Omnistep (Thule Single Step 460)

[Jack]

The offending step has stopped working as it should, struggling to fully activate any movement. The step just about moves when the switch is pressed. I have trawled through the relevant previous post and picked up that the battery could be on it's way out. The habitation battery is a good quality make and has not given me any indication, other than the current step problem, that it is deteriorating but accept they don't last indefinitely. However I have swapped the battery with a spare, fully charged, and the step still remains in a state of inactivity!

On the control panel when the switch is pressed the Amps that are being drawn climbs to 10amps+ which should I would of thought be enough power to move the step fully out or in, however, my technical know-how is limited.

 

Are there any other checks I can do to determine where the problem lies?

 

If it turns out to be the step can a strip-down be something to consider (and how difficult would this be) or is it a new step?

 

Many thanks

[Alanb]

Jack,

 

From your description, it sounds as though your step could benefit from a good clean, and perhaps lubrication.

 

I am not into reinventing the wheel, so I am attaching two posts, one from a long standing member of this foru m, (Sorry Brian but I never did manage to remove the bushes.) and one for another forum.

 

PLEASE TAKE CARE! The exposed mechanism can amputate fingers. Remove supply fuses before exposing mechanism, and only restore for very careful testing.

 

Alan

 

(Name corrected - Keithl)

Omnistep Dismantle.odt

Omnistep Repair.odt

[Keithl]

Alanb - 2021-03-06 9:00 AM

I am not into reinventing the wheel, so I am attaching two posts

Alan,

 

Please could you post links to these two threads as I am unable to open your attachments so assume others may not be able to either.

 

Thanks,

Keith.

[lancepar]

Keith,

 

I use LibreOfficeWriter, they open in that, maybe Alan uses that and not MSWord

(Should also open in ApacheOpenOffice)

 

HTH

 

. B-)

[witzend]

lancepar - 2021-03-06 10:36 AM

 

Keith, I use LibreOfficeWriter, they open in that, maybe Alan uses that and not MSWord

(Should also open in ApacheOpenOffice) )

Downloaded both and they opened in MSW Thanks couple for the library

[Keithl]

OK So I tried again and they opened in MSW! Don't know why they wouldn't earlier, I just got an unable to open message!

 

But it would still be useful to add links to the original posts as the full context of the threads could then be seen.

 

Keith.

[Jack]

Thanks for all the helpful replies everyone.

[Alanb]

Keithl - 2021-03-06 11:39 AM

 

OK So I tried again and they opened in MSW! Don't know why they wouldn't earlier, I just got an unable to open message!

 

But it would still be useful to add links to the original posts as the full context of the threads could then be seen.

 

Keith.

Sorry, but both articles are from my library, and originally saved for my own reference. I do not have direct links to the originals, but in both instances the posting date, and posters name are incuded as an acknowledgement. If any member wishes to investigate further, they are welcome to do so.

 

I also confirm that I use Open Office.

 

Alan

[Derek Uzzell]

Keithl - 2021-03-06 11:39 AM

 

OK So I tried again and they opened in MSW! Don't know why they wouldn't earlier, I just got an unable to open message!

 

But it would still be useful to add links to the original posts as the full context of the threads could then be seen.

 

Keith.

The files that Alan provided have a .odt extension (Open Document Text file format).

 

This forum won’t display .odt files, but (as has been mentioned above) they can be downloaded and may be openable in Microsoft Word or by some other applications. On my Mac I can open an .odt file by dragging it into Text Edit.

 

(Tekkie details here)

 

https://docs.fileformat.com/word-processing/odt/

 

.........................................................................................................................

 

The ‘Dismantle’ .odt file is a copy of a 2008 post on this forum and the ‘Repair’ .odt file a copy of a post on the MotorhomeFacts forum. I have copied the texts below

 

.........................................................................................................................

 

DISMANTLE

 

If you can actually reach the end of the step while operating the control, try gently pulling at it while activation the switch. It should come forward, albeit a bit stiffly.

 

It is a nicely engineered little unit, let down by poor installation and bad sealing by Omni. If you remove the plastic shrouds at each side of the step, you will find two screws each end behind these. Remove these, and you can take off the front plate. Watch your fingers around the aperture where the step emerges, the concealed edges are almost surgically sharp! There is a neoprene blade below the step, which you have to fold up to pass it through the "letterbox" slot in the front plate. Once the plate is off, coax the step forward and you will see two crosshead screws in the top of the step towards its rear, with nuts below. At around this point, it would be a good idea to remove the fuse to prevent accidental actuation!

 

Next, carefully release these nuts/screws and remove them, and the bushes through which they pass. You can then ease the step right out, leaving the operating arms behind. If you want to test that the motor is still OK - which I guess it will be unless your kick has done it a mischief - reinsert the fuse and give the control a gentle prod. Keep your fingers well away from the operating arms if you value your fingers, the mechanism is powerful and moves quite fast so involuntary amputation is not impossible!

 

What I guess you'll find is that there is is a load of grit inside the box, and all over the step guides at the sides of the box, which has simply jammed the step.

 

If it is a real mess, it may be better to drop the whole unit from under the van, dismantle it some more, remove the electrical connections at the motor, and take it away to do a proper job. You'll probably find that the top of the box is a steel plate carrying the motor abutting a sheet of rigid PVC, with tape (mostly!) over the joint, both of which slot into the aluminium extrusions that make up the sides of the box. The top to sides joints are not sealed. The floor of the box is another sheet of PVC which also slots into the sides unsealed. The cable enters through a top or rear casing slot, which on mine was less than sealed. So, in the nice clinical environment under a motorhome, just in line with the front wheels, on a wet day it all stays nice and clean and dry - not!

 

Having done all the above once and found the step sticking again, I got fed up with it and made up a kind of inverted protective tray that covers the top, sides and rear (relative to the step) of the Omni box, then used Duck tape over all the exposed joins in the top of the Omni box, lengthened the cable and re-routed its entry through the rear facing side of the tray, using shrink on sleeving between the new length of cable and the existing flexible conduit. I'm hoping this will suffice to keep the grot out in future. Who knows? It lives in a very harsh environment.

 

.........................................................................................................................

 

REPAIR

 

The slide out Omnistor step on my 4 year old van finally refused to move at all. It had responded to a kick or a pull for a year and was making louder creaks. I had removed it several times and cleaned out the grit which gets inside, lubricated the slides and replaced it only to find it soon sticking again.?I came to the conclusion that the motor was no longer able to move the step and a complete dismantling was required. It was quite easy to remove and strip down. ?First remove four small screws in the black plastic blocks either side of the step and then the four screws exposed. Put a support under the step unit and remove two nuts which support the rear. Slide the step unit back and lower to the ground. If there 's enough slack cabling put the step on the support beside the van. If not cut the leads one at a time to prevent short circuits, it would be safest to remove the fuse but I couldn't be sure I had the right fuse as the step wouldn't move.?Remove the metal front which the step passes through, the rubber strip underneath has to be pushed through the slot. Remove the black plastic sticky tape which crosses the top from left to right and slide the plastic panel out. Slide the bottom panel out in the same way.?The actuating arms are attached via bushes and two bolts, M10 nuts.?The aluminium bushes the bolts pass through can be awkward but penetrating oil and small tools will remove them. There are plastic bushings in the end of the arms, remove them.?The next step is to remove the motor and gearbox unit, four screws on the top, then take the gearbox off the motor, three screws. There's a washer on top of the pinion (smaller gear) ,easy to lose.?Disconnect the motor from the wiring, two tags and note positions.?I took my motor to the workshop and clamped it to the bench, connected it to a 12 volt battery and it didn' t turn, although it tried. Reversing the polarity changes the direction of rotation. ?I concluded that the gear and pinion inside the sealed plastic case were seized. I couldn't find a way into this unit and so drilled a 5mm hole through the case beside the pinion, I could see white through the hole, probably nylon gears. I dripped lots of oil through the hole and eventually the motor was whizzing around so I drained the oil and pumped grease in. The hole was sealed ,after cleaning with solvent,with a piece of insulating tape. ?Reassembly is straight forward. The awkward bit is getting the two bolts at the back through the holes and the nuts on. I found putting two front screws in loosely with the unit on the support and lifting with a lever worked. Otherwise get an assistant. ?I reconnected the wiring with domestic screw connectors and sealed with Sylglass tape.?The step is not designed to be out in the rain, never mind under a van. The gearbox had a little blob of grease in it, but not on the gears which were dry, and road dirt can enter the gearbox.?I didn't lubricate the slides because the oil or grease would make an abrasive paste and wear the nylon slide bearings.?Works perfectly now and I bought some new binoculars with part of what I didn't spend on the step!

 

.........................................................................................................................

 

Both postings relate to slde-out steps, whereas a Thule Omnistep 460 is the ‘dropdown’ hinged variety.

 

 

[Alanb]

In view of the furore that my well intentioned .odt files have caused, I have converted them to pdf files, which I will now attach.

 

Alan

Omnistep Dismantle.pdf

Omnistep Repair.pdf

[mtravel]

Alanb - 2021-03-07 10:55 AM

 

In view of the furore that my well intentioned .odt files have caused, I have converted them to pdf files, which I will now attach.

 

Alan

However Open Office allows you to save files in Microsoft Office format (odt --> docx or doc, odf ---> xslx or xls, etc).

[Keithl]

Alanb - 2021-03-07 9:55 AM

 

In view of the furore that my well intentioned .odt files have caused, I have converted them to pdf files, which I will now attach.

 

Alan

Thanks Alan.

 

I hadn't realised that you had previously saved these pages for your future reference and had been wondering why you had used such a convoluted way to post a link to an old thread, all is now explained!

 

And it appears MSW rejected my first attempt at opening as it did not recognise the file format but on my second attempt it allowed me to reformat the layout to display.

 

Cheers,

Keith.

[plwsm2000]

I have a Project 2000 step with the "see-saw" action that is very similar in design to the Thule version, and I have never seen the current rise above 7Amps even when the motor has stalled (the motor stalls if you leave the button pressed after the step has reached the end of its travel).

I agree that it probably needs a good cleaning but 10+ amps seems a bit on the high side to me.

 

I took some current waveforms awhile back and when my step is moving, it draws about 1Amp while going out (down) and about 2Amps when going away (up). The difference is due to the increased load on the motor from the weight of the step.

 

Just for anyone who is curious, these two oscilloscope traces show the current when my step is going down (first trace) and (second trace) when it is going back up. The yellow waveform is the current (2Amps per division) and the green is the voltage on one side of the motor. Typically, the step takes 1.1 seconds to travel down and 1.3 seconds to go back up.

[Derek Uzzell]

Besides the two files not relating to the disassembly/repair of a Thule Single Step 460, it may be worth saying that there are also differences between the old Omnistor slide-out steps and the later Thule equivalents. For instance, I fitted an Omnistor slide-out step to my 2005 Hobby motorhome and accessing the 'guts' of that step while it was in situ was not practicable - whereas getting inside the similar size/type Thule step fitted to my 2015 Rapido proved to be fairly easy without having to remove the step from the motorhome.

 

(Thule acquired the Omnistor brand in 2005 and I think Jack's motorhome is a 2007 Hymer B544 SL)

 

There are drawings on Page 80/99 of this link that might help

 

http://www.motorcaravanning.co.uk/pdf/2017_Thule_Step_Spares.pdf

 

as might this YouTubr video when disassembly is needed.