|639 forum posts|
On a workbench I'm designing I want to stick a small jib crane onto it. 80kg swl at 1 meter so I can hang vices or large bench tools on a rear shelf and generally save my back.
Jib boom is made out of 50x50x6 T section. Probably going to also add a extra wire or bar support coming off top.
Issue is I want a suitably matched hoist and chain hoists seem to be 1000kg, electric hoists are bulkier and still start at 200kg. Has anyone made a minitaurised hoist or seen plans published for one?
|Michael Gilligan||31/08/2018 17:59:05|
14011 forum posts
They may no longer be manufactured, but there seem to be plenty of secondhand Haltrac 'engine hoists' available on ebay.
They are/were very lightweight & compact, but surprisingly capable !
If nothing else, you could buy one and copy the design in something a little more robust.
Edited By Michael Gilligan on 31/08/2018 18:06:57
|Clive Foster||31/08/2018 18:00:22|
|1840 forum posts|
Not seen plans for a mini hoist but basic electric hoist shouldn't be too hard to build once you have a power unit sorted. The robot building folk seem to like power window motors with worm drive to the output shaft. For example :- **LINK** . Probably not enough ooph for you as rated torque is only 30 newton centimetres and stall torque 100. But maybe something similar with more power could be found.
As the lift will be short distance I suggest you use a webbing strap rather than wire to do the lifting as it can be much better behaved on the winding drum.
Always seem to be a selection of electric swing lifts out of van bodies on e-bay for around £100. Ex-BT Penny Hydraulics made ones seem to be flavour of the month right now. Bulky and way, way overbuilt but all the bits will be there.
Edited By Clive Foster on 31/08/2018 18:06:30
Edited By Clive Foster on 31/08/2018 18:07:14
|Mike E.||31/08/2018 18:37:16|
|192 forum posts|
Consider a hand crank winch, the type used on small boat trailers to winch boats up on to them out of the water at a loading ramp.
|John Reese||31/08/2018 20:05:44|
|782 forum posts|
If considering a hand crank winch it should be a brake type winch where the brake engages automatically.
|Howard Lewis||31/08/2018 20:19:03|
|2337 forum posts|
If you visit a yacht chandler, you could buy some small pulleys (blocks) and some suitably strong rope and make up your own multiple purchase hoist. (They may even offer double or triple sheave blocks, which you could use, and save a little space. Haltracs were four fold purchase, from memory.
Possibly, for what you have in mind galvanised pulleys for washing lines from a D I Y store would suffice, although possible a little bulky.
With a fourfold purchase, each line would be carrying a quarter of the load, so unless you are planning to lift 400Kg, fairly thin ( 5 - 6mm dia?) polypropylene or nylon rope would suffice.
It would not be self braking, so you may want to add a lashing point to the bench so that you can tie off the rope whilst moving the load from Bench to Shelf, (or vice versa) before lowering.
|Michael Gilligan||31/08/2018 20:37:11|
14011 forum posts
Here is the Silverline 'tribute' to the Haltrac: **LINK**
Silly cheap ... but I'm not sure if it includes the Autolock function, which was useful on the Haltrac
4724 forum posts
If you used one of the over the top ones you mentioned initially it could be put under the bench and the wire fed up through a steel tube or Bowden cable tube. The problem with the Haltrac is that without a load it is difficult to pull the hook down.as the multiple pulleys add a lot of friction.
|Michael Gilligan||31/08/2018 21:22:00|
14011 forum posts
I've been looking for this whilst listening to Marin Alsop's Bernstein Prom ...
Success at last : **LINK**
The Haltrac patent ... with an excellent drawing.
|Paul Lousick||31/08/2018 23:01:10|
|1168 forum posts|
Small hoists using ropes and pulleys are available **LINK**
also 250kg chain blocks (they are fairly small)
I would suggest that the design on your bench hoist support may need bracing as it may flex when under load
Edited By Paul Lousick on 31/08/2018 23:09:00
|Clive Foster||01/09/2018 00:21:55|
|1840 forum posts|
Time to do some diagrams of the area the lift jib needs to cover along with the highest and lowest end point positions. I too have a jib crane lift thingy concept on the go and currently having issues reconciling jib end positions and hoist mechanisms to get something that works well in all positions.
My take is that multi fall rope and pulley systems work well if you have headroom. Rapidly become something of a PIA at low level. As has been mentioned before multi fall systems have considerable inherent drag and may well not come down unaided unless decently loaded.
Hand winch systems tend to be easiest to use standing up with the winch around waist height. With a swinging jib you need either to pass the lift cable or strap through the centre of the pivot or have some sort of guide to stop it coming off the pulleys. Swinging a hand winch with the jib works with the winch on top but in other positions it can be hard to use. Personally I don't like cranking on something that isn't properly solid.
Dipping jib systems, as frequently used to lift in mobility scooters into cars, are very effective. Especially if you can be cunning about jib shape and pivot position. Probably the most versatile arrangement combines a dipping jib with some means of adjusting the cable or strap fall length. A proper winch is overkill. I'm looking at a ratchet strap mechanism for this job.
Electric power drive makes the design much easier. Whether via winch or using a battery drill turning a threaded rod to move a dipping jib. If you don't need a vast movement on the lifting eye a threaded rod and battery drill can be adapted to pull the lift cable or strap. Pass the lift cable or strap round a pulley so the length change is twice that of the nut movement on the screw. I guess maximum feasible length of the screw would be in the region of 4 ft.
Needs to be a simple hook on and go system. If you have to futz about with it to set up for particular jobs you will only use it in real emergencies once the novelty has worn off. If then! How do I know? Put my back out 4 times so far 'cos it was "too much faff" to use the lifting gear I have. Not helped by it being "too much faff" to sort out something really easy to set up and use. Chain falls and I beams in the workshop now. Car loading and outside jobs still a work in (slow) progress. Folding engine crane is "too much faff" personified.
|Boiler Bri||01/09/2018 07:23:52|
806 forum posts
How about using a boat trailer winch if your load is not too heavy?
340 forum posts
The 100kg hoist on this site may be of interest it seems to be a compact design. Here Mike.
|117 forum posts|
What about a pull lift. The smallest I use are rated 250KG. Maybe look for a second hand one on the auction sites.
Like this one.
|larry phelan 1||01/09/2018 09:35:20|
|502 forum posts|
I used a trailer winch when I made my elevating barrow some time ago. It works very well,has no bother dealing with full gas bottles or 40kg bags of coal,from my van to the store. Ideal for lifting my milling vise [a big sod ] to and from the table and lathe chucks up and down.
You need to be aware that such winches are not rated for lifting,since there is no brake to prevent them running free under load,but unless you lose your grip on the handle,this is not a problem. They are cheap and effective,and very kind to bad backs.
Two things I dont like about them.
A The way the cable is fixed to the drum is primitive. Should be a better way,a clamp,perhaps ?
B I think the drum dia is too small.This is not kind to the wire rope. While a bigger drum would hold less rope,it would be kinder to the rope. How much rope do you need anyway,even to draw up a boat?
|Ian S C||01/09/2018 11:28:24|
7447 forum posts
I built a hoist using a garage door opener motor, it hangs on a T section rail formed by welding two angle iron bed rails back to back.
Ian S C
|Ian S C||02/09/2018 10:17:54|
7447 forum posts
I do have another one(no photo), I built it for one of my hot air motors. With double purchase it will drag two foll 20L water containers across the grass, (given time), or hoist one of the 20L containers, just shows what 5W will do if it's geared down far enough.
Ian S C
|639 forum posts|
Thinking about it I realised that the various hand powered options are going to be to some extent a pain in the ass to use when trying to reach over the workbench and to the upper shelf. And as Clive mentions if its a pain to use then I'm gonna end up doing my back in cause of the faff.
I quite like Bayzles idea of a large hoist motor mounted out the way then fed to the crane. Only issue I can see is that I would have to keep the trolley fixed in place or else the force of the lifting would act to roll the trolley towards the motor. Thinking either a leadscrew working in line with the jib boom or a cable looped around a drum and then connected to the trolley. Adds a extra layer of complexity though. Might be able to use a dipping style or otherwise articulated arm to replace need for a trolley entirely, as per mobility scooters. Still working that one out tho.
Ians set up looks pretty compact so will have a motor hunting party and see if I have anything that could be suitable.
Also realised I could forgo T section and make my own T using some 50x6 flat then weld (XX)x6 flat with whatever variable for XX to either make a same size but cheaper cost boom or use like 80x6 and get a stronger one for the same width
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