Scraping the Gingery Lathe Bed Flat (and cheating) | Gingery Lathe Part 2

[@PaulsGarage]

Resource list: Find the books here: amzn.to/3KztaSR (large one) amzn.to/3zVWgHe (small one) Surface plate: amzn.to/3s8y8AJ Blue Dye: amzn.to/3OQ4ZC3 Scraper: amzn.to/3DO9ub4 *You'll have to supply your own shoulder and back massage therapist after doing this. They don't sell those on amazon. Want to learn sand casting using your 3D printer? I can teach you!: paulsmakeracademy.mykajabi.com/joinus

[@sierraecho884]

There are really cool old techniques where you can for instance sand 2 non flat parts against each other and make both flat. This stuff is super old, pre industrial age basically so I never studiert that in detail but there are really cool things out there even without a flat reference surface because this flat reference surface had to be made without a reference surface as well if you know what I mean.

[@sierraecho884]

Isn´t there an easier way altogether ? You could buy a flat steel piece to begin with and overmold it ?

[@dizzolve]

8:00 you can use a yellow on the part and a blue on the plate for clearer viewing

[@PaulsGarage]

That's a good idea! Contrast would definitely help

[@rlbadger1698]

Or... plan A , go to a machine shop, tell them what your doing and have them chuck up your part on a surface grinder. 20 mins later and $60 0r $80 bucks it's flat. Plan " B " cast two plates the same size as your surface. Now swap between the 3 surfaces grinding with polishing grit each other.

[@paulwomack5866]

Nice job - I don't know which guides you read, but you learnt the BIG secret. Don't go too slow/gentle/precise in the early stages. Your metal removal rate and ink thickness should always be roughly proportionate to the (estimated...) remaining error. In the really early stages, you don't even have to remove metal where it's a blue spot. You can remove metal in AREAS where there are multiple blue spots. (I've mainly done metal bodied planes, I'm a woodworker).

[@4kays160]

Doing my engineering degree, 20 odd years ago, we had to make a slide with these dam scrapers and blue exactly like yours to pass a module at university, so i took my work piece home and to work the next day and put it on the surface grinder till it was perfect haha, then i scraped it with the scraper in a cross hatch so it looked like i had taken all week to get it perfect when i handed it in for grading 😂 i got a distinction for that module 😂 .. i suggest in your case just take it down to the local machine shop put it on the counter and say how much to mill this thing flat and level on both sides? , they'll probably do it for $30, or less on there lunch break, then id just cross hatch the pattern in it at home because the cross hatch scrapings are a good oil float for slide way's... haha

[@PaulsGarage]

Lol I like the way you think!

[@MikelNaUsaCom]

smarter... not harder... nice =D

[@billshiff2060]

cheater!

[@asafoetidajones8181]

Where'd you go to school? I'm tattling

[@kecclest]

I picked up my Starrett 24x36 granite surface plate from an industrial auction. Think I paid $100 and it came with a heavy duty stand. It was used in their metrology department, so it was basically brand new.

[@PaulsGarage]

Lucky! I'm never at auctions, I'll have to check those out. People keep telling me of great deals like that and I always miss out

[@kecclest]

@@PaulsGarage I googled local auction sites and bid online. I had to drive a couple hours with an engine hoist to load it in my truck, but it was worth the trip.

[@Pinworthy]

Check out Stone counter top installers. Stone counters are ground flat and polished on the good side. They cut the stone counter tops for sinks of all sizes. I'm sure the cut outs will be large maybe not square but big enough for you needs. Just have to make a base that you can level the cutout on. See if they have any sink cout outs you could have or buy..

[@IGBeTix-Electronique]

Very happy that you're coming back to this project ! Yess !

[@PaulsGarage]

More to come!

[@cavemaneca]

I think with just two episodes you've gotten further than 90% of people who try to make the gingery lathe

[@PaulsGarage]

I suspect the bed casting is the most daunting step, and then scraping the bed is the most tedious step, so you're probably right. Get through this part and it gets more interesting

[@shootgp]

@PaulsGarage Thanks for a heads up on that carbide scraper you linked to. It's currently on sale for $42. Hope that was an affiliate link 😊. Went ahead and ordered one. 👍

[@mfsamuel]

Is there a reason you don't spray adhesive sandpaper to the reverence surface and pass the face you are flattening back and forth until you have flatness? I have use this to flatten other surfaces with good success. Also, for other people without a reference surface, to save some money a good piece of thick glass is as flat a almost anything you can buy. If you are not beating on it, and just using it to mark high spots it may be a cheaper alternative. Off cut granite counter tops are a also very good, but may need some attention to get them perfect.

[@PaulsGarage]

I'm sure you could to get it roughed out faster. I think half the point of a normal scraped surface is the texture that holds oil better, but that's doesn't exactly apply in this case.

[@wackyvorlon]

You won’t get it flat that way, it ends up dishes. You have to move in a figure-eight. But first you need to get it kinda flat so it’s not rocking. If it can rock it won’t end up flat even with a figure-eight.

[@wackyvorlon]

@@PaulsGaragethat part about moving it back forth, you’ll never get a flat surface that way. Need to move in a figure-eight.

[@khester7397]

@mfsamuel Look up "Whitworth three plate surface method" It's pretty cool.

[@jackskalski3699]

When you talk single micrometers you won't get it flat this way. Gravity affects stuff and you end up with one surface concave and the other convex. That's why they came up with the three plate method to average out the error between two pairs and with proper sequence you can get it flat indeed. There are videos on KZbin about that. See also how lapping plates are created from scratch.

[@martinpanev6651]

I cant wait to see the final product- even if it take two more years!! I am looking into building a Gingery Shaper- and this is very inspirational! Luckily, I have a full machine shop lol. *What I would have done in your place, instead of the grinder, or even a scraper, would have been to glue Sandpaper or Emery Paper onto the surface plate and drag the bed forward and backward on it to flatten it, which would even it out almost perfectly and leave absolutely no surface imperfections!*

[@jackskalski3699]

but that would ruin your surface plate... I think a better option would be to experiment with first wit worth 3 lapping plates. Once you get these flat just Lap the damn thing with these lapping plates. These 3 plates probably will require re-lapping after first way but that would do it.

[@martinpanev6651]

@jackskalski3699 Yep! Thats a good way to go as well! The thing is, from the pictures he showed us of the "surface plate", and from looking at the listing on amazon, it is used for gluing down emery paper to it and Flattening the Soles of Planes.

[@PaulsGarage]

I hope it doesn't take years! The only issue with the sand paper on the plate is that this alloy (za-12) gums up sand paper really bad

[@martinpanev6651]

@@PaulsGarage Makes sense! You would go through $500 of paper to finish lol

[@paulwomack5866]

It's nearly impossible to make a flat surface this way. There's a super strong tendancy to create a convex surface by removal more metal at the corner/edges. As a cheap/easy proof, try rubbing a 6" piece of pine flat on a table covered in sandpaper. If ya' can make it work, sure, try it on metal. And further, the workpiece is under heavy pressure during the metal removal - so even if you're creating a flat surface during the stroke, the workpiece can flex to "some other shape" when you take the pressure off. @@PaulsGarage

[@Rouverius]

Yeah, I always wondered how you could do that by hand. Thanks!

[@PaulsGarage]

Do it for a few hours and you'll see why they invented machines to do it for us 🤣

[@sto2779]

1:19 - Correction, it's "Precision Machinists", many Machinists doesn't require high accuracy work. I have seen hundreds of videos on this topic, did years of research on this and your overview and explanation of precision metal scraping on it is excellent.

[@scott98390]

I've seen people make a flattening sled for wood using a router... I wonder if you could rig something up like that to be more consistent with a carbide bit?

[@laragwen102]

Not looking forward to this part of the project! Do you recommend the flap disk step or go straight to the scraper? I was confused at the end of your video. Thanks.

[@PaulsGarage]

I'd recommend careful use of the flap disk to get it pretty close, and then switch to the hand scraper for the final flattening. Hand scrapers are really slow but they are very precise and work very well

[@roscoepatternworks3471]

There are some really nice files for aluminum. It's like having a series of scrapers in one tool. At least 2 types, curved and flat sides and 2 flat sides. A lot more control than a flap grinder.

[@PaulsGarage]

Never heard of that, I'll have to check that out thanks

[@TinkerTomUK]

Keep a consistent temp use kiln dried hard wood and sealing it with a thin waterproof barrier when you make it, and it will definitely help keep dimensional accuracy when casting.

[@blazunlimited]

Glad to see more Gingery lathe build. Will it be all Gingery all the time for a while now?

[@PaulsGarage]

I'm shooting for once a month on the gingery but it might be more or less depending what else I have going on

[@DrMackSplackem]

Couldn't you make a top-down router sled and bed and go through a few el cheapo surfacing bits? That was my first instinct. Maybe not the best idea for something this large, but so far I've had pretty good luck with routing softer stuff like aluminum. Super light passes only, of course.

[@brett8090]

Thanks for the update video. Looking forward to the lathe. Question, why bother with the steel plate and scraping? Why not use a linear rail and set this project into overdrive?

[@ziggyboogydude1]

it's about the ritual !

[@RustyEast]

I built the shaper and I have a video of it running. I have been thinking about building the lathe.

[@PaulsGarage]

That's awesome! Shaper is next for sure.

[@johnmccanntruth]

Nice job! I think you’re well on your way.

[@PaulsGarage]

Thanks! I certainly hope so, I really want a lathe lol

[@raa6504]

I cand relate so much, when u whipped out the grinder with the flap wheel. Gosh i wish i had a lathe. 😅😂

[@wackyvorlon]

Go to a monument maker, and ask about spoiled granite grave stones. Those can be very flat.

[@PaulsGarage]

Interesting idea, I know where one of those is. Maybe I'll give them a call

[@NOFX0890]

Or laminate some removed granite benchtops together.

[@scott98390]

@@PaulsGarage if you get three, you can use them to flatten each other.

[@quantum_beeb]

Also consider using a $200 electric Surface Conditioning Tool. Pretty much like a surface grinder, but a paint-roller type end

[@jackskalski3699]

very funny and nice. One question though is how will you make sure that you'll end up with two of these with identical height ? Can't wait for the rest of this series.

[@PaulsGarage]

The legs? The patterns will be the same height (I'm doing separate ones, not identical like the book says). They will inevitably be a little different but I can scrape them to match the bed

[@Takunrsx]

question, wouldnt been easier to lay some sandpaper on the slab and rock the bed back n fort? thats the old school method for resurface cylinder heads so the surface goes to flat if they warped from overheating

[@wackyvorlon]

Fun fact: that’s a great way to make a warped cylinder head. It does not end up flat.

[@PaulsGarage]

It would be possible I suppose but this alloy really gums up sandpaper like crazy

[@swdweeb]

Just sayin' hi bud. Finally broke down and bought new control board, thermostat, and defroster coil the other day. Got tired of tearing the thing apart and attacking it with the steam cannon. New board has been in for three or four days. We'll see 😀

[@PaulsGarage]

Good to hear from you! How are you doing these days?

[@swdweeb]

@@PaulsGarageDoing pretty well, saw the surgeon again today, still healing and still not able to really lift anything. I feel good and have good energy again. I'm preaching this Sunday 😀

[@PaulsGarage]

Glad you're feeling good! Healing takes forever sometimes. I have an Uncle who never wanted to sit still and let the healing happen after his back surgeries and ended up with a much worse back in the end. Hope you heal well and hope Sunday goes well!

[@Iowa599]

Could you sand it smooth, by gluing sandpaper to the surface plate?

[@PaulsGarage]

You probably could. The only issue I see with that is the za12 gumming up the sandpaper. This stuff is pretty bad at that

[@Iowa599]

@@PaulsGarage I haven't tried that material, but if you do, wet sanding is probly the way. It is for bonda, because without water, the 'paper loads up. Use a bit of dish soap in the water, that helps. I figured it would work… The way of resurfacing a cylinder head (in the ghetto) is sandpaper glued to a piece of glass, then sliding the head on it.

[@wackyvorlon]

@@Iowa599doesn’t work, it’ll make a dished surface. You want it precise, you scrape or you use a surface grinder.

[@FranksWay]

love it,want to get into sandcasting,what sand is being used

[@PaulsGarage]

I use petrobond

[@wackyvorlon]

@@PaulsGarageyou can also make your own green sand. It’s a mixture of about 90% sand with 10% bentonite clay. When we were playing with it we used cheap clumping cat litter as a convenient source of bentonite clay.

[@khester7397]

Suggestion for the next video series in which Paul works toward developing a crippling case of carpal tunnel: How to lap your own precision surface plate.

[@PaulsGarage]

Way ahead of you, already had carpal tunnel surgery in both hands years ago 👍👍

[@khester7397]

@PaulsGarage Well I'm right behind you. I've needed the surgery for years, hoping to get both wrists done over the next year or so.

[@PaulsGarage]

The surgery worked right away for me. No symptoms at all afterwards, only some pain (pillar pain I think it's called) but that has all resolved now.

[@khester7397]

@PaulsGarage That's encouraging, thanks, Paul. Hey, I love your videos. Super cool, fun to watch, very informative. Keep it up!

[@PaulsGarage]

@@khester7397 thanks! Will do!

[@jasonburguess]

Sandpaper taped to a piece of glass, then put the lathe bed on the sandpaper and move it, the sandpaper lays perfectly flat on the glass, so you just work it back and forth untill its flat, it's a poor man's way of flattening an engine cylinder head that has warped. WaaaaY faster than this. Takes about two hours. Hope that helps

[@PaulsGarage]

Sounds like a good idea! This metal gums up sandpaper really bad though

[@jasonburguess]

@PaulsGarage they make an aluminum oxide sandpaper for belt sanders specifically for steel, it gums up a bit, but not as fast as sandpaper for wood. Also if you start with a very coarse grit and work your way down to extra fine it will work better and yield a better finish. Just sand the coarse until it's totally gummed up and then switch to a new sheet that's finer than the last and so on. Also they make specifically wet/dry sand paper that works well with a little water and that helps the gumming a bit too. I used this method to fix a small engine cylinder head and block and its still running 10 years later. Good luck, hope it works!

[@rlbadger1698]

you rule dude did this trick with a machine flat

[@bobweiram6321]

You can get large granite cutoffs from countertop fabricators. They literally dump tons of this stuff and it's a matter of just politely asking. A Dremel is an excellent alternative to both hand scrapers and power scrapers. You can lower high spots with pinpoint accuracy and the process is incredibly fast. I've flattened large areas in less than an hour. One way to avoid the scraping is to cast a precision ground cast iron surface in place. It works well for epoxy granite.

[@PaulsGarage]

I'd love one of those giant cast iron plates. Those have to be scraped flat too lol so I couldn't pull that one off on my own

[@steverenken5143]

When I've had problems like this with wood, I would put a straight that line down each side, and C-clamp a piece of wood on each side of what you want to straighten. They will keep you from rounding the edges of your peace. Then just hit with a belt sander.

[@nunyabiznez8120]

I know this is 1 year old, but I watched it to see how you did it. There is an 'easier' way... You have to have at least 3 of those plates and some valve grinding paste. You take 2 plates and put a thin layer of paste on one. Put them surface to surface, slide back and forth and at slight angles. This will remove high spots. Issue is, with 2 plates you end up with mating surfaces. That is where the 3rd plate comes in play. Do the same thing to the 3rd plate with BOTH of the 2 you flattened. Then again with just the 2 starting plates. Introducing the 3rd surface makes surface matching ALMOST impossible. Grinding all 3 plates against each other can be very time consuming, especially with harder metals. BUT you don't need the granite or the scraper. How do you think they got the first flat plates?

[@Mlodymic]

I worked with people, with over 40 years of scraping experience. Yo're not supposed to scrape from "hands only". Rest you're right hand on your hip, with scraper in your palm. Left hand provides pressure and guides the scraper. Use your hipps to for that forward motion XD

[@snakejawz]

.....why no belt sander?

[@wackyvorlon]

It’s very easy with stuff like that to load the belt, and also to end up making it significantly less flat.

[@PaulsGarage]

What he said. I also only have one belt, a super coarse one that would probably just ruin everything. It probably work with a careful hand and a different belt sander though

[@snakejawz]

@@PaulsGarage valid point, i got a DIY variac for tools that have a fixed speed, plus a couple belts. i didn't think about that.

[@jakeehrlich8113]

You can get an import surface plate that’s grade B (same as Wood River ones) for about $170

[@PaulsGarage]

I'll have to check that out. Grade B is more than good enough for me, I'm not flattening engine blocks or anything critical

[@ryanpeterson5239]

Check out Grizzly's surface plates also@@PaulsGarage

[@FintaruS]

Would it be any better to 3D print the paden, wouldn't that be more faldt?

[@ChucksSEADnDEAD]

I'm almost certain that has been done on youtube. But the finished casting will have to be scraped anyway so it's more of a decision based on what you already have. If you have woodworking tools you'll probably be faster doing it out of wood scrap. If you have a dialed in 3d printer you'll probably spend less time on the print than buying tools and wood.

[@Takunrsx]

it wont cause the metal shrinks and contracts when it cools down, you can make your mold and have as flat as you want, but metal and thermodynamics will do its thing anyway

[@FintaruS]

that makes sens, didn't think about the. @@Takunrsx

[@PaulsGarage]

Yakinrsx is right, the metal will still warp. It doesn't warp much at all, but we are measuring to a super flat surface plate so any deviation is relatively extreme. I get some pretty good prints off my old prusa printers but even those have some warpage if you compare them to a straight edge

[@txkflier]

That was highly entertaining..

[@michaeledmonds5789]

Hey yo use some wax on your flap disk to keep it from gumming up , great for aluminum

[@awldune]

Somehow I thought the bed was going to be the ways. So now you'll get to also scrape the ways?

[@PaulsGarage]

According to the book, you scrape the back edge of the ways, then later scrape the front edge parallel. I don't think he wants you to scrape the whole surface of the ways too but maybe I will who knows

[@lornablewettandlee504]

I'm sure your way is probably the better way to do it, but I'm lazier. I would buy either a cheap new jack plane or a decent used one. A jack plane is a long plane, about a foot or so, used for jointing boards. So also called a jointer. Flatten that on your surface plate, and then glue various grades of emery paper, or a tough sand paper, to the bottom of the plane and use it to flatten the bed. It might just work. You say this video is part two. Is that part two of scraping the bed, if it is then I missed part one, or part two of something else? I am a bit baffled. But I am old, so just a normal day.

[@wackyvorlon]

It may be okay for roughing, but it will not get you anywhere near where you need to be.

[@SlaviSokol]

Yes carbide is better. But! Not all carbide is the same. For scraping fine grade is required which is not that common. The blade needs to be honed and for carbide you need diamond stone. Overall a HSS blank is dirt cheap, can be sharped with common tools, for soft material carbide does not make that difference.

[@neffk]

Flattening with power tools is allowed!

[@Iowa599]

Is your hair turning red?

[@PaulsGarage]

You mean redder than before?

[@Iowa599]

@@PaulsGarage I figured that was the side effect of equipment you're building.

[@steverenken5143]

In the end you would have to do it the way you say though

[@mikeking7470]

I looked, and couldn't find Part 1, having a Part 2 implies there is a like titled Part 1, I would have liked to watch Part 1 first, oh well.

[@PaulsGarage]

kzbin.info/www/bejne/lZnWdICwZ86oqaM there you go 👍

[@CandyGramForMongo_]

You know what else is flat? Glass.

[@PaulsGarage]

Yes it is! Glass can be flexible though unless you get a super thick chunk. My bench isn't totally flat so I would probably flex the glass just a little bit if I pushed down on it and it could transfer the twist into the markings on the part

[@SateenDuraLuxe]

A random plate of float glass is pretty flat, but it doesn't come close to a granite surface plate, not even grade B.

[@jakeehrlich8113]

I use glass and sandpaper to lap stuff pretty flat but surface plates are an entirely level…I use the glass as a sacrificial first pass and the granite surface plate as a second pass.

[@Pinworthy]

Hell, just mix up some thickened epoxy and set your lathe bed on it. No need to scrap it..

[@tubbysnowman]

You could have done the whole job with a guitar levelling beam.

Brah-I bought those books when I was a teen with paper route money or birthday money(can't remember) and did zero of them. My dreams of lathes and mill dashed by.........................lack of effort I guess or ability. Truth hurts.

[@wompastompa3692]

Just cast 3 beds and scrape the 3 surfaces all together.

[@jackdawg4579]

i used a belt sander rather than flap disks

[@PaulsGarage]

That would probably work. I don't have much of a belt sander or other belts here or maybe I'd try that

[@DerekWoolverton]

I would just cheat, an go find a Bridgeport I can use for an hour. Here in Iowa they seem to be everywhere, because ... tractors. Yes I live in the city that's the world headquarters for John Deere.

[@PaulsGarage]

I know of a few Bridgeports around here but I think that's even more cheating than a grinder lol

[@jan-olofharnvall8760]

There is flat and then there is the flatness that will make you nauseated🤧

[@asafoetidajones8181]

I personally think Gwen Stefani is quite hot.

[@user-qy9rg3nt2l]

My favorite hand scraping video. Wish I could locate this style tool, but making one seems easy enough. kzbin.info/www/bejne/inemh4Jmm72KZ80

[@PaulsGarage]

Wish I could read the subtitles 😂

[@ThantiK]

Throw it in a wood planer!

[@PaulsGarage]

R.i.p. blades lol of course my planer claims to have a lifetime warranty and I'm pretty sure the manual doesn't specify "no flattening zamak beds" 🤣

[@Bertrp]

How is this cheating? You make up the rules. You want this to work or be bench art. Your choice

[@PaulsGarage]

Good point!