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Thread: Wheel chair lift
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24th Mar 2021, 05:01 PM #31Most Valued Member
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dentistry in the shed
Hi fella's, I thought that I had better have a squiz inside this winch motor, its not too bad but it did need a couple of fillings....
I have always managed to be able to avoid cutting a gear, not this time, so this is my 1st gear and it is prolly not perfecto but it should do the job.
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24th Mar 2021, 05:56 PM #32Member: Blue and white apron brigade
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One way around this problem (and you might want to do this anyway) is to drill holes through and weld a couple of nuts into a corner of the tow bar hole. Bolts through the holes wills lock the tow bar well and truly into the hole. I first saw this on a truck hitch used for were towing a bobcat trailer about 10 years ago when I saw the bloke putting them in. Anyway I just so happened to see that hitch the other day - smothered in grease but still tight as a drum.
I've used this approach several times - this was a locking bolt for a removable vice inserted into a SHS post on my MW bench.
For the vibe experienced by a motor vehicle an extra locking nut would ensure it stays on the vehicle.
Attachment 391331
For your setup you'd probably also only need one bolt.
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24th Mar 2021, 06:09 PM #33Most Valued Member
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Thanks Bob, I have a plan for an anti rattle device that might also double as an anti theft device, for the mechanically challenged that is.
Bob when trying to view your pic i get this
"Invalid Attachment specified. If you followed a valid link, please notify the administrator"
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24th Mar 2021, 06:12 PM #34Member: Blue and white apron brigade
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I'll try uploading it in a different way (using manage attachments instead of the insert image icon)
lockingB.jpg
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24th Mar 2021, 06:36 PM #35
Hi John,
Lovely job on that gear ! Thanks for the pictures.
I didn't realise that those motor drives were so heavy duty. Next chance I get I will see if I can salvage one to play with.Best Regards:
Baron J.
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26th Mar 2021, 04:31 PM #36Most Valued Member
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Back to the drawing board
Hi fella's, I did a little lifting test today, the result was not so fantastic as the winch motor did not have big enough balls.....
It struggled to lift 56 kgs and I need/want 100 kgs from the winch, I had fitted new brushes and everything turns smoothly?
The battery I used is in good nick, the winch unloaded turns at 60 rpm and pulls 3.5 amps, lifting the 56 kgs it pulled 13amps.
This winch has one more chance to pull its socks up and do its job or else it will be replaced with the chinese winch
The motor might work more efficiently with 24v so I will see how it goes with one of these before I chuck it in the bin.....
https://www.ebay.com.au/itm/Waterpro...wAAOSw2nxf4sCv
some pics....
ooopsie.... I should read things properly before pushing the buy button...i will suck it n' see i spoze...
"Note:This item cannot be connected to the motor, which will produce high voltage when starting and damage the product."
The output of that step up converter will be wired to the motor reversing relay, if I put a diode on the pos wire would that be enough to stop any voltage spikes from damaging the converter? Maybe an electrolytic cap also? This was supposed to be a reasonably simple job.....
Last edited by shedhappens; 26th Mar 2021 at 04:44 PM. Reason: more info
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27th Mar 2021, 07:06 PM #37
Hi John,
I agree that as it stands you probably need a higher voltage to drive that motor to its full potential !
Putting a diode in series won't suppress any spikes coming back from the motor, you really need a snubber across the motor to do that. A 0.01 uf 1Kv ceramic cap or two might help if you go down that avenue. They need to be as close as practical to the motor brushes, you might even be able to put them inside if the space is there.
You made a brilliant gear to replace the damaged one and I think that you geared another device down, would it be practical to put a 2:1 gear in between to give you the extra torque ?
Alternatively could the cable run be modified to give you the extra pull, a bit like a pulley block. Either way the lift will be slower, but that might be an advantage !
HTH.Best Regards:
Baron J.
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27th Mar 2021, 07:32 PM #38
Nice job on gear, it looks really great.
Sent from my 5007U using TapatalkUsing Tapatalk
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27th Mar 2021, 09:17 PM #39Most Valued Member
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Hi John, thanks for the heads up for the snubber.
A 2:1 gear reduction could be a possibility......
Today I put quite a bit of time into trying to get another pulley in there, one more pulley would give a 3:1 reduction ratio and also slow the lift speed a bit. So far I have not had a light bulb moment, no matter where I try to position another pulley it interferes with arms, other pulleys and the travel in some way to the top.
Tomorrow I think that I will pull the chinko winch apart again, that thing would not last very long out in the weather so maybe I can fit seals to it and put flowable grease in the gearbox, that might shut the horrid rattles up a bit.
Also thinking that I will give some thought to fitting a lower amperage motor to it???? Have to see what I have that is reversible.
Thanks Dave
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28th Mar 2021, 09:51 PM #40Most Valued Member
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I cleaned out the gearbox on the chinko winch today, there was a couple of metal flakes and quite a bit of small grit sized particulates in the grease.
I put it back together with some new grease and clamped it onto the lifter for some testing to see if it was going to be worthwhile spending some time on it.
I loosened and turned the end cap on the motor as far as it would go anti-clockwise and nipped the screws up, the 1st lift was the same 56kg as in the earlier tests with the wimpy winch, no probs lifting it and I got a reading of 36-37 amps.
I then turned the end cap as far as it would go in the clockwise direction and repeated the lift, 21 amps
This was promising as I need it to work at under 30 amps, that is all the juice that I have at the back of the car and would like not to have to upgrade that wiring.
So I piled on some more weight and brought it up to 103 kg, a few lifts seemed to average about 23amps.
I will now see what I can do with this winch, it really is a POS and its current design would not do many lifts before it fails.
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28th Mar 2021, 10:16 PM #41
Hi John,
You might find a sweet spot when adjusting the brush position !
Looking good !Best Regards:
Baron J.
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1st Apr 2021, 03:36 PM #42
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1st Apr 2021, 07:39 PM #43Most Valued Member
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nah.....not the chinko winch
I think that to bring the chinko winch up to scratch is beyond my capabilities..... 1st I know nothing about gear cutting and I always look for a way to get out of it, I reckon this gear would present some difficulty to make from steel.
The main problem as I see it with the chinko winch is the aluminium alloy output ring gear, I don't think it would last too long before it buggered up, I have no idea how long it would last before the spline stripped out of the centre or the ring gear stripping or breaking, not much meat in the centre there, but I don't trust it and I want to be confident that I don't get stuck somewhere with the chair with a bent axle from descending rapidly or not loaded back into the car.
So I was poking around looking for gears and found these gears from a ride on mower transmission, 1st and 2nd gear sets will give another 5.08:1 reduction. The plan is to make a new spool with larger id brgs and run the drive shaft through the spool to the other side into the new reduction box that will drive the spool from the opposite end to the motor, so basically i will be copying a 4wd winch.
The new chair was delivered today so i had better get my finger out.....
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11th Apr 2021, 03:12 PM #44Most Valued Member
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gears and shaft
Hi fella's, the gears are made out of sintered metal and are very hard, one gear was bored out and rather than welding centre's into them I made flanges, riveted the gears to the flanges and welded one flange to the shaft, it could have done with a bit of a larger weld bead but it will hold and it wont have much thrust there so it should be ok.
Just out of interest I did a bit of trial welding on an unused gear, the mig would not touch it, the weld just built up as if welding against copper. I tried a 2.5 316 stainless rod (90amps) and got slag intrusion between the gear an the square bar i was trying to weld to it, i chipped and blew out the slag and upped the amps to 120 and it welded fairly well even though oil came pouring out of the gear, being sintered they are porous and are full of oil. I thought the flange idea was a better option as i could true the flange after welding whereas the gear could have been all over the place and no way to true it.
The flange on the larger gear is 4140 and the other is 1020, the rivets are made from hot rolled soft stuff.
The splined shaft was cut and used for 2 shafts, for the motor drive shaft i used hot rolled 4140 and finishing on the shafts was done in the T&CG.
The shafts need to be trimmed to length but i will do that after the spool and gearbox housing are made.
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29th Apr 2021, 06:16 PM #45Most Valued Member
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gear case
Rusty steel is in fashion these days so......
here is some progress pics.
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