All I am trying to design a 16" lathe steady rest for a wood lathe. The attached file is just the drawings to get me to a point where I can cut out the center round part and 3 arms that will pivot from one end and have a 2" skate wheel on the other. In the center I need a slot so I can push the arms in and lock them in place.
This will similar to an iris type setup with the arms coming in and hit against the bowl/spindle and then have a bolt to lock it into place. The locking bolt will need to ride in a slot. My problem is trying to figure out the angle of the slot.
Each one of the pivoting arms is about 9" from the pivot hole to the top hole where the skate wheel will be.
This is just in the design stage and nothing in concrete except the 16" inner circle. The outer surface is current at 18" but I can make it wider if necessary. Also the arms can be made wider if necessary for a slot long enough to get the pivoting arms close to the center of the 16" circle. The skate wheels do not have to go all the way to the center but at least to a 4" diameter circle. I want this to steady bowls I am turning and not steady small spindle work.
Since we have a lot of smart people on the forum I was hoping someone could help me figure out the arc of the slot in the middle of each arm. All 3 arms will be identical and are at 120 degrees from each other.
Any suggestions would be helpful. If any of the pivoting arms need the 3 holes re-positioned to simplify this that would be ok. This is just a rough drawing and not anything final.
Your slot is just going to be the region between two circles, both centered on the pivot point. What size hardware are you using - 1/4-20, 5/16, something else?
So, how wide is the slot, and how close are you willing to get to the edge of your piece?
Here is a slot 0.26 wide, that stops 3/8 (0.375) from the edge. I centered it on the hole that was there, assuming that that was the radius you wanted. jet_16_steady_rest.c2d (572 KB)
How I did it:
Ungroup the piece so I can work with the bits
Measure distance from pivot to other hole, center to center - 4.65"
Create two circles, both centered on the pivot, size 4.65+0.13 and 4.65-0.13. The slot is centered over the existing hole.
Take outline, and do ‘Offset Vectors’ to the inside, distance 0.375.
Take one circle, intersect with that vector.
Repeat the ‘Offset Vectors’, intersect other circle.
Select both circle segments (outside first! Order matters!), then “Boolean Subtraction”.
Thank you for your input. I will download the file and cut a prototype. This steady rest is to support the urn I am currently making for a friends ashes. I have a Jet 1642 VFD Lathe and want to make a steady rest big enough for a bowl support. Most steady rests are for spindle turning. I want to be able to get near the 16" capacity of my lathe. I found the iris example on youtube but he had no plans. The main part is just a circle now but it will need to have some parts added and this drawing was just to work out the mechanical aspects of the steady rest.
Again thanks for taking the time to help with this. Your explaination was spot on and dont know why I was having trouble visualizing what you did. Basically you were using a circle centered on the bottom hole and splitting the hole in the middle position. It is so clear now, DUHHHHHHH on me.
Now that the slot is figured out I may need to make the parts a little wider so I can use it for spindles and for bowls. Spindle turning is very rare for me but bowl turning is something I do all the time. Also I need to flatten out the bottom and make a lathe mount. This is just a skeleton of the prototype.
Not sure I have enough plywood but it will be sunny tomorrow so I can go and get a sheet. The base is 24" x24" X 2 for a 1.5" base. The iris arms is 20" x 22" single layer.
After the iris arms are cut out I will need to make a countersink on the back side for a carriage bolt to hole the skate wheel on.
I will cut this out in a day or two and make sure everything is working before I order any more parts to complete. I likely have almost all of the hardware but not sure about the 2" skate wheels. I know I have some 3" skate wheels from previous projects.
If I have a half a sheet of plywood I will glue it up tonight. That way I can cut it out tomorrow.
I included the files but dont download them or use them until I make sure everything is working. This is technically a prototype and may not work as is. FYI
You technically don’t need to worry about getting the 2" wheels if the arms pull high enough out of the opening so not to impose on the whole opening. Then it is just a matter of adjustments to put the steady rest in place properly. Don’t spend more money on something that you may already have something that will work. Besides, having a bigger wheel that clears the main big opening means you can hold even smaller diameter things.
Normally I would have rigged up some type of clamp for nearer to the middle but that will all be carved away.
Here is the glue spreading. I used a glue bottle with a roller on top to spread the glue. My TiteBond III became a dead soldier with just enough glue to finish up.
While the glue is drying I will be the blank ready for the arms. I would like to cut them all from a single piece but if I cannot I will cut them one by one or maybe two at a time and then a single. I dont want to waste my plywood so I will use scraps.
Got my base and iris arms cut out. Some success and some failure. In the present configuration I need to move the left arm down to get the skate wheel at 90 degrees on the left side. I may also need to drill another hole to have the skate wheel lower. I think I can use this version to get my urn turned. It looks like in this configuration I can get up to about a 10 inch bowl in the steady rest.
Changing the position of the left iris arm down and drilling a new hole I will be able to get the skate wheel at the 90 degree mark. That is where all the cutting pressure is with your gouge. The other two arms will work but eventualy I will need to redesign and get optimal size of the bowl in the steady rest. A D shape on its side might work better. I have a 16" lathe and the bottom of the inner circle will limit me to about 10" no matter the configuration. The only way to get it bigger would to thin out the bottom that sits on the bed ways. that might make the rest unsteady.
Many woodworkers call turners wood wasters. I hate to waste anything so I will think about my round disk and make something. Maybe even some wall art. But it will not go to waste.
I think this iris design will eventually work with some modification.
Here is view while cutting. The job took 3+ hours. In CC I told it the tool path tool was a #205. I used a 4" OAL bit with a 1.5" cutting depth. It is just a 1/4" upcut bit just longer than the #205.
In all the steady rests that I used for manual metal lathes had the bottom two wheels, or bearings, at about 5 and 7. Then the top one was at 12. This helped that both lower wheels/bearings had equal control in centering the stock of the material to the spindle. The top one was for pinch so nothing would move during any cut.
Maybe flipping one of the lower arms to mirror the other lower arm so they both come in around 5 and 7, then you can make the top one a drop straight down arm or a swing arm like you have now. Your steady rest is not supposed to completely hold your part as like the chuck does. It is supposed to just help hold the part in center while you cut and it wont let the part go out of round.
Another design idea would be to make Y arms that slide in and out with a dado guide slot that keeps the arms in line to the center of the horizontal center of the central plane of the lathe. This design would allow for two smaller wheels on each side of the Y tip and the lock guide beside the dado slot.
Your biggest hurtle is going to be the base in how you will hold down the steady rest. I have a few ideas and even a few other ideas for being able to increase the diameter of the 10" opening of your original design. But let me not help complicate things for you. Looking forward to seeing what you come up with.
Good ideas but I wanted to try and get one arm at the 90 degree mark on the left side. When turning wood that is where the most stress is. Most steady rests are for doing spindle work. Like you your metal lathe the metal is a lot stiffer than a wooden bowl. Most of the steady rests people make for wood lathes have the wheels at 120 degrees apart (360/3=120). I have also seen ones that just have two wheels that are mounted on the turning side just above and below the cutting point. Wood lathes you cut at the center line. That type of setup would give me the full 16" capacity but not sure how steady it would be. Wooden bowls start whipping when you get the sides thin (1/4") or less.
For now this one will work to get this project finished. Then back to the drawing board. This iris type seems promising but it needs more refinement. I have even seen ones that have 5 wheels that ou can adapt to take some away if you only want 3 or even 2.
Got all the hardware I need. Need to make an L bracket to attach to the back side to hold the steady rest to the lathe ways. that will be easy and I will screw the L bracket to the base and make a hole in the L bracket and a block the size of the ways and another block below for the screw to hold the bolt that secures the steady rest. The only thing I dont have is on order. I ordered some skate wheels. I had 3 but they had no bearings. Those wheels will be Monday or Tuesday. The put an Amazon fulfillment center in Dallas so most of my Amazon stuff comes via USPS now. The post office takes an extra day. I love the efficiency of the postoffice that we spend billions to have. Talk about snail mail.
I have made steady rests before. The skate wheels are 8MM and dumb me did not realize that 8MM is almost the same size of 5/16". This one is all 5/16" hardware. I can get metric bolts but the SAE ones are more available and cheaper. Live and learn.
Got everything I need to assemble and start using lathe steady rest. I got some 2" wheels. I originally designed the iris arms to fit 3" skate wheels. I decided to get 2" wheels to get down to spindles if I want to turn them. I need to maybe move the skate wheel down a little and reshape the wood behind the skate wheel.
I could have made a conventional 3 arm set up but then the arms stick out and can be in the way. Plus I have a Shapeoko to make anything I want. When I update the CC files I will post them here so if anyone wants to make one for their lathe they can.
I placed an L shaped bracket on the upright part of the steady rest. I cut a piece of oak to slide in the area between the ways and just a little bit shallower then the height of the ways. Then I cut another piece of oak big enough to capture the steady rest on the bottom of the ways. That piece had a 1/4-20 tee nut inserted and a 1/4-20 threaded nut to clamp it down. The very bottom piece with the tee nut should be wide enough to capture the steady rest but small enough to be able to slide the steady rest back and forth. Most lathes have reinforcing beams under the ways. Just make sure you can slide the steady rest back and forth or you will have to remove the bottom clamp, move the steady rest and reinstal it.
Here are the files for the steady rest. There is a base and the iris arms. Modify the files to suit your origins and check all settings. Your plywood might be thicker or thinner. I tend to use the center as origin and bottom of material to keep from cuttng up my spoilboard. The basic steady rest will work for just about any lathe. You could adjust the size for your lathe. Having the 2" base at the bottom will limit you to 14’ on a 16" lathe. In the iris arms I made an additional hole 1" below the original. If you decide to use the lower hole you will need to reshape the area above the skate wheel so the arms do not contact the rotating turning project. I will try out the existing hole and then the lower hole. Not sure you could leave the top hole in place if you decide to use the lower hole. The arms would likely hit the project. I just used a sander to shape the top of the original arms I made.
This was just a prototype but I will use it for a while and make any refinements to it as needed. The iris arms were rounded over more on a sander to make sure the 2" wheels were free to move.
