BT mobile base - materials

[poolhound]

I am close to completing my design concept for my BT mobile base and am mulling materials. As usual its the dillema of what do I have on hand vs buying a bunch of new materials.

My base will be ~5' long and will have a 4" high torsion box at its base with a number of case modules built on top of it. I have a variety of sheet goods on hand although a lot of it is 5/8 rather than 3/4.

I guess I am thinking "out loud" here trying to figure out what my best solutions are. In a perfect world I would go by a bunch of new 3/4" ply but dont necessarily want to pay for it I have....

A good amount of 5/8" MDF in lengths up to 8'
approx 2 sheets worth of 1/2" MDF lengths up to 8'
about a sheet and a half of 3/4" mdf but largest piece is 4'x4'
a sheet of 5/8" maple ply
enough 3/4" quality laminated particle board to make frame of torsion box.

I also do have some good quality 3/4" veneered (maple and Oak) MDF but its rather too good for this project methinks...

So, given that I dont really want to go and throw a bunch of cash into new materials (need to pay for a woodpecker router lift) what do I use for the materials for my base???? MDF vs. Ply, 5/8 vs. 3/4"

Always happy to hear what you guys think.

Yours - Puzzled of Phoenix (scratching head in woodshop)

[RayintheUK]

You could make the torsion box from ⅝" with ½" ribs. If that part is well-made and rigid, then providing that the boxes that sit on it are also plumb and square, then ½" or ⅝" should suffice.

I made mine totally out of ¾" MDF, edged with oak, but then I always did tend towards over-engineering!

If you haven't seen the WIP pictures, they're here.

Ray.

[Uncle Cracker]

Here's one way to look at it: You probably have enough material to do the deal, and if you have a clever design and good workmanship, then every time you see that BT riding proud on your stand, you will be able to take pride in your ingenuity, and the fact that you used what you had on hand, without any serious outlay of new dollars for materials.
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The flip side of the coin is that, if you blow it, every time you see your poor BT lying amid that pile of rubble, you'll be reminded of how you should've probably spent more time designing, and more money getting the right materials...

God, I love decisions like this...

[poolhound]

You could make the torsion box from ⅝" with ½" ribs. If that part is well-made and rigid, then providing that the boxes that sit on it are also plumb and square, then ½" or ⅝" should suffice.

I made mine totally out of ¾" MDF, edged with oak, but then I always did tend towards over-engineering!

If you haven't seen the WIP pictures, they're here.

Ray.

Thanks Ray, I have already spent some time studying your design especially as yours uses nearly all MDF. with 3/4" throughout that beast must weigh a ton!!

[poolhound]

The flip side of the coin is that, if you blow it, every time you see your poor BT lying amid that pile of rubble, you'll be reminded of how you should've probably spent more time designing, and more money getting the right materials...

God, I love decisions like this...

Hey Uncle C you must be reading my mind. I hope that what I design and build wont end up a pile of rubble but I do want to ensure that the end product has the strength, integrity and asthetic required.

As Ray points out I figured that a combination of the 5/8 and 1/2 MDF should make a plenty strong torsion box. Once I get a first idea of a cutlist I can see what else makes sense.

[tribalwind]

what ever happened to the page with all the various mobile bases people made?
used to be linked from the old homepage

[poolhound]

what ever happened to the page with all the various mobile bases people made?
used to be linked from the old homepage

here it is

http://www.bt3central.com/index.php?page=articles

[Garasaki]

I think using different thickness materials throughout would be enough to drive me crazy.

Your brain will thank you if you try to settle one particular thickness IMO.

The torsion box might be a good exception though.

[tribalwind]

ah!
thanks'

[rcp612]

I made mine totally out of ¾" MDF, edged with oak, but then I always did tend towards over-engineering! Ray.

I followed Ray's plans to the letter (almost) and, yes!!, do get heavy duty casters for it. You will never move it without them.
That much MDF is very, very heavy but, totally eliminates vibration and/or BT3 alignment problems.

[Tom Miller]

I bet you could get by with 1/2" mdf for the sides and back IF you beefed up all edges with ~1.5" wide strips of 1/2" or 3/4" mdf. That would give you 1" or 1.25" of contact at the joints. Picture butt joints with 3/4" mdf glue blocks.

Regards,
Tom

[poolhound]

Well I broke down and today bought 2 sheets of 3/4" maple ply. I got it from the same guy thats in the process of closing down his WW biz that both Carlos and I got a bunch of stuff from a couple of weeks back. $35/sheet, not gloatworthy but a good price, about half what I would pay if I got it new.

I still intend to make the torsion box from the 5/8 and 1/2" MDF and may use some of the 5/8 ply for drawers and/or drawer fronts.