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LP12 Set-up - a brief overview.
2011-02-10, 14:33
Post: #21
RE: Setting up your LP12 - a brief overview.
troll - yes

John - correct packaging from HQ would mean none if the retailer received the box un-damaged from HQ.

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2011-02-10, 21:47
Post: #22
RE: Setting up your LP12 - a brief overview.
(2011-02-10 12:23)moomintroll Wrote:  
(2011-02-10 10:31)Cymbiosis Wrote:  
(2011-02-09 21:32)ThomasOK Wrote:  [1) The T-bar is a bit of a loose fit on the bolt (I've heard the new one is improved but I can't yet confirm that). This means you have to check the level by pushing the T-bar lightly to one side and then the other and averaging the two to determine the actual level.

Yes Thomas, the new one is slightly improved, as the fit is now a little more snug on the thread.

Does this mean that Linn have resumed production of these?

'troll
troll,

They are around £60.inc VAT .
Mud.
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2011-02-11, 09:13 (This post was last modified: 2011-02-11 09:16 by k_numigl.)
Post: #23
RE: Setting up your LP12 - a brief overview.
I dislike to mix comments into the stream of serious information, but
obviously there is only one thread for both.

In my opinion, this is the most valuable thread anywhere in this forum:
Precise information in a concise style helping to develop the overall
performance of LP12s everywhere. It could only be topped by a hands on
workshop in parallel (perhaps something to discuss during the LP12 event).

An elevated level of common knowledge has always helped to develop a
higher level of culture. There will still be peaks standing out, but they
start at an elevated niveau and thus reach higher. And without some basic
knowledge about my Toyota (from 'How to repair it yourself') I would not only
be unable to discuss what is there to do about the car with my garage keeper
(I never touch the car myself for repair), but, more important, I would
have no clue how to value his work. With the contrast between a Toyota
and an LP12, how much more valid is this for the service of the latter?!

As an appetizer you may see here what other people do:
http://www.mehr-als-werkzeug.de/category...AF56EE0477

Vigorously applauding,
Klaus
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2011-02-11, 11:32
Post: #24
RE: Setting up your LP12 - a brief overview.
(2011-02-10 21:47)Mudcrutch Wrote:  They are around £60.inc VAT .
Mud.

Thanks Mud.

I actually made my own, after getting dimensions from Peter, but stainless steel tubing is very hard to work with when you only have hand tools and I wouldn't want to repeat it in a hurry.

'troll
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2011-02-13, 10:25 (This post was last modified: 2016-01-27 19:49 by Cymbiosis.)
Post: #25
RE: Setting up your LP12 - a brief overview.
Ok, I have received permission from HQ to proceed, provided we ensure all relevant safety information is always present.
Remember, this thread is merely a guide, “A brief overview” and in my opinion you are obviously far better seeing your dealer for any work that you require. It follows that I or any other participating members do not accept any liability whatsoever for works attempted following your reading of any information contained here.

So, on to motors, and to start with the AC motor, it’s a 24-pole precision synchronous low noise motor and has been used as far as I can tell, pretty much from day 1. Obviously, there have been a few small changes over the years, but essentially it is the same animal as you can see from the three in the picture:
[Image: 2ctSZt.jpg]


Early motors had a nylon thrust pad within the motor cap and this was changed for a ball bearing in 1989. When using the original or Valhalla power supplies the thrust pad should be left in place. However, when using the Lingo, this should be removed as it is not required anymore and can cause start-up problems. Modern motors have a small cap factory fitted (glued in position) to reduce noise and this was introduced in 1991. This motor works with both Valhalla and Lingo.


The motor is isolated from the top-plate by four small metal domes (two on each mounting) please ensure the rounded face of the domes are in contact with motor – not the flat.
Motor fitting is awkward if you have the deck the right way up, so having ensured nothing will fall if you turn the deck up-side down (like the sub-platter!!!!! - And please ensure you have the red bearing cap fitted or you will have oil everywhere! – Arm tethered too!Rolleyes ) when you place the deck in the jig upside-down. If you need to fit a belt guide to the top-plate, attach it now!

The order of placement is, firstly introduce the two M3 allen bolts through the two motor slots in the top-plate and hold them there by using finger and thumb. Place one dome on each bolt, flat side to top-plate and rounded side facing upwards. Then place the motor onto the two bolts aligned with the motor wire exit facing towards the back of the deck (as illustrated in the picture of the Majik LP12 below). This allows for correct motor wire dressing.
[Image: p10101401.jpg]


Following this, slide the remaining two domes down the M3 bolts with the round faces towards the motor. Finally, thread up the two M3 retaining nuts until finger tight. Only at this point you can remove your finger and thumb and place the deck back in the jig the right way up.

Before final tightening of the two bolts, please ensure that they are diagonally located within the top-plate slots, this allows for the motor to be centrally located within the pulley hole in the top plate. It is wrong to have the two mounts either both pushed in the slots towards the main bearing. Or pulled fully away from it. Diagonal arrangement is the only correct way please, and then nip up the bolts firmly.

Now is the time to gently screw in the two motor speed adjustment screws in the two remaining top plate holes. As mentioned previously, these will probably be imperial threads on very early decks and M3 on everything after about (1976 best guess here!). Gently screw these in equally until they just touch the top of the motor. Speed adjustment is achieved, by these screws tilting the motor and hence the pulley and will be discussed in detail later in the thread.

By contrast, fitting of a Radikal DC motor is more straightforward as the two M3 Torx bolts just bolt the motor housing to the top-plate and so with this motor I find it easier to install with the deck in the jig the right way up, carefully offering the pulley up through the pulley hole in the top plate with the motor housing orientated with the flat edge of the mounting flange facing where the sub-chassis will be. As shown in the picture below:
[Image: p10505051.jpg]



Care is essential at this point, as you can easily mark and damage the pulley if you are clumsy when offering it through the top-plate hole. Push the motor up into position thus compressing the foam ring on the motor housing beneath the pulley. Rotate the motor housing carefully until the two M3 fixing threads on the motor mounting flange come into view through the two mounting slots in the top plate. Once the two bolts are started in the thread properly you can relax a little. Rotate the motor housing so the bolts are diagonally located in the slots, just like I described with the AC motor above. Check the foam interface is evenly clamped between the motor housing and top-plate (as if it’s not, remove the motor and repeat the process until it is!) and tighten the two housing bolts up. Personally, I nip them both up, leave them for a couple of minutes to let the foam settle following its compression and then tighten again and a little more than just nipping the bolts. This is very much a feel thing and is probably a discussion that could have its own thread as we all know the importance of torque when it comes to fixings on the LP12.

For me, the important thing to stress here, is do not over-tighten these two mounting bolts as you will strip the relatively fragile threads in the motor housing as they are not metal, they are just threads into the housing material! An expensive mistake, so please don’t make it. Remember, caution is good and take care when tightening.
Motor connection wires will be covered later......................................

BTW. I can include more pictures for clarification of specific points if required, but remember, this is only a brief over-view and fine details are better discussed in specific threads.

Once again, I hope people can see that there are so many things required in setting up one's LP12 correctly, and why it's always best to let your LP12 Specialist Retailer service, upgrade and set up your deck for you.

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2011-02-13, 10:54
Post: #26
RE: Setting up your LP12 - a brief overview.
Peter,

This continues to be interesting. A couple of things that you may well be covering later but link what you have said already:
1. The relative significance of the top plate screws vs the top plate bolts/nuts at either end of the crossbrace. Both potentially tighten the top plate down.
2. The two motor tilt adjustment screws. As you do I do them both up until the both just touch but then I turn each a half turn tighter so that they exert slight pressure on the motor housing and no chance of rattle but also no possibility of bending of the motor plate. Perhaps you do this too but are going to talk about it when you discuss speed adjustment.

CJ

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2011-02-13, 11:10 (This post was last modified: 2011-02-13 11:12 by Cymbiosis.)
Post: #27
RE: Setting up your LP12 - a brief overview.
(2011-02-13 10:54)CJ1045 Wrote:  Peter,

This continues to be interesting. A couple of things that you may well be covering later but link what you have said already:
1. The relative significance of the top plate screws vs the top plate bolts/nuts at either end of the crossbrace. Both potentially tighten the top plate down.
2. The two motor tilt adjustment screws. Perhaps you do this too but are going to talk about it when you discuss speed adjustment.

CJ

CJ 1) A subject for a specific thread I feel, as this one is going to be long enough for most readers and is meant to be a "Brief Overview"

2) Indeed I am and you can't put the cart before the horse! As with no PS installed, let alone any of the other running gear and arm, there is no way to set the speed yet! So just leave these two screws as stated above for now.

KR

Peter - Off to LHR now................

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2011-02-13, 17:12
Post: #28
RE: Setting up your LP12 - a brief overview.
(2011-02-13 10:25)Cymbiosis Wrote:  Before final tightening of the two bolts, please ensure that they are diagonally located within the top-plate slots, this allows for the motor to be centrally located within the pulley hole in the top plate. It is wrong to have the two mounts either both pushed in the slots towards the main bearing. Or pulled fully away from it. Diagonal arrangement is the only correct way please, and then nip up the bolts firmly.

Don't forget there is still some LP12's in US using the 60Hz motor, Peter. They should pull the motor fully away from the bearing due to its smaller pulley.......

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2011-02-13, 18:36 (This post was last modified: 2011-02-13 18:40 by Cymbiosis.)
Post: #29
RE: Setting up your LP12 - a brief overview.
(2011-02-13 17:12)HBerg Wrote:  Don't forget there is still some LP12's in US using the 60Hz motor, Peter. They should pull the motor fully away from the bearing due to its smaller pulley.......

Thank you HBerg. Yes, although I have only ever fitted 50Hz motors myself, there are some certain circumstances where the 17mm 60Hz motor pulley may be fitted. These are with the original PS, some original Valhallas and if you use an Armageddon. In this situation one would have both motor mount bolts at the extreme outside of their slots, thus the motor is pulled away from the sub-platter and belt tension preserved. Speed adjustment is then achieved in exactly the same way as a 50Hz motor - To be covered soon.

BTW all later Valhallas use the 50Hz pulley including those supplied to the USA, as do all Lingos and likewise all Hercules use the 50Hz pulley AC motor too.

I'm sure Thomas can fill in any blanks with respect to this, if he feels there are any as there is little further information I've been able to reference on this.

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2011-02-13, 20:36 (This post was last modified: 2012-12-26 20:11 by Cymbiosis.)
Post: #30
RE: Setting up your LP12 - a brief overview.
Now the motor is in place. The next thing to do, is to ensure the main bearing is securely bolted up to the sub-chassis, whether it be the steel sub-chassis, early, late Cirkus or the Keel, they all need to be bolted up securely (for specific torques see other threads as again, this is a whole topic/thread in itself).
If one has an Aro Keel one would also mount up the Aro arm base on the Keel/A first before fitting. However, leave the arm rest off as it will foul on the plinth during insertion of the Keel/A. It can be attached later when the deck is the right way up again.
Personally, when fitting sub-chassis, whichever they are, I like to do this with the deck upside down in the jig. Extreme care must be taken to avoid damage to the sub-chassis (particularly the Keel). Also ensure that the Keel avoids contacting the plinth and damaging it on insertion. – I’ve heard some horror stories about this, so take your time.......................... I insert the sub-chassis into the deck from underneath through where the armboard normally would sit, motor (more pointed) end first, carefully lifting it over the three spring bolts as I feed it in, then lowering the sub-chassis around them. Take particular care if it’s a Keel, that the arm board end does not contact the plinth and damage it.
Pictures say far more than words here.........

Before:
[Image: p11004491.jpg]


During:
[Image: pic11a.jpg]


After:
[Image: p11004521.jpg]


A Keel/A showing arm mounting collar already attached.
[Image: picture1941.jpg]


Once the sub-chassis is in position, firstly fit the large grommets then place three selected* springs in their correct places, then the small grommets followed by the mudguard washers and finally a turret lock nut (all metal) locks the assembly into place on the M5 spring bolt thread – N.B. This is different to the Nylock nuts used elsewhere on the LP12. They are better than the Nylocks and are needed here as a lose nut on a spring bolt is really bad news as you can imagine!

*Spring selection to hopefully achieve an even better bounce! Springs vary in their compliance and how straight they are. K_numigl has been doing some research on this, and has recently sent me some interesting pictures, following his recent set-up session here at the shop with me, where I had initially pointed out the differences to him!

Despite these variations, the springs are considered “within tolerance”, but it’s useful to be aware that they vary and to use these small variations to ones advantage!

The springs which appear more difficult to compress can be used where most of the sprung mass is supported. i.e near the arm. The softest springs can be used on the left side of the sub-chassis near the motor, as the spring at this end will be supporting less of the overall sprung mass. The spring at the front, to the left of the arm board supports a mass between the other two and so I use a spring who’s compliance is intermediate to the other two. This does help a little I think, when trying to achieve the very best and most even and pistonic bounce.

Once the springs, grommets, washers and nuts are fitted then the sub-chassis can no longer move about freely. This is good as soon the deck will be turned the right way up again. However, not before the fitting of the cross-member, otherwise known as the wire strap to the plinth.

[Image: p11004541.jpg]


Wire straps (I prefer to call them cross-members) have changed over the years. In the early days with the original power supply there was no need for plastic stand-offs. Later, additional holes were provided for these. Valhalla, Lingo and Geddon boards need to use these stand-offs in order to be secure inside the deck.
Early cross-members only have holes at either end, for the top-plate bolts. The additional holes for the two self tapping screws located either side of the bolt hole at either end came later. These cross-members are also longer than modern (2009) ones and this can cause problems if they are being fitted to a modern/new plinth. So, briefly............... They will foul at either end and consequently the cross-member doesn’t sit properly and doubtless would sound awful if left. The problem is shown below. - You can see the marks left, either side of the block at the rear:

[Image: p10503171.jpg]


There are two solutions I would suggest: Fit a new shorter cross-member, or if none available to you, you need to put four small slots in the plinth either side of the blocks as shown below:

[Image: p10503191.jpg]


The important thing is for the cross-member to sit flat up against the surface of the block and I did remove and refit the crossmember shown above after deepening the slots just a little more.... I never took another picture thoughRolleyes. Personally, I wouldn’t cut down the cross-member to make it fit.

Once the cross-member is securely fitted to the plinth and springs etc are on, then we can move on to power-supply board fitting (if required) and wire connections and dressing, which will be the next subject to be covered......

Just a quick point here, I will be covering main bearing and chassis identification within an appendix section at the end of the set-up, as I think this is such an important area and the subject of so many questions like: Which one do I have? That I think it needs to detailed away from the set-up side of things.

KR

Peter

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