Rotating Chassis Vise

[bnwitt]

Ok, so I've always been dissapointed with my amp cradle cause it is about as low tech as it gets and I hardly ever use it cause it doesn't hold a chassis in a postion where you can work on it.  I've been searching for a better deal for quite some time now and I found something in an old eBay listing that fits the bill.  Unfortunately, both the seller and the buyer have no idea who made the darn thing.  I have done all of the sherlock holmes digging I can and have come up with nada.  Panavise has nothing like it nor does any other company I've been able to find.  So this forum is my last hope.  Anyone recognize this contraption?

[bnwitt]

another view

[EL34]

No help here but that is a pretty cool looking amp cradle.

[bnwitt]

No help here but that is a pretty cool looking amp cradle.

yeah and it rotates 360 degrees.  gives me a chubby! ;D

[Ty]

just a stupid thought but it kinda reminds me of a lathe(sp)? you kno... the thing that holds a piece of wood that youd rotate as you carve it up. a speciallty wood working place may have somthing similar for hobbiests.... idk if you have a rocklers near you. hmmm


Ty

[bnwitt]

just a stupid thought but it kinda reminds me of a lathe(sp)? you kno... the thing that holds a piece of wood that youd rotate as you carve it up. a speciallty wood working place may have somthing similar for hobbiests.... idk if you have a rocklers near you. hmmm


Ty

Ty,
 I've been searching the internet on woodworking, machining and every kind of industrial site for the last three months and not found anything similar.  Let me know if you do.

[d1camero]

I wonder if a bench bicycle stand could be adapted:


http://www.parktool.com/products/detail.asp?cat=23&item=PCS%2D12

[PRR]

Savvy piano technicians have a similar contraption to hold an entire 88-key keyframe at odd angles. The one I saw was about a third as nice as this one. It didn't have bars down the length, it used the keyframe to keep it from falling over. The clamps were crude. And "yours" seems to have micro-adjustable screws to set the chassis angle (and so it doesn't get away from you when you loosen the rotation locks) instead of a crude clamp.

If you are into cars: think how you port-and-polish a cylinder head. OK, you jam it between your knees and a stump, propped with a whiskey bottle to hold the angle, and push the grinder until it slips and goes through your thigh. Well, if you got your act together you would have an adjustable bracket like this. The one in the picture is too lightweight and too precise to do a cast-iron GMC Six head, but might be the ticket for a little Honda Civic alloy blocktopper.

I'm sure it was adapted from some other use. Tool-and-Die-Maker bench support. D'oh, that's probably it. The clamps and width-adjustment would fit a wide range of typical casting/forging/molding dies, which have to be hand-detailed at odd angles. Maybe angles so odd and critical that the micro-adjusters are essential.

[PRR]

You could, in concept, just screw a plywood circle on each end, with circle-center on the amp's center of gravity (CG), and it would set at any angle and protect the tubes.

Of course it won't, but you don't need infinite angles. An octagon (square with corners hacked off) would give you the basic positions, and be fairly stable.

For classic Fenders which hang on 4 bolts, you could screw 3/4"x3/4" angle-metal to the plywood octagons, and run the case-screws through chassis and angle to hold it together.

Run a rope from a ceiling hook almost to the floor and back. Take a Fender chassis, stand it on end, set the power transformer in your rope so it hangs. Move the PT back and forth in the rope until the chassis hangs dead vertical. The rope is now on the amp's vertical center of gravity. Measure distance from rope to the top of the amp, the surface which kisses the cabinet top board. Try every Fender in the shop: a Champ will have its weight a bit lower than a Super Twin, but maybe not a huge distance.

Set the amp tubes-up on the bench. Slip a dowel under it lengthwise. Balance the amp on the dowel. This finds the front-back CG. Measure it relative to the mounting holes.

(You could get both measurements at once. Drive a big nail in the floor. Hold the amp vertical and balance it on the nail. When it is equally unstable in all directions, the place the nail hits is the CG you want.)

From that point, measure the circle needed to clear the tubes and other protrusions.

Draw that circle on plywood, draw a square around it, use a 45 degree triangle to get diagonals which touch the circle. Cut the octagon.

Measure off the distance from CG (circle center) to mounting surface. Mount the angle-metal there. Measure the distance from CG to mounting holes. Remember the two sides are mirror images. Drill.

Now how do you put it on? I guess you set the amp tubes-up on a stump. Hold an octagon to the end and run the mounting bolts through. Once you got the octs on, it should sit on the bench at 8 different angles. And it cost like two bucks.

[PRR]

> piano technicians have a similar contraption...

Idiot. Not a keyframe, an action. And they call it an Action Cradle. Costs in the area of $230; I did not shop around.

http://www.mypianoshop.com/store/product.php?productid=16406



I believe the legs are plain electrical conduit. You can cut and couple various heights and lengths for a couple bucks (if you own a conduit hickey, or buy Ells). The ends slide in and out a couple inches, so one set of legs might cover 19" to 23" chassis. It can handle a little off-balance, such as wood hammers and pushrods; I dunno how it would handle 17 pound transformers several inches off axis.

[gehicks]

PRR.

I grew up in Mississippi where my dad owned an auto parts store.

The scenario you so delicately described was the first 17 years of my life.

Ok, I didn't use Jack Daniels for lubricant until I was 6 or 7 but hey, we ported a LOT of camel hump heads that way!   ;D

Cheers,

Jerry

[sluckey]

Take a look...

http://chassi-swing.com/main/

...Steve

[bnwitt]

Take a look...

http://chassi-swing.com/main/

...Steve

I wish people would quit showing me stuff that's no longer available. >:(

[phsyconoodler]

Weber sells them now.i have one but I could have made one.
  Here's another one I think has not been built yet.

[sluckey]

"I wish people would quit showing me stuff that's no longer available."

Sorry. Thought it might give you some ideas.

...Steve

[Lucid_Alice]

Looks like it would be easy enough to build something along the lines of the examples given. But it's pretty clear that the market won't stand for the price needed to make them by hand and turn a profit. The volume would be too low for a manufacturing operation. Probably why you can't find one to buy.

[pabloxyz]

try this:

ftp://https://amptechtools.powweb.com/cradle.htm

evidently that link does not work. Anyhow, go to webervst.com/  then click on "amp tech tools" then "amp cradles".

hope this helps.
p

[bnwitt]

"I wish people would quit showing me stuff that's no longer available."

Sorry. Thought it might give you some ideas.

...Steve

Sluckey,
 I'm just kidding.  you'll get used to my strange sense of humor eventually.  I am misunderstood often.  If fact, your pic did give me some ideas for sure.  I might just have to build that.

[HotBluePlates]

Yeah, I was looking at that chassis cradle and thinking any master carpenter can slap one of those together for you. Whether you'd want to pay him to do it is another matter....

[bluesbear]

"any master carpenter can slap one of those together for you. Whether you'd want to pay him to do it is another matter...."

I think any basement tinkerer could slap it together. It might not be pretty but looks are not of the essence here. No way the wood and hardware would cost over $50 for something servicable.
Dave

[tbeck]

I can't imagine it costing more than 20 bucks for the hardware if you already have some plywood sitting around, wouldn't take much plywood.  Do you save the circles when you cut a baffle for a 12 inch speaker?  There's your end pieces.  Look at the clamps on that last picture, basicly angle iron, aluminum would do, and a strap with long enough bolts to clamp the ends of the chassis.  You could bolt a Fender chassis right to the angle iron.  I haven't figured out the swivel clamp yet, but I'm working on it.  I'm thinking that a DIY hardware kit with plans would be a lot cheaper than a prebuilt cradle.  It don't have to be pretty, it just has to work.

[bnwitt]

Well in fact I have a DST cradle sitting around I could probably modify so that will save me some time.

[malt]

Hi , found this old post again the pix are gone but it was this post that inspired me to build this chassis swing or cradle . Made it at work out of alu and ss + some parts from an office chair.