Reed 3P armboard mounting


This is question is steeped in ignorance. Does anyone have experience mounting a Reed or similar tonearm to a wood armboard? The 3P seems to use three M5 screws. I would guess the most reasonable approach is installing threaded inserts into the armboard, although that creates more variability in getting an accurate P2S distance. In contrast my current tonearm is attached with a threaded post clamped the armboard with an underside nut. There is enough side-to-side shuffle in this arrangement to get a very accurate P2S. Thank you. 
ohlala
Mount the armband, measure accurately from the spindle and mark out hole centres.

Rule of thumb is measure twice, cut once.

Cut holes 1mm oversize, this will give you enough wriggle room to ensure accuracy.

Use nuts/washers on the underside of the armboard - this will be far more rigid than using inserts.

Personally I would not use wood, it is not rigid enough. Try aluminium or gunmetal.

There are plenty of small engineering shops with small scale manufacturing CNC machines. If you can provide an a drawing with accurate measurements, the cost of cutting an armboard is not huge.

My Reed 3p screwed directly to the teak wood armboard and fixed with nuts. I have a template with my tonearm from the manufacturer.

I think you don’t need threaded inserts if you can’t make precise PS measurement.

If you have a protractor like Feickert NG you can check PS quickly and easily.

P.S. Manufacturer recommended WOOD (not metal) armboard when I asked him about it long time ago.
I do. I have two Reed 3P's. See my profile. My advice is to not sweat it. You do not need inserts, assuming an armboard of say 3/8's or greater of hardwood. As I have stated multiple times in this forum and only had agreement from the experts here, P-S is not an exacting spec, assuming a slotted headshell. Your cartridge and stylus have no idea about and don't give a crap about P-S so long as the stylus hits the desired null points. Proof lies in the modern SME methodology. With modern SME arms there are no headshell slots-the cartridge can only be mounted in one fixed position and the solution is to slide the tonearm mount closer or further back-CHANGING the P-S! There is an invaluable lesson to be learned by the SME method of obtaining alignment. The take-away is that as long as the cartridge can be fixed in the headshell to meet your two preferred null points you are perfect. 
The exception COULD be if you rely on an alignment tool similar to a Mint Protractor that is custom made to a given P-S. In that situation, without exact P-S, your custom made protractor is of little use. You can still get perfect alignment using a universal tool like Feickert's though. So let me say it again-with a Reed 3P you can be 2-3 mms off either too close or too far and be fine with most cartridges. Beware too of cartridges that have abnormally long or short cantilevers. 
Think of it this way btw-the specified P-S is meant to permit the user to align the widest variation of cartridges in terms of mounting screws to stylus distance. 
Proof lies in the modern SME methodology. With modern SME arms there are no headshell slots-the cartridge can only be mounted in one fixed position and the solution is to slide the tonearm mount closer or further back-CHANGING the P-S! There is an invaluable lesson to be learned by the SME method of obtaining alignment.

Nothing new here, Luxman made it for ALL tonearms on PD-444 in the 70’s with metal armboards on the rail (can be moved to the left or to the right to change PS distance).

Nowadays Feickert did almost the same on his turntable.

*New SME tonearms are the ugliest on the planet in my opinion.

Aesthetics are so so personal. For moi, I am not a huge fan of that gaping void on the Feickert and all similarly designed decks to allow for changing the P-S. Is it clever? Hell yes. The pivoting arm board leaf used by Woodsong does the same thing for me-nothing. In fact, I firmly believe that the pivoting arm board leaf in fact compromises sound by promoting unwanted vibration. At least the void on the top surface inherent in the SME and Feickert designs don't constitute an engineering compromise. 
Dr. Feickert just copied today what was made 45 years ago in Japan by Luxman (much better design in my opinion). 

Pivoting gunmetal armboards also designed way back by Micro Seiki as far as I know, and I think it's worst that Luxman metal armboards on the rail, because Luxman armboard can be fixed properly.  
Slotted head shells and adjustable bases are supplied to accommodate various cartridges. The idea being to maintain the proper overhang dictated by the effective length and offset of the arm. The pivot to spindle spec is chosen to get you in the ball park. The cartridges geometry will dictate the exact location.
Using threaded inserts in wood is fine in this context if done right. Wood is soft. The threads of the insert will displace the wood upwards causing a dimple. The tonearm will then not lay flat on the arm board. You have to counter sink them then plane the surface flat. What you are doing is converting a machine screw to a wood screw.
Running machine screws through the arm board and bolting the tonearm down is a bad idea. Again, wood is soft and will expand and contract with humidity and the seasons. Through bolts will always loosen even if you use washers. Of course this is not true for metal and synthetic materials. These you can drill and tap. Best for wood is wood screws. Just size them appropriately and predrill the holes. As fsonic relates the exact pivot to spindle distance is not critical but if you get to far off you may not be able to adjust the arm for certain cartridges. 
fonicsmith-
As I have stated multiple times in this forum and only had agreement from the experts here, P-S is not an exacting spec, assuming a slotted headshell. Your cartridge and stylus have no idea about and don't give a crap about P-S so long as the stylus hits the desired null points. 
Exactly what I was going to say. Because it is correct. Biggest problem around here is the vast numbers of people unable to refrain from posting stuff that is just plain wrong, and then compounding their error by refusing to even consider correct information. 

This is not one where its even necessary to rely on "experts". You can prove it to yourself in a few brief moments simply by looking at the situation and doing something that may or may not come naturally: THINK about it! 

Every pivoted arm swings in an arc. So the cartridge swings in an arc as well. Just look at it. Put an alignment template on the platter and look at it. Pretty obvious the tracking angle changes constantly as the arm arcs across the record.  

Its never perfect, except at two "null" points. If you move the arm, change P2S a bit, all that happens is the null points shift a bit. Which you correct for with cartridge alignment when setting overhang. Who ever heard the sound shift and said, "Wow it sounded perfect there for a second, but now its gone! No, wait, its getting better again, now its gone!" As the arm swings from one null to another? No one. Ever! Therefore, logically, who is going to hear if they shift a millimeter one way or another? No one. Ever! 

So why all the fuss? Good question. Drill your holes. Mount your arm. Just Do It.
Thank you for the help. Glad to hear going through and using nuts works.