Davit Winch Test and Modifications
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- Опубліковано 19 лис 2021
- The "Love Me" tender is not your normal little boat carried along for getting to the dock and back in flat water. "Love Me" is a 1600 pound beast that you can take into rough water, bang into wrecks, and drive up onto the rocks. The down side is she'll not be hauled up by two people and a couple little blocks. She requires some machinery to do the job.
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"CLOSURE" preformed by Doug Waterman
Mechanical engineer here. You’re going to need more than one bearing to support that David pulley system. Yes having one right Next to the chain works but there’s still so much deflection. That bearing will get smoked super fast. Put one or two more bearings evenly spaced between the existing bearing and the support on the other side. Will take away most of your deflection and save you some major headache in the future. The boat is looking great!!
Considering the FPS and the duty cycle. We could use wood and it would outlive us all.
@@SVSeeker I think end grain ironwood, with grease, would make a good bearing. They used to use that for wagon bearings. And it would have less compression than plastic. And, a few across the length of that pipe sounds like a good idea too.
@@troyboyd3100 A family friend owns an old build the has an original Otis elevator serial number 112. To say it's old is an understatement. It uses either ironwood or similar for its guide rail. They just grease it a couple of times a year and it will last into the foreseeable future. People have forgotten how strong old-growth hardwood is.
A small screw jack between the winch itself and a support bearing would probably help keeping the tension up too and might be less liable to slip than bolts through slots.
Perhaps the 1/4" hull plating is just too light to carry the load without a backing plate to spread out the load. Unifying the whole motor mount and sprocket drive system into a single unit, then attached to the hull with connecting brackets might be the last option.
You know I think being stuck there waiting is going to turn out to be a positive for Seeker. You are getting all of this time to find these little things while you are still local help.
When I worked with agricultural equipment, there is a huge difference in chain quality. While twice the price, OEM chain from a known brand, JD, New Holland, is exponentially stronger than Tractor Supply and other china bulk roller chain. The cheap stuff stretches too much and rides the sprocket, which stretches it more until it pops. Also, when you have a chain “set”, the teeth must be in phase so the chain rides up and grabs the next tooth evenly to keep the load even between the chains. It doesn’t seem like much but if they’re not in phase, the load peaks will be more than 50% per chain, which defeats the purpose of double chains to split the load.
Reputable chain is pre-stretched by the manufacturer. Cheap import is not.
Found the very same thing. Good on you for remembering to share
Sometimes... ya just have to let them live and learn. Its a great philosophy. However, you won't live long enough to learn all the mistakes that could have been easily learned.
@@jasonmendela1020 I don't see a lot of learning going on here. Just a lot of rebuke.
*WHO "WILL" SUPPORT ..."COMMUNIST CHINA"..!! I PAY FOR "REAL" THINGS*
*AND WILL .."NOT".. HELP TO (DESTROY MY OWN COUNTRY)*
*...NEVER IN MY **#LIFE** .. I AM NOT A **#IDIOT** ...*
I have covid pneumonia and have been coughing up blood for a week. Looks like I might be on the mend but it will be 6 weeks before I can go back to work. Your videos are a joy to my day brother. Be safe with those fingers.... had an uncle remind me to not put my fingers anywhere I wouldn't put my pecker.... lol
Your philosophy is so helpful at the end of this. Weather has not been suitable to fish this weekend but your philosophy has got me up doing something constructive
making stuff.
Grateful to you!!!
The most important message is right at the end. Thanks!
you could put some convex shape to the davit roller pulley to help the strap track to the center better, like a bandsaw pulley. love your videos, keep up the great work Doug!!!
Was gonna say the same thing. With a crown on the pulley it might help.
yep, a convex pulley may look unconventional by it works. science
Simple fix, instead of 2 separate chains, use a double link chain, add a pair of supports for the shaft evenly spaced on the transom. Or move the drive motor and sprockets to the center of the transom. Either way you need a double link chain and sprockets.
Can't without also changing the sprockets on the elevator lift as the teeth are 1/2 a tooth out of alignment. And they are really expensive in stainless steel.
I know nothing about anything I see on this channel, I just enjoy watching and learning a few things. Keeping it simple.
It "looks" to me that 1 of several things may be happening with the chains powering the tender lift. 1. The sprocket pairs don't match in teeth or diameter ( large or small) 2. The chains may not be the same length 3. The chains and sprockets may not match in pitch 4. The chains and sprockets are not in alinement with each other. It does not take much of any one of these conditions to be "out" for the problems you are experiencing to show. If you need 2 chains to lift the tender, you might consider changing from 2 single chains to one double chain which will entail replacing both sets of sprockets and the chain, but that arrangement probably will be more reliable in the long run.
Yeah, most of the time all of the load will be on only one of the chains (with occasional shift from one to the other).
I'm not sure the bracing that you installed is sufficient.
The idea is: you only need to prevent the motor from co-rotating with the long axle, other than that: for alignment it is best if the motor follows any flexing of that long axle.
For a mounting that accomplishes that you would need a second bearing, with a mounting such that the motor sprocket is kept in alignment/positioning with the axle sprocket, and something like a rod connection (universal joint rod) between the motor and the boat frame. That way the motor is free to follow any flexing of the long axle (keeping the sprockets aligned), but will still wind the flat webbing straps.
(Comparison: in a car the transmission is bolted onto the engine, not bolted onto the car frame.)
Exactly what I was going to say.
Was thinking something similar, when you look at the video the outboard sprocket seems to be feeding chain at a slightly higher rate than the inboard sprocket, leading me to think that there may be a 1 tooth difference or a pitch / diameter difference between the sprockets. An outrigger bearing support would also help its lifespan.
They are alternating slack. I vote for number 4 :)
Yea the only thing I can think of is 1 bigger heavier chain instead of 2.
I'm concerned about your use of flat straps...IME, they tend to twist and slide while a boat is pitching. I'm curious to see how your system will work in moderate to heavy seas. Nice that you'll be able to fab a solution at sea!
Hi Doug. That’s a pitch mis-match issue on that chain bud (haven’t watched to the end, maybe you figure it out). That’s why the chain is climbing the sprockets teeth I think. Chain stretched? I’d be surprised. Metric vs. imperial maybe 🤔🤪😂
No, it was just alignment. ..and I could grind more chamfer in to the sides of the teeth.
The sprocket on the end needs to be a little bigger then the one on the inside
@@SVSeeker defiantly a pitch problem. we did this at collage . study duplex chain drive. Doug think about the diameters/pitch of sprockets. chains will constantly fight each other ware on sprockets will be abnormal.
You are such an inspiration Doug.
What I've seen work (huge loads, 24/7 operation ) is double or triple chain, such as is used on fork trucks. Also make them longer and add a chain tensioner that you can adjust without moving the powered item. Much better than slots that will let the seas in. Far easier to take up a half turn on an adjuster than moving all that powered stuff. Others have addressed the strap issues. Must admit I would have used regular blocks and dyneema line.
The elevator lift used separate chains and sprockets with teeth, 1/2 tooth out of sync. No idea why they designed it like that but I have to replace those too. And the stainless steel chain was something I already had from another project. And, It's working. : )
Watch your upload this am. Then went and worked on my own boat that I've built. Didn't plan on it today after a long ass week at work . But your message was motivating. Thanks.
Loved your finish, but understand that there are people who watch you who are on a different journey. I watch your channel specifically when I’m in the hospital. I’ve had my fair share there and your upbeat, up and at-‘em, no bull is an inspiration for me to get back out there. Thanks!
What did I say "Get off your ass?" ...I think the hospital gives you an exemption. Just keep in mind that it's just a shoe. It's totally up to you to try it on. I did. I liked the fit. : ) Here is to: out there!
WELL OK!! I got your message, I was relaxing just a little bit today, but back to work I go. :) Life is beautiful thanks.
I go around and hit areas starting to rust with fluid film. Works really well.
Really cool problem solving. Is it possible the transom of the ship itself is also flexing? Would it be beneficial to weld a rigid plate in place to keep the motor rigidly in place? It may not be the primary problem, but would it help to provide secondary rigidity?
Yes, it’s flexing a bit, but not much. Shims did most of the work. Just needed To straighten the elevator Drive match the shaft.
Between motor reduction gear box and shaft use a tensioner torsion arm with a bearing on the shaft close to the gear and perhaps substitute the single chains for double slat chain
I may try one of those Floating tensioners at the elevator or box was designed for two sprockets and not a duel chain. The teeth on the sprockets are half a tooth offset. Not sure why they did that.
I am subscribed to Ship Happens. As for watching your videos and Ship Happens is the fact that I am retired and in my 70's and live a long way away from water now. But when I was younger I restores a 7 ton wooden motor sailer and did a lot of sailing with the Oneida II. But I am sill not completely retired. I am building a 1930's SG 38 Schulgliter as well as building a 1930's midget Racer and oh yeah I have to keep working on my wifes 1949 Studebaker Champion. I also drive a 1971 Honda CB 350 that is a One Owner. A lot of year of fun biking.
That's a chunk of deflection for sure. Sadly the cheap chain tends to stretch and deform a ton when new. It's almost like it needs to be hardened a bit and they just skipped that step.
But anyway I am sure you will get it all figured out. Been roofing again. It's a pain doing it alone but got about 15% of the 2000 sq feet done and that had cuts along the one side with about 1/2 of them being angle cuts. Going to take a break for the holiday and then get another section torn off and sheathed, underlayment installed and then roofed. Probably end up splitting each side into quarters or somewhere around there but hopefully have it all done and NEVER have to do it again.
Have a good holiday Doug and I'm sure you have a place to head to but if not drop a line and head my way. It's only about 60 miles out here and a nice drive along 412 and 64.
Harbor freight titanium or tantrum 110v small welder works awesome. Welded 3/8 good. Pulls very little, and is super light. Pushed it to thermal shutdown and it took a while.
Looks to me like there are two things happening with the roller chain. One is that the sprockets are eccentric, so the chain comes in and out of tension. The second is that when the chain comes under tension it stretches, so that it doesn't match the pitch of the sprocket, which increases the tension more. I think that is why they are riding up and popping.
I think I just need a little more chamfer on the teeth if anything at all.
@@SVSeeker Yeah, try the easiest stuff first. You could open up the gaps in the sprocket a little if the chain stretch continues to cause problems.
@@peripheralarbor That’s the plan.
Hey Doug. Just my 2¢ but if you look at the time 13:57 it looks like the davit arms are flexing and throwing the alignment off for the pulleys making the web belt track. If the davit is only used for that boat, measure the distance between the lift points on the boat and weld a spar between the davit arms to keep the same space under the heavy load of the boat.
I think it will move a lot more than that when at sea. : )
Doug great work on the boat love the content... Just a suggestion you should install a breaking system on the main lift shaft not to break when lowering but to hold when in transit, I've seen the break in motors just like yours fail an if you're break faild when sailing you might sink your dingy
Yes. There are a couple of things done for whale boats that I saw and liked while at Mystic Seaport. That will be coming later.
Love the Ship Happens Channel !
Doug, do you think you might have a smoother davit drive using the webbing to replace the chain drives... use the strap/webbing with a pair of pulleys to replace both chains and pulleys... no synching etc..the webbing can handle that load right ? Pick 2 pulleys, with the smaller having big cheeks or sides since it will have more turns of strap winding up altogether when boat is raised. The new drive mount will give more clearance for small pulley re to big one..
No webbing I know of.
Hay doug I love your vids have watched them all reminds me of being able to fix fabricate and build anything I'm now disabled in wheelchair blew my back to bits at work can't wait to see you in the water chur chur from tauranga new Zealand
You always lift my day
Have you considered attaching a chain tensioner similar to a cars fanbelt tensioner? If you put one on each chain they would act independently of each other keeping constant tension on each chain or even something similar to what's used on a 10 speed bikes rear wheel ?
If I do add a tensioner it will be more like a bit of plastic or a floating tensioner.
@@SVSeeker that's kind of what I meant, the one on my car engine has a spring pushing on the tensioning wheel keeping a constant tension on it , actually the bike one also does if you push on it ,it will spring back against the chain when you let go. I'm a thousand pct positive that you will come up with the perfect fix. Your an amazingly smart man who never ceases to amaze me with how well your designs turn out. I was just putting my 2 cents in lol. Can't wait to see you splash her.
I appreciate YOU, Doug. The videos, the project, the ups and downs are just part of the picture, it's your attitude that really makes the difference.
Thanks. It's the attitude that takes most of the work and is also the most rewarding.
If there's any stretch in that flat webbing you used, you might actually (counterintuitively) need a convex pulley to stop the strap walking off. Something about the differential stretch across the webbing means it will self-correct.
Could be wrong, so don't just take my word for it!
Nope, you're correct! Same as sanding belts.
I picked up a couple of keel rollers for a boat trailer. They have short side to them so I think they'll work good.
Whatever works is all good! Keep it up. I love this project!
@@SVSeeker add a link so that they can swing.. I’ll think you’re good
I had similar thoughts, you would think a pulley with flanges works better, but actually causes a flat belt to slide off. A crowned pulley will help. It looked like it was hanging uneven too. The crown may not be enough compensation.
Good luck Doug.
Is this boat ever going to be put in the water?
Tuesday
Hey sir, the problem with your winch reel is that the shaft that you were sitting on, is bent and causing the chain sprockets to be out of alignment. Also, apparently the two chains are different lengths or have stretched to different lengths. You aren’t going to be able to fix the problem until you fix the cause. Good luck! Now I’ll finish watching the video.
Some side guidance will help but you can also make the roller slightly barrel shaped. The barrel shape will help the strap self-centering on the pulley. They do the same on engine timing belt setups and in the past the used it on belt driven farm equipment.
Yeah, I've tried that with little to no success but I may give it another shot here.
If you can't get the bushing to work, you could look at a worm drive to eliminate the chains altogether. It would have an added safety feature since currently if both chains break, you will dump the tender and possibly get hurt. They are used on boat lifts all over the Gulf Coast.
Thanks mom we’ll be careful
One of the designers at my dad's marina decided to control the davits on his seawall with a garage door controller. My dad told him it would work but would have issues with interference. Being the early 80s those controllers were not as secure as they are today. So of course he gets home and finds the bow of his boat almost to the top and the stern was in the water. He tried to change the settings but the next day his wife called him from home. She said it was fine until a little after 5pm. As people came home it started going up and down. 😆
Doug For the pulleys for the flat webbing you need the pulleys to look like this () the curve will keep the belt in the center by forcing the outsides of the belt to run slower then the inside because of the different radius's in that shape pulley. If you look at the end end rollers in a belt sander they have a tiny bit bigger center diameter then end diameter. this along with proper alignment helps keep the flat belts in the center
Yeah I've had lackluster experience with that on my belt sander, but I might give it a try.
Great ending message
From my days of motorcycle riding and other chain drive things: The chain and sprocket teeth don't match in pitch. That's why it keeps popping off. Either the sprockets are worn or the chain is the wrong size, most likely the sprockets. You can see the chain climbing the teeth until it finally pops over to the next one. You can get split sprockets (from side to side) that bolt into place and can be changed as they wear.
Those are sprockets I made, the only thing they might need is a bit more bevel on the side of the teeth, but there working good enough as is.
@@SVSeeker Check the form of the teeth they should not be straight up the side. They should have a shape that cups the roller of the chain to retain it. There should be stuff on line from bearing/gear companies that discuss the shape of the teeth. I can see the chain roller climbing up the tooth as it goes into strain just before it pops off and to the next tooth.
Beautiful Boat
I need to remember that. ( Appreciate what you have today. )
I could not tell for sure but it looked like your sprockets were not in time with each other, it will make a difference if you have a strap link or a roller link coming over the top when you are running duel chains,
They are not. They are a 1/2 tooth out. Just like the sprockets on the elevator drive. No idea why that designed it like that, but that's what they did.
Thanks Doug, been following Ship Happens for a while, but as you say true grit, big boat !
When the boat is pitching and rolling, what are the chances the engine room door will slam into the V Mac?
None. There is a door latch that will stop the door and hold it open. ua-cam.com/video/WdEGvxrA2f8/v-deo.html
On your portside shiv, when you remake the roller with cheaks, do you think putting a crown in the roller would help it track center? Just a thought.
Might bevel the teeth in a bit more but only then if it needs it.
Thank you for the mention Doug! I don't know how we inspire and motivate you as you are a highly motivated person and you are unstoppable! Your bottom will be wet in no time as we all know by now you get stuff done!
Congratulations guys!
Your in the big-time now!
Don't forget us lil guys when you get Uber famous 😉😁😅
the problem with 2 chains is a classic one you see in lots off engineering like using 2 regulators (electrical or pneumatic)
unless there 100 percent perfect to each other (not possible) one will always do all the work.
they make duplex chain for this reason though
That's an exaggeration, but as the second chain is redundancy it also makes no difference.
@@SVSeeker It's mismatched pitch, the sprockets are loading each chain at a slightly different point, and each tooth increases the error until it's too great and the chain jumps. You just need 2 double sprockets and a double chain. Have run these of combines for 30 years with no problems, just can't time 2 separate sprockets unless they're keyed on the shaft in exactly the same position. You'll get there. Hope to see you on the water soon. ;-)
@@paulm3080 You should talk to the guy that designed the elevator it came out of. : )
@@SVSeeker Initially he is largely right, and what you demoed it is definitely the case. You can see the slack in the tension side of one chain. One is slightly longer (or closer) than the other so the shorter will take the whole load. As long as they are close to start as it wears they will even out. Unfortunately I think you are going to have troubles with in until you put independently adjusted idlers, with adjusting screws (not springs), pushing inward. Then the large differences can be compensated for, and pushing inward will increase the chain contact with the sprocket reducing the chance of slipping.
I hate to say this as I know you don't like it, but that looked pretty dangerous wiggling that chain under load the way you did. It could have been the little bit extra needed to cause it to slip another tooth. Use a screw driver or something and keep your fingers. I get it when it's things like guards that make it difficult to work, take longer or otherwise interfere, but cases like this there is no need. Pliers or any rod would work.
Good luck figuring this one out. The lack of rigidity of things could make it problematic hopefully the bearing was enough.
I am not engineer but I don’t need to much knowledgement to say the same as the others guys here, those sprocket aren’t matched and it’s easy to see it, better to use double chains sprocket.. it’s up to you to continue with it or change the whole thing
Do you have some type of safety catch that clicks going up but going down would catch unless you manually kept if from doing that, similar to a car lift safety feature? Just wondered what would stop it from free falling if both chains broke? I have a boat lift that was built in the early 50's that was designed to lift classic wood boats from the D rings and its a cable in cable out system like how your old outboard steering is wrapped around the hub. My grandfather built his boat track system like that in the early 60's. Would be happy to email photos of both if could aid in something in the future. Thanks for all you share.
Water would stop it from falling if both chains broke. : )
@@SVSeeker Doug that was so funny when I just noticed you responded. I agree but not so good if when you were practicing over the trailer or pavement. lol. Was so cool to see your response, maybe someday will send you photos of what I have done.
Sorry too busy to watch this week Im busy making something today!!🤣🤣🤣. Hope you get afloat soon 🙏 sir. Watching in 🇮🇪 Ireland
When u re build the pulls might try having the center cuped some to help keep it centered also having some feed rollers in front to keep centered so when boat isn't on flat ground it doesn't get off center then also.... I seen comment about a speaker bar that might actually make more issue causing a hinge point cause more flex issues
Might add a little more bevel to the sprocket but it's working well as it is.
@@SVSeeker tilt the boat 5° side to side an see how those pulls work with that strap is what I'm getting at seeing the frying issue on shore makes think that will be a bigger issue not so much as in Port but in a Anchorage when u go to shore
I've followed your videos from day one, as a disabled person it's been inspirational and helped get back to welding, I also follow Gemma and Simon (Ship Happens) the make me feel like anything is possible! Thank you one and all!
Anything is possible if you put in the hard work and stick at it! Doug has proved that! Xx
Hi Doug, for that flat strap that rides to the edge of that pulley, it might be a long shot, but I once saw a demonstration that a convex roller will keep a strap like (in the demo it was a rubber band) from wandering to either side. It's counter-intuitive, and had to do with the band (strap) material stretching more in the middle. Something about that caused it to ride to the high spot, oddly enough. Might be worth a shot to see if it works on that strapping. Since you have so much weight on it, it might behave like a band?
Yeah, a lot of folk commented with that. My experience with it on my belt sander has been lackluster.
Could you use double roller chain?
Growing up on the farm as a kid most of the equipment uses double roller chain. I assume it’s more durable and might help in this situation as it’s double wide
It was previously an elevator and was designed with one sprocket 1/2 tooth out of sync with the sprocket beside it. We have no clue why they did that.
We used to use straps on our Corsair Trimaran to raise the mast using the trailer winch. Several people with the same boats had the straps break and the mast fell down during the raising process. The designer specifies to only use dyneema line on the trailer winches if the trailer winch is used to raise or lower the mast. Straps fail two ways, one the sun weakens the nylon. Two a fray becomes the weak link and the strap tears from edge to edge. Inspect your straps often, of go to dyneema
Everything gets old and breaks. Even dyneema.
@@SVSeeker yep but dyneema on the raceing sailboats I am used to lasts way longer than the polyester and nylon lines while taking far higher loads and chafe. Dyneema is fantastic
Chain tension is pulling motor and gearbox up the slide holes. Need tension bolts to hold it down.
No, it's holding tight.
Did you rebuild the belt pully yet? I was thinking you need a center crowned pulley wheel like a band saw pulley or old farm equipment used to use, that would keep the belt on center.
Video is up now on patreon. www.patreon.com/svseeker
what about cutting out ! link on the loose side and add a half link?
I like the slots better, they give more adjustment range than a half link.
I've seen all of your videos.... Unfortunately for me I live in a spot that I can't go out and work on any of my projects... Can't wait to get a place with a garage, yard and NO HOA!!! Also look forward to seeing how you fix the roller on that pulley as well as seeing old girl floating!!
Yup. I lived in an HOA once in my life. Never again. : )
Thanks for more teaching of Life's ups & downs BTW, you get lots of informative COMMENTS, too! Shows the 💟 you get.
BTW, PLEASE cover the chain & sprockets. They are finger, and everything else, separators.
I like that there right at Nutsack height. I figure that if you’re stupid enough to get your nuts in there that you will undo some of the damage done to human DNA by bicycle helmets.
👍 🤣🤣🥴 hey, 🦈 gotta eat too! 😎
Used chain drives on some older wrecker setups. An idler sprocket would also work
Yeah. I might try a floating plastic tensioner. Saw one on a boat prop drive once.
Been watching Ship happens for a while...love the project but that is soooo much boat to work on out in the marsh..I really hope they succeed cause it a beautiful boat..
Ship happens is great and have watched all yours 😉 had a lot of down time at one point still keep up to date but watch yours and there’s as I know it helps and pays you shame your not in water yet but it will come
Toujours au boulot bravo 👍👍👍👍👍
When you finally get the winch sorted out, make a cover for the chains and sprocket..OSHA hahahaha
Fuck that. If you can't figure out to keep your balls out of there, then it's best you not have any.
Is there something to keep the boat from just falling down if both chains break? My mind went to thinking a ring and pinion setup but with deflection it probably would just skip a tooth
Water
I wonder if a slightly concave pulley would help self-center that strapping and prevent it from running up on you like that.
Might, but I've not had good results with that in the past.
Having done my boat dream, when she hits the water, your entire set of issues are gonna change. CHeers.
I have been watching Ship Happens since the first month!
The stainless chain well needs a good lubrication system. Preferably a wet system where the lower sprocket runs in oil. The motor must have adjusting bolts so the pull of the chains will not move the motor out of adjustment. Non-stainless chain well lubed would last longer.
A little grease is ok but you can't us oil over the water.
How about adding another sprocket to the mechanism with a tensioner.
Your chain looked like an O Ring chain. They stretch to easy on high loads. I choose an X Ring chain on my motorcycle. Maybe that will help you. Also keep an eye on the bearings? May need different bearing setup?
Hi Doug. Constructively, the bearing is helping but looking at the video in slow-mo it looks like the ratio of the motor drive sprockets to the shaft sprockets is off. It's all about Ti-ming 😁The ancient art of Japanese synchronicity. The smallest differential in any of the drive sprockets to shaft sprockets is multiplied by number of revolutions. This is why it starts off fine then goes out of sink causing the chain to be forced in to jumping the sprocket. All four sprockets do not appear to be the same ratio (sizes). Look at your footage in slow mo. Note the lag in the chain drives one to the other. Something is out of size. When you make your new strap rollers; give them a flange but don't make the centre section flat. Make it convexed like the old time belt drive worksop pulley's were. This helps keep them running central and in lign. Hope this helps. Sail Safe mate. Ant, Cid & the pooch crew.
Sorry, I have the ability to look at it many more times. And from many more angles. Pardon me if I trust my eyes. :-)
Doug, why not just some idlers on the chain? Some springs to hold the tension on the loose side to take up the slack.
Don't think it needs it now, but I might try a floating tensioner latter as they are easy to make.
Will the flat dingy straps work in rough seas?
You think the straps are afraid of rough seas?
Damm Doug you just gitter down good luck keep on trucking
Would switch out for something other than flat straps also. Still change out the roller style up too and and some more bearings spread out to decrease the deflection. Other grab a laser level and cast a line up and down everything just to verify it's all inline. Just some thoughts like everyone else. 🙂
Might use line but it's a lot better to try it first before giving up. Too many give up too easily. And the boat's life points were built to the davits. Besides, we're not going to get laser level when lifting from rough seas. : )
A Double spring Loaded Idler Sprocket attached to the Bulkhead that would keep constant tension up the sprocket chain thus allowing the slackness to be taken out of the chain...
I don’t know how to express my love of your migivership abilities.
I hoist my 9ft dinghy with its 5hp outboard by hand. I have a two double pulley system on each line. Couldn't hoist it with just one single pulley.
That tender weighs about 1200 pounds.
@@SVSeeker I can tell it's heavy. That's why I suggested more pulley power.
If the chain is crawling out on the sprocket like that it means that the chain is worn long.
You can check how bad it is by pulling out on the chain when it is tight on the sprocket. If you are able to pull out some chain links at all then you need to replace the chain. If the chain and sprocket module length is the same you cant pull the links out from the sprocket.
No I think it does that because there’s not enough chamfer on the teeth and the alignment was not ideal. The fact that I can work fine on One chain I believe to be evidence of that.
@@SVSeeker it still shouldn't happen if the is no wear. If the chain and the sprocket aren't worn the chain can't crawl out like that.
Hey lifting with those straps, just put a crown curve on the pully to center the belt if you didnt already. Look up Crowned Pully. (this is assuming you didn't already do this or know about the physics of it)
I may give that a try, but results on my belt sander has lackluster.
I just got an idea for a tensioner that works both ways.. - a wheel between the sprockets that you pull towards the small one to tension..- so that it can swing to the slack side..
Ok. But the chains are only loaded on one side. Up or down.
Yeah, I think the area that the motor is mounted needs to be reinforced,the whole transom could be bending.
I does some, but very little and not enough to stop it from working.
Spring loaded sealed ball bearing idler on both sides of chain?
Split and sealed ball bearing at that, and for 4 FPS over 2 minutes working time? No.
I’m in favor of idler sprockets on springs to keep tension on the chains. All you really need to do is keep the slack of the trailing side from binding up or getting so loose it wants to wander off.
Maybe but I think it's just a little more grinding a chamfer on the sides of the teeth.
Think I would have just made a tensioner like on a timing chain on an engine just to hold the slack from the chain could have been any sacrificial piece of softer metal like brass or bronze aluminum even
Plastic is often used for a slide tensioner.
Am I seeing it right that if both chains popped off the tender would free fall?
Yes, but don’t worry. I am going to install water underneath the tender. ; )
@@SVSeeker and some keep clear stickers too? :)
when is the splashed date now ?
Tuesday
I bet a slightly V shaped shiv on the pulley for the webbing would help to keep it centered.
Maybe. Most of the time the argument is for convex, however I've had lackluster results with that in the past.
A friend of my friend is my friend?
Are the two big gears timed? Could be the camera but it looks that they’re not..
Yes. See one of my other 30 replies for more.
Use a thick trans chain usually in awd's, I'm rebuilding a GM 6T45 trans that has a massive 1"+ output chain!
Just use the whole chain/cog set & weld or smith the correct shaft connections
Really like the stainless steel chain for our purpose.
try a duplex chain and duplex sprocket set and install a chain tensioner simple jockey wheel should work fine.
It looks to me that the sprocket and chain are different pitch. Maybe imperial v metric??
Looks like the motor shaft needs support. It might be flexing a bit too
No it's like an inch and a quarter. There is more flex in the hull.
Why use the chains? Could you make the sprockets into gears and just have them mesh up directly? I might be missing something obvious, just a thought!
It's an old elevator lift and it used chain.
I think the easiest way to stop those chains from popping off is to put the sprockets and motor in the center of the shaft. I think what is happening is, in a non loaded state the driven sprockets are parallel with the motor. As you load it the shaft it deflects, and the driven sprockets are no longer parallel with the drive sprockets. So in that case think of it like a differential in a truck. The inside chain is turning slower by a tiny amount than the outboard chain. Where in a differential when you turn and your rear wheels are moving at different speeds you have a mechanism to let one of the wheels slip in order not break the axle half shafts. If you had one larger series chain and sprockets, you could probably get by with the location you currently have. Even if you shim and adjust it like it is, it will always give you problems.
: ) That is creative thinking. I hope to go on the build things.
Is it me, or is the hull where the drive is bolted, not parallel with the pulley shaft? That would cause the chain sprockets to not be parallel.
That's why I shimmed it. And why it's working now.