Fonken Floorstander Dimension Problem

[ChrisR1983]

Hi There

I'm relatively stupid and I'm getting really confused about the Fonken Floorstander MK2.

I'm using Dave's excellent plans and I'm going to pick the timber up and get it cut at good ol' B&Q on Friday. Plan is to build them over the weekend while my girlfriend is at silverstone.

I'm writing out the panel sizes but I've noticed the plans are drawn using 15mm material but I can only get my hands on 18mm. I'm BOUND to make a mistake (being relatively stupid)

Which parts do I need to increase in size? Will the back wall (the pipe like piece) being 3mm larger affect the sound?

Does anyone have a cutting list for 18mm or have it drawn using 18mm material?

I'm not being lazy (I've drawn this out a dozen times already) I just have terrible spatial awareness and want to get it right

Cheers

Chris

[chrisb]

I've built enough of Dave's designs to note the following:

- try to maintain the net internal CSA and port lengths, etc. that means the width and depth will increase by a total of 6mm each -( i.e. to 195mm and 161mm respectively);

- many of the MLTL or resistively ported enclosures have proven in real world use to be quite tolerant of minor variations of dimensions (I've made more than a few cutting/assembly errors over the years, and only a few have resulted in unmitigated failures to launch);

- this particular enclosure has a lower void chamber intended for ballast that can be reduced to retain overall enclosure and driver height, even when filled this box can be tippy, so an enlarged base plate (not shown in sketch or photo) wouldn't hurt;

- the final cutting plan will depend on how you want to overlay the sides / front/ back - personally on the designs with slot ports, I find it makes for quicker assembly and easier finishing to overlay the sides, but that does mean the sides will be a different width than the internal driver brace, so careful cutting and dry fitting will be necessary to ensure tight fit;

- simple butt joints are more than adequate for this one (use biscuits if you like, but I tend to just use air nailer) - dadoes, splines, glue mitre joinery will only complicate the assembly and would of course completely change parts dimensions;

- I'd highly recommend running the driver brace longer than shown on Dave's drawing, and interlocking it with the lateral panel that forms the slot port;

- plan ahead as to type and location of input terminals/wiring/damping materials, this is a tall skinny box parts of which are virtually impossible to access after assembly;

- see my hasty dimensioned sketch attached (as noted above, some part dimensions would change depending on how you overlay panels, so a detailed cut plan could be pointless)

[ChrisR1983]

Chris

Absolutely awesome reply - really helpful!

Nice work on the veneers above btw

I'll post some pictures when I've started

Cheers

[planet10]

Originally Posted by ChrisR1983

Plan is to build them over the weekend while my girlfriend is at silverstone.

You are staying at home and the GF is going to Silverstone? Were you a bad boy?

dave

[planet10]

Originally Posted by chrisb

- see my hasty dimensioned sketch attached (as noted above, some part dimensions would change depending on how you overlay panels, so a detailed cut plan could be pointless)

Chris has pretty much covered it. When rounding the dimensions, round up.

The only change necessary is that due to a 3mm increase in the depth of the back panel, the length of the length of the piece that defines the port slot needs to be shortened by 3mm to 252mm.

It also is possible to arrange the vent as show in the attachment for a bit more floor loading.

dave

[ChrisR1983]

Great! I think I might prefer the port at the front actually... Hmm options!

Look forward to silverstone all year; as much as I love F1 I like the house to myself even more. I can sneak all kinds of stuff into the house when she's not here. Doubt she'll even notice these little floorstanders

cheers for the help!

[cjkpkg]

which driver are you planning on using? I built a pair of these with the CSS EL-70's and they sound GREAT - lots of bass.

I have not had the gumption to yank them out of duty and finish the cabinets...

Just beware of the depth of the driver cutout on the brace as the plans are geared towards the FE127E wich is NLA...

[chrisb]

Originally Posted by cjkpkg

which driver are you planning on using? I built a pair of these with the CSS EL-70's and they sound GREAT - lots of bass.

I have not had the gumption to yank them out of duty and finish the cabinets...

Just beware of the depth of the driver cutout on the brace as the plans are geared towards the FE127E wich is NLA...

yes, you definitely want to dry fit the brace to magnet (with driver screwed in place, including whatever gasket came with or you're subbing) before buttoning up the box

[planet10]

Originally Posted by cjkpkg

the FE127E wich is NLA...

I still have them... althou in tarted up guise. (tarted EL70s too)

dave

[ChrisR1983]

Going to use a stock fe127e, fit everything and then modify the driver later. So general concensus is to build them from the baffle backwards I guess?

Going to get the timber cut after work tonight. Plan is to use 18mm birch ply (difficult to get 15mm over here) and to finish in some kind of veneer. I like cocobolo but it's rather expensive so don't know yet!