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lazy susan bearing

Posted: Fri Nov 30, 2007 5:27 pm
by David Pengelly
This subject may have already been discussed on a previous thrad on the old site , if so i opologise for any repeat.
The turret rotation on my Tiger 1 is at best sluggish and jerky.
Having spoken to someone recently who has fitted a lazy susan to thier Tiger i propose to do the same .
Unfortunatly the person who fiited the lazy susan cannot remember what company supplied it ( it came from the US ) .
Has anyone else fitted a lazy susan bearing and if so do they have any information as to where they got it from.
Obviously the plasic type that is used for cake decorating turntables will not have the weight loading suitable for our application.
Any info would be appreciated.

Posted: Fri Nov 30, 2007 6:11 pm
by Tim Bowman
Hi David

I like the idea of a lazy susan type bearing

I just did a quick search online and found a whole bunch of suppliers of lazy susan bearings. They all seem to be suitable for the weight but the ones I saw were 9" or 12" DIA. for cabinetry use and off the top of my head I don't know the diameter of the Tiger ring needed. Just some of the search results

http://www.woodcraft.com/family.aspx?familyid=1061

http://www.bearwood.com/HARDWARE-LAZYSUSAN.HTML

http://wwhardware.com/catalog.cfm/Group ... showprod/1

Hope this helps. Good luck

Kind regards

Tim

Posted: Fri Nov 30, 2007 7:21 pm
by David Pengelly
Hi Tim , i did in fact look at those sites but didnt go any further as they are in the USA. I am looking for a supplier in the UK.
If all else fails then i will ask "Woodcraft " if they will ship to the UK .
I think the 12" would suit as it will also have no problem supporting the weight of the turret and it is only 5/16 inch thick.

Posted: Fri Nov 30, 2007 9:33 pm
by Simon Lambert
Hi David

Funnily enough I was looking through their catalogue the other day and spotted these!

http://www.axminster.co.uk/product.asp? ... e=1&jump=0


Good luck!
Simon

Posted: Sat Dec 01, 2007 2:24 pm
by David Pengelly
Hi Simon, I to have looked at these, and unfortunatly the 300 mm dia one is not big enough, as the turret diameter is 323 mm dia . I am now looking at commercial lazy susan,s and thrust bearings , both roller type and ball type. I think the roller type would be thinner though more exspensive as the rollers would be tapered.
I have found a Chinese manufacturer of bearings that say they will make any size thats required.
As the turret isnt turning at any speed the quality of the bearing is not paramount , as long as it works.
Just out of curiosity does anyone know how lazy susan,s got thier name ?
Cheers Dave

Posted: Sat Dec 01, 2007 2:38 pm
by Doug Pinkerton
Hi Fellows,

Sorry to butt in on your conversation, but I think the idea of a lazy Susan type bearing may be overkill. If the Armortek brass bearing is properly seated and smoothed, the turret contact surface is smoothed and shaped to prevent any friction-caused hang-ups, and you apply a bit of automotive grease, you should have no trouble with turret rotation. If that doesn't do it, I believe I read that Armortek will soon be marketing a more powerful turret rotation motor which will retrofit to earlier models. Just a thought.

Best regards,

Posted: Sat Dec 01, 2007 8:46 pm
by David Pengelly
Hello Doug, the whole point of the exersize is to reduce the amount of friction which the motor has to overcome to turn the turret.
I would have thought a lazy susan would be far preferable to a flat ring of brass, no matter how well it is lapped in and greased
Also a lazy susan is a cheap option compared to a bigger motor, which would also put more current drain on the main batteries.
A standard motor would have no trouble turning a turret mounted on a lazy susan.

Posted: Sat Dec 01, 2007 9:31 pm
by Doug Pinkerton
Hi David,

Of course, you are correct that a ball bearing type rotation system is more elegant and functional than a simple friction bearing. I only meant that to me it's a matter of need, and if the simple friction bearing is adequate to allow the turret to turn then the lazy susan solution is technically overkill. As for a larger motor, I have that, courtesy of Vince Abbott, and I believe several others do too. I think that any additional current drain from the rotation of the turret by the larger motor has a negligible effect on a two-battery 24 volt system. Since you seem intent on the lazy susan solution, perhaps I should not have chimed in with my opinion. Sorry for the intrusion.

Best regards,

Posted: Sat Dec 01, 2007 11:51 pm
by Joe Boylan
Hi Doug:
Could you send me the address of the Chinese Mfg for the 323 mm beaing? I really want to see if they make a thrust bearing that size.
A thrust bearing is much better than a roller or ball type. In our 1969 AMX and drag car transmission we installed all thrust bearings between gears and what a difference it made! Thrust bearings can take allot of pressure, and weight is not a factor for our Tigers. Try to keep the size as small as possible for clearance - the more rollers the better!

I have manufactured a one piece brass ring that fits my Tiger perfectly and am thinking about mounting the thrust bearing into it. As the guys have stated - if the brass ring is slick enough you really don't need to put a bearing under the Turret, but what the heck - its your model and no two are alike anyway. have fun trying I might too!
Thats my 2 cents!

Good Luck
Joe

Posted: Sun Dec 02, 2007 2:22 am
by JWFGoode
The bearing used on my modified Tiger 1 is from http://www.mcmaster.com/ part no. 8635A52

Details on fitting to the deck are in the gallery at:
http://www.armortek.co.uk/gallery/main. ... &g2_page=3

It works for me. Happy building
John

Posted: Sun Dec 02, 2007 4:05 am
by Joe Boylan
Hi Doug & Dave:
Check out slewing rings - slewing rings - very interesting!
Joe

Posted: Sun Dec 02, 2007 1:43 pm
by colin fairweather
hi all

this part number might be better suited from http://www.mcmaster.com/ 18635A54 or

i am thinking of boreing equal holes around/in the brass turret ring and placeing ball bearings in them the top of the hole will have tobe slighty wider to stop the bearing gamming in the hole i've been pondering over this for a long time or is this just too simple :roll:

colin :)

Posted: Sun Dec 02, 2007 5:07 pm
by Lucien Runge
To all;

On my tank I found that the two piece turret bearing was the problem because they were not round toward both ends of the bearing halves. In fact, my turret bound up every time it was placed in position on the top deck. I remedied the problem by ordering the one piece bearing from Armortek. After installation, the problem was instantly solved. The turret rotates smoothly and without problems and I haven't even applied any lubricant yet.

The McMaster Carr turntables are a good solution. There also exists a bearing set up which has individual bearings set in an attachment plate that you could screw down to the deck with four miniature machine screws. I used to have some and I liked them because they were very thin. I will try to find the supplier of this ball bearing set.

Lucien

Posted: Sun Dec 02, 2007 6:08 pm
by David Pengelly
Hi Doug, no way were you intruding, all imput is good. At the end of the day its all to do with personal preferance, and experiences.
Cheers Dave

Posted: Sun Dec 02, 2007 6:47 pm
by Doug Pinkerton
Yes, I think experience is the key. Those engineers out there like Lucien and John,who have the access to the right machines and experience to craft custom parts, are able to come up with elegantly constructed systems that often put the more simple systems of the stock Armortek Tiger to shame. However, it's important for the non-engineers out here among us to know that these sophisticated and complex engineerng solutions are not always necessary. My only point in chiming in was to point out that turntables and other aftermarket bearings are not necessarily required to provide adequate functionality regarding turret rotation, which for most of us is all that is needed. Engineers truly operate on another plane, and certainly should feel free to suggest any and all solutions that are within their capabilities. I'm now officially out of this discussion. Clearly I was in over my head to begin with....