Eddystone Variable Cap Seized Up - UK Vintage Radio Repair and Restoration Discussion Forum

SolderSmoke · 17th Aug 2014, 5:12 pm

I have a very nice old (1930s) variable cap from Eddystone. It came out of a homebrew British regen. I have succeeded in getting the old receiver going (with solid state devices vice valves) but today I ran into a strange problem: the tuning cap kind of seized up. Previously it had been completely loose, with the rotors spinning freely. Now, it is very tight -- too tight for the reduction drive. Any idea why this would happen and what I can do?
More info and pictures here"
http://soldersmoke.blogspot.com/2011...ech-regen.html
Thanks, Bill

Peter.N. · 17th Aug 2014, 5:30 pm

The grease on the bearings has probably dried out and they have jammed, try squirting them with WD40.

Peter

SolderSmoke · 17th Aug 2014, 8:43 pm

Tried that -- it doesn't seem to help. I'm trying to disassemble the cap so as to be able to get at the area where the rotor meets the frame, but no luck.

Ed_Dinning · 18th Aug 2014, 7:49 pm

Hi Bill, look for broken insulators on the stator or a collapsed bearing. If the bearing was very slack initially one of the balls may be displaced and causing the jam.

Ed

SolderSmoke · 19th Aug 2014, 12:17 am

Ed: I can't seem to get the ball bearing case open.
Bill

AC/HL · 19th Aug 2014, 12:46 am

Could you post a picture or two, that might help in the diagnosis.

SolderSmoke · 22nd Aug 2014, 10:56 am

Here are some pictures, re my Eddystone cap woes:

Station X · 25th Aug 2014, 10:43 am

A soak in penetrating oil may do the trick, but try a small drop first to make sure it isn't going to damage the brass.

Do I see a grub screw holding the vanes to the shaft? If so removing it may enable the vanes to be pulled off the shaft giving better access to the bearing.

Does the shaft nut hold the frame to the bearing. If so it may have been over tightened distorting the bearing.

Removing the front circlip may enable the shaft to be GENTLY tapped out of the bearing.

HamishBoxer · 25th Aug 2014, 12:12 pm

Is it worth soaking in paraffin?

25th Aug 2014, 12:18 pm

Yes, won't do any harm.

Station X · 25th Aug 2014, 3:15 pm

I don't know what the situation is in the USA, but in the UK paraffin (kerosene) is more expensive than petrol. Typically around £7.00 for 4 litres.

So unless you have some paraffin handy, penetrating oil or some other cleaning fluid might be a cheaper option.

17th Aug 2014, 5:12 pm	#1
SolderSmoke Retired Dormant Member Join Date: Aug 2014 Location: Falls Church, Virginia, USA Posts: 5	Eddystone Variable Cap Seized Up I have a very nice old (1930s) variable cap from Eddystone. It came out of a homebrew British regen. I have succeeded in getting the old receiver going (with solid state devices vice valves) but today I ran into a strange problem: the tuning cap kind of seized up. Previously it had been completely loose, with the rotors spinning freely. Now, it is very tight -- too tight for the reduction drive. Any idea why this would happen and what I can do? More info and pictures here" http://soldersmoke.blogspot.com/2011...ech-regen.html Thanks, Bill

17th Aug 2014, 5:30 pm	#2
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Eddystone Variable Cap Seized Up The grease on the bearings has probably dried out and they have jammed, try squirting them with WD40. Peter

17th Aug 2014, 8:43 pm	#3
SolderSmoke Retired Dormant Member Join Date: Aug 2014 Location: Falls Church, Virginia, USA Posts: 5	Re: Eddystone Variable Cap Seized Up Tried that -- it doesn't seem to help. I'm trying to disassemble the cap so as to be able to get at the area where the rotor meets the frame, but no luck.

18th Aug 2014, 7:49 pm	#4
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Eddystone Variable Cap Seized Up Hi Bill, look for broken insulators on the stator or a collapsed bearing. If the bearing was very slack initially one of the balls may be displaced and causing the jam. Ed

19th Aug 2014, 12:17 am	#5
SolderSmoke Retired Dormant Member Join Date: Aug 2014 Location: Falls Church, Virginia, USA Posts: 5	Re: Eddystone Variable Cap Seized Up Ed: I can't seem to get the ball bearing case open. Bill

19th Aug 2014, 12:46 am	#6
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Eddystone Variable Cap Seized Up Could you post a picture or two, that might help in the diagnosis.

22nd Aug 2014, 10:56 am	#7
SolderSmoke Retired Dormant Member Join Date: Aug 2014 Location: Falls Church, Virginia, USA Posts: 5	Re: Eddystone Variable Cap Seized Up Here are some pictures, re my Eddystone cap woes: Attached Thumbnails Last edited by AC/HL; 22nd Aug 2014 at 11:31 pm. Reason: Images uploaded

25th Aug 2014, 10:43 am	#8
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Eddystone Variable Cap Seized Up A soak in penetrating oil may do the trick, but try a small drop first to make sure it isn't going to damage the brass. Do I see a grub screw holding the vanes to the shaft? If so removing it may enable the vanes to be pulled off the shaft giving better access to the bearing. Does the shaft nut hold the frame to the bearing. If so it may have been over tightened distorting the bearing. Removing the front circlip may enable the shaft to be GENTLY tapped out of the bearing. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

25th Aug 2014, 12:12 pm	#9
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Eddystone Variable Cap Seized Up Is it worth soaking in paraffin? __________________ G8JET BVWS Archivist and Member V.M.A.R.S

25th Aug 2014, 12:18 pm	#10
Guest Guest Posts: n/a	Re: Eddystone Variable Cap Seized Up Yes, won't do any harm.

25th Aug 2014, 3:15 pm	#11
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Eddystone Variable Cap Seized Up I don't know what the situation is in the USA, but in the UK paraffin (kerosene) is more expensive than petrol. Typically around £7.00 for 4 litres. So unless you have some paraffin handy, penetrating oil or some other cleaning fluid might be a cheaper option. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.