Meade #882 Tripod locking cam the locking cam lever has broken off need to replace the cam.

-Providing that the image shown is the tripod you own..., the top leg lock levers on each leg is designed to lock the spreader angle of each leg.
-If this is not holding the leg at the correct angle...., either you are putting more weight on it than it was designed to hold..., or the 'cam' on the various locks has worn.
-A 'stop gap' fix for this problem is to insert a very thin wedge between the lever & the leg tube..., thus providing a greater amount of pressure on the tube, (this would need to be done every time the tripod is set up).
-Replacement parts are not available for this tripod & they were not designed to be user serviceable ...., sorry!!!
Peter

You might be able to drill a hole through the plastic knob and use a washer and a bolt to hold the screw tight. Or do something like this fix:

http://www.schlatter.org/Dad/Astronomy/etx90decknb.htm

Sometimes you can find these for sale at these web sites--

Sometimes--

http://shop.telescope-warehouse.com/

and here:
http://astronomy-mall.com/astro.parts.outlet/

You might try calling Meade directly:
http://www.meade.com/support/index.html

ONLY Meade would have parts. You can call them and see if they will sell the parts and or a new tripod.

http://www.meade.com/support/index.html

However you need to know that this is a "deal" scope sold by Meade in discount stores. It has a lot of PLASTIC everywhere and might be suitable for a child but is not very durable. Next time buy a 6 inch Dobsonian telescope for one that will last you for many many years of good service. Here is a picture of the DOB telescope, which is our #1 recommendation to beginners in the Astronomy hobby-

http://www.telescope.com/control/product/~category_id=classicdobs/~pcategory=dobsonians/~product_id=08942

Yes you can use a photo tripod-- also Meade may have a replacement. Call them here:

http://www.meade.com/support/index.html

You cannot. Except maybe at a well stocked hardware store, there might be something that would work. This is a VERY low cost refractor. Mostly made of plastic.

Contact Meade directly and see if they have a replacement tray.

http://www.meade.com/support/index.html

or build one to fit from a piece of wood or metal.

Contact Meade directly for any replacement parts. You might also find something at a well stocked hardware store that will also work.

http://www.meade.com/support/index.html

Try going to the Meade website home page, find your Tripod parts section and see if you can order a rplacement foot for it. It should be fairly cheap.
or try this link:
http://www.shopzilla.com/+Meade+plastic+foot+on+the+tripod+leg/search

Meade can probably sell you one :
http://www.meade.com/support/index.html

You might also find something that would work to tighten it at a well stocked hardware store.