Keith's FH3 Build - Slow Progress

[keiths]

I've decided to post the progress of my Frugel Horn Mk3 bulid project here. Progress to date has been very slow - hopefully by posting here, it may spur me on a bit.

I've now aquired everything I need to build these. I'm not an experienced DIYer by any means, so if there are any better ways to do things than the way I describe here, please tell me :) Also my tools are few in number and of basic quality.

I got the 18mm birch ply from my local timber merchants and they cut the 8' by 4' sheet to the following:

http://www.simister.com/public/fh3/cutting.jpg

I decided to make a template for the curve that needed cutting into each side panel from some scrap 10mm MDF. The curve is a 1,753mm radius, so I made a jig from some long bits of timber, bolted the router to the end and cut the template

http://www.simister.com/public/fh3/curve_jig.jpg

I then used a template cutting bit to cut the curve out on the first of the side pieces

http://www.simister.com/public/fh3/curve_route.jpg

and the same template cutting router bit to copy my first side piece three more times

http://www.simister.com/public/fh3/four_sides.jpg

I've decided to use biscuits to joint the panels

http://www.simister.com/public/fh3/internal_biscuits.jpg

Unfortunately, I managed to break my 5/32" cutter whilst cutting one of the slots for the biscuits :steam: So I'm waiting for a replacement (actually, a five pack of replacements) to arrive off eBay

http://www.simister.com/public/fh3/internal_fit.jpg

So that's my progress so far.

[Reid Malenfant]

At least you have started Keith, I really want to get to work on my new speakers, but I have so much other stuff to do it's driving me nuts :eyebrows:

I think I need another 4 sheets of 2440 x 1220 x 18mm MDF, might need to make that 6 actually :scratch: Looks like I'll need to work it out & then get Wickes to deliver a load :)

Keep up the good work fella, hopefully the broken bit will inspire you to get a move on when the new ones arrive :D

[keiths]

Thanks Mark.

Actually, there's lots I can be doing before the bits arrive - I need to devise some sort of jig to route 5 degree bevels on the edges of some pieces and I need to make a jig to cut out the hole for the driver. Then there's the plates for the terminals and aluminium flat bar to shape, drill and tap for the feet - so the lack of router bits isn't really holding me up...

[aquapiranha]

Slow? I haven't even started mine yet and I have had the drivers for two weeks! that is what you call slow. I am using EL70's, what drivers will you be using in these?

Steve

[keiths]

Hi Steve - Mark Audio CHP70 MK1. I've had those drivers for over a month now :)

Cheers,
Keith.

[Reid Malenfant]

Don't feel too bad Keith, I have had some of my drivers I bought new for at least 3 years :doh:

Nice to hear you can do other stuff & you are not totally stuck :)

[Stratmangler]

Hi Steve - Mark Audio CHP70 MK1. I've had those drivers for over a month now :)

Cheers,
Keith.

Good choice :)

[sondale]

Thanks Mark.

Actually, there's lots I can be doing before the bits arrive - I need to devise some sort of jig to route 5 degree bevels on the edges of some pieces and I need to make a jig to cut out the hole for the driver. Then there's the plates for the terminals and aluminium flat bar to shape, drill and tap for the feet - so the lack of router bits isn't really holding me up...
Hi,

Try one of these for cutting rebate and holes for drivers, one of the best tools I ever bought. Being an American device it is in inches (1/16ths) and it accomodates American routers but I found it easy to use with a Bosch router. - just a minor adjustment to the base plate.

http://www.amazon.com/Jasper-200J-Circle-Cutting-Plunge/dp/B00009K77A

Alan

[aquapiranha]

Hi Alan. I remeber looking at those a couple of years ago but I was put off by reports of them cracking when tightening the screws that hold it onto the router. Do you know if this issue is resolved? Steve

[sondale]

Hi Alan. I remeber looking at those a couple of years ago but I was put off by reports of them cracking when tightening the screws that hold it onto the router. Do you know if this issue is resolved? Steve
Steve,

I have used this jig for well over 3 years and I have had no problems with cracking even though the jig has been removed/attached to the router many times. Having said that it will probably now crack the next time I use it!

I did not realise that there were any problems when I bought it.

Alan

[keiths]

Thanks Alan, though being a cheapskate, I will probably try and knock something functional up myself first.

[Martinh]

Hi Keith,

Looking good so far.

Is that Baltic Birch Ply or Birch ply or is that the same thing?

How are you planning to finish them?

Cheers,

Martin

[keiths]

Thanks Martin. All my local timber place had was 'birch ply' - I don't know if it is BBP or not. Still not decided on the finish, but at the moment I think they will be mostly painted but with veneer on the front of the baffle. I will need to include grilles as my dad has dementia and tends to 'poke and prod' at new things.

[keiths]

Was going OK today (but still waiting for router bits - I guess there's no post today?) until drizzle stopped play.

I knocked together a Heath-Robinson-approved jig for cutting 5 degree-ish bevels with the router:

http://www.simister.com/public/fh3/bevel_jig.jpg

Works pretty well! (Note: the horizontal piece in the photo - the top of the speaker - still needs sanding down to the pencil line)

http://www.simister.com/public/fh3/bevel.jpg

so time for a quick dry assembly check of the pieces done so far:

http://www.simister.com/public/fh3/taking_shape.jpg

[keiths]

Well, I'm not speeding up any, that's for sure :rolleyes:

Little progress since last week; I've had a pretty bad week culminating in my dad being taken into hospital in fairly unpleasant circumstances - so with hospital visiting etc. there's been little time for my project.

At least my router bits arrived, so I've been able to carry on cutting biscuit slots and I've managed to get a few more pieces cut to size and trimmed up, so time for another dry assembly:

http://www.simister.com/public/fh3/dry_1.jpg

http://www.simister.com/public/fh3/dry_2.jpg

Not too bad - everything more-or-less fits: a few post-glue-up corrections via the sander won't go amiss (plus a bit of filler here and there :doh: ). Let's hope I can get some more done this week.

[Martinh]

Well, I'm not speeding up any, that's for sure :rolleyes:

Little progress since last week; I've had a pretty bad week culminating in my dad being taken into hospital in fairly unpleasant circumstances - so with hospital visiting etc. there's been little time for my project.

At least my router bits arrived, so I've been able to carry on cutting biscuit slots and I've managed to get a few more pieces cut to size and trimmed up, so time for another dry assembly:


Not too bad - everything more-or-less fits: a few post-glue-up corrections via the sander won't go amiss (plus a bit of filler here and there :doh: ). Let's hope I can get some more done this week.

Shaping up nicely Kieth.

That side view reminds me of my old Royd Abotts or a dalek ;)

Martin

[Toppsy]

For inspiration to keiths and in good old Blue Peter fashion: here's a pair I built earlier for the Fostex FE126En driver though not my favourite of drivers in this design I might add. These are finished in Ash veneer over the bare ply.

http://www.lurcher.org/nick/colin/Fostex_FH_02.jpg

So get on finish them and enjoy ;)

[keiths]

They look great Colin. Mine will definately be painted - I do have some (ambrosia maple) veneer hanging around, but nowhere near enough to do the whole of the speakers, so I might just veneer the front of the baffles (or not - the last time I tried veneering, it didn't turn out great).

[Toppsy]

veneering the front baffle would be a good idea even though you are going for a painted finish. It will mask off the visible end grain of the ply which will need a lot of sanding to make a perfect painted finish.

Try using liquid contact adhesive to glue the veneer in place. Cut your veneer oversize and spread the glue evenly and thinly with a spatula to both faces. Place some thin material (say 2mm -3mm thick in say 75mm wide strips spaced apart on the ply front baffle and place the veneer over this. Once the veneer is centralised slip out the thin seperators one at a time and press home the veneer. Then trim back the veneer. Simples:eyebrows:

You then have a nice flat face to paint.

[keiths]

The end grain will be covered anyway because I'm adding a 6mm thick 'supra-baffle' to the front (full height, 176mm wide) as I'm not confident enough to router a 6mm rebate in the baffle to flush-mount the driver. Also, I'm worried that with the rebate cut in the 18mm thick baffle plus the 45 degree chamfer on the inside of the driver cut-out that I won't leave enough wood there to securely screw the drive unit to :scratch:

A quick question - I am right in thinking that the hole for the driver is cut so that the centre of the driver lines up with the top of the internal partition?

Cheers,
Keith

[Toppsy]

A quick question - I am right in thinking that the hole for the driver is cut so that the centre of the driver lines up with the top of the internal partition?

Correct.

[keiths]

Correct.

Thanks Colin :)

A short but reasonably productive session this evening -

I knocked together a couple of precision-engineered :eyebrows: hole-cutting jigs (one for the 102mm hole in the main baffle, the other for the 124mm cut out in my 6mm thick supra-baffle)

http://www.simister.com/public/fh3/hole_jig.jpg

and used the 51mm radius one to make a nice neat hole:

http://www.simister.com/public/fh3/hole.jpg

and then cut a 45 degree bevel on the inside:

http://www.simister.com/public/fh3/hole_bevel.jpg

I should be able to start glueing-up the first speaker tomorrow - I've only enough clamps to do one speaker at a time, so I can 'catch up' the other speaker (which still needs biscuit slots cutting, the baffle cutting to size and the hole cutting) whilst the glue is drying on the first speaker.

[keiths]

Let the glueing commence :)

http://www.simister.com/public/fh3/glue1.jpg

[keiths]

I'm using "Polyten" wood glue - same stuff I used to do my Lenco plinth. It starts to stick after 10 minutes, can be handled after 30 mins and is "stronger than the wood" after 2 hours. So after 3 hours I removed the clamps and glued the top, baffle and bottom

http://www.simister.com/public/fh3/glue2.jpg

I'll leave it clamped up overnight to make sure it's well stuck :)

[Reid Malenfant]

Coming together slowly but surely Keith, nice work fella :)

[keiths]

Cheers Mark. I'm enjoying doing it, so I might as well carry on taking my time.

[keiths]

Well, it all went quiet for a bit - visiting my dad in hospital plus a million and one other things to do...

Anyway, progress - damping glued around the driver and 'poly-fluff' damping added

http://www.simister.com/public/fh3/damping.jpg

and the side panel glued in place

http://www.simister.com/public/fh3/glue3.jpg

around this time, I thought I'd better spend less time taking photos and posting them here :doh: and more time actually building speakers - so...

FINISHED :)

[sorry about the terrible photos - not much light]

http://www.simister.com/public/fh3/finished_1.jpg

http://www.simister.com/public/fh3/finished_2.jpg

The finish on the baffles hasn't turned out great - I mght need to do something about that later on, but I can live with it for now.

The drive units have spent around 150 hours breaking in (connected them up in the cardboard box they were supplied in and played cds on repeat for 6+ days) before being fitted in the enclosures.

First impressions are very favourable indeed. They 'disappear' like no speaker I've owned before and image like a b*stard. Bass is tight and plentiful - but I will keep my REL Strata subwoofer in the system and use when the music demands it. The midrange is something else - Lizz Wright, k.d. lang, Diana Krall etc sound fantastic and the highs are sweet and extended (I've bought the bits to make the 'Frugel Super-Tweeters', but am not sure if I'll bother building those yet)

I've yet to play with fine positioning etc, but am delighted by what I hear so far - well worth the effort :)

[Spur07]

great work keith, you've become a dab hand with that router. :)

[keiths]

great work keith, you've become a dab hand with that router. :)

Thanks - I think that router is just about the best £25 I've ever spent

[Ali Tait]

Nice one. They are lovely speakers indeed.

[Stratmangler]

Excellent build Keith.
The Frugal Tweeters are worth the effort to build - they do things to the bottom end attack that make things sound more plausible, and bass seems to go lower as a result.

I find that my FH3s struggle a bit with Metallica sans FTs but cope wonderfully with the FTs doing their bit :eyebrows:

[falcoron]

Excellent build Keith.
The Frugal Tweeters are worth the effort to build - they do things to the bottom end attack that make things sound more plausible, and bass seems to go lower as a result.

I find that my FH3s struggle a bit with Metallica sans FTs but cope wonderfully with the FTs doing their bit :eyebrows:

any pictures of the tweeter?