I take dilivery of the new Mk2 Mamod Ltd. Loco
- Sir Clothem Cap
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- Chris Cairns
- Driver
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- Joined: Mon Oct 29, 2007 7:25 pm
- Location: Glasgow, Scotland
- Chris Cairns
- Driver
- Posts: 2366
- Joined: Mon Oct 29, 2007 7:25 pm
- Location: Glasgow, Scotland
Lloyd,
I've been wondering if the gland used by Mamod is actually compressing the 'O' ring enough on the piston rod. They seem to be using the same style of gland for the Mark I & II, William II & Brunel locos, but as I currently only run my locos indoors any leak from the gland is not as obvious as your outdoor cold & windy video shows. And the Diamond Jubilee Saddle tank loco that was on eBay had steam coming out of the glands on the accompanying YouTube videos.
On my Brunel as the cylinder is mounted vertically the condensate gets pushed straight out the gland onto the drive shaft below washing out its lubrication. So I've added some graphite thread inside the gland to reduce that leak.
There are no 'O' rings on any Mamod pistons. I believe the gland housing is pressed into the cylinder block making it very difficult to remove.
Chris Cairns.
I've been wondering if the gland used by Mamod is actually compressing the 'O' ring enough on the piston rod. They seem to be using the same style of gland for the Mark I & II, William II & Brunel locos, but as I currently only run my locos indoors any leak from the gland is not as obvious as your outdoor cold & windy video shows. And the Diamond Jubilee Saddle tank loco that was on eBay had steam coming out of the glands on the accompanying YouTube videos.
On my Brunel as the cylinder is mounted vertically the condensate gets pushed straight out the gland onto the drive shaft below washing out its lubrication. So I've added some graphite thread inside the gland to reduce that leak.
There are no 'O' rings on any Mamod pistons. I believe the gland housing is pressed into the cylinder block making it very difficult to remove.
Chris Cairns.
Leaky cylinder
I have just completed a run out side in the cold, to see things better. The two O rings I saw looked fine so being puzzled I ran and observed. No leaks, till the very end of the run. It could just be a lowering of oil in the mix towards the end. 90% was fine and the running slows anyway due gas going down, it being a cold day. Loves the cold as there is water left and good exaust plume for photos.
The copper exaust pipe by the way is cut to level, on the front chassis plate, to allow oil to seprate from steam, so steam goes up the chimney but not oil. There is no oil residue on top of the loco at all. It collects on the front plate.
It would make an easy Summerlands chuff conversion but on the MSS job I did not think it worth it, as the sound was so quiet after the fit. I MAY do it to see if excess oil can be ducted away after in some way. I did drill a 5mm hole in the front plate to help oil leak away onto the track. It does not get as far as the front buffer now.
The copper exaust pipe by the way is cut to level, on the front chassis plate, to allow oil to seprate from steam, so steam goes up the chimney but not oil. There is no oil residue on top of the loco at all. It collects on the front plate.
It would make an easy Summerlands chuff conversion but on the MSS job I did not think it worth it, as the sound was so quiet after the fit. I MAY do it to see if excess oil can be ducted away after in some way. I did drill a 5mm hole in the front plate to help oil leak away onto the track. It does not get as far as the front buffer now.
- Chris Cairns
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- Location: Glasgow, Scotland
Just checked my Mark II with a micrometer. The threaded portion of the gland nut plus the uncompressed 'O' ring measures 1/4". The depth of the gland inside from the outer face to the 'O' ring retaining plate is 17/64". So in other words the piston 'O' ring is not getting compressed enough if at all.
If you do not have have any graphite thread packing try sticking some rolled up PTFE tape inside the gland instead around the piston to get a better seal. That will probably help with your loose gland nut as well.
Mamod also seem to have changed the exhaust. My Mark II is from the 1st batch with the shorter chimney. The 1/8" exhaust pipe has a larger pipe soldered to it where it goes through the apron/footplate, and it sticks up 1/2" from the bottom of the boiler into the chimney. Seems that thicker pipe has been dropped and all the photos I've seen of recent Mark II & Diamond Jubilee locos just has a 1/8" pipe just sticking up above the apron/footplate but not reaching the bottom of the boiler.
Chris Cairns.
If you do not have have any graphite thread packing try sticking some rolled up PTFE tape inside the gland instead around the piston to get a better seal. That will probably help with your loose gland nut as well.
Mamod also seem to have changed the exhaust. My Mark II is from the 1st batch with the shorter chimney. The 1/8" exhaust pipe has a larger pipe soldered to it where it goes through the apron/footplate, and it sticks up 1/2" from the bottom of the boiler into the chimney. Seems that thicker pipe has been dropped and all the photos I've seen of recent Mark II & Diamond Jubilee locos just has a 1/8" pipe just sticking up above the apron/footplate but not reaching the bottom of the boiler.
Chris Cairns.
Can't do much more! FIN (still very pleased)
Last edited by steamie1 on Thu Feb 14, 2013 8:35 am, edited 1 time in total.
- Chris Cairns
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Drivers for Mk2
E-mailed him twice..I'll try again now.
- Superbiker_uk
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He does still sell via his ebay account "bobbusybody"Last I had heard on another forum was he had ceased trading?
http://www.ebay.co.uk/sch/bobbusybody/m.html
Try and message him this way. I have purchased from him numerous times directly and via ebay.
- Chris Cairns
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- Location: Glasgow, Scotland
Being a one man band Rob seems to have suffered from his own success, and pops up on the 16mm NGM Yahoo group after another dissatisfied customer posts a "displeased with lack of service" Topic (last one in Nov 2012).
I even had problems with the Busy Bodies Mamod driver I won on eBay and it took a few eBay messages to sort it out.
I did hear (but cannot remember where) that his 'With Brass Knobs On' range is no longer available (made by Ray Smith, ex Bywater Models).
He does have a couple of models on eBay at present so as Peter has suggested an eBay message may be the best form of contact.
Chris Cairns.
I even had problems with the Busy Bodies Mamod driver I won on eBay and it took a few eBay messages to sort it out.
I did hear (but cannot remember where) that his 'With Brass Knobs On' range is no longer available (made by Ray Smith, ex Bywater Models).
He does have a couple of models on eBay at present so as Peter has suggested an eBay message may be the best form of contact.
Chris Cairns.
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