De Ranged Posted July 14, 2023 Share Posted July 14, 2023 Gidday all, I'm designing a gantry crane..... made the call to give up the lease on my workshop... landlord has put the rent up by 50% in 6 months lol, so I need something to help me move. The low roof means I'm limited in the use of a forklift and while there is a sticker on the side of my engine crane saying it has a 2ton limit, it was made in China and I really doubt that claim (12mm bolt in beam load to hold the hook, in the end of a piece of 50x50x3 SHS that is the beam of the crane) I suspect 2 ton is the failure load rating lol. As it so happens I have one piece of plant that is just over 2 ton an old english milling machine (by the sales brochure its 2 ton without the vertical mill attatchment) I'm basing my design around a couple of lengths of 150x150x7 "H" beam that I got from work, I'm doing a double beam carrage with a 3 ton endless chain block mounted up in between them (for the 3m span these beams give me a 2x safety factor) running the chain up and over a roller Now the reason I'm here is I've never used a mobile gantry before..... I mean a small wheeled unit lol, I use big shed ones at work all the time.... so I'd like some imput from you guys if you've used them before My design brief: Adjustable height from 1.8m over all to as high as I can get it (so I can run things into my garage under the roller door, later on if I can build a shed I'd like up to 3m) Max load 3 ton (weight of a 4wd) Low profile carrage to limit lost lift height due to chain block mounting, hook and sling angle etc Want it able to break down and fit on a trailer or ute deck Max width 3m Some considerations: I want a steel caster wheel so no deformation of the wheel when left loaded When I have another shed sorted and setup I'm only really going to be running this back and forward in one bay so I might design it with a pin to lock the casters " I suspect being a manual carrage (side to side) I'm going to have some issues rolling it.... so I'm thinking a weighted rope running over rollers at each end of the gantry to improve efficency I'm also tempted to try and work out some sort of steering system for the casters, as moving my engine crane around when loaded can be challanging Any issues or advice ? Quote Link to comment Share on other sites More sharing options...
muzaz Posted July 15, 2023 Share Posted July 15, 2023 Not exactely what you need, I built a fixed over head gantry crane out of 100x50x5 i beam to take out the engine. One advice I'll give you regarding the carriage, if its not geared it will want to centre itself when under load. So the gantry needs to be level. Carriages are u channel with bearing rollers. 3 Quote Link to comment Share on other sites More sharing options...
B reg 90 Posted July 15, 2023 Share Posted July 15, 2023 8 hours ago, muzaz said: Not exactely what you need, I built a fixed over head gantry crane out of 100x50x5 i beam to take out the engine. One advice I'll give you regarding the carriage, if its not geared it will want to centre itself when under load. So the gantry needs to be level. Carriages are u channel with bearing rollers. Nice effort! Quote Link to comment Share on other sites More sharing options...
jason110 Posted July 15, 2023 Share Posted July 15, 2023 Something like this? moving skates are very handy too Quote Link to comment Share on other sites More sharing options...
De Ranged Posted July 16, 2023 Author Share Posted July 16, 2023 Very cool muzaz, unfortunatly for me... IF I'm able to build a new shed on my place (I'm trying to sort the concents at the moment) cost wise what I build is just not going to be strong enough to fit a gantry crane too lol why I'm thinking of a mobile one like what Jason has put up Yes I did consider load skates but they are something that has a singular use.... I did consider building them in such a way I could turn them into "wheel" skates after I've finished.... the reason I haven't gone down this path is they can't load to a trailer I spent a bit of time looking at what pre-built options are out there to buy, problem is the market in NZ for these over 2ton is small enough there are only a couple of companies making them (cheapest was $5k + frieght and came welded no abilty to dis-assemble for transport) the chinese stuff stops at 2ton (not that I have faith in there ratings lol look at the one Jason found, consider if the block is over one side thats potentially 2ton on 2 casters, so you'd think they will be one ton rated casters..... having spent time trying to find casters with this sort of rating I'd expect the wheels to be around 200mm dia which they are not lol Thanks for the tip Muzaz I honestly hadn't thought about that issue on an uneven floor (my current floor was made sloped for washing down) lol it could have made for a little drama... I can deal with this easily enough, I was planning on a rope n pulleys across the top so I can pull the carrage with Left and Right with a vertical motion from the ends..... I'll add in a tie off point for security So far I've given up on buying casters lol since I'm planing on a 3ton chain block I want at least a 1.5ton rating/ability from the casters.... I found some at the local wheel shop catch is he couldn't do them with a steel wheel. If you have ever tried to roll a full roll cab tool box after it has sat for a while, the flat spot that you have is why I don't want plastic or rubber So I've designed my own that are based off an offcut from a damaged main boom ram off an old 28ton digger I had 192mm dia heavy wall Rear caster is fixed front one turns on a AXK4060 bearing with some old graphite bushings I had as locators, the wheels are running on a pair of 6004rs bearings in 1.5" cyclinder tube... I've added a steering arm connection to link both casters.... in theory I'll be able to steer this.... wait n see if it works lol..... still got to add in the anchor for a 2.5ton ratchet strap to the top sleave tube so I can raise/lower the side leg to pin them at height and the wheel bearing tubes Currently working on the carrage to carry the chain block The design is a little excentric in that I'm trying to design to use material out of my rack to reduce what I have to move lol Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted July 16, 2023 Share Posted July 16, 2023 @Deranged oops wrong one sorry @De Ranged I made one of these a few years ago for lifting my lathe and milling machine, it is also adjustable height Regards Stephen Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted July 16, 2023 Share Posted July 16, 2023 Personally I think you're over complicating things a bit because you want it to be usable in multiple situations (whilst laudable it may make it more difficult etc). Your first problem of extracting the milling machine I'd just be looking at scaffold poles and a little garden winch or something similar. I moved by 2 tonne G Dufour mill across my workshop like this, just a crow bar under it to lift it piece by piece onto strips of plywood then 2x4 and then slid the poles underneath. Then my difficult was in something to anchor it but my hydraulic press and workbench provided enough weight with a rope between to put a little garden winch into to control it across the workshop. Just winch a little, reset rollers, winch, reset etc. It was actually very little effort and went quite quickly. Quicker than all the shunting required to get the JCB in. A friend of mine used the same technique to move a 5t lathe that he acquired and once on the scaffold poles took almost no effort to move on a flat floor. Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted July 16, 2023 Share Posted July 16, 2023 4 minutes ago, Ed Poore said: Your first problem of extracting the milling machine I'd just be looking at scaffold poles and a little garden winch or something similar. I did exactly this, easy to move on a concrete floor with round bar rollers and vehicle winch, my A frame was going to be used to then lift machines into my trailer Regards Stephen Quote Link to comment Share on other sites More sharing options...
Snagger Posted July 16, 2023 Share Posted July 16, 2023 I had to move 9t bank safes across concrete floors in the same manner, just with solid steel bars for rollers rather than tubes. More portable, more adaptable to confined spaces and a lot less effort to create or set up. They did require a pretty smooth floor, though, and a nice flat base on the safes - I can imagine heavy workshop tools having very irregular bases that wouldn’t lend themselves to stability on a set of rollers. Quote Link to comment Share on other sites More sharing options...
De Ranged Posted July 16, 2023 Author Share Posted July 16, 2023 Stellaghost your spot on its the get it on and off the trailer thing.... the current leased workshop is about 15kms from home. Plan is move all the tools to my car garrage till I can get a shed built or if not allowed from there to another leased shop that is cheaper lol There is another reason for the crane and its size.... If I am able to build I'll need something to get the kitset off the truck.... fingers X'd Lol Ed guilty as charged, I do over complicate my things, odd given that when I do stuff for mates I generally keep it clean and simple and nock it out.... call it a character flaw lol The "H" beam we had at work from building renovations and they have just been rusting outback.... they have cost me a couple of donations to the social fund lol, the bulk of the rest from my steel stock why the bottom beam looks so funny. Once I've finalized design and gotten our design engineer at work to check it and my calculations over, then I send off the DFX files and most of the plate stuff will get cut at the local CNC cutters..... I'm estimating I'll spend more time in design than building Thanks for the link to your thread Stellaghost I'll read through that tomorrow night Currently stalled on the design I need to have another look at whats under the steel rack to make some decissions.... a couple of evenings and I'll have the carrage assembly design sorted and you'll be able to see what I'm talking about Quote Link to comment Share on other sites More sharing options...
muddy Posted July 16, 2023 Share Posted July 16, 2023 If you can find some old rollers from a mangle these are excellent for moving stuff, 6" round fence posts are pretty good for winching/rolling stuff up ramps on to flat trailers as they take up surface imperfections better. Take a look at twin stick garage on YouTube he had a gantry made for him and one end has an overhang so you could lift a gearbox out say and transfer straight sideways onto a pallet/trailer/picup etc weight dependent obviously. How about a threaded hole about M24 near each wheel so you could wind a bolt down the the floor to make it static and or level it up I have a very hi lift trolly jack that has these. Quote Link to comment Share on other sites More sharing options...
De Ranged Posted July 17, 2023 Author Share Posted July 17, 2023 19 hours ago, muddy said: If you can find some old rollers from a mangle these are excellent for moving stuff, 6" round fence posts are pretty good for winching/rolling stuff up ramps on to flat trailers as they take up surface imperfections better. Nope lol I've waited yrs to get my hands on something as cool as this old thing.... I'm not running the risk of this falling over due to a small base and top heavy weight.... not when I can engineer a better option, to give you an idea of how much I don't want this damaged when I pick it up this weekend I have made a steel pallet so it can be bolted too, once on there it will be lifted onto a transporting trailer and the pallet will be welded to the trailer for the 7hr journey home, it will stay on the trailer till I have the crane made then its going into my garrage till I have another shed lol Quote Take a look at twin stick garage on YouTube he had a gantry made for him and one end has an overhang so you could lift a gearbox out say and transfer straight sideways onto a pallet/trailer/picup etc weight dependent obviously. Oooo cool channel love the old K100, I'd love to get one and hotrod it lol that gantry crane is an interesting idea but with the adjustable height that I want.... that would get awfully interesting lol also I'm limited at 3m width as that is the door size if I build 20 hours ago, muddy said: How about a threaded hole about M24 near each wheel so you could wind a bolt down the the floor to make it static and or level it up I have a very hi lift trolly jack that has these. For leveling up its not really practical given the 3m wide by 2m deep wheel pattern, but it got me thinking about a simple brake A couple of 10mm plates I'll get them cut and a bit of M20 threaded rod, to lock the wheel just tighten till its up against the steel wheel Oh got the offcut of Cylinder Tube on the back of the bike... I'm taking it to work to cut in the band saw, works one is alot better than mine... interesting riding with 15kgs of steel strapped to the back of the bike lol 1 Quote Link to comment Share on other sites More sharing options...
De Ranged Posted July 23, 2023 Author Share Posted July 23, 2023 Not guite the couple of days to design the carrage and still got a couple of little bits to add.... so I can include a rope n pulley for side to side (or tie off, cheers Muzaz) The red bit is a slightly modified 3 ton endless chain block that is bolted into the cradle where the old mounting hook was The chain will run over the idle chain roller (sqaure purple chain roller top of pic) down and under then up and over the grey roller and down to the hook, there is a safety strap built into the chain block that stops the chain getting slack and slipping around the endless chain block The intent is to modify the 2-1 pully hook that gave the chain block the extra rating (3 ton ) so I can pull a pin and take it off.... the end of the chain that was bolted to the bottom of the chain block is now going to get a hook, this will give me 1.5ton at a faster speed on the endless chain..... if I need the 3 ton I put the hook into a hole just below the top roller and pin the pully hook on and it is 3ton This gives an idea of what I was working to achieve everything just skoots under the top of the two 150x150x7 H beams.... on the 1.5 ton the hook will go up till it is almost flush with the bottom of the H beams on the 3 ton that will hang 70mm below..... that is as good as I can get it and its lowest safety margin is x2 (so 6ton!) All the rollers have bearings apart from the idle chain roller (sqaure purple one you can see at the top) but since its got no load I'm not worrying about it, all the pins are loose fitted to the boss's with grub screw locks and a C clip to hold the bearings of the rollers so worst case its easily rebuildable Now to send off the DFX (CAD) files to get cut.... Yes Ed I have over complicated things lol I hate compromise on my projects 1 Quote Link to comment Share on other sites More sharing options...
De Ranged Posted August 8, 2023 Author Share Posted August 8, 2023 Gidday all Finally finished designing this Gantry... I did say I'd spend more time designing than building lol I've changed the design a bit... talking to people about it I got some suggestions and it helped me spot room for improvements so here it is I don't know if the idea of steering will work but its got to be better than kicking free casters when they are under load lol.... I don't think it will roll well as a single person mover when the load is on but as a two person (one pulling on the steering handle and another on the opposite leg pushing... it might work) I've changed the route for the idle end of the lifting chain... too wrap more of the chain around the drive (sprocket ?) on the chain block and added a guide tube on the idle end of the lifting chain (so if your pulling the idle chain away from something your lifting you can't miss align it on the top roller).... this does mean the I'm going to have to modify my chain block to fit the idle roller inside it I've sent off the DFX files (cutting files) to the profile cutters.... the simple and small plates I'm cutting myself to use up some of my steel stock and offcuts Already started fab'ing it up, got the lower leg beams cut and mostly welded sort of aiming at having it done in two weeks Quote Link to comment Share on other sites More sharing options...
simonr Posted August 8, 2023 Share Posted August 8, 2023 It looks like you're using the chain block upside down & reversing the direction of the chains - to increase the lifting height under the beam? Good idea if the chain runs nicely over the idlers - and there's no reason it won't. It also looks like you've incorporated ratchet straps to raise the overhead beam - also a clever idea. My only reservation (if that's the case) is how you would lower it in a controlled manor? I guess they could be strap winches rather than ratchet straps? Quote Link to comment Share on other sites More sharing options...
miketomcat Posted August 8, 2023 Share Posted August 8, 2023 The cradles at work move surprisingly easily on castors even with 6ton on boat on them. The trick is largest wheels you can use, one of ours has around 4" castors which will stop on a small stone. The others have about 8" castors and they are much better. I can move them one end at a time on my only, as long as the wheel is pointing the right way. If not a nudge with a pole to get it started is all that's needed. Mike 1 Quote Link to comment Share on other sites More sharing options...
simonr Posted August 8, 2023 Share Posted August 8, 2023 2 hours ago, miketomcat said: The cradles at work move surprisingly easily..... Good point. A double wheel castor will steer more easily than single - because it doesn't have to scrub as it steers. We have a couple of pieces of heavy equipment at work mounted on double, pneumatic castors. While the pneumatic wheels have a tiny bit more roll resistance than solid, they will roll easily over uneven or even dirt floors. Quote Link to comment Share on other sites More sharing options...
De Ranged Posted August 8, 2023 Author Share Posted August 8, 2023 3 hours ago, simonr said: It looks like you're using the chain block upside down & reversing the direction of the chains - to increase the lifting height under the beam? Good idea if the chain runs nicely over the idlers - and there's no reason it won't. Yep spot on.... and yes that is a concern lol, got an idea for a bolt on weight as a stop for the far end of the chain just to give it bit of extra assurance it will pull the chain back through Quote It also looks like you've incorporated ratchet straps to raise the overhead beam - also a clever idea. My only reservation (if that's the case) is how you would lower it in a controlled manor? I guess they could be strap winches rather than ratchet straps? You can use tie downs as winches backing them off one or two clicks at a time, done it enough times off the trailer with dead trucks... lol poor mans winch, the reality is the top isn't too heavy, I'm able to move a single rail (H beam) by my self so I think I'll be able to lower down just using the thread through of the ratchet as a friction device... if I'm wrong it should be funny lol Your comments about the bigger casters are spot on, I did a fair bit of research trying to find an off the shelf option and just kept hitting walls with the 1.5 ton rating, only option was a rubber bonded 180mm wheel at almost $500 a corner, lol so I've got some old hydraulic cyclinder tube (192mm dia), less than $20 of new bearings some recycled composite bearing and $50 of profiles and some time Quote Link to comment Share on other sites More sharing options...
bishbosh Posted August 8, 2023 Share Posted August 8, 2023 I would strongly recommend battening the top flanges of your main beams together. It will add a huge amount of stability (and strength) for little effort. Quote Link to comment Share on other sites More sharing options...
De Ranged Posted August 8, 2023 Author Share Posted August 8, 2023 (edited) 6 hours ago, bishbosh said: I would strongly recommend battening the top flanges of your main beams together. It will add a huge amount of stability (and strength) for little effort. Initailly I did plan on this but after calculating the required thickness of the center web of the "I" at a web height of 150mm and a span of 3000mm (same calculation for rating a bridge "I" beam) I got a thickness of just over half of the 7mm thickness I have on just one beam I made the call not to join them other than the end mounts as this ment I could go higher with the carrage and as they are, individually the beams are on my ability to lift one at a time lol My father was fond of saying (about farm mechanics and engineers) "enough knowledge to be dangerous...." and I consider my skills in this theoretical level of design to at that level lol so if anyone wants to challenge my calculations..... please go for it lol I have no problem with humble pie My beams are a web 151mm tall, flanges are 151mm wide top and bottom, My span is 2600mm (inside edge of support to inside edge) Max lift 3000kg (the biggest block I own) As for the end supports The legs are 75x75x6 SHS, here is a view of the ends where the beams bolt onto the legs The light purple are 6mm plate, that is 200mm long (along the length of the beam), the dark grey plate is 70mm in from the rear edge of the purple plates and is 12mm plate, the pink is a packer support of 50x50x4 SHS all of this will be fully welded and welded to the top of the Leg SHS with a couple of plug welds on the 200mm deep that goes into the SHS leg The mounting bolts to the beams are going to be M14, 8.8, 4 of them to each web to take the load I can shim these to get correct spacing for the rollers as these beams arn't machined... there is also 2 more mounting bolts in the top... I don't feel I need them but I put them there to make the top flange stuctural and take out any potential flex I've left the bottom unsusported so it transfers the weight to the web of the beams I hope all this makes sense (my discription and my thinking) Edited August 8, 2023 by De Ranged grammer bad is was Quote Link to comment Share on other sites More sharing options...
bishbosh Posted August 9, 2023 Share Posted August 9, 2023 The battens aren't there to help the webs, but to stop buckling of the compression flanges. If you added say 3 flat plates at the 1/4 points, each plate say 150mm long and welded to the top flanges of the beams (batten plate extends to outer edge of the top flanges) they will effectively make the two beams into one with a much greater buckling capacity than the sum of the two individual beams. They will also help (to a degree) restrain the beams against rotation which may help the trolley move more freely. I accept that capacity-wise you may have more than you need as it stands but this simple mod would give you a much more robust gantry. Picture nicked from the interweb as apparently it pints a thousand words... 1 Quote Link to comment Share on other sites More sharing options...
De Ranged Posted August 11, 2023 Author Share Posted August 11, 2023 Hmmm I see your point and the gain if this was an "I" beam what I have is "H" beam, the flanges are as big as the web.... these are normally used on structural steel as the uprights as the bigger flanges resist movement.... comparible size "I" beams have somewhere between 1.5-2:1 web to flange ratio (there is normally a little extra thickness tho) with "H" beam it is 1:1 You have me curious now to see if it will deflect.... I think I'll have to have a play around and measure it when its built lol..... I'm committed to this design as CNC have already started cutting the profiles, I could do a bolt on brace (means the parts are still manuverable by my self) but it would need to be bent to clear the top of the chain (it is just above flush on the top of the beams) Quote Link to comment Share on other sites More sharing options...
bishbosh Posted August 14, 2023 Share Posted August 14, 2023 The gain is the same more or less for I and H sections. Don't want to get into an interweb argument so will leave it there. Bish MEng CEng MICE MSOA 😛 Quote Link to comment Share on other sites More sharing options...
De Ranged Posted August 14, 2023 Author Share Posted August 14, 2023 Lol, On the internet it is often hard to know the people (there experiance and knowledge lol) that you are talking with.... Mechanical and Civil Dam! impressive.... the MICE thing I have come across a civil engineer in Australia with it, its an accademic organisation not a qaulification? MSOA I have no idea about and google didn't help.... ? I've started building it..... having had to lift the beams around abit I'm really loath to weld them together, I'm able to lift and move them but.... I'm sucking it up to do it lol, 2 of them and I'll need a crane to move them lol That doesn't mean thats the end of your idea... I was serious when I said I wanted to measure the deflection With my mechanical calculations, I'm basically reseaching for a calculation that will give me a qauntifable result (the rating of an "I" beam on a bridge) similar application and conditions so I'm happy.... I don't have the yrs of learning to develope these calculations beyound a basic level (and I'll be honest I doubt my abilitys to do this correctly lol enough knowledge to be dangerous ) So I like to, when I can test to see if I'm right As for argument lol harden the f up (in a nice way) I'm one of the dirty engineers that work in the back of the shop building what you design.... I'm loud, blunt and I swear lol I though we were having a discussion Would you mind continuing to discuss this.... because while I see a gain to be made I don't know if its worthwhile, next if I fix these as your pic with a single weld on the end (the beams strength isn't the web its the flanges in compression and tesion while in parrellel) so your batten is there to aid in keeping them parrellel I see its gain being mainly one sided (since a picture is worth a 1000 words) the side that wants to go out (away from the carrage) the batten is levered into the flange the other side the weld will bend because the batten is a lever and allow the beam to twist.... a bolt makes more sense to me, it creates an area of clamping that will tie the flanges to the batten lessening this.... If I have a bolt either side of the web (lessens the leverage even more) is that worth the compromise to the strength of the compression flange lol or is this all errelevant..... as silly as it sounds I'm now interested in measuring what sort of gain I would get lol I need to go build some shi... stuff Quote Link to comment Share on other sites More sharing options...
bishbosh Posted August 15, 2023 Share Posted August 15, 2023 If you don't want to weld the battens on you can always bolt them so you can disassemble. 1 Quote Link to comment Share on other sites More sharing options...
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