Do you think a 'L' Gantry is justified or needed on a 6040 sized machine, or do you think the size doesn't warrant it?
Is 40 x ? Extrusion thick enough for a 6040 Gantry?
Steve
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Do you think a 'L' Gantry is justified or needed on a 6040 sized machine, or do you think the size doesn't warrant it?
Is 40 x ? Extrusion thick enough for a 6040 Gantry?
Steve
How can anyone answer that without knowing what you are intending to cut with the machine.? . . . Also 40 x ? profile will be very hard to find. .:joker:
Now if this helps, the L shaped gantry design is simple and it's strong for the type of machine I designed it for originally, which was a small Strong wood router (6090). However, it's also been used on larger heavier duty machines for cutting Aluminum, etc so it's well-proven.
To me the little extra it costs and the flexibility it gives along with strength make it worth using no matter what machine. But you could say I'm a little biased, but you could also say "He's built shit loads of machines using it and everyone is happy so it must work well" . . . Or not.!
I was trying to get an idea of the size of Extrusion one would use if designing a L gantry for a 6040 sized machine.Sorry if I was vague. I was referning to the '40' sized extrusion.
My present incarnation is using 80 x 160 extrusion for the Gantry ( no L section.)
If I was going to use the L configuration, would I still need to use '80' extrusion or could I get a good result buy just using '40' extrusion in L configuration?
Its a early question that affects the rest of teh design and important to get right.
thanks for your help.
If it helps, this is what I used on a 1m wide gantry, and is commonly recommend here because of the spacing matching up well with BK12s.
https://www.aluminium-profile.co.uk/...file-kjn990300
Some of the bits I think are important are the heavy duty nature and the associated increases in moment of inertia which can be used to calculate deformation under load.
I've combined two of these into an L, so my gantry occupies 135 x 90.
Thanks Andy...It all helps.Quote:
Originally Posted by AndyUK
My Gantry will only be about 680mm wide, which is not that far off what yours is , I guess.
Are both parts of the L usually of the same dimensions to get the required rigidity?
"Required rigidity" is quite subjective. Certainly this design is well tested around here and provides "enough rigidity". You have two options at this point; copy something that works, or do all the maths and arrive at your own answer based on what you want to cut and your machine design.
There's a mechanical deflection spreadsheet around here somewhere, probably in the gantry design threads. You can use that to see how different dimensions on the L will affect the maximum deflection given a standard set of conditions like gantry span and weight of the Z axis. Because your width is smaller than mine if you used the same profile you'd get less deflection for the same Z weight.
I suggest you go and have a play with the spreadsheet to discover the relationships. Ultimately it depends on what tolerances you're happy with.
Quite happy to follow in someone else footsteps...lol
I want to see if there were any examples of 6040 size machine using L Gantries, but none have surfaced yet.
Thanks...will check out the spreadsheet.
I assume I could use fusion to get a idea of distortion under certain loads?
WIll have a play with that as well.
Here's a 6040 sized machine and it easily cuts everything up to Aluminium. I've built several machines this size which cut everything from MDF to Carbon fibre parts for RC cars and Clocks which require fine tolerences so don't worry about it being upto the job.Quote:
Originally Posted by Sterob
The best profile to use is 45 x 90 because it makes things easier with mounting ball-screws. However, 40 x 80 will work on smaller machine but you'll just need to make plates to mount BK/BF bearings on for ball-screws.
Attachment 27435
Thanks guys....just what I wanted to know.:beer:
I'll be using Item24 so will see what sizes they offer.
All the best with your project mate :)
That appears to be one short cut I won't be able to use as the supplier to have tenatively chosen does not supply 45 sized extrusion., only 40 and even that has to come from the other side of the country.....Quote:
Originally Posted by JAZZCNC
Some googling has found 1 or 2 suppliers that use 45 but the quality is unknown.
I'll either have made adapter plates for each bearing block or mount the bearing in another way.
Look for Bosch Rexroth or equivalent BR style profile. 10mm slotQuote:
Originally Posted by Sterob
Do you know if there is any significant price differences between BR and for example Item profiles? Both are offering 45 series profiles with 10mm slot.Quote:
Originally Posted by JAZZCNC
EDIT: Just checked and Item does not offer 45 series profiles, only 40 or 50 series. I got a quote from Item on 1000mm long 80x160 profile: 220 Euro. That seems expensive, dont you think? I need to get a quote also from BR.
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Thanks Jazz, I found a supplier of Bosch Rexroth in Perth, 200 km away.Quote:
Originally Posted by JAZZCNC
They also supply other brands so have asked about them as well.
Hi Steve,Quote:
Originally Posted by Sterob
Please would you let me know their price for Bosch Rexroth 45 x 90 Heavy profile once you know it.
Whereas it's dead simple going online 24x7 to get accurate pricing for this kind of thing in the UK, as I'm sure you know down here it's like pulling hen's teeth and requires phone call(s) or email(s) requesting pricing, and I haven't the foggiest idea what these things might cost down under and how badly "they" would rip off us buyers.
Thanks, Andy
Will do Andy.Quote:
Originally Posted by AndyGuid
Have requested some 'tenative' pricing as I don't exact dimensions yet.
Whats the preffered method of attaching Bosch Rexroth Extrusions to Gandtry plates?
With Item24, its easy....4 or 8 bolts threaded into the end of the Extrusion...
I see many connection methods in catalogue, but nothing seems to address this issue.
A single bolt in the centre doesn't seem to be it.....
Steve
The 45x90 and the larger 90x90 all use multiple holes. I wouldn't use any thing less than 45 x 90 and certainly not 45 x 45Quote:
Originally Posted by Sterob
Google KJN aluminium I have no problems at all you need to configure to get the right price, remember VAT.Quote:
Originally Posted by AndyGuid
I'm very lucky because I live within 5 miles of them, they cut all my extrusion and cnc drilled it for me.
Rip off merchants KJN try these lads. Based in Germany but yet I can get them quicker and cheaper than from KJN and lot more accurately cut.Quote:
Originally Posted by Desertboy
https://www.motedis.co.uk/shop/index.php
I might be blind Jazz but they don't seem to sell the heavy duty version, prices are very good. I recovered the aluminium extrusion from a magazine printer and KJN charged me 75p a cut and £1 a hole so at least for me was lucky to have KJN on my door step. I had 3.6m lengths to deal with lol it was all the heavy duty profile.
I watched them cut mine so maybe them spent more time on it lol because it was spot on, I'm sure they have a DRO on the saw but was couple of years ago and they have multiple saws so maybe not all have the DRO.
The drilling is a cnc drilled so shouldn't be any issue there.
If that other firm sell heavy duty version I certainly use them next time if I don't buy another magazine printer to scrap.
That source is a bust.
They will only sell 6m lengths. They will cut it but you still have to buy the whole length!
$2530 ex gst plus shipping.......Splitters!
back to plan; 'next'
That is insane.Quote:
Originally Posted by Sterob
Whats to stop you getting a mate in the UK to buy and ship out to you?
1m of 90x45 is £25 + VAT = £30
Shipping of 5kg 1m x 10cm x 5cm box to generic "aussie location" major port = £38
That price applies up until 185cm - anything more they don't like, but thats a decent gantry span. Posting directly to Australind or Packenham is £39, 1-3 day service apparently.
Lets double the cost to account for me being an idiot and not accounting for import duties... Say £135 per metre door to door.
Thats way better than your quote of £1400 for 6m ~ £233/m not including shipping.
It seems to the norm in Australia.
We get gouged all the time.
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I'd say his aussie flag in his profile lolQuote:
Originally Posted by AndyUK
My aluminium in the machine weighs 60kg's+ but I found a few extrusion suppliers in Oz and also could ship from China cheaper than UK.
Need to look harder.!Quote:
Originally Posted by Desertboy
https://www.motedis.co.uk/shop/Slot-...:99999415.html
I can't remember exactly what size I asked then to quote for but one Perth supplier wanted well over $600AUD for two 1m lengths of aly profile inc delivery. That was why I spent $180 on a stick welder and built my gantry out of steel I scavenged off the tip.Quote:
Originally Posted by Sterob
I'm with Kit on that one - I'm sure that alu profile is quicker and easier to use but if you can't find it at a sensible price then steel is good. I'm a (very) novice welder but my steel gantry works fine. If circumstances force you down that route, that fine - you can still build a decent machine. Just remember the home-builder's mantra - if you can't build accurate, build adjustable!Quote:
Originally Posted by Kitwn
You were Lucky! (apologies to Monty Python....)Quote:
Originally Posted by Kitwn
I can't even find anyone to sell me less than 6 metres!....lol
Can you remember who that was?
Yes, steel maybe a cheaper option.....
Will probably explore buying from UK, or failing that *shudder* china......
Early days.....Have to get the shed up first!
Who are these prices from Andy?Quote:
Originally Posted by AndyUK
I think it was Statewide Bearings in Perth. I can't easily search my old emails at the moment as I'm away from home but it was for heavy duty profile of quite large dimensions, 120 x 60 perhaps. My rails are fitted on the front face of the gantry so it needed to be quite deep and was going to be an 'L' shape. Even ally bar is a crazy price down here and, as you say, finding someone who will sell you less than a full length is near impossible. Steel on the other hand we dig out of the ground by the meggaton so is a much cheaper option.Quote:
Originally Posted by Sterob
I'm now using 2 pieces of 50 x 100 steel welded together to give a 200mm high face for the rails and more of the same for uprights and feet that bolt onto aluminium plates holding the linear bearings. This was my first attempt at welding but after a bit of careful grinding and copious applications of car body filler and paint it looks quite neat!
Yeah...they are agents for Modular Components.Quote:
Originally Posted by Kitwn
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Thanks for the reminder. I used Statewide for exactly that reason.Quote:
Originally Posted by Sterob
Have sent emails to UK and China enquiring about 45 series extrusion...no good leads yet.
In the mean time, it seems that some supplies do not offer an intemediate size, ie 90 x 135mm.
This means I have to use a different sizes for the Gantry.
I was wondering if there is a difference in the stiffness of a Gantry between these 2 options?
Steve
Attachment 27489
Option B is my preference, if joining on the back is acceptable to do.
I'd have said option A will lead to a stiffer machine, simply because you've increased the mounting distance between your rails? What does the gantry deflection calculator tell you?
Haven't looked at that . Will have a look now.Quote:
Originally Posted by AndyUK
Later.....
Thats going to take a while to get my head around.....lol
What size machine you building because 90 x180 profile arranged in L shape will make for a BIG gantry. To give an example I've just built a 10 x 5 machine with 2mtr wide gantry and it's only using 80 x 160.
Also, The point of the L shaped gantry is to have the bottom profile laid flat which is the stiffest direction for the cutting forces.
Its basically a 6040 sized bed but the frame will be larger so the tool will reach the whole bed area ( at this stage. )
Re: 90 x 180, yes I agree it will be huge. Most suppliers don't seem to offer anything between 90 x 90 and 90 x 180.
I have seen 90 x 135 ( and that is my preference ) but that seems uncommon.
Just got a quote back from Parts-On in the UK. 800 pd total. 350 pd of that is postage. doh......Works out to $1500 AUS.
Might have to conceed defeat and use 80 x 80, etc......
Not that keen yet.....
Check out Misumi (massive Japan based industrial supplier) - they have a fair range of big profiles and appear to have an outlet down under and whilst not always the cheapest you might get much cheaper shipping.