home made camper jacks - 12v motor suggestions needed

#1
I'm thinking of making some camper jacks myself from fibreglass pultruded profiles "inspired by" the basic Rieco Titan mechanical design attached - concentric tubes, single direction threaded rod, top thrust bearing. I'm UK based, so jacks this long are not widely available to buy, and are so heavy that shipping makes them even more expensive than they already are.

As far as i can tell the 90 degree bevel gearing on the top of the jack is a 1:1 ratio, and RT sell an adaptor to allow them to be driven by a normal handheld drill, so that given me some idea on speed and torque needed to drive them.

So, if I want to add motors to each jack powered by the camper battery what is going to be my best source of motors? The obvious choice to me would be the motor and gearbox from a cheap 12v cordless drill body. Or a similar 12v corded impact driver like this one may be slower but with more torque, but would the impact action damage the jack over time?

https://www.amazon.com/Wagan-2257-12V-Impact-Wrench/dp/B0038KNJQ6

of should I look to other automotive motors such as wiper motors, electric window motors, or more generic 12v motor/gearbox combinations from ebay but then what speed and torque /gearing ratio would be suitable?

https://www.ebay.co.uk/itm/DC12V-Reversible-High-Torque-Turbo-Worm-Geared-Motor-0-6-120RPM-Self-Locking-UK/263753103864?hash=item3d68e8f9f8:m:mlOEqH5BlKnIhLYUSK_5wEQ&var=562966073948
 

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#3
How tall open / closed? Do you need them?
probably around 900-1000mm total length closed, with about a 600-700mm travel depending on whether i base the camper on a Ford Ranger or Nissan Navara and whether i lift the body or suspension. Its all still at the planning stage at the moment, but i'm trying to get all my design work done early so that when I am ready I can purchase everything i need quickly to get started. As soon as I start to build my subframe i'll need to make and fit the jacks to that so I can mount it on and off the truck easily
 
#4
Better finalize your plans a bit. because in my brain something keeps telling that's a real odd size, but the voices have been wrong before.
 
#5
The Rieco -titans advertise 36" lift and happijacs 34.5"

The standard bed height on a Nissan is 457mm, add upto 100mm suspension/body lift on that, allow for a bit of uneven ground and you get to about 600 mm from the base of the camper when they are retracted to the ground - i don't expect the camper to be anywhere near as high off the ground as some large US pickups, so won't need as much lift and clearance. And I can always start by making them overlength and cut them down if needed - certainly easier that way round than extending them once they are built.

But the main thrust of the question was cheap motors to drive them ......
 
#6
If you use the MOTOR from either a drill or Impact it shouldn't make any difference. It's the gear box / drive portion that's problematic. We use plain old Scissor jacks For camper stability, nose and rear of the frame. I use a Dewalt cordless impact.
If these are permanent mount I'd go with the worm drive you showed, IF they are weather proof.
 
#8
If you use the MOTOR from either a drill or Impact it shouldn't make any difference. It's the gear box / drive portion that's problematic. We use plain old Scissor jacks For camper stability, nose and rear of the frame. I use a Dewalt cordless impact.
If these are permanent mount I'd go with the worm drive you showed, IF they are weather proof.
You might Google images ”12V DC gearmotor”. You will find plenty of examples to gain ideas from.
I don't think just the motor will work - generally electric motors spin fast and rely on a gearbox to slow this down to something useable and increase the torque. And of course in this use the gearbox has to be strong enough to cope with the torque needed.

Lots of 12v gear motors on google - trick is finding the right one with the speed and torque that I can get easily in the UK, hence i tend to search on Ebay as its easier to find country-specific vendors

However, I think talk of scissor jacks has led me to a winner

https://www.ebay.co.uk/itm/2Ton-Car...Repair-Wheel-Change-Garage-Tool-/122963781351

the motor must be the right speed and torque for lifting the sort of weight i need as a scissor jack is a similar mechanism, the gearing to the screw looks flat enough to fit over the top of the jack leg neatly , and it comes with a manual crank handle so it means i must be able to turn it manually if the motor fails, and it even comes with a switch i can cannibalise to make a plug-in remote control box for all 4 jacks.

thanks
 
#10
I bought gear motors on ebay and fabricated screw jacks. They’re pretty quiet and have a high torque rating. If you look through my Facebook photo album you’ll find pictures
definitely interested but i'm a fecalbook holdout. Any chance you can point me at which of the dozens of ebay vendors you bought from here? yours look lot chunkier than anything I've found on ebay so far, and the strongest I've seen documented on there only come in at around 3Nm which is about the same as a hummingbird with a jewellers screwdriver....

thanks
 
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#11
I tried to look up who I bought them from but can't find it. They were surplus modine gear motors used on CNC machines I believe. I think I paid $100 for the pair.. The last number is the bodine part #. They are kind of big but very robust and torquey


Your purchase
Gearmotor 12 Volt VDC 41 RPM 5/8"
HIgh Torque 23 Amps Bodine
42A3BEPM-E3
 
#12
Thanks but i don't think they are going to be viable for me - only 1 seller has 12/24v versions and at 8rpm the ones he has are too slow for the travel I need and they are only available in the US for USD135. add international shipping for that weight at about USD90 and they are also just too expensive. :-(

but good to know someone else has done this....and it looks like you got a great deal on them
 
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