
Long live the BN and the RS3K!

b2major9th
Posts: 497
Joined: Sat Apr 11, 2015 9:44 pm
Location: Torrance, California USA

Re: Leslie S Head Repairs

Postby b2major9th » Thu May 31, 2018 12:16 pm

Mafarnz wrote:Question about the feasibility of repairs. I’ll post these publicly since I’m sure I’m not the only one with these issues.

1) I have a bronze tab head with a thin nozzle, about 1/16”. Is this too thin to remachine?

It depends on how uneven the wear is on the nozzle. If only a light "skim" cut (on the order of a few thousandths of an inch) can level the nozzle, then it may be possible to get it functional. Not much of a relief cut can be made on the surface leading to the bore, but not a lot is required since the diaphragm does not flex much in that direction anyway.


2) I have a S cap with a crack along about half the length of the dome. Is this cost effective to repair?Probably not cost effective for the following reason. Not so much the weld cost itself, but when it is cracked like that in close proximity to the diaphragm locating surfaces, it would also require a full remachining job, and lots of die grinding/filing to make it look acceptable from the outside. By the time you add up the hours for repair, it would be more economical to replace it with a functional cap. I once repaired an aluminum tab cap cracked that way, but tab caps are getting hard to find and at least in the eyes of the owner, the expense was justified.


Return to “Locomotive Air Horns”

Who is online

Users browsing this forum: No registered users and 1 guest