Glue for form ply for sp10 plinth?

snap, crackle and pop
cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 12 Jun 2014 23:53

bra10n wrote:Personally if I was looking for a straight forward build I'd be using the Hoop Pine with an A/C face from the link I posted above or similar. Ultimately the decision is yours but as the plinth will be veneered I think you'll appreciate the flat and stable substrate when you reach that stage. From memory 9mm thickness is a 7 ply, 12mm 9 ply.

I have no affiliation with the company but I have used them before and I know as a wholesaler they are 'distributor' orientated... just how near to you is the question. Otherwise search out Austral Plywood distributors in the far north.

Best wishes

Edit: Noticed your question on the arm board...

Not sure what design you favour but ply would allow you to customise each plywood layer as you're building the plinth leaving you with something like a drop-in panel that can be fixed with screws...
If you were buying flitch (veneer) you might also consider buying an additional matched leaf section from which to cut the veneer from for the arm board so it grain matches when assembled.
There is a place in Tolga who is quite good, but when I originally looked at this project a while ago I went in and asked him then about ply and he said nothing cloes close to the weight of form ply. Here is a link to my Orpheus Silex project viewtopic.php?f=18&t=59173 I was planning a simple plinth like this, but more square of course and with an arm board maybe. My Commonwealth does not have an arm board the arm mounts directly to the plinth, I am wondering about maybe fitting some kind of isolation washer under the arm board. The Orpheus sounds great, but the plinth is really not very heavy at all so I wanted a much more heavy and dense ply this time.
Regards
Chris

bra10n
long player
long player
Australia
Posts: 1036
Joined: 25 Oct 2013 01:38
Location: Sydney Australia

Re: Glue for form ply for sp10 plinth?

Post by bra10n » 13 Jun 2014 00:10

A couple of things to note from the link;
- the plywood used in the link looks to be interior ply and hence a softwood albeit it may have hardwood skins.
- looking at the construction it appears to be 18mm and only 5 ply + outer skins.

Again, this is why I suggested you take into consideration density and construction. If you get the opportunity you should really feel the weight of something like marine ply which will be on par with the Exterior Hoop I mentioned.

Have you considered adding pockets or wells of lead to add the required weight?

I was wondering to how the Orpheus plinth was holding up given the above but then I read you applied ??? coats of Danish oil... even though, I'd still be keeping my eye on it.

cats squirrel
long player
long player
England
Posts: 2465
Joined: 16 Dec 2008 16:13
Location: Glorious Devon, UK

Re: Glue for form ply for sp10 plinth?

Post by cats squirrel » 13 Jun 2014 00:29

Hi Chris,

one of the tendencies people have with ply is to use multiple layers, so that the plinth ends up about 100mm thick. At first glance, this would seem to meet the mass and even stiffness criteria, but damping is woeful. And as plywood has a critical frequency of 16kHz for 1mm, a 100mm thick plinth will have a critical frequency of 16000/100, which equals 160Hz. As the plinth will probably resonate at a frequency above this, no amount of extra weight(mass) is going to make a jot of difference.

I'm not sure what the cut-out of the SP10 is, but I would guess it's a major percentage of the plinth area. Have you thought about a frame type, rather than a panel with a huge hole in it? An air dried eucalypt may be your answer, I have one growing in the back garden here that needs to come down! :(

pcutter1
senior member
senior member
Posts: 533
Joined: 23 Aug 2013 21:54

Re: Glue for form ply for sp10 plinth?

Post by pcutter1 » 13 Jun 2014 00:59

I recently found an adhesive called Methyl-Methacrylate, it's a 2 pack similar to Epoxy but seems to be a lot stickier and stronger, it sticks to the silicone mixing palette I used the first time I mixed some. It sets pretty quickly so work time is restricted, it smells like the stuff my dentist uses so it could be a commercially available version of that.

phonomac
senior member
senior member
Scotland
Posts: 378
Joined: 25 Mar 2011 09:23
Location: Hunsbury

Re: Glue for form ply for sp10 plinth?

Post by phonomac » 13 Jun 2014 07:52

Hello Chris,
The SP-10 Mk2 will have the arm mounted directly to the plinth.

I used a separate armboard when I did the Lenco plinth. Made out of MU25, just like the plinth, and I used threaded inserts in the plinth to take machine screws for the armboard.

regards

Angus

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 13 Jun 2014 09:55

Hmmm, I might go and see my friend and see what he has got cut, but I was thinking ply simply as all the layers are different densities which should IMO be good for a plinth. I was too busy to get to the wood place today, but I am going that way on Monday I might go and see what he has got and see how the marine ply and other plys he might have feel. I have mucked about for ages with different plans and i want something simple like the layered plinth as plinths like the Commonwealth plinth apart looking great take ages and I want to hear my sp10 soon :D
I am a bit busy over the weekend, but I might too try a few experiments with some scraps of form ply trying to glue them together early next week as this stuff is seriously hard and dense it seems ideal and it is cheap. I have made a few shooting bench tops for people out of it and it resists years of rain never moving one bit.
Thanks for all the input guys you have given me a lot to think about :D
Regards
Chris

cats squirrel
long player
long player
England
Posts: 2465
Joined: 16 Dec 2008 16:13
Location: Glorious Devon, UK

Re: Glue for form ply for sp10 plinth?

Post by cats squirrel » 13 Jun 2014 11:24

pcutter1 wrote:I recently found an adhesive called Methyl-Methacrylate, it's a 2 pack similar to Epoxy but seems to be a lot stickier and stronger, it sticks to the silicone mixing palette I used the first time I mixed some. It sets pretty quickly so work time is restricted, it smells like the stuff my dentist uses so it could be a commercially available version of that.
methyl methacrylate is the monomer from which acrylic (perspex) is made.

Chris, density, per se, is not important, stiffness is more important, and intrinsic damping is most important. Can you get hold of resinated bamboo, as in chopping board? :D

I would always go for a separate arm board, given the opportunity. :D

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 13 Jun 2014 13:55

cats squirrel wrote:
pcutter1 wrote:I recently found an adhesive called Methyl-Methacrylate, it's a 2 pack similar to Epoxy but seems to be a lot stickier and stronger, it sticks to the silicone mixing palette I used the first time I mixed some. It sets pretty quickly so work time is restricted, it smells like the stuff my dentist uses so it could be a commercially available version of that.
methyl methacrylate is the monomer from which acrylic (perspex) is made.

Chris, density, per se, is not important, stiffness is more important, and intrinsic damping is most important. Can you get hold of resinated bamboo, as in chopping board? :D

I would always go for a separate arm board, given the opportunity. :D
Hi Cats,
On a side note I had the Lenco on this evening, ahhh one TT I will never sell :D
The missus calls it TUNK! as mine is the gl78 as you know and and the end of the record the arm lifts and it goes TUNK! and turns off. If I mod a Lenco it must be another as i cant loose the auto TUNK!! :lol:
Re the arm board thing I feel an arm board with some isolation would be a good plan too, I am just not sure how to do it best. What I do know is I am now itching to get this sp10 going :D
Regards
Chris

cats squirrel
long player
long player
England
Posts: 2465
Joined: 16 Dec 2008 16:13
Location: Glorious Devon, UK

Re: Glue for form ply for sp10 plinth?

Post by cats squirrel » 13 Jun 2014 16:44

re: SP10.

go with a largish piece of very hard timber, supported by sorbothane hemispheres. Mount an arm on the wood, directly. The wood should not be more than 25 mm thick. Because the motor is deeper than this, I would make a picture frame support. This should be do-able quite easily. Moving on, you could incorporate a separate arm pod.

re: Lenco 78

I have had the same thoughts, I bought a 78 at the same time as you, without arm or auto device, so no tang. I am going to build a very special plinth for it, as outlined above, but using my L75 modded arm (carbon fibre wand and Hadcock headshell and CNC counter balance weights), with electronic sensing of arm position, and solenoid activation of the Tunk mechanism. All will be in silver and mostly black, hence an early christening of 'Blackie'. I'm using parts from guitars, too, like lever covers, I also want to make a speedometer for it, and a paddle damping device for the arm. When all that will happen, I don't know...

I can't hack my 78 about, either, so I bought just the top plate from another 78, and will use that, with all the bits from the other 78. Then, when I'm sloppy dead, they can re-assemble it (I will provide instructions) and sell it to someone else to enjoy.

Re: hot here in Devon
Had a hairy experience today with a Lenco 75, went to start it, and heard a loud clunk (it was definitely not a tunk :lol:) , and the platter stopped turning, although I could hear the idler trying to engage, so motor was still running. Took off the platter, nothing to see, so replaced platter, same problem. I then noticed the platter was very low, in fact it was resting on the top plate!. So I had a look at the bearing from underneath, all seemed OK, then I saw that the circlip holding the thrust plate (and hence the bearing and platter) had disengaged from its groove. Popping it back in solved the problem. Temperatures have been very high in Devon, today (keeping customers out of our shop!) but I didn't realize the brass tube which holds the bronze bushings would have expanded that much :lol:

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 13 Jun 2014 23:08

cats squirrel wrote:re: SP10.

go with a largish piece of very hard timber, supported by sorbothane hemispheres. Mount an arm on the wood, directly. The wood should not be more than 25 mm thick. Because the motor is deeper than this, I would make a picture frame support. This should be do-able quite easily. Moving on, you could incorporate a separate arm pod.

re: Lenco 78

I have had the same thoughts, I bought a 78 at the same time as you, without arm or auto device, so no tang. I am going to build a very special plinth for it, as outlined above, but using my L75 modded arm (carbon fibre wand and Hadcock headshell and CNC counter balance weights), with electronic sensing of arm position, and solenoid activation of the Tunk mechanism. All will be in silver and mostly black, hence an early christening of 'Blackie'. I'm using parts from guitars, too, like lever covers, I also want to make a speedometer for it, and a paddle damping device for the arm. When all that will happen, I don't know...

I can't hack my 78 about, either, so I bought just the top plate from another 78, and will use that, with all the bits from the other 78. Then, when I'm sloppy dead, they can re-assemble it (I will provide instructions) and sell it to someone else to enjoy.

Re: hot here in Devon
Had a hairy experience today with a Lenco 75, went to start it, and heard a loud clunk (it was definitely not a tunk :lol:) , and the platter stopped turning, although I could hear the idler trying to engage, so motor was still running. Took off the platter, nothing to see, so replaced platter, same problem. I then noticed the platter was very low, in fact it was resting on the top plate!. So I had a look at the bearing from underneath, all seemed OK, then I saw that the circlip holding the thrust plate (and hence the bearing and platter) had disengaged from its groove. Popping it back in solved the problem. Temperatures have been very high in Devon, today (keeping customers out of our shop!) but I didn't realize the brass tube which holds the bronze bushings would have expanded that much :lol:
I have a thick piece of gum tree in my shed that might do the trick. I thought about it for making the Commonwealth plinth, but one side had some white ant damage (dead now) so it was not much good for a layered plinth, but for a single layer with good side up of course might do. What I get back in this afternoon I will run the tape measure over it.
Re the weather here it is the dry season but it wont stop raining it is even foggy this morning :shock:
Glad to hear the CLUNK was nothing serious :D
If it looks like the wood will do I will post some pics
Regards
Chris

cats squirrel
long player
long player
England
Posts: 2465
Joined: 16 Dec 2008 16:13
Location: Glorious Devon, UK

Re: Glue for form ply for sp10 plinth?

Post by cats squirrel » 14 Jun 2014 10:59

I see a business opportunity, 'grow your own plinth' :lol: A packet of seeds and a long weight. :^o

We have a gum tree in our back garden, but its a few years off plinth dimensions, unless its a frame plinth. 8)

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 14 Jun 2014 12:55

cats squirrel wrote:I see a business opportunity, 'grow your own plinth' :lol: A packet of seeds and a long weight. :^o

We have a gum tree in our back garden, but its a few years off plinth dimensions, unless its a frame plinth. 8)
:D It was a rather busier day than expected so it will be tomorrow afternoon before I can check the wood. I am hoping it will do as for a single layer it would be ideal if it is big enough.
This wood is actually off my property that my friend cut for me so it would be great if I could use it it would be really growing my own plinth :D
Chris

cats squirrel
long player
long player
England
Posts: 2465
Joined: 16 Dec 2008 16:13
Location: Glorious Devon, UK

Re: Glue for form ply for sp10 plinth?

Post by cats squirrel » 14 Jun 2014 13:26

from trunk to tunk... :lol:

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 14 Jun 2014 22:26

cats squirrel wrote:from trunk to tunk... :lol:
:lol:

cafe latte
vinyl addict
vinyl addict
Australia
Posts: 11403
Joined: 11 Oct 2009 04:27
Location: Cattle property near Ravenshoe Qld Australia

Re: Glue for form ply for sp10 plinth?

Post by cafe latte » 25 Jun 2014 04:48

Bit of an update, I have not done much as I have been preparing for a big shooting comp in Cairns actually I won :D . Anyway I have another comp in a couple of weeks so I am rather still focused on other things, but I went to check out my wood and it is not looking too good :( I wonder if it might do though, any thoughts?
The top is fine but there is white ant damage starting about halfway through which is dead now. Here is a pic..
29533
The other side is much worse than I remembered :(
29534
29535
I do have an undamaged piece but as you can see it is not as wide so I dont think it will do..
29536
Oh hum...
Chris