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| | #1 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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Hi All, Well I'm about to make a new lowering/lifting device, Hopefully on the cheap..but not on quality, So I thought I would raise a few pionts in the way I make this. So on the brake side of the device a bigger radius is better???also I'm thinking of incorporating a boat winch in as well, either mounted below the brake, or taxing the mechinism and incorporating into the brake drum some how??any suggestions?.. and by the way i'm not trying to reinvent the wheel,just a cheaper device,with materials at hand.Any Ideas? brake pipe dia: 130mm Winch : hand cranking 2000lbs Mounting plate:Flat plate??large section of channel?? This is what I have so far. JayD ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #2 |
| Admin - Owner Palm & Tree Services in Brisbane Join Date: Jan 2007 Location: Brisbane
Posts: 12,986
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The channel. Where it meets the tree have it serrated (saw toothed) so it bites. Also have it just long enough for the mounting straps coz it's bloody heavy. Where the lowering drum goes into the channel, welding alone I'm very suss on. Be great if it were bored and press fit in welded both sides, perhaps even a flange collar on the front to distribute the load across the channel. That would also prevent weekening from welding at the same place
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| | #3 |
| Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis
Posts: 952
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If anyone can do it, Jay D, you can. I can't claim to know much in the ways of tree-mounted bollard/winch systems, have messed with a few at tree shows, but never actually used one. I have a 12V capstan rope-winch (power bollard) I got from a place called surplus supply. I think it was built to go on a battleship or something. It will replace the 12V cable winch on my chipper. Maybe something like that can be used, like figure out the mounting system, get a pair of jumper cables, car battery and go to town. I only mention this because they say they will ship anywhere and it cost me somewhere over $300 usd, which isn't bad, considering. OK, that may be stretching it a bit, the power bollard (but maybe not???) but if you will use a boat winch, I have a very good suggestion. On my biggest log arch there is a two-stage winch, one regular speed, and a second gearing in which the speed goes to half, the power goes to double and the direction of the rotation of the winch handle reverses. The boat winch itself isn't all that much bigger than a normal one, but it is the cool bomb. The high-to-low gear changeover can be done under load. Hope those links in the previous sentences help better describe what it is I'm describing. |
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| | #4 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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Hi Boys and Girl's, I've been doing heaps of thought on this device,I'm a little torn which way to go!, Firstly I have a 2000lb boat winch which I'm thinking about taxing the mechanism and adapting it to a rotating bollard similar to what you see already on the market but running on a trailer axle with bearings, with what you drew Ekka, very similar mounting but I was going to gusset and weld for support and to spread the stress of it working underload, The other thought running thru my mind is having the breaking system stationary with a come-a long mounted of to one side so it's easy to use, Remember I'm trying to do this as cheaply as possible,but not on quality..so it's safe to use not some try hard 2 bob approach....yeah you can say buy lewmar and just mount it, but then we have not achieved anything but pinched someones idea,I like their concept, But the price is a bit steep,so which way would should I go?? JayD
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #5 |
| Admin - Owner Palm & Tree Services in Brisbane Join Date: Jan 2007 Location: Brisbane
Posts: 12,986
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Well personally. Have a porty or a GRCS style boat winch job. No need for a go between really, you get pissed off having a new lowering device that doesn't winch ... not worth the work IMHO.
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| | #6 |
| Mature Tree Join Date: Feb 2007 Location: Melbourne, Victoria, Australia.
Posts: 1,594
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I agree with ekka, if you keep a keen eye out you can pick up a good 2nd hand yacht winch from $200-500 for a standard winch or $400-$800 fro a self tailing winch. The harken winch alone on a GRCS retails for about $1800! Thats what makes them so expensive. Score a cheap winch, fabricate the rest which will be only the same amount of work as what your looking at doing anyway, then youve got yourself an awesome tool real cheap. Ive got the bits, just need the time to get it put together now.
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| | #7 | |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
| Quote:
I think i'll hold off until I make my mind up, Good luck with yours Trev. ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 | |
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| | #8 |
| Former Member Join Date: Oct 2007 Location: Bakersfield, Ca
Posts: 2,497
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Well this fits the catagory, but I'm feelin a little low-tech here... I had bought a 6-bar BMS descending Rack. It's made of stainless steel, is tested at 2,000 lbs, and the frame strength is in excess of 20,000 lbs. Works with two ropes. Dimensions: Length 13"; Width 5"; Depth 3/4". Made by Bassett Metal Studios. Nice thing is it's got a double hyper-bar on it, allowing for really easy tie-off of one or two ropes. I'm still stuck with groundies who I don't trust to touch ropes yet, so for many contracts I still do the rigging, the cutting, and control the lowering; and they just unclip it at the bottom. (some I have convinced that they're lucky they get to do that.... and haven't figured out that *without* them doin that I'd be royally screwed. Not so bright huh? Yeah, its scary.) Up until now I've been using a rescue-sized figure 8...lol... Just doin what I was used to. Got sick of it twisting my ropes, etc. So the new Rack shows up, and I take it out for its first run. 80ft Pine TD, simple stuff. Got everything all set up, took some special precautions since it was a new piece and I was unfamiliar with it, and rushed right into attempting to drop a 15 foot piece with it..... I goofed, my fault, got hasty, gotta learn to calm down. It jammed up tight, no budging. I accidentally put the load on the "top" side of the rope instead of from the bottom. Mostly an innocent mistake, though I couldn't claim to have ever seen one used before. (doh!) Had to flip back down to below where it was clipped in and cut the bottom of the branch off. Got it down to a workable 75 pound chunk that I was able to unweight using a second anchor point, and my anti-return pulley ( Petzl Minitraxion). What a mess! I planned for possible problems, got one, solved it, and lost only my time. But learned a valuable lesson about rigging with that device. Does anyone else use these? http://us.st11.yimg.com/us.st.yimg.c..._1973_59716829 |
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| | #9 |
| Mature tree Join Date: May 2007 Location: sydney
Posts: 419
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G'day Therrin Haven't used on like you have in the pic. Only a normal rappel rack for abseiling etc. Like you said, you rig from the bottom up. Ie if you have a five bar rack and only rig three bars for your size then start from the bottom. In theory that way you can add wraps whilst on rope. I haven't actually done this myself but I assume there is a practised technique to this. They are a good device. Inline anything definately beats twisting eights. Any pic of he device in action?? Cheers |
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| | #10 |
| Part of the Furniture Join Date: Jun 2007 Location: orlando,fl
Posts: 4,948
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okay I don't know if you came up with a device yet jayd but if its okay with Ekka I'll posta few limks to companies the sell winchs and things that i pesonally think could be made into lowering devices.
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| | #11 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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It doesn't bother me, Clear the links with Ekka first,Just holding off on making this device has paid off in Good ideas, such as were the comercialy made lowering devices fall short..I dont know if Trev's gone any further with he's idea? Problem is..and I'm not kidding..Is TIME ITSELF..to do it..and then get it certified..Which means I have to make two..Just reading posts about developing differant tools,climbing,lowering lifting,It's all food for thought but you have to realise what's good idea. JayD ![]() ![]() ![]() PS, Nice to hear your smarter and wiser now,..RE Tree Work.
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #12 |
| Mature tree Join Date: May 2007 Location: sydney
Posts: 419
| ![]() ![]() ![]() Hey guys Here are some pics of my own lowering device. It's the second one I made about 14yrs ago as there were no commercial ones available. Its simple compared to the self tailing one available now but if your making one on a budget you may get some ideas. Its a piece of steel channel (UC) with a single speed capstan I got from a second hand shipyard. I welded "ears" for a truck strap (although on really big trees we use chain with truck tensioner), welded a steel crab for a rope guide, and a loop at the bottom for a redirect. VERY simple and cost less than $150 to make. It is not rated although initially we did alot of lifts/controlled lowers with it and nothing has bent/broken. The only change is the crab now compared to the initial rope guide which the groundies requested and like. The truck strap gets changed each year. We use 16mm 3 strand and 18mm double braid. Three raps with the double braid and we can lift good size timber. A two speed would be nice, and a self tailer even better. But we all love this one and has served us very very well. We can get alot of tension with the strap and only occasionally "bed" the device into a tree when doing a takedown. Hope this helps. |
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| | #13 |
| Admin - Owner Palm & Tree Services in Brisbane Join Date: Jan 2007 Location: Brisbane
Posts: 12,986
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You can post links as a matter of discussion of course. To clear the air on this it's links to other rival forums that wont work, links dropped by advertisers like spamming (usually starting a thread though). ![]() Remember, all links out of here are rel=nofollow so they dont get much juice. But links for the purpose of discussion or expanding the topic, illustrating things etc, cool.
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| | #14 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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Nice Shaggs, Simple, Price is right, But I want something that bridges the gap where these ideas fall short, They have been mentioned in other posts.As soon as I get some spare time I will be addressing this device...maybe over Xmas? ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #15 |
| Part of the Furniture Join Date: Jun 2007 Location: orlando,fl
Posts: 4,948
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Heres a few links.Hope these help. Surplus Center Pressure Washers, Portable Generators, Mowers, Lawn + Garden | Northern Tool + Equipment W. W. Patterson Homepage Sail Gear - Winches - Andersen Self Tailing Winch 46ST 50246 - Discount Yacht Supplies, Nautical Accessories, Parts, Marine Electronics, Garmin, Humminbird, Lowrance, Jensen, Jbl
__________________ Have your say join us today.![]() old schooler Last edited by newguy18; 15th November 2007 at 08:52 AM. |
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| | #16 |
| Mature tree Join Date: May 2007 Location: sydney
Posts: 419
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Hmmmmmmm self tailer......drool drool... The problem is for the tree guys who used larger 18mm rope etc. By the time you get a winch capable of this size rope the costs are really high??? Its just the winch that is so friggin expensive, the rest is easy to fab... |
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| | #17 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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And this is were this post came from...LOL...but with a little patience and good ideas, We should be able to get around this..Then we will have an affordable tree tool which gives value for money! ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #18 |
| Former Member Join Date: Oct 2007 Location: Bakersfield, Ca
Posts: 2,497
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Hey, that thing looks pretty cool Shaggs. Looks heavy though. What would you figure for max estimated strength? I'm toying with the idea of pullin out the welding equipment now. I'll have to work on a design. Btw, JayD, what did you mean by "bridging the gap where the other's fall short"? What does the gap consist of? (or rather, it being a gap and all, what doesn't it consist of) I hadn't realized this thread was just for discussing the makings of a new lowering device. I considered my device "new", so I posted about it. Heh.
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| | #19 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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OK, Firstly is the price, all be it a good piece of equipment it's expensive,Most devices on the market are stronger at either end of the use,,better for lifting,handles more load for lowering,spool to short for a good selection of rope thinknesses,Please dont think I'm saying whats out there is not up scratch,but I feel we can make a device that is strong allround with all the good pionts that have been mentioned in various posts. Ideas allways start someware such as the the Wright brothers first flying machine,look at it today! So comments, even small one's that seem insignfiicant can spark a whole new appraoch and or even take the product out there to it's next step of evolution....Let's see what we come up with? All The Best JayD ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 |
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| | #20 |
| Admin - Owner Palm & Tree Services in Brisbane Join Date: Jan 2007 Location: Brisbane
Posts: 12,986
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Only $700 for this puppy including the chainsaw engine! RULE Gas-Powered Winch 3500-Lb. Capacity, Model# G1800E | Gas Powered Winches | Northern Tool + Equipment
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| | #21 |
| Mature tree Join Date: May 2007 Location: sydney
Posts: 419
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G'day Therrin My device weighs about 5kg's, but is total one man worker. ![]() As max working capacity, thats the downfall with any "home made" gear. All I know is that when it was first made we dropped some big timber (150-200kg's) with factor 2 falls and it held. Although we did break some 12mm 3strand rope. I suppose seeing what it HAS done, we dont go past that. Like any bit of gear, keep it smoooooth. Looks good and goes good. |
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| | #22 |
| Former Member Join Date: Oct 2007 Location: Bakersfield, Ca
Posts: 2,497
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I'm lookin at pickin up some 5/8" kernmantle bull rope. As much as I hate making open-ended claims, I think the kernmantle-type rope holds up better to shock-loading than does the stranded rope. (but I could be wrong) I just know that I've dropped pieces up to 1500 pound (that'd be 680kg) on a 7/16" (11mm) Bluewater static line with a FF=2. Interestingly, some people claim that you can't achieve a FF greater than two, which isn't quite true. If a piece is attatched 10 feet above the "belay" point, and when it starts to fall, you take in 3 feet of rope; the piece will fall 10 feet to the belay, and 7 more feet to the end of the rope. This is a 17 foot fall with only 7 feet of rope out when it stops. 17/7 = a FF of 2.43 Which goes to show that pulling in slack when a piece starts to fall is actually exerting more force on the rope when it becomes loaded. Synthetic fiber kernmantle ropes also have a "plastic deformation" factor as opposed to natural fibers which tend to just snap. |
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| | #23 |
| Mature tree Join Date: May 2007 Location: sydney
Posts: 419
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Therrin, nice theory on the fall factor. I haven't heard that one before. At first I was sceptical but in the end it sounds feasible. My only doubt is that would it not be called a "fall" as the load is starting at 10 feet up. A factor 2 fall with 7feet of rope would have the load starting at 7 feet up. In you scenario it would be like (if not pulling in rope) starting the load at 7 feet up already with accelleration on it...thus not a fall??? What do you reckon?
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| | #24 |
| Admin - Owner Palm & Tree Services in Brisbane Join Date: Jan 2007 Location: Brisbane
Posts: 12,986
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Lets clear the air. Fall factor doesn't determine kn force on rope does it? You can have two same fall factors produce very different forces. Found this document.
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| | #25 | |
| Semi-mature vigorous tree Join Date: May 2007 Location: Pittsburgh
Posts: 54
| Quote:
The main things that determine the force on a rope that catches a dropped load are (1) how much weight, (2) how far you drop it, (3) how much rope catches the fall, (4) how much the rope slips, and (5) what rope is it. Lets assume we are always talking about the same weight and rope. If we assume that (1) the rope doesn't slip and (2) the rope stretches elastically according to Hooke's law (e.g., linearly), the fall factor determines the peak load. Too bad this isn't the case. Ropes do not hav perfectly linear elongation vs. load and they show some anelasticity (energy absorbtion), but still, they are close enough to allow you to use the "same fall factor = = same load" as a first approximation. Where it really breaks down is in the "no slip" assumption. The big slip is in the knot attached to the load (and to the anchor, if appropriate. Drop a person-weight load on a 10-foot FF~2 drop and the knot pulls tight, absorbing energy along the way. Drop the load twice as far at the same faal factor and the knot does NOT absorb twice as much energh (the knot can only get so tight) - so the energy goes into increasing the peak load on the rest of the rope. They don't like to say it, but some climbing ropes hold 12 or 15 UIAA falls, but if you double the drop and keep the same fall factor, they break in 2 or 3 falls. Bottom line: The knot does a lot to reduce the force on a rope. Too bad you can't calculate how much, at least not very well when you are out in the field. But who cares? Still, fall factor is a good concept. It is simple and it gets the point across that the ratio of the length of fall to the length of rope catching it is very important. It avoids the need to solve differential equations, and can be taught to ___(insert name of your favorite group to riducule here)___. Just don't think that the "same fall factor=same force" rule is EXACT - it isn't. ----> Gary | |
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| | #26 |
| Part of the Furniture Join Date: Jun 2007 Location: orlando,fl
Posts: 4,948
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So those that mean a lifeline or rigging line about 1/2" should be retired after a shock load?
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| | #27 |
| Semi-mature vigorous tree Join Date: May 2007 Location: Kununurra WA
Posts: 124
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Hi my names Dave,here's my lowering device.
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| | #28 |
| Veteran Heritage Status Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland
Posts: 1,981
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Welcom Dave! Good looking bit of gear ....is that an African Mahogany take down?
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| | #29 |
| Moderator - Previously known as JayD Join Date: Feb 2007 Location: TreeWorld, Sydney Australia
Posts: 2,056
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Hi KimTree, Nice tool that, Simple, Two points of attachment, Looks robust...looks like ongoing thought and refinement aswell...variations are appearing now..ideas are sometimes very subtle, You just have to reconise them. Good evening, Gary,nice to have your input I found it interesting and informative. When I get off my backside and start to fabricate the device, At first I will use mild steel...why because it's cheap, robust and will do the job, As soon as I finnish all my tweaking off my device I will be refabricating it all using alloy steel lighter,stronger, It will be strong from what ever angle the load is applied,I want it to be able to lift a modest amount of load not enought so all you are doing is breaking your craning forks outs. soon as we get some time I will start and I will be posting as I go. ![]() ![]()
__________________ Member: Australian Tree Association Join the Australian Tree Association...Have your voice heard ! Arboriculture, A life long study for some, a passing phase for others © Jeffrey J Darby 2011 Last edited by Jeff Darby; 16th November 2007 at 09:38 PM. Reason: Fat Finger Syndrone |
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| | #30 |
| Semi-mature vigorous tree Join Date: May 2007 Location: Kununurra WA
Posts: 124
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It's a harken 46 2 speed self tailer cost $1700 from whitworths marine 2 years ago.For non takedowns the angle plate unbolts and a piece of timber and high density rubber sits between it and the tree yes it an african mahogany |
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