Hoist with track needed

Haydo · Post by **Haydo** » Thu Jul 17, 2003 7:30 am

John, It seems to be a very timely topic, I appreciated getting to see your kiln images the other day. Very neat. Hopefuly I'll get to see you one day for a bit of a yarn. The big kiln will be a project for next year after Bert brings out his glass kiln building manual. - Haydo

Tony Smith · Post by **Tony Smith** » Thu Jul 17, 2003 7:32 am

This is the type of lift mentioned earlier and is available from harbor freight for about $129. It is adjustable both vertically and in boom length. The trick would be to anchor it so the overturning moment doesn't pull the bolts out of the floor, but you should be able to do that without a lot of effort. The other issue would be having enough room to swing the bell in a radius (and enough flexibility in the power cable) and to position the tables at the right distance from the pivot (minor issue).

What about using a hydraulic engine hoist? You could move it out of the way during the firing. They are relatively inexpensive and pretty maneuverable. You might even find one for sale locally at a used tool shop. Look for new ones at http://www.northerntool.com, http://www.mcmaster.com or http://www.harborfreight.com. They start about $150 new.

Tony

Bert Weiss · Post by **Bert Weiss** » Thu Jul 17, 2003 12:21 pm

Tony Smith wrote:This is the type of lift mentioned earlier and is available from harbor freight for about $129. It is adjustable both vertically and in boom length. The trick would be to anchor it so the overturning moment doesn't pull the bolts out of the floor, but you should be able to do that without a lot of effort. The other issue would be having enough room to swing the bell in a radius (and enough flexibility in the power cable) and to position the tables at the right distance from the pivot (minor issue).

What about using a hydraulic engine hoist? You could move it out of the way during the firing. They are relatively inexpensive and pretty maneuverable. You might even find one for sale locally at a used tool shop. Look for new ones at http://www.northerntool.com, http://www.mcmaster.com or http://www.harborfreight.com. They start about $150 new.

Tony

I think that an I beam and trolley would cost the same or less and can be mounted on the ceiling. Check out a used steel yard. It is much less hassle and can move the bell in a straight line as opposed to a radius. You still need enough cable to do the stretch, but this isn't too big a deal. You can buy flexible welding cables and bundle them with wire ties. They make these wire drop clamps that can go on the wall above the switches that can stabilize the wires so they can't pull out. They are an electrical supply item.

I go to the trouble of raising my bell and then lowering it on to heavy chains before it is moved. This way the weight is being supported by chains or by the bell itself except when it is being raised or lowered.

I do like the idea of rolling the bell along a track, but a creative way to lower it an inch or more is necessary to get a good fit. Maybe the track can be raised and lowered an inch? If the V track were welded on to a piece of plate steel and that steel was set up on a cam of some sort, the track could be raised and lowered enough to make it work.

I also like the idea of having a ring with side elements for a deep slumping kiln. I have thought of making one of those for my big rig, but it is just too cumbersome for me. Would be useful though.

I am planning for my kiln designs to be published by this time next year. Knock on glass. I will cover the basic design parameters so that people can be creative with the details of how they execute them.

Victoria Nelson · Post by **Victoria Nelson** » Thu Jul 17, 2003 5:16 pm

Hi there,
The kiln we built (4 x 8 foot firing surface) has the lid going up and down with the base rolling under on wheels that are a bit larger than the ones you can see on the 'Jack Bowman' photos. The rubber composition of the wheels acts as a shock absorber so that the intricate glass patterns I lay out do not bounce around. (Yes, I do still glue the glass). You need to deceide if you what fixed or swivel type wheels. I suggest two of each. I have 4 swivel and it takes a bit of floor space to get the leading edge of wheels to swivle around to move in the opposite direction... eg returning the base to the under lid firing position.
The lid glides up and down smoothly with uni-rail track and wheels and is lifted with a 12 volt winch using a deep cell battery.

It was suggested that I use v-groove metal wheels on an inverted angle iron track to make it easy to line up the base and lid, but I think that the metal will create to much cavatation and the unfired glass will really shutter and move.

The draw back of not having a track is that it takes a bit of fiddling to line up the base. But with practice and a few line up marks on floor I can do this all solo!
Sorry my scanners shot or I'd post photos. A friend might have photos on a CD.... If you are interested post back and I'll pusue this.
All the Best. Victoria

Jack Bowman · Post by **Jack Bowman** » Thu Jul 17, 2003 10:13 pm

Victoria,

The only advantage to my small wheels is the small turnaround space. I would like to see your pictures whan you ge a chance. I want to install roller guides on the lid and a pin/socket so it hits the same place every time.

Jack

Tony Smith · Post by **Tony Smith** » Thu Jul 17, 2003 10:37 pm

I had sent this design concept to Brad earlier today... I thought it would be a great way to set up a two sided kiln. The arm could even be counterbalanced to eliminate any need for a winch.

In this concept, the table is 36" high and the top of the swing is just over 7 feet. Brad pointed out that he wanted an aisle between the tables, but maybe someone else would like to use the idea.

Tony

charlie holden · Post by **charlie holden** » Thu Jul 17, 2003 10:54 pm

Brad Walker wrote: Charlie, I don't understand how rolling the entire lid/hoist assembly would work. Do you have a photo or a link to a place that would help?

I have a CM chain hoist. http://www.aceindustries.com/091CMHandCha.htm

It hangs from a CM trolley. http://www.aceindustries.com/141CM632Trolley.htm

A four chain sling hangs from the hoist chain. http://www.aceindustries.com/Slings/000ChainSlings.htm

The sling goes to four points on the bell, each in from the corner about a foot. I just lift the thing up and shove it over. The trolley rides easily enough that I can push on the bell hanging almost ten feet below the I beam and it moves with little trouble.

For a couple of not very good reasons, (it turns out) I have my two bases oriented at 90 degrees to each other. So I have to turn the bell as I move it from one base to the other. It works with little trouble. I don't have any guides to line up the bell. I just hold on to it with one hand as I lower it with the other. I have successfully lowered it around glass on a drop out ring with only a half inch clearance inside each side of the insulation. You can go very slowly with a manual hoist.

Nelson Tan · Post by **Nelson Tan** » Fri Jul 18, 2003 9:38 pm

A view of my kiln.
Many pulleys. One worm gear winch from Grainger.

Table pulls out.

Nelson

http://www.sgo.com.ph

Nelson Tan · Post by **Nelson Tan** » Fri Jul 18, 2003 9:39 pm

sorry forgot the link

http://community.webshots.com/scripts/controlPanel.fcgi

nelson

Clifford Ross · Post by **Clifford Ross** » Fri Jul 18, 2003 11:46 pm

Wrong link, Nelson

Nelson Tan · Post by **Nelson Tan** » Mon Jul 21, 2003 4:23 am

Dear Clifford,

Please try again. It is fine when I click the link.
Look in the Kiln album

Nelson

Tony Smith · Post by **Tony Smith** » Mon Jul 21, 2003 5:37 am

Nelson,

You probably have a cookie on your computer that signs you into your Webshots page every time you click the link... all we get is a signup page.

Tony

Phil Hoppes · Post by **Phil Hoppes** » Mon Jul 21, 2003 12:13 pm

I'm building a 4'x4'x16" interior dimension bell kiln with two rolling bottoms. A few notes here. My concrete floor is CUT. There are no expansion joints and the concrete is very smooth. My bottoms are on very heavy duty castors that have leveling screws. There is a fixed front and back to each base and there will be tracks to run into so that each base will be in the same position each time they are placed under the bell. Once I level the bases in place they should be level for all time. Point well taken on moving may move the glass....that will remain to be seen. It may or may not be a problem. My hoist is home made from 3" box steel. I am planning on using a Dayton 1000 pound winch (Grainger) that will be on a pulley system such that the load on the winch itself should not be greater than 250lbs. This winch has a built in break which is useful however I plan on having set pins for the bell to rest on when it is in the up position.

A few things people need to remember when you are designing a bell kiln from a safety point of view.

1) You should have a ground return cable from your bell to your hoist. If you get an element short to your bell, if you do not have this ground return all of the juice will go up through your hoisting mechanism to ground. If you are using a chain this is probabaly ok but if you are using a cable, depending on its size and the degree of the short, you could melt the cable and your bell will come crashing down. Oh, yes your hoist should be connected to electrical ground also.

2) My bell is supported from 4 equidistant points from the center via forged screw eyes which are connected to chains which are connected in the center to the winch cable. Most people (not engineers) think that if they have a 500 pound load supported by 4 chains this way are putting a 125 pound load on each chain. This is wrong. Each chain has a 176 pound load on them and yes the sum of all for chains is greater than 500 pounds. This is important as if you are using screw eyes you need to clearly understand the amount and the direction of the load on the screw eye. A 1000 pound screw eye is rated at that load ONLY in a vertical direction. If the load on the screw eye is at an angle to vertical the rated load of that screw eye is dramatically reduced. You need to check this. If you look at the web page of McMaster-Carr (that is where I'm getting my screw eyes) they show you the derating of the load capacity of the screw eye vs the angle of the load applied.

Phil

PS - My math for the above calculation is based on a 500 lbs static load and a 45 degree angle to the screw eye. As you reduce the angle towards zero the load on each line will approach 125lbs. As you increase the angle towards 90 the load will actually approach infinity, which is interesting if you really want to spend a lot of money on very expensive screw eyes

Nelson Tan · Post by **Nelson Tan** » Tue Jul 22, 2003 4:07 am

Dear Tony,

please try this link. If it does not work what should I do?

http://community.webshots.com/scripts/e ... D=81825392

Nelson

Tony Smith · Post by **Tony Smith** » Tue Jul 22, 2003 6:26 am

Nelson,

Post a question on the help section of this board. Brad or Paul might be able to help. My experience is that some photo site work and other don't. They should be able to tell you which ones work.

Tony

Haydo · Post by **Haydo** » Tue Jul 22, 2003 7:54 am

Nelson, You must be giving the user address instead of the public address to your albums. - haydo

Nelson Tan · Post by **Nelson Tan** » Tue Jul 22, 2003 8:59 pm

Thank you very much Haydo!!!

http://community.webshots.com/user/yamatan

Nelson

Don Burt · Post by **Don Burt** » Tue Jul 22, 2003 9:58 pm

Tony Smith wrote:I had sent this design concept to Brad earlier today...

Elegant low tech solution. Could do a cool three-table-one-lid variation by having the axle on a gear that traversed notched hills.

Tony Smith · Post by **Tony Smith** » Wed Jul 23, 2003 7:33 am

db wrote: Elegant low tech solution. Could do a cool three-table-one-lid variation by having the axle on a gear that traversed notched hills.

Like the old time carousel horses... now you just need the nickelodeon. When the music ends, the glass is done!

Tony

Bert Weiss · Post by **Bert Weiss** » Wed Jul 23, 2003 9:39 am

Nelson Tan wrote:Thank you very much Haydo!!!

http://community.webshots.com/user/yamatan

Nelson

Nelson

Great pix. I love the dancing lady.

I think that my kiln design is simpler and has features that I like better. The good news is that yours is working well for you.

I will start a new thread over on the picture board with an image of my rig. I think it will be helpful for people to compare notes about which design features work better than others.

WarmGlass.com

Hoist with track needed

My 2cents