That is brilliant and relatively cheap.

That looks a LOT like the Mianne Lift Gate!  The design looks identical, right down to the cable routing to actually operate the gate!  You even appear to be using the same winch set, though I ditched the yellow control for dual switches in the layout fascia so I can operate it from either side.

One of the big take aways from this project is the stability that Arctic (or Northern or Russian) Birch brings to any form of  bench work construction.

Dan,  Your design and workmanship are exceptional.  I am looking forward to additional  photos of your layout construction.

Yep, it's amazing how polished that lift gate looks, a very professional job!

Thank you guys! I appreciate it.

Tom and Gunrunnerjohn, I've learned from the experiences posted by you guys and have great regard for you both. I was tickled it worked out for the most part the first go around. I get to meld two of my hobbies, the other being woodworking. This is a few simple, square tables and no finishing work. Right in my wheel house. I pretty much did all of the milling with a table saw, tenoning jig, and hollow chisel mortising machine.

This is absolutely based on Mianne lift. I have great respect for that product and the price he can offer it for. It is very reasonably priced, imho. And you have support if you need it.

It took me the better part of 10 days to glue up legs, mill parts, and assemble, so I have a lot of sweat equity in this. It is a simple straight forward design, also used in cabinetry for tv lifts, etc.

I support DIY efforts when I can, I'm happy to share where I sourced parts. It may be possible to find better suited parts and get the price down.

The hoist is from flea bay. It is a light duty engine hoist. Besides being light duty rated it also has a decent rate, 26 feet per minute without a sheave, so it goes up and down at a reasonable rate.

In my internet searches I found these used to be available through WalMart and a few other places. My showed up with the head of one of the bolts mounting the hoist to the metal frame was snapped off. Probably why many places say "discontinued". Easy to replace but it got me a $10 refund. $70 bucks shipped. I just left the weight hanging, it helps keep tension on the cable a little bit.

I may have to re-address the hoist mount. It is only held to the table with two bolts through the plywood. It does flex on the bolts, the plywood doesn't flex.

If you haven't seen this thread, you might want to consider it. Mianne Lift Bridge Lower Limit Switch Enhancement

I found while you can "usually" get the switches adjusted, the Mianne method of using standard momentary toggles with an angle bracket lends itself to easily getting "out of whack" and you have a real problem on the downward travel if the switch doesn't trip before the lift gate hits the stops.  This makes the downward stop about as bulletproof as I can imagine using simple switches.

The drawer slides are listed as 28", but they measure 27 1/2. They are rated at 100 lbs each. Cabinet parts dot com.

The pulleys took some looking. I almost went with old window sash replacement pulleys but these were much cheaper although overkill. These came from e rigging, surface mount pulleys. ~$48 shipped for all 6. They are 1" diameter at the bottom of the groove. It just worked out that 3/4" spacers result in about 1/4" peaking out beyond the plywood. I used a 3/4" mortising chisel to cut the openings and a 3/8 chisel to cut clearance for the rivet shaft.

The interesting part was what to do with the spring and weight on the cable just above the hook. This weight would move a lever and trip the limit switch when the cable was fully retracted. I cut the hook off and as show before I left the weight at the hoist.

This is what I came up with. In the up position there is spring tension but the bolt prevent fully compressing it.

When the table is down the spring tension is reduced and the cable end has little tension. If you look closely to the left of my finger you can see the pencil marks in the plywood where I measure how much movement there was at the bolt.

Here are the parts for the low voltage control for the wench. Switches are from Digi-key, rated sufficiently in case I end up wiring everything 120 vac. Two normally closed SPST for the up and down limit switches. Two DPDT, (on) - off - (on) switches for control on either side.

I plan to wire in the 5 vdc usb chager to the wall socket side, hopefully with some spade connectors. This will power the two relays which are normally open and active low. That means the enable line just needs to be grounded to close the contacts. So the limit and side control switches are just grounding one side or the other to go up and down.

My plan is to use a 4"x4"x4" junction box to house the usb power supply, the relays, and the motor cap from the yellow handle. That cap just needs to be wired across the blue and white wires from the motor.

I'm still working out in my mind how I might implement some kind of minute adjustment for the limit switches should it prove necessary. Perhaps in addition to angle brackets there could be a bolt threaded through the bracket with a lock nut on top. The bolt head would then make contact with the switch.

@gunrunnerjohn posted:

If you haven't seen this thread, you might want to consider it. Mianne Lift Bridge Lower Limit Switch Enhancement

I found while you can "usually" get the switches adjusted, the Mianne method of using standard momentary toggles with an angle bracket lends itself to easily getting "out of whack" and you have a real problem on the downward travel if the switch doesn't trip before the lift gate hits the stops.  This makes the downward stop about as bulletproof as I can imagine using simple switches.

John, I've drooled over that spring loaded, idler pulley and micro switch you used. I couldn't find anything like that. I also take heed of your warning on adjustment issues. I'm hoping what I did with the spring on my hoist will simply keep some tension when the cable goes slack, certainly won't stop an unwind.

I've also noticed a good deal of noise from the cable. It appears loosely wound and will grab hairs on your head, so I think the noise is from it tightening under load. It sounds like grinding gears but I'm sure it's the cable.

@turkey_hollow_rr posted:

I'm still working out in my mind how I might implement some kind of minute adjustment for the limit switches should it prove necessary. Perhaps in addition to angle brackets there could be a bolt threaded through the bracket with a lock nut on top. The bolt head would then make contact with the switch.

Did you look at my thread?  The spring loaded switch sensing the slight slack in the cable really solved my problem of unreliable lower limit switch activation.  Obviously, the upper limit switch isn't all that critical, you just have to make sure you don't go past the point where you run out of travel in the cable or slides.

Below is how I wired mine for two-sided activation.  I did contemplate something much fancier with relays and interlocks.  However, upon reflection I figured that was gilding the lily and wasn't really needed.  I just wired the two switches in parallel, and then I inserted a PTC to guard against the unlikely scenario where two people were operating each switch in opposition.  This was a whole lot easier to put together than my first plan.  The PTC makes sure we never have a direct short with switches in opposition.

Funny you should mention the 4 x 4 box, I found one at Home Depot that was 4 x 4 x 4, I put the cap and PTC and all the junction of the wires in that box.  I pitched the yellow control handle, I had no use for a single control, my bridge is four feet wide.

Since there's four switch machines and power to three different loops on the lift bridge, I have loops of wire hanging between the fixed and movable sections of the bridge to bring power and control in, one set of wires on each side.

Send me an email, and I may be able to help you with the parts.  I know I have the switches with the long arm, and I got the spring loaded pulley from Tim at Mianne, so maybe you can get one from him as well.

I think we have a time lapse in our posts.

Yes, I've read that thread several times. I'll have to pay more attention to the cable play, maybe it can be done without the spring loaded pulley. The spring and washer on my cable may also work, unbolted that end moves about 1 1/4". Maybe that bolt should ride in a slot back and forth. You have me thinking more, glad I have plenty of time.

In my case the box is from Lowes. The mounting wings, size, and availability work nicely. I agree the low voltage isn't necessary if wired correctly. I'm just having some fun and doesn't cost $5.

Just saw your offer and thanks. That micro switch might just work with the sliding bolt. I'm out this evening getting my yearly free meal on the kid so I'll check in tomorrow.

Yep, I noticed while I was typing you were obviously answering as well.

I will say that detecting the cable slack was the silver bullet for me, that eliminated the tricky adjustment of the lame toggle switch limit.  It also insures the bridge is fully into the stops and aligned with the fixed section when the motor stops.

I actually had a design for a low voltage control that had all the 120V in the box, but it was more complicated than just using the two switches.  In the end, expedience won out and I went the simple route.  The PTC was my nod to making sure that I couldn't get a direct short with inadvertent multiple operation of the switches.

Dan, Something to sneak up and hit you in the face...precision deck alignment  We found it to be extremely critical for the two side foundational modules to be PERFECTLY level.  Not a single hair off.

Then, align all the other bench work to the lift assembly.  Consider using levelers on all platform legs to assist in leveling all the framework.  Shown are plastic faced Monoco swivel levelers and Tee nuts  available from Outwater Plastics in NJ.

That good sized elevator surface will spotlight any off level surrounding bench work and make multi track alignment of the lifting deck unstable and unattainable.

Much less of an issue if only one track crosses the lift bridge.

Yep, leveling turned out to be a major issue if not perfect!

@Tom Tee posted:

Dan, Something to sneak up and hit you in the face...precision deck alignment  We found it to be extremely critical for the two side foundational modules to be PERFECTLY level.  Not a single hair off.

Then, align all the other bench work to the lift assembly.  Consider using levelers on all platform legs to assist in leveling all the framework.  Shown are plastic faced Monoco swivel levelers and Tee nuts  available from Outwater Plastics in NJ.

That good sized elevator surface will spotlight any off level surrounding bench work and make multi track alignment of the lifting deck unstable and unattainable.

Much less of an issue if only one track crosses the lift bridge.

Tom, thanks for the Outwater tip! Very interesting things there beyond levelers. Alas I have already purchased levelers and inserts from McMaster-Carr, enough for all of my layout plans. The ones I bought don't swivel and I had to add my own lock nut. Those Monocos are the way to go.

I assume that is a Mianne leg? I didn't notice the capping block before. I added 1/2 ply blocks to my table legs just to protect the the ends of the layers so they wouldn't split as I drilled the ends for the levelers. If there is one knock against the plywood it is that there more susceptibility to splitting between layers I guess Mianne is adding support for a lot more weight than my layout would provide.

I understood going into this project the importance of (1) keeping four sliders in parallel over whatever length slider is used, (2) the force to lift needs to be centered to help assure (1).

I did get a feel for the level and plum reaction when I first began to operate the hoist. The table was a bit shaky as it started down. I found one leveler not fully seated and added extra bracing across the table. That really smoothed it out. The levers skate easily on the bare concrete (except the hoist side) and that works against keeping things in place while it's in the shop. It will be installed on berber carpet so that, and getting the side tables fastened to surrounding benches, should help with repeatability. It looks like it operates smoothly but as you suggest once I get to aligning plywood, track, etc, the warts will show.

Dan,  That leg in the photo is a 2 x 4 split diagonally with one half turned around and reattached.

<<< Opposite view

This arrangement stabilizes grain warping.

The block of wood at the bottom of the leg??  Your assessment of my refinement is somewhat over stated!  I am a recycler.

My layout is built primarily from left over modules, reused modules from my last RR, modules graciously obtained from clients estates,  left over pre-curved side rail stock plus a stash of cutoffs.   Any new material came from pocket change.

Sooo... those blocks were added because the legs came off a layout built for a shorter customer.  The legs were simply an  1 1/2" too short for my new application.  (insert laugh track here)

Ha! That's me over-thinking again.

I set up my first command control layout in my shop, about 12" above all the benches, and use 2x4's ripped in half for the legs. I hadn't considered cutting and re-orienting the grain, great idea to help with seasonal changes.

@gunrunnerjohn posted:

Send me an email, and I may be able to help you with the parts.  I know I have the switches with the long arm, and I got the spring loaded pulley from Tim at Mianne, so maybe you can get one from him as well.

Thanks again, John. This just might work out with the long arm micro switch for the lower limit switch. Slight downside is that it means wiring the micro switch on the opposite side of the walk through.

I need to get my router bits sharpened.

Control wiring is complete and the yellow remote is gone. The cable to the remote has been re-wired to bring common, neutral, and the two motor leads over to the 4x4x4" box.

I was intending to use a plug-in usb charger for 5 vdc power to the relays but I happened upon an ancient satellite radio wall wart. After cutting it open I was so impressed with it's looks it just had to go in the box. Plus it fit along side the motor cap. You can see the two relays occupying the balcony section.

My intent was to hot glue the boards down but I had to remove the psu a few times to fix the wiring so I just left the glue out. I did cut a piece of 1/4" plywood to keep the parts separated.

The two enable lines and a ground were extended to the outside of the box for easier wiring and it also gives access to control the hoist with a jumper wire if needed. No voltage in any of the control wires, just a circuitous path to ground.

I received the micro switches from @gunrunnerjohn and he is correct that these switches make setting the limits much easier and seem to be very repeatable.

Here is the upper limit switch mounted to the upper stretcher of the hoist-side table, wired normally closed. A small block of plywood was attached to the lower stretcher of the rising table and that makes contact with the switch lever in the up position. I am getting a consistent 64 3/4" table rise.

And now the most worrisome limit, the down position. I worry no more, it worked out so well with the cable spring and sliding bolt. The bolt is pulled to the limit in the slot before the table can rise, and the table is fully seated before the bolt is released. It worked the first time and I haven't had reason to touch it yet. This switch is wired normally open.

Up

Down

And last, one of the toggle switches mounted to the table leg. One on each side of the table. These may move in the future depending on how the rest of the benchwork turns out.

Looks good, and sensing the cable slack seemed to be to be the foolproof way to insure the table was down and seated before the limit tripped.

That long lever really helps as well. There is still at least 1/4" of play on both limit switches when they are in the tripped position, so there's no binding or crushing worries. And to think at one time I was considering unwinding the cable and removing the spring. I would still like to replace the cable, it sounds like grinding gears, but I don't want to lose the spring.

The flex in the long lever really helps to avoid things getting bent out of shape at the limits.  FWIW, the winch that comes with the Mianne benchwork is pretty noisy, but I've learned to live with it.

I don't understand replacing the cable, is it getting damaged?

I don't think there is any damage and this particular grinding sound only happens when the cable is pulled tight and is lifting, not on the way down. I think most of this noise is due to the cable not staying nicely on the reel. You probably observed the same issue when the cable gets too slack and unwinds a loop or three. It is necessary to disassemble the middle to be able to carry things through the doorway so I expect the cable to need some adjusting again. Once set in place I'll see about attempting to rewind the cable.

Listening this morning the noise is much less than it was now that the limit switches and spring are providing a little more tension control. Still the wrap loosens enough that the wrap below protrudes into the wrap above. When the cable tightens there is some cable dragging back into place on the reel. Also, each time the cable jumps across a previous wrap.

The cable mess.

Once I got my Mianne lift bridge adjusted, there is no issue with cable slack.  I think your tangle of cable is because you have too much cable on the reel.  When the bridge is down and you're seated, there should only be a couple of turns of cable left.  My cable is never slack at any point in the travel, that was the whole point of the spring loaded switch.

Here's what my cable spool on the winch looks like down and up.

Bridge Down and Seated

Bridge Fully Up

Ok, the cable is cut down so there are about 3 coils of cable on the reel in the down position, now wishing I had done this before. Easier to deal, no more noises, and some of those extraneous parts are gone.

Lookin' good, and an improvement in function is always nice too!

Thanks for the tips, John!  I believe it is done.

Two things I would do differently. First, the side tables can be wider. 18" wide would be easier to work with. Second, the hoist needed to be mounted more securely and was lowered to avoid rubbing the plywood decking due to slight flexing during the lift.

The Mianne side tables are only 12" wide, however the winch is mounted on a 3/4" plywood board, and there's no flexing of anything under there during operation.  The one place I see flexing is on the bottom of the moveable bridge section where the pulley redirects the cable up and under the bridge.

I don't know the specifics of how Mianne mounts the hoist but I ended up sort of doing the same. Before adding this plywood mount and all four mount bolts, the hoist was only secured by two bolts through holes in the stretcher. The flex was due to the steel hoist mount pivoting on just two bolts. I under estimated how much tension there would be. When I laid a straight edge across the top of the stretchers the hoist cleared, but when lifted, it would come up 1/8". I can image the noise that would make once the plywood surface is added. There are cross members between the upper stretchers on either side of the hoist mount on both end tables so the upper stretchers can't flex.

When the table is up I see the lower stretcher of the lift table flex toward the pulley on the hoist-side table where the upper limit switch is located.

This is my acceptable looking compromise for attaching the hoist. No more hoist movement. Had I planned better this could have been cut from one piece as part of the stretcher. Ideally, the hoist would have been mounted about 1/2" or so below the surface plywood.

Mianne mounts the winch on a horizontal piece of 3/4" plywood in one of the side structures.

@turkey_hollow_rr posted:

When the table is up I see the lower stretcher of the lift table flex toward the pulley on the hoist-side table where the upper limit switch is located.

That's exactly what happens with the Mianne design as well, and it looks like yours has the same design.  I suppose it's fine, the bridge hasn't collapsed yet for me.

Due to the fact that any of us have a serious reduction of follicle based scalp protection I would suggest something to consider would be adding some premium 3/4" hot water pipe insulation with a lengthwise slit  to the bottom edges of the lift framework.

A round over router bit could also be helpful.

The pipe insulation on mine has saved my scalp a number of times!

I have to admit I have already whacked my head on the corners of the two middle cross supports a couple of times. I haven't learned to keep my head down ALL THE WAY across.

The pipe insulation is a good solution. We have some around here that is pre-split. I'm thinking about 1/8" hard board bent along the curve of the arches for a ceiling when the table is up but there are still two outside edges waiting to scalp me.

Those went on right after the second divot out of my scalp!

For a better view here are the hockey pucks I make for the Monaco swivel levelors when used over carpet.  They are a 3 1/2 X 3/4" plywood disk with a recessed inset for the adjustable base.

On the bottom of the disk I fasten a 3 1/2" round disk cut out of plastic office chair protector with the plastic nipples which are set into the carpet nap.  This makes for secure positioning.

With the legs firmly embedded in the carpet and fastened to both the cross members and longitudinal stringers,  a free standing peninsula can be held steady.

Typical installation

@Tom Tee posted:

For a better view here are the hockey pucks I make for the Monaco swivel levelors when used over carpet.  They are a 3 1/2 X 3/4" plywood disk with a recessed inset for the adjustable base.

Tom,

That's the smallest circle I can mill with my bandsaw, a 1" Forstner bit works great. Somewhere I have a router jig for circles but I'm not sure it gets to 3".  Anyway, I can clean this up on the disc sander and use a thinner bandsaw blade.

My bench work will be very similar in style to your picture but simpler, basically a 10 x 22 with an aisle down the middle. I have 3 bridges to work in so there will be a few sections that drop lower for future scenic work similar to what I see in your picture.