The ones available at the pet stores have several disadvantages: They are usually too short, have too small diameters and an annoying platform which doesn't allow 'full speed' upward.
This design allows you to make a scratching post from floor to ceiling, in whatever length your cat prefer, and it's also very stable and doesn't require any holes or screws to fasten. It is also possible to re-wrap the Sisal rope in the future.
The relaxing platform and staircase described at the last step are optional.
Step 1: What you need.
* Sisal rope, diam. 8 mm, approx. 47 meter for each meter of the pipe length.
For example: A diam. 110 pipe with length 2.5 m will need 117.5 m.
Sisal rope can be quite expensive, so check out where you can buy it cheap.
An affordable supplier is http://www.ropesandtwines.com (delivers worldwide).
(See below in comments section for the formula used for exact calculation).
* Tee nuts, M8, 4 pcs.
* Hexagon head bolts, M8, length approx 50 mm. , 4 pcs.
* U-bolts, 2 pcs.
* Fake MDF wood tiles. (Or a similar hard surface material).
* Cork gasket sheet, thickness 3 mm.
* Wood screws.
* Ordinary hand tools.
* And the most important: One helpful and curious cat
Step 2: Make upper and lower plugs.
Start making the upper and lower base plugs by forming 45 mm thick wooden pieces equal to the PVC pipe inner diameter. Two grooves for the rope and U-bolt is needed lengthwise.
Create 3 circular discs of MDF fake floor tile (or equal hard surface material). Diam 150 mm.
Connect the plugs and discs with some wood screws to create 2 units.
One of the plug units should be equipped with 4 tee nuts and 4 bolts, acting as spanners. Drill holes through the plate and plugs. Punch them into place with a hammer.
The third MDF disc is used under the spanner bolts.
Cut out two circular cork discs. Thickness 3 mm, diam. 150. They are needed for surface protection, anti-slipping and compression.
Measure the distance between roof and ceiling.
Find out the thickness of the upper and lower plates, bolt heads, gaskets and also a 5 mm mounting clearance, and you will have the needed pipe length.
Important: Measure again! Think again!
Cut the pipe.
Step 3: Preassembly.
The assembly order counted from the floor should be:
- Cork disc.
- Protection MDF disc.
- Spanner plug unit.
- PVC pipe.
- Upper plug unit.
- Cork disc.
Put the soon-to-be scratching post in position using a level to get it vertical. Mark the upper and lower positions with some masking tape at the floor and ceiling.
Turn the 4 spanner screws at the lower plug unit counter-clockwise and the pipe should start pressing between floor and ceiling. Tighten the spanner screws until the post is securely fastened.
When satisfied... remove it all and mentally prepare for a couple of hours wrapping more than 100 meters of rope. A nice cold beer will help.
Step 4: Sisal wrapping.
Drill two small holes opposite of the cut-outs for the U-bolt. Position the U-bolt to allow one turn of the rope without any gap.
Put a knot at the rope, inside the tube, close to the plug. Guide the rope through the cut-out. Mount the nuts on the U-bolt and tighten the rope. Press the plug and start wrapping the rope from the floor plug unit and up.
Pull the rope hard when wrapping, and after some turns hammer the turns together. A pair of gloves and someone to help you guiding the rope is necessary . When you need a break, secure the rope with packaging tape.
Wrapping long lengths of rope is much more difficult than it sounds. It will twist, turn, tangle and be a complete mess if not handled correctly. Plan your wrapping!.
When the whole pipe is wrapped, tighten the rope with the U-bolt at the top, cut the rope (give it 2 extra meters for some re-wrapping in the future). Put the upper plug unit in position.
Step 5: Final assembly.
Great success! Full speed ahead!
(Continue to the next step, if your cat also demands some extra options).
Step 6: Optional relaxing platform and staircase.
Start out with a simple prototype made of cardboard. A distance of 150 mm between the platform and climbing post seems perfect... enough clearance for a climbing cat, and not to far away for him to reach.
Decide the dimensions of the platform. Suggestion: Length = 600 mm and width = 300 mm, that should be enough for a full grown cat laying down.
Cut out a base plate in a wooden plate. Create chamfers on one side.
By using triangular profile wooden pieces, create a safety edge. Trim the edges to correct length.
Cut out a soft sheet for the cat to rest on. For example, use a car heat insulation sheet with aluminum foil.
Wrap a soft cloth around the platform and fasten it on the underside by a industrial stapler.
Use some sort of nice looking wooden plate on the underside to cover up the cloth edges. ( I used a fake MDF oak wood tile). Countersink the screws.
Two purchased wall shelf brackets/consoles will complete the platform.
To make it easier for the cat to come down from the platform, mount two extra shelves to the wall, and they will act as a staircase. Suggested plate dimensions: Length = 450 mm and width = 170 mm. A distance of 450 mm between each step seems suitable for a young cat.
I later found out that a hard surface sometimes can be a little to slippery for the cats if they have a high speed, i.e. chasing each other. It can be a good idea to cover the stairchase plate with some non-slippery material.
Step 7: Updates
2011 - After 1.5 years and 30 times a day heavy cat use:
Well, after 1.5 years and one more cat, the rope started to slack a little. This was expected and easy to fix. Just remove the U-bolt and compress all the turns from top to bottom and add some of the extra rope hidden inside the tube. 3-4 more turns was enough. Therefor I suggest that mostly of the spare rope is available to add from the top, but also allow some to be added from the bottom if needed.
At the same time I rotated the pole 1/4 of a turn due to some cat-claw-wear. After 1.5 year and two cats, the wear is almost not visible and I think the rope will go for another 8 years. Could it be that a 10 mm rope will wear less? Maybee user DreamingSheep can give some feedback later on about the wear for a 10 mm rope?
We also moved to another appartment which had a 25 mm higher ceiling. I solved this (very quick-and-dirty) by adding a piece of wood between the two upper disc. (Not very beautiful, but works without any problems).
2013 - Another move:
Moved to an old house with a 150 mm lower ceiling. Had to cut off the PVC pipe, make new holes for the U-bolt, rewrap and tightening the upper part of the rope. Put the extra rope lenght into the pipe.
2015 - Rope status:
Still no major wear to the rope. Will do for a couple of more years.