Need to design an adjustable height altar

[Cliff Polubinsky]

I need to come up with a design for an altar that can be adjusted so that it can be used by a presider standing or in a wheel chair. Most likely a square rather than a rectangle, but that part isn't set in stone. For esthetic reasons I'd prefer to stay away from metal legs. And I'd prefer that the height adjustment mechanism not be obvious. In other words I'd like the altar at either height to look as if it was designed to be that height, rather than something that was obviously compromised to adapt.

The design has to make it past the Archbishop who not only is a Liturgist (the only difference between a Liturgist and a terrorist is you can negotiate with a terrorist http://www.forums.woodnet.net/ubbthreads/images/graemlins/yellowlaugh.gif) but has a degree in Architectural art.

Has anyone seen anything that might give me a starting point?

Thanks for any suggestions.

Cliff

[Neil Bosdet]

What would the height of the alter be at the 2 extremes?

[Marc Myers]

This might seem a bit silly, but the first thing that came to mind when you mentioned 'adjustable height' and 'height mechanism not obvious' was something Norm did in the New Yankee Workshop. Remember the 'Shop Helpers' episode with the rolling cart, benchtop tool stand, and roller table? If you took the theory for the adjustable height on the roller table and applied it to your piece, I think you would get exactly where you need to go. It was a crank setup with some threaded rod and what pretty much was one box sliding inside another as the height moved up and down. If you did a design similiar to that, obviously puffed it up quite a bit from simple plywood that he used for the shop, I'd bet it would work out great! The legs would look good no matter where you set them for mass and the crank mechanism would be hidden in the top where no one could see. You're not reinventing the wheel, just reapplying the theory behind it. I'd love to see a picture when you're done!

[Neil Bosdet]

This might seem a bit silly, but the first thing that came to mind when you mentioned 'adjustable height' and 'height mechanism not obvious' was something Norm did in the New Yankee Workshop. Remember the 'Shop Helpers' episode with the rolling cart, benchtop tool stand, and roller table? If you took the theory for the adjustable height on the roller table and applied it to your piece, I think you would get exactly where you need to go. It was a crank setup with some threaded rod and what pretty much was one box sliding inside another as the height moved up and down. If you did a design similiar to that, obviously puffed it up quite a bit from simple plywood that he used for the shop, I'd bet it would work out great! The legs would look good no matter where you set them for mass and the crank mechanism would be hidden in the top where no one could see. You're not reinventing the wheel, just reapplying the theory behind it. I'd love to see a picture when you're done!

That's kinda what I was thinking too. I haven't seen the Yankee workshop with this table, I just thought of it and I was thinking to use a hydraulic lift inside. That's why I was asking about the extremes of height. A crank up would allow more height adjustment but the hydraulic would be easy for anyone to use including someone in a wheelchair.

[Cliff Polubinsky]

Neil,

At the lower position we'd need 30" - 31" clear under the top. That would give clearance for someone sitting in a motorized chair. At the upper position the top would be around 36". So if I figure 2" or so thickness for the top/stretchers, a 3"-4" change should cover it.

I haven't seen the NYW episode you mention. The woodworking shows are on Saturday mornings here and I'm in the shop then rather than watching TV.

Cliff

[Jim Neeley]

I started thinking of the 120V motorized TV lifts like they have at Woodworkers Supply (amongst other places) but they're pretty pricy and would give you far more lift than you need... from 10" to about 30".

[Marc Myers]

http://www.newyankee.com/getproduct.php?0603

Here's a link to the NYW page of the episode I'm referring to. Look at the bottom right and there is a video clip you can play. The info is there as always to buy the DVD and measured drawings if you choose.

[Russell Sansom]

ALTER doesn't bring up a specific picture for me. Is it a 3-sided box with a top or a table with legs and a top? I assume the top is tilted towards the speaker, or is it flat?

[Charlie Barnes]

Cliff,

I had the honor of building an altar and ambo (pulpit) for our new church about 2 years ago. Fortunately, I only had to make the ambo wheel chair accessible and not the altar. I ended up using essentially a larger "box" over a smaller "box". It has a 12" range of motion and is controlled by a DC linear actuator. The relationship between the two "boxes" is controlled by 4 wooden sliding dovetail drawer slides. I went through 2 actuators before I found one that was quiet enough for my requirements.

While this doesn't apply in your case, many churches that I benchmarked simply use a 2 part design with the smaller top part being removable. I didn't want to go that route because I think that would require the speaker (in a wheel chair) to obtain assistance in converting the ambo. I've never been in a wheel chair, but I don't think I would want anybody to help me in that way if I was. In about a year and a half of use, we've really only used the height adjustment to accommodate children's masses for the school where they are doing the readings. It sure beats them getting up on the old rickety step stool they used to use in our old church! Anyway, my point is to consider how the mechanism will be actuated and to make it easy for a person in a wheel chair to manage it if at all possible.

If you go with a system similar to what I have described, I would highly recommend using DC electric actuators vs. hydraulic. It’s much more simple and cleaner.

Your comment about getting the design approved brought a smile. I had to face a 3 person “Arts and Environment” committee at the Archdiocese. Two were priests (and OK to deal with). The third was an outside hired consultant who apparently didn’t feel she was earning her money unless she rejected all of my ideas at least 3 times! I think I spent more time debating the design with them than I did building the altar and ambo in the first place.

But, the most important advice I can give though is to enjoy the process. It was likely a once in a lifetime experience for me and I’ll never forget it. Sorry for the long post.

Charlie

[Andrew Pitonyak]

Disclaimer: Anything that I design is likely to fall apart just thinking about using it

You do not mention how often this will be adjusted or how many people will be around to help adjust it, or, how much money you can spend on a fancy mechanism. That said, how about something very simple.

In my mind, I envision a few different variations on this, consider this simple visualization.

Place a box on the floor so that the opening is down. Now, place another box on top of that box. You have a specific height.

Pull the top box off, place a spacer (similar to say four leg posts) on top of the first box and place the second box on top again. This time, the second box is higher.

This type of solution is easily adaptable for many types of altars (fully covered so that you cannot see through it, and also closer to a dinner table with a top and legs). The important items in this design is that it is an inexpensive mechanism, but, it would probably require multiple people to change the height. On the other hand, changing the height is probably pretty fast (depending on what you design). This could be as simple as spacers that are similar to say a 4x4 attached with a hinge so that it can fold down out of the way and allow the top to drop. This does not provide significant flexibility in adjustments, but....

Another similar idea is that the top portion has legs that drop into a base. The base provides a method for you to insert stop blocks to prevent the base from dropping.

Certainly something similar to say a car jack may be easier to raise and lower, but, it is not clear to me where the jack is placed? Would need to be in the center if it were to raise everything at one point.

I am sure that you hvae seen the adjustable wood workers work bench.... looks nice. Has an adjustment on each side.

[Tom Grant]

+1 on the linear actuator. I'd go for an AC one though.

I bought two very cool electric drafting tables last year that work like that. They are very stable and use a quiet 20" linear actuator. The actuators themselves are worth more than the $100 I paid for the tables. Tables like this are still sold new for $2k to $5k.
http://www.draftingsuppliesdew.com/images/Mayline/8698B.jpg

I love Charlie's example! One potential design enhancement would be to make it with three visible side sections: upper, lower and then an outer decorative cover that was kept centered over the gap between the other two sections.

Sideways example:

|.----.|
|===.==|
|===.==|
|.----.|

|..----..|
|===...==|
|===...==|
|..----..|

rather than:


|----....|
|...=====|
|...=====|
|----....|


Hanging the outer cover via a pulley between the other two sections would keep it centered.

[Cliff Polubinsky]

Russel,

Try Altar, not Alter. As in the table used in Eucharistic liturgy. It can take many forms but the table is always flat (you don't want the chalice sliding off onto the floor :eek: ;)).

Cliff

[Neil Bosdet]

Charlie, that's terrific. It's exactly what I was envisioning for Cliff.