Need to replace carry strap that uses metric hardware
 

I'm the new owner of a 2004-vintage Fender Rumble 100. I got it cheap, because it was absent casters and carry handle.

Casters were easy.

The handle's turning out not to be. Looks like Fender chose to use very unusual hardware sizes. The screws holding in the electronics use the same thread, but shorter.

At first, I thought they were 8-32 because they thread into an 8-32 nut, but loosely. I got some 8-32 screws, and they won't thread into the nut-serts on the amp chassis. What metric thread is close to 8-32 (the electronics assembly says Made in Japan, so metric was likely anyway)? Ah, M-something-0.8. 0.8 mm per thread is 31.75 threads per inch, clearly close to the 8-32's 32 threads per inch. But the OEM screws are smaller diameter. M5-0.8 is standard, but WAY too big in diamer. M4-0.8 is not standard. M4-0.7 is, but that's the wrong thread. I have found evidence that M4.5-0.8 does exist but as rare as the proverbial hen's teeth.

So, it seems Fender used a unique size here. Were I to guess, I'd say they were M4.5-0.8 X 35mm, and they are indeed black oval-head phillips screws.

I called Fender, they said all parts should be acquired through authorized Fender service facilities. I called several said facilities and they said they won't deal in such small items (I don't blame them.).

Has anybody found a source for these ellusive screws?

Or, what do you think of my two backup plans:

a) Trust luck and try to re-thread the nut-serts to 8-32 and use standard 8-32 oval head screws

or

b) The heck wtih the top carry strap, it's silly on a 60 pound bass amp anyway, cut holes in the sides and install two side-carry handles. And hope a band-mate will hellp.

Thanks,

El Clumso

It looks like a normal black strap handle. T-nuts? Should be easy to replace.

Handles are easy. Put one of these on each end (or similar handles that lock the handle at 90 degrees). No need to cut holes. Much better than a strap handle and makes it easier to carry. Mount with 1-inch #10 screws....job is done in 5 minutes.

Trying to carry a 60-pound combo amp with a top-mounted strap handle is ridiculous. Add the trunk handles and it's much easier to tote.



Here are some chrome ones at under $5 each:
http://www.mcmelectronics.com/produc...FexaMgodhD4Ajg



Or Google for "speaker handles surface mount".

These black colored handles on Ebay are perfect: http://www.ebay.com/itm/Speaker-cabi...item5d3a314e0a

Hi.

^This.

You can choose whatever thread You want (/they sell ;)).

A little bit of OT, but I just hate when manufacturers use odd threaded fasteners.
The British pitch based system ("cycle thread"?) for example is easy to understand from a manufacturing POV, a single roller die spits out most of the needed studs and bolts of any dia, but if one needs an replacement, turning the stud/bolt (or fabricating a tap) is the only option if NOS fasteners can't be found.

Edit: If You choose a type of handle Pilgrim there suggested, do Yourself a favour and make sure that it's spring loaded ;).

Regards
Sam

60 lbs. Missed that. Poor old strap handle just couldn't take it. I have a 60 lb cab that has recessed side handles. I use them to heft it into the back of the Mini but tote it with one of those folding hand truck things. Mine was about $35 from the local home store.

Thanks Sam for posting this edit. Now I don't have to! :D

The handle is ordinary, but no Tee Nuts
 

The amplifier chassis in this one mounts "inverted"...the baseplate is the top plate, and is pressed fully up against the top piece of particleboard. This aluminum chassis has PEM nuts (nutserts) pressed into it. I suppose I could blast out those PEM nuts, enlarge the holes and make clearance for T nuts.

How do you get a T nut fully inserted into particle board when there's no room to swing a hammer? I've struggled with that.

I'm liking the side handles more and more.

Clums

That's the other option for me. I use one of those to tote keyboard and its stand already. The Rumble's casters are too far apart for the cart, but they're easily removed.

C

Every hardware store I know of sells metric bolts.

Hi.

:D, no problem.

The drummer in my last band decided to buy the handles for a few cases we made and to put it mildly, he's a cheapskate. Too narrow (3 finger) and without a spring :scowl:.

They looked almost exactly like that black one up there.

The rattle annoyed even him.

Regards
Sam

Yes - but just as there's at least 2 flavors of "SAE" fasteners (UN-C and UN-F) there are usually two - and sometimes three - different pitches available for metric.

You can almost always find the 'more standard' stuff, but if you need one of the alternate pitches - it can be tough.

I looked through the offerings at my 3 favorite suppliers - McMaster-Carr, Maryland Metric, and - a third one I have bookmarked but can never remember...

McMaster-Carr didn't show the M4-0.8 the OP wants. Maryland Metric shows it but I couldn't find the actual product - their catalog/web page is a bit arcane...

But not an M4.5-0.8. They're very rare.

Got an answer from Fender
 

I got through to "consumer relations" at Fender. Here's the scoop.

Their low-end amps are generally made in Indonesia. Fender retains fairly tight control over the things that create the sound...they specify the speakers, they approve the design of the amp (they don't generally do the design themselves), and such. They require the electronics to be built with parts that are generally obtainable through US distribution, and Fender will stock replacement parts for the amp itself, speakers, pots, knobs, etc. However, the Indonesian manufacturer is free to use locally-sourced woods and cabinet hardware, as long as the final appearance is to Fender's satisfaction.

He said the screws in question are likely to be M4.5-0.8X35mm because they've seen those coming in Indonesian-made amps, but they have never found a domestic source for them. He sugggested switching to side handles.

C

If you must pursue it, skip the hardware store. Even here in a country town like Ballarat we have an establishment that specialises in 'bolts & fasteners'. They stock every conceivable odd size of nuts-n-bolts or can locate it if needed. I haven't failed yet to find replacements from there for some mysterious looking missing bits I've needed.

Peter

I'm actually pretty connected with industrial hardware suppliers because of my job in microelectrnoics. What they all told me is that in an M4 or M4.5 size, it would be very weird to have a 0.8 thread pitch because that is coarser than standard. Normally, an odd thread pitch is finer than standard, not coarser.

One guy guessed that this is an Indonesian attempt to make 8-32 threads that missed the mark a bit!

C

That or it's from a really, really worn die that started out at 4,0mm ...

but as for installing Tee nuts - I think the hot setup would be not to hammer them in from the inside, but to pull them through from the outside by threading a nut and washer onto a long machine screw and then screwing it into the Tee nut. As you tighten the nut down, it will pull the Tee nut into its recess. Just a thought...

How about a bolt/nut with washers on both sides and tighten it up?

I've done that with plywood, but in a small size like 8-32 into particleboard (aka glue with some wood chips), I break the bolt before the tee nut is seated. But it's worth the risk- if the tee nut isn't seated, I can bang it back out.

I was going to say faghedaboudit but you made me think it through better and there's a chance it'll work.

However, I did order some black flush-mount side handles, spring-loaded with rubber cushions (so they won't rattle) from PartsExpress. Made by www.pennfabrication.com - cool company, never heard of them, whoever suggested them they have KILLER stuff for road cases.

Thanks

C