Installing a Delay Line Cart on the Anorad Air Table

CP and JDM  -- Updated Sep 2000
Current NOTE: Not all jigs, spacers, and shims may not yet be properly labeled.

You will need the Anorad Jig and Spacer Tool Kit ($19.95) to install a delay line cart on Anorad air table.

Remove south end track components (HeNe interferometer block and spring).

Clean Granite Surface

First, secure air bearings to cast table using rubber bands and JIG-CP1 (for two smaller top pads) and JIG-ML2 (for large top pad). If you do this poorly, the roller bearing balls (.312" = 5/16" diameter when you need to order the replacements) will fall out.

Disconnect all tubes from table to outside world so as not to tangle them during installation.

Make sure to remove all pulldown magnets from the cast table, however it is fine if they are on the pulldown straps (with SHIMS hopefully!).

If you expect to have to adjust the position of the table with respect to the air bearings (you probably will), then you might as well loosen the locking screws which are easy to see when the cart is off the table.

Take out winding assembly from track, if it is still on the track.

Recap: At this point, the pull down magnets should be definitely OFF the cast table, but could be either 1) loose, to be planted later. or 2) already "planted" on the pulldown magnet bars (with SHIMS). We find the former (1) to be safer and less likely to lead to problems.

Lift the table carefully over the track, being careful not to bump the bearings (thus dropping roller bearing balls); this is much easier with two people, one on either side of the track.

Connect air and make sure the table can move more or less smoothly (one can not expect perfect operation without the pulldown forces of the magnets).

Move table out of the way, ~3 ft up the track.  You can turn off the air, if you want.

Prepare the motor assembly piece by removing the top panel, by unscrewing ~10 screws along the edge. These might be kind of tight, but are not glued in (anymore).

Now insert the motor assembly onto the track and ensure that it slides OK.  If a top magnet is already planted at the south end of the track, then one must first either a) remove it, re-planting later, or b) remove the central obstruction in the center of the motor assembly piece (which holds some cabling).  We have found it easier to just remove the magnet using JIG-CP2, as per the PLANTING procedure (described in a separate memo).

If the top pulldown magnets are not already planted, then plant them using JIG-CP2 on <=0.25"(white) shim.  Use the (still removed) top panel of the motor assembly as a guide for the placement in the longitudinal direction.  This can be done by laying the panel above the motor assembly and marking on the track (with a red pen) the approximate locations of the screw holes for the pull down magnets. The hole pattern is not symmetrical and so be sure to note the locations of all 3 rows of holes per magnet.  A good estimate of the final lateral displacement can be made by using the provided SPACER-1 (or SPACER-2) with 0.025" (white) shim, shoving the spacer and shim combination into the space between the pulldown magnet plate and the inner edge of track (space to the east of magnet), avoiding the bolt-heads.  This lateral spacing is critical later when the cast table is bolted onto the motor assembly, because there is A LOT of slop in those screws -- more on this later (keep the spacers+shims handy).

Once magnets are planted, use the (loose) top panel to make sure all the holes line up with the magnet tapped holes.

Reattach top plate to motor assembly, trying to keep it flush with side surface. Make screws TIGHT.

Line up motor assembly over the magnet.  Place any necessary shim on the top plate now (e.g., yellow+pink shims).

At this point you can plant all the side magnets (with shims) if you'd like. It could be done later too, but we found it convenient to estimate the locations and plant them at this stage.  When on (white 0.025") shims, the magnets can be slid around to line up with the table holes after the next steps.

(With air turned on) move the cast table over the magnets and motor assembly until the holes line up.

It is important here to USE the CORRECT SCREWS in the next step!
Unfortunately, this appropriate length is slightly different between the two tables. If the screw is too long, you will push the screw directly into the back of the magnet, which will either a) break the epoxy bonds and you will hear the magnet CLICK loudly onto the pulldown plate (will require complete backtrack and re-gluing : Krazy
Glue is recommended by Anorad), or b) crack the magnet (bad).

Slowly tighten these 12 screws above the North and South top magnets. You should use the above mentioned Spacer (1&2) and shim (0.25" white) along the inner edge while tightening to make sure the assembly plate
is in the (approximate) right relative location to cast table. This may be a tight fit and might call for some adjustment of the side (table) bearing screws. Remove spacers when done.

When fully tightened, the magnets should be lifted off the pulldown plates enough that you can slide out the shims.  If NOT, then you will have to lift them higher by raising the table on top of the air bearings. This is done with slight clockwise turns of the 3 large flathead screws on top of table (one above each air bearing). Recall
that there are locking screws (small allen wrench needed) under the table in a metal collar above each air bearing. Perhaps it is better to loosen these in step 1, when the table is off the track.

Now the cart should be able to move along track.  Adjust height so that motor assembly slides ok without scraping or binding inside U-shaped magnet channel. Use long thing strips of brown (0.010") shim to check clearance above and below the motor (see separate memo: How to adjust table orientation for optimal air table
operation - Not available yet).

Maneuver table and slide the side magnets around until you can pick these magnets up too. Again:
USE the CORRECT LENGTH SCREWS !! See note a few steps back.

When the magnets are fully pulled up, the shims should fall out. Do this for all 4 side magnets. Note that this can be a bit of a pain since the hole alignment must be quite close and the magnets are bit hard to push around on the pull down plate.

You are done with the installation, but you must now adjust the height and orientation for smooth operation -- This we haven't quite figure out yet.

Estimated time if all goes smoothly: 1.5 hr
Estimated time when it doesn't go smoothly: 4 hrs

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