Oxy-acetylene at home

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  • Head tramming on a round column mill can be done with a little mod and not much effort.

    Mount a laser to the spindle of the mill. Mark the laserdot location on the opposite wall. Raise the head, lower the end spindle and then match the head orientation by getting the laserdot to the same location on the opposite wall.

    It's really accurate due to the fact that you're measuring an angle over the length of the room.

    It was a hot tip I got from Armour custom cycles

  • Be aware that lasercut tolerances are usually a combination of two tolerances. For example it's common for the tolerance of +-0.2mm to be quoted, this for example could be made up of a +-0.1mm positional tolerance and +-0.1mm profile tolerance.

    As you go to thicker material the profile tolerance will get larger as this is the edge profile of the edge that the laser is effectively burning away.

    While the positional tolerance will not change as this is the tolerance that the cnc lasercutter can hold while running on it's leadscrews.

    Best bet for something where accuracy is desired is to get some test cuts of your chosen thickness rather than relying on the stated lasercutters numbers.

    Testcuts including both hole diameter and slot width.

  • Yeah, I’ve read about that. There are all sorts of workarounds but I still prefer knee or dovetail columns for ease. I wind the head up and down all the time for tool changes and with the amount of shite in my garage, getting line of sight to the opposite wall is a challenge…:)

    The little machine continues to impress. I squared up some hot rolled box section for a jig with a 50mm shell mill the other day and it didn’t complain too much, even if it took a while.

    @Ph1ll1p I know exactly what you mean mate, I just finally got half set up and now the poxy rain has cracked the back wall again, so I’m back to fixing that again.

  • Some of those fixture tables look amazing. I wish I had the space and budget for one.

  • We just added this shallow 1200x1200 one to the workshop yesterday.
    The way I justify it is that it costs £1700+vat but I could sell it for £1200+vat after using it for 5 years. They hold their value if you look after them.


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  • Nice! Very useful bit of kit, but alas, I'm only a hobby-nodder, making bits for me and space is limited to say the least. I'm saving the tiny bit of room I have left for a tube bender. I'd like to make a motorbike frame at some point, so maybe I'll re-jig then.

  • I've not been on here in ages (hello) and I came across this thread and very interested in these DIY lasercut fab tables mentioned by @Fishfabs and @retrodirect/glowbike

    Did anyone get one in the end?

  • I made one myself. It's really very flat and didn't cost much in materials - £200 for a 1x1m table top with a 100mm skirt around the outside and inner ribs - That was 6mm sheet, so would start to deflect with heavy use. Most of the stops and clamps are better in 12mm table tops though.
    I don't think the MAC industry tables are good value considering the costs of the lasercut parts isn't huge. I'm sue they have their reasons for the price.

    But if it's a table you'll use most days of the week, I'd cut out the middle step (lasercut version) and get a siegmund or buildpro table - I think alot of people upgrade after using a lasercut one for a while.
    https://www.siegmund.com/en-gb/Offers,6665.php
    Have a look at these offers - buy from Escco - shipping can be £150 and take a couple of weeks. And then add VAT.
    ..... but it'll last forever and you'll always get 75% of your money back if you need to sell.
    I don't get any discount btw!

  • Any table wouldn't be put into serious use. I have a sort of side thing going (metal but not bikes, low precision) on but unfortunately it keeps getting interrupted by actual paid desk work.

    MAC were the ones I was looking at. I've been looking (casually) for a decent lasercutting service for a while for my other activities, so if you can recommend one I'd appreciate it.

  • Try Cutting Technologies - Cuttec - they are in the Midlands but are incredibly efficient at palletising and sending out parts on time at a competitive price.
    Lots of firms about, but costs vary a lot with the smaller companies I find.
    Some welding table CAD files are on eBay for cheap, can't vouch for them though!
    A friend designed his own 2x1m table recently, he's talented and it's a nice design. I can ask if he'd sell/give the DXF's, if that size suits?

  • Hey, that would be cool if he's willing to sell or give the files. I am a member of a maker space so I'm sure someone could help me shrink those files to my desired size (maybe more like 0.8x1.2m).

  • The DXF files don't scale down unfortunately, as they have tabs/slots that interconnect and everything changes.
    It may be worth buying a drawing set from one of the ebay sellers that list them - you have some size choices then :) Hope it works out.

  • No worries cheers pal. I'll check them out

  • Escco just put a summer offer out for a 1200x800 table with accessories for £810, if that become viable.
    https://www.escco.co.uk/product/siegmund-workbench-1200x800/

  • I've got some files for this already done that you can have, if you're still looking.

    It needs a test-cut before ordering the final thing to really get the tolerances on the holes bang-on but it's otherwise ready to go.

  • I've always wanted to do some metal work and I'd like to add some braze-ons to a frame I have.

    Prices for this sort of stuff has increased which got me wondering what the diy cost would be.

    So what would be the cheapest set up to add some stops and mounts? OXY-ACETYLENE? OXY-PROPANE?

    What are all the hidden costs I'm forgetting about?

    Cheers.

  • MAPP torch would be cheapest for simple braze-ons

  • MAPP torch would be cheapest for simple braze-ons

    True, though I’d argue the upgrade to oxy propane, which will be cheaper to set up if not run* than oxy acetylene is worth the investment.

    *with oxy propane you burn through more oxygen than you do with oxygen acetylene so long term running costs might work out better with oxy acetylene but you’ll have some big costs to start with.

    To get set up with oxy propane you’ll need a torch, hoses, regulators and flashback arrestors which are available as a kit from a few places, Weld Equip look good on price and might be where I got mine. You’ll also need gases so I’d factor about £70 deposit and £70 for the gas for each. I’d upgrade the standard single flame tips from the kit to the multi jet tip from welders warehouse, you need a neck and a tip (I use a #3 for everything) so probably, £50. Flux and rods, £25ish for a tub of decent flux from Ceeway. You’ll need one for brass and a different one for silver. Brass (some people say Bronze, I dunno?!) rods are pretty cheap, £20 would get you started. Silver rods are about a fiver plus vat each. You can get some short ass Johnson Matthey rods on eBay for not very much but you’d be better just getting 5 or 10 rods off of Ceeway.

    You’ll also need eye protection (the kit maybe comes with goggles, I prefer glasses), something to light your torch with, a fire extinguisher should almost certainly be part of your set up costs. Some vessels to hold water to soak flux off in. Maybe some clamps to hold things in place, I started off with one of those soldering things that has a heavy base and a magnifying glass, £5-10 on eBay/amazon etc.

  • Cheers.

    Looking into it the mapp idea sounds appealing.

    I came across this video (skip to halfway through)
    https://youtu.be/Nu_4JlJBcfg?si=K8KdHDKAFOmsBzh4

    The guy has much more welding experience and more fancy kit than me, but it doesn't look too difficult.

    I guess silver makes more sense as it's to use on a frame with lugs that's been braze with brass.

    I know it's a bit vague but how much gas would I need to do:

    • 4 mudguard eyes (2 pairs)
    • 2 water bottle bosses
    • 2 cantilever bosses (1 pair)
  • I know it's a bit vague but how much gas would I need to do:

    4 mudguard eyes (2 pairs)
    2 water bottle bosses
    2 cantilever bosses (1 pair)

    Some!

    Haha, how long is a bit of string?! You’d get that out of a single mapp bottle.

    The canti mounts will be a challenge though. You should probably do them with brass not silver. Mapp should be hot enough to melt brass. It will not be easy. You can probably do them with silver, I have.

  • Cheers. I appreciate it.

  • I haven’t tried it, but I don’t think you’ll get brass flowing on brake bosses with Mapp. Maybe Fillet Pro would work?

  • Yeah I really struggled to get the heat to get brass to wet out to anything with mapp but there was always people telling me it was possible!

  • Buy a two bottle brazing kit in France.

    https://www.bricodepot.fr/catalogue/poste-a-souder-bi-gaz-compact/prod13363/

    Tho look around as mine was cheaper from another DIY chain

  • They lie, mapp gas is more like the upper end of propane. So even with a proper mapp gas tip I have not had any luck

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Oxy-acetylene at home

Posted by Avatar for Ph1ll1p @Ph1ll1p

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