Concrete Lathe Adventure

[Tom Dunn AL]

Newer Member, first post...

Okay, I readily admit that I have no business designing a lathe, when I have very little experience using one. But, I want one and economics dictate this is the means to get one. And, I very much enjoy the DIY approach to matters and the learning curve associated with it. So, being greatly inspired by Mark Norman, I am cobbling together the Concrete/OpenSource/Multi-Machine bed approach with Gingery style aluminum castings done from Lost Foam models and a trailer axle hub and spindle head stock idea that I saw on YouTube.


My first design is not to intended to meet all needs, or desires. I just want to go through the learning process(es) and end up with a small, usable unit that I can play with and learn on. It will, however, have enough muscle and versitility to do both metal and wood turning (1-1/4" Spindle and 3/4 HP Motor.) See jpeg. I will make the components portable, so that they can be reused later in more advanced designs. All that will be lost is the concrete in the bed... that's less than $12.


This design has an 8" swing and 17.5" from the face of a plate mounted chuck to the end of the ways. The distance between the centers will depend on the tailstock design. I plan to use a threaded rod coupling, an old drill chuck and more concrete for that. The ways will be of bed frame angle iron that I have on hand. The unit will come in under 250 lbs, sans the motor, which I will mount remotely.


So far, expenses have only been $53 for the Hub and Spindle, plus I will need the $12 of concrete. Most everything else will be items I already own, or from scrap. I think I can easily bring this lathe to life for $100. I already have the motor.


Finding a used lathe has been a long term bust. I would greatly appreciate your input and help to bring this idea to fruitition. Mostly, I need help with any specifications that would make it more useful... As an example, maybe you would think that I don't need 8" of swing, if say 6" would cover 95% of common turnings, but I could really use two more inches of way length... That kind of information would be great.

One thing that really has me wondering is how the ways are trued to the spindle. I am casting mine directly into the bed to save a little money, so I have to get this right on the first try. Also, as I will be using the lathe to build the lathe, I will need to know how to turn down the end of the spindle to take the chuck plate. I have plenty of rebar to throw in, but I will not be using threaded rod to create compression, again, to save a little money.


So, I am hoping you will come along for the ride and help me out!

238874

[Thomas Canfield]

With the arrangement you show for the bearing/shaft bolted to the concrete frame, you can shim it some to help with alignment. I think that the bearing/shaft arrangement will result in deflection with the drive belt and then the turning piece extended so far from the bearing. A double bearing arrangement with the drive on the outside or between bearings would be much stronger. What will this be mounted on? The height shown will need to sit on a strong stand to get the center to a suitable turning height.

I would go with the larger clearance over bed length. It is somewhat easy to add length, but almost impossible to add clearance.

Used lathes are hard to find, but this looks like a major task that will end up costing $ with all the details, and getting the accessories will be next to impossible to find and you will be making those.

[Mike Cruz]

Tom, I feel you...I really do. This is a huge undertaking, but when you like the journey, there's nothing like it.

Your skills are way above mine, but I do have a question for you, since I am more savy WITH the lathe than building one... When you say an 8" swing, do you mean 8" from the spindle center to the bed, or do you mean 4" from the spindle center to the bed? 8" from the spindle center to the bed is what is referred to as a 16" swing. If that is what you are planning, then yes, 16" will likely do you fine. However, I would say that to keep you from having to go through this whole process over again at a later date, I would increase the swing to 18-20". That way, you'll only have to do this once... Best of luck to you!

[Tom Dunn AL]

Thanks so much to both of you for your help!

@Thomas: Good suggestion with using shims. But, I guess my real question is "How do you take the measurements between the spindle and the ways? A squaring tool of some sort? Measurements? Your observation about deflection is keen. But, this trailer hub set up is being used on a precision metal lathe with success and acceptable run out. These bearings are design to handle significant lateral load, also. And, the back of the hub is embedded in the head stock concrete, adding even more rigidity. At 250 lbs, I can make a beefy 2x4 stand that will handle the weight, but a concrete stand would be much more rigid. Mike concurs with a greater height over the ways. That's easy enough to design in at little extra cost. Yes, I will have to make all of the accessories. YouTube for "Lost Foam" to see how I plan to accomplish that. I am keeping my expectations low. If all I end up being able to produce is file handles and Christmas tree ornaments, I will be a happy clam!
@Mike: Thanks for the clarification of the terminology. Yes, 8" over the ways, for a 16" swing. Can go up a bit, easy enough.

I have been considering embedding the trailer hub back 2" into the face of the head stock. That will put the leading edge of the hub even with the face of the head stock and gain two more inches of usable way length. My only concern is that I am reducing the amount of concrete behind the hub. I just don't know what the effect might be. I have already cheated the Open Lathe/Multi-machine head stock design down from 12" to 8". But, I don't plan to do anything nearly as heavy as that full-size lathe is designed to handle.

[John Keeton]

Tom, I have no engineering background, so my input in that regard is worthless. The one concern I have is the flow of chips and shavings into the belt drive. With the drive open and in close proximity to the chuck, this seems problematic. At the very least, it could make for a bumpy drive, and worse, a jumped belt.

[Tom Dunn AL]

John, that is a great observation! Note to self, add a cover over the belt. Actually, a sheet metal "box" attached to the rise of the head stock should do the trick...

[Rodney Walker]

If you're still in the planning stages, give yourself the extra capacity. It's a lot easier to turn something small on a big lathe than something big on a little one. You may consider additional length as well unless you're certain you just want a dedicated bowl lathe. Judging by other lathes I've seen, you can go out to about 3 ft length with angle iron rails. I don't think I've seen any longer than that so I'm guessing after around 3 ft deflection starts becoming an issue.
If the funds are available, consider having morse tapers bored into the head and tail stocks as well, or at least design them with the possibility in mind. Many lathe accessories are designed on a morse taper and you may find it more ecomomical in the long run to not have to start from scratch every time you need a new accessory.
Looks like a fun project.
My two cents,
Rodney

[Tom Dunn AL]

Rodney, you are a big help. Morse tapers are in the bigger picture. The head stock spindle will be bored in place. That's part of the lathe-building-the-lathe approach. The tail stock will likely also be cast from concrete. If so, I have seen instructions on using a Morse taper insert/receiver cast in the concrete. I just need to leave a hole for the taper tool and weld a washer flat on the back end of the receiver to keep it from pulling out of the concrete.

I would like to know if the taper will cause the chuck plate to sit forward of the face of the spindle. If so, how much? Thomas's concerns about deflection might need more consideration.

If the taper does significantly increase the spindle length, then I may be pushed to recess the hub back into the head stock to maintain the useful bed length. Then, I am back to the strength question. I am still giving consideration to increasing the swing height and way length. But, I have to keep reminding myself of the purpose of this first endeavor, to end up with a small, usable unit and learn the process. Going bigger means pouring a full bed, instead of just "legs" for the ways.

Thanks for your input, keep it coming!

[Rodney Walker]

The morse taper on the head stock end is generally for small diameter items like spur centers. Chucks and faceplates are generally attached using screw threads on the outside of the headstock. For the outside threads again it may be useful to you to pick a thread pitch and diameter that is commonly used.
Rodney

[Donny Lawson]

It sounds like your on your way to a great lathe. Looking foward to seeing a picture of it when you get it finished.

[Mike Cruz]

The thread diameter and pitch that Rodney is referring to is either 1" x 8 tpi (for smaller lathes) or 1 1/4" x 8 tpi (for larger lathes). The morse taper "hole" is inside the threaded part of the spindle, so it will not protrude any further out, or obstruct anything that is screwed onto your spindle.

[Tom Dunn AL]

Rodney and Mike,
Thank you for such great information! Yep, I was/am aware of the spindle taper and thread arrangement. I'm glad to know that Morse attachments won't add length to the setup. I am also glad to know about the spindle thread. I was going to call a chuck vendor to find out what might be common. The spindle is 1" in diameter through the bearings. Past the seal, it enlarges to 1 1/4". I am thinking of turning it down to 1", so that I can develop a shoulder for the chuck plate to sit against. From what I have read, that seems to be important. Could you tell me more about the shoulder?

[Mike Cruz]

My main lathe, a PM90, has 1 1/2" x 8 tpi threads. I think the OD of the shoulder is 2". The bowl lathe I just had built for me was done the same so that all my chucks and faceplates will be interchangeable. Not the most common, but common in my shop. ;) It seems most of the new lathes use 1 1/4".

[Tom Dunn AL]

Thanks, Mike!

[Barry Richardson]

Very cool! I've been toying with the idea of building a lathe so I will follow with great interest! Particularly, the forming and casting of the 'crete.

[Tom Dunn AL]

Hi, guys,
Sorry to have been away for a bit, but life has its duties... In this case, a new 26'x14' treated wood deck... I am still scratching my head as to what I would like to do... Progress has been made with gathering scrap wood to build the form, thanks to the deck project. Also, my brother has been enlisted to help me fashion a temporary pulley from MDF. He builds HiFi speakers, so he is skilled, and equipped, to cut precise rounds out of MDF.

[Steve Kubien]

Tom, I just caught this thread and skimming the comments, my observation was not addressed... The angle iron from any bed frame I have ever seen is not thick enough to act as the ways of your lathe. It will flex so much that the vibration will (just a guess) make it impossible to get a clean cut. Sure, the concrete will absorb a lot of vibration but it will not be able to stop it between the ways, up to your tool rest.

If this has been addressed and I missed it, I apologize.

[Doug Herzberg]

Tom, I just caught this thread and skimming the comments, my observation was not addressed... The angle iron from any bed frame I have ever seen is not thick enough to act as the ways of your lathe. It will flex so much that the vibration will (just a guess) make it impossible to get a clean cut. Sure, the concrete will absorb a lot of vibration but it will not be able to stop it between the ways, up to your tool rest.

If this has been addressed and I missed it, I apologize.

Think RR rail stock or I-Beams like they use in framing houses - maybe a cutoff? Just my $.02.

[Tom Dunn AL]

Hi, Steve and Doug,
Thanks for jumping in... Steve, various folks have pointed out the need for a better bed/ways. I apologize for not addressing you directly. I am still exploring designs, but I like the idea of incorporating the ways into the bed. Basically, the bed iron is used to wrap the corners of the bed "legs". This improves rigidity, but doesn't do much to improve accuracy. I am also considering just using this design for a wood lathe. I do have a friend that works for the railroad and I am going to see if he can get me some track. I would still have the task of developing ways.

Thanks! Keep the suggestions coming!

[Rick Markham]

I think dealing with RR track is going to be a task itself. I'd be inclined to go to the local scrap yard and look for something with a little more workability. Pretty sure beyond the extreme weight of the rail stock itself, it's going to be incredibly hard to cut. I don't know for sure, but my suspicion is that rail stock is probably hardened, in which case you are going to have to anneal it before you can cut it. (Maybe someone here knows for sure) You have to consider that it was created with the purpose of supporting several million tons moving at high speed on a regualar basis (On hardened steel wheels) for many many years. I doubt it's very workable. (Like I said this is all conjecture on my part.) At the very least even if it isn't hardened when it's made, then a used piece of rail track is certainly going to have an extensive amount of work hardening due to the years of trains travelling over it.

[Tom Dunn AL]

I think dealing with RR track is going to be a task itself. I'd be inclined to go to the local scrap yard and look for something with a little more workability. Pretty sure beyond the extreme weight of the rail stock itself, it's going to be incredibly hard to cut. I don't know for sure, but my suspicion is that rail stock is probably hardened, in which case you are going to have to anneal it before you can cut it. (Maybe someone here knows for sure) You have to consider that it was created with the purpose of supporting several million tons moving at high speed on a regualar basis (On hardened steel wheels) for many many years. I doubt it's very workable. (Like I said this is all conjecture on my part.) At the very least even if it isn't hardened when it's made, then a used piece of rail track is certainly going to have an extensive amount of work hardening due to the years of trains travelling over it.

Hi, Rick... and thanks! Yes, there are DIY bowl lathes out there using RR track. But, not much direction on how it was accomplished. And, 100% metal.

I think I have honed in on a Bench Top Wood Lathe design that I can live with as a first attempt [thanks to Anon's napkin idea on my sister thread at alloyavenue.com.] Here's the sketch:

[Tom Dunn AL]

Progress includes removing the lug bolts from the hub... Measuring the lugs - 1/2"... Measuring the hub... And, creating a hub template on OpenOffice/Draw to layout the head stock boards... I am thinking I will use 5000# PSI concrete...

[Rick Markham]

Tom, if there are guys using Railroad tracks then it's possible. I'd say stick with that if it works, heck you won't get any deflection in the ways! If it were me, I'd go for Big. But I tend to go overboard on things! (I don't like making things twice either)

[ray hampton]

a railroad track are only HEAVY on the top, the bottom section of the track are about 1/2 inch or 1 inch thick shape like a upside down T , cut the top off and weld two bottom sections together, another method will require three sections of tracks, weld one track between the bottom of the other two tracks

[Tom Dunn AL]

Rick and Ray,
Thanks for contributing! I have spoken with my RR contact and he is going to look for some. In the meantime, I am going to forge ahead on the smaller scale.

A little more progress.
Rough Draft of General Layout of Cuts.
Efficency of materials layout sacrificed to obtain maximum factory board edges for trueness.
Pour will be made into the inverted lathe mold to allow maximum smoothness of bed leg tops and leveling of bottom of lathe.
Head stock and bed leg pours will each be another box within the main box.
Head stock dog ears will be accomplished with triangular bracing cut from sufficient solid board stock.
Form bracing and rebar to be added.
I note that I have a few errors to clean up... But, now, it has gotten late...

[Rick Markham]

Tom, speaking of Railroad stuff... I was doing some research trying to find any pictures of people using track for ways, I didn't find any. (If anyone has pictures, I'd be interested in seeing one) but I came across Pre stressed concrete RR ties. It might be something worth looking into, you could avoid building a bed yourself completely. Attach your Ways to the the tie where the track is fastened. If you think about it, other than having to blow chips out from under the ways (If you suspended them above it would allow the shavings space to be easily blown out and not compact) It's actually a pretty simple solution to a complex problem, The fasteners are built to be exactly the same height, etc. (Tight tolerances) If you did an accurate job of attaching the ways you'd be golden. You won't ever have to worry about the thing flexing (Assuming you support the length of the tie, maybe the a RR track running as a spine under it) you build some legs, headstock, tailstock, and your in business. (that's the easy part right :rolleyes:) Here's the linky to the ties http://www.roclatie.com/ (I'm not affiliated with them, nor have I even seen one)

[Tom Dunn AL]

Rick,
Interesting site... That's a very creative solution... If I were building up a large lathe, that might be the way to go... Great idea!

[ray hampton]

A rail road track will work but you can buy smaller tracks, overhead heists or cranes use a lighter track

[Jeff Nicol]

Well It has been a while since I have had time to check in on the Creek and this thread is right up my alley, but I would have to do some redesigning of the headstock before doing anything. First if you have enough length on the axle I would mount the hub on the opposite end away from the ways of the lathe. To do this correctly you would need to run a pipe through the concrete that the spindle would go through with a mounting plate welded on each end for attaching another bearing on the spindle side to support it. Part of this would be to make the form to allow the pulley in the center of the headstock, this would be done with the pipe I mentioned earlier it would be made in 2 sections with the steel plates on each end. The plates in the center where the pulley will be would be used as part of the form, and rebar would be able to be welded between them and a cage would be created to continue rebar through out the headstock. This allows for the pulley and belt to be out of the way of the work area and the replacement of bearings, pulley etc would be made fairly easy. Also then you will be able to alighn the spindle with the ways very easily too.

As for the train rail for the ways, the "T" portion would be used as the ways as they are roughly 5/8" thick and width is determined on rail size. When you figure out the distance you want the "Gap" to be in the ways, a portion of the rails could be cut off so as to make the bed roughly 8" wide and the heavy tops would make excelent weight for lathe stability. I know this may seem like a lot of work, but in the long run you would have a very servicable lathe that would last a long time. I will draw up a quick sketch and post it in a little bit to give you some more insight to my over active mind!

Jeff


Here is the little sketch that if quick and rough, but it should give you an idea what I mean. The squiggly lines in the side view are rebar and in the top view you can see a little more what I mean. I would maybe instead of re-bar on the through tubes I would put 4 pieces of pipe either 3/4" or 1" black iron pipe that would be placed in areas that you could drill and tap mounting holes for the bearing in front and the spindle hub in back. I guess I would take the whole axle to a machine shop and have the nose threads turned, maybe an aditional collar made true to the spindle to add more surface area for the chucks and faceplates to mount to. Also I would have them put a groove for a woodruf key that the pulley would slide onto and the set screw would tighten into place on.

I get a little over the top on explanations but hope this helps,

Jeff

[Tom Dunn AL]

Thanks, Ray and Jeff!

Great input Jeff and thank you for the effort of sketching the design. I like the way you set up the groove for the pulley belt. Good thinking...

There has been lots of observation by many that a pulley centered between the bearings would be a superior design; I agree completely. My choice of hub and axle was based purely on economics. I did check on spindle and bearing prices before making my purchase. Best I could tell, I was looking at several hundreds of dollars, plus machining. I chose the trailer hub approach, only after seeing an operational unit and reading discussions of the sufficiency of the design to manage the high lateral loads of turning. I do not know the outcome of this prototype, but I am enjoying the adventure of working through design and assembly. Wheel hubs off the front end of automobiles have also been used.

Today's progress has just been in doing a little poking around with the supplies I have and mentally working through the assembly to find problems. One issues I was having was how to box off the recess for the hub in the head stock. It was really taxing me, until I realized that the hub came in a plastic container that could easily be cut down to box the recess. The container even has tangs that will make it easy to attach it to the head stock mold. I also re-drew my parts layout to fit on the two half-sheets (48"x44") of plywood that I have on hand.

One thing that I am searching for is information on is how to cut the woodruf key way with just hand tools. I am seeing that it has been routinely done by others, but I have not seen a procedure that I think suits me. Any suggestions would be welcomed. It also occurs to me that, since I will cast all the parts, I do not have to use the attachment methods that manufacturers use. If it is easier to file the end of the spindle into a square and cast the inside of the chuck plate bore to match it, maybe that kind of thinking has merit. Thoughts?

Thanks for taking this journey with me!

[Grant Wilkinson]

Tom: Your original post mentioned using this for as both a metal and a wood lathe. In a subsequent post, you seem to have decided to limit it to a wood lathe. Is that where you are at now? I ask because, if you are still considering using this as a metal lathe, I believe that your design, and pretty much all the suggestions so far do not lend themselves to the requirements of a metal lathe. There seems to be no way to move a tool post, for example.

[Tom Dunn AL]

Tom: Your original post mentioned using this for as both a metal and a wood lathe. In a subsequent post, you seem to have decided to limit it to a wood lathe. Is that where you are at now? I ask because, if you are still considering using this as a metal lathe, I believe that your design, and pretty much all the suggestions so far do not lend themselves to the requirements of a metal lathe. There seems to be no way to move a tool post, for example.

Hi, Grant,
Thanks for joining in. Yes, I have down scaled my ambitions to just creating a bench top concrete lathe. I hope to be able to "learn the curve" on using concrete for this application, build/cast parts that can be used on a future upgraded metal turning model and get a modestly usable wood lathe.

I am doing a mirror/sister thread on alloyavenue.com to get advise on the metal side of the equation. And, as you have noted, the present design is not adequate for metal. But, their members can help with metal matters.

In my last post, I mentioned that I am doing my homework on cutting a woodruf keyway in the spindle with just hand tools. I have learned of a specific chisel, a "cape" chisel, to do the job. I will be giving that some thought and pondering how to make a jig to keep the keyway true... Maybe clamp the spindle in two pieces of angle iron with the keyway defined by the gap between the two pieces of angle iron. I also have various other power tools that I can throw in the mix.

I appreciate your interest and input. Please continue!

[ray hampton]

[QUOTE=Tom Dunn AL;1977566]Hi, Grant,




I will be giving that some thought and pondering how to make a jig to keep the keyway true... Maybe clamp the spindle in two pieces of angle iron with the keyway defined by the gap between the two pieces of angle iron.
unless you got narrow angle iron , you will need to made some different thickness of spacers to hold the two angle iron the correct distance apart, do you own a welder ?

[Jeff Nicol]

Tom, If you have a drill press and take it slow and light cuts you could get the correct size endmill and mount that in the drill press and make a simple jig so you can move the shaft back and forth to cut the keyway. To start you could drill the corresponding size of the required key size with a regular drill or a center cutting endmill, three or four times in row to remove as much waste before cleaning it up with the lateral movement with the endmill. It would take a little bit of time but the out come would do the job. I know how it is to want to build things on a shoestring and do things without the correct tools, but over the years and many tools later it is much faster for me!

Stick with it and it will all come out in the end, lots of patience and perserverence and of course LUCK!

Jeff

[Tom Dunn AL]

[QUOTE=Tom Dunn AL;1977566]Hi, Grant,




I will be giving that some thought and pondering how to make a jig to keep the keyway true... Maybe clamp the spindle in two pieces of angle iron with the keyway defined by the gap between the two pieces of angle iron.
unless you got narrow angle iron , you will need to made some different thickness of spacers to hold the two angle iron the correct distance apart, do you own a welder ?

Ray, hmmmm.... I am a bit confused... I know that I posted a reply to this, but now I don't see it??? So, this is what I recall... No welder... I think I understand your thinking... Banging on the chisel will shake the spindle loose... Great observation! I think I had other comments, but I just don't remember... My apologies...

[Tom Dunn AL]

Hi, Jeff,

In my research, I have found others asking about milling a keyseat in a drill press. The general thought was that it would not work... But, I don't recall anyone suggesting tapping the line with a regular bit, first. Seems to me that your approach has good merit and is worth serious consideration. So, that it will certainly receive!

I am seeing lots of postings about successfully cutting a keyseat with a cutoff blade chucked on a Dremmel and just using a steady hand. Sort of hard to believe... But, some testing would prove it out. I know that I would make something of a jig for this. My hand just isn't that true, anymore... Can't cut paint in at the ceiling anymore, either:D

Thanks. I'll keep you posted.

[Tom Dunn AL]

Here is a jig on point... Not sure it's still available... Would be expensive... Does not work with my 1-1/4" OD... Looks like it can be powered with just a wrench... SearchTempested CraigsList, but no joy...

http://books.google.com/books?id=M9gDAAAAMBAJ&pg=PA181&lpg=PA181&dq=mcdonald+portable+keyseat+cutter&source=bl&ots=F7ThRYFqtv&sig=8IOgDpIX7xaOcO5LFvANM3tDtXs&hl=en#v=onepage&q=mcdonald%20portable%20keyseat%20cutter&f=false

[ray hampton]

[QUOTE=ray hampton;1977632]

Ray, hmmmm.... I am a bit confused... I know that I posted a reply to this, but now I don't see it??? So, this is what I recall... No welder... I think I understand your thinking... Banging on the chisel will shake the spindle loose... Great observation! I think I had other comments, but I just don't remember... My apologies...

narrow angle are angle iron 1/8x1/2x1/2 inches on up to whatever, the impact from your hammer will loosen your clamp but this were not the reason for the welder, clamp the two angles to the spindle with a spacer betweem them to hold the space for your groove and weld a steel angle to both angle to hold them , the drilling of the groove with a drill press sound like a good idea

[Tom Dunn AL]

Weld a spacer... Good thought, Ray.

I am still scratching my head on making a jig. The easiest I have seen has been a Dremmel mounted router-style under a table top with its height set to the center line of the spindle. Multiple cutoff wheels are chucked to just less than the needed width. A swinging fence is used to advance the spindle into the wheel with each pass. The fence swings from a single pivot/screw point on the diagonal, but this is of no consequence as depth is the only factor of interest. The spindle is steadied in a v-block.

I am rather certain that I will give this method a try. But, I do have other ideas. I have a clamp-on hand drill press that could be adapted to use the lever to advance the spindle back and forth. Wisdom would be to use the KISS method, though:)

I am going to my brother's house, tomorrow, to work on shop projects, together. Guess what I am going to be working on:D

[Tom Dunn AL]

Made good progress at my brother's. Cut all the plywood to size. Need to make a few more trim cuts, though. Also, need to cut the angle braces to make the dog ears. Used a circular saw jig for most of the big plank cuts. Very good precision with that method. Tapped the HS face and back for the spindle and bolts. Went to HF and purchased rotary tool diamond disks. They have better reported performance for cutting and longevity. I have even seen them mentioned specifically for spindle keyseat grinding. Lots of fun and fellowship on a beautiful day!

[Mike Cruz]

Tom, just a note. Though you might not get a lot of responses to you progress updates, they are being read. Keep 'em coming.

[Tom Dunn AL]

Mike, thank you for the encouragement. It is well appreciated!

[Rick Markham]

Ditto what Mike said! We want pics too :D

[Mike Stephens]

You are on a roll. We want to see this through with you.

Thanks for posting.

[Tom Dunn AL]

Thanks, guys! I hope to do some of the mold assembly on Sunday afternoon. That might be picture worthy. I hope to be able to use a pneumatic stapler to tack the mold together. I think that will allow me to have enough flex to true the frame in all axis, before finishing with screws. I also need to travel up to my property to round up some scrap rebar and my diy rebar bender. We'll see what progress I make...

[Thomas Foster]

Sounds like an interesting challenge. Based on your description of the spindle size (1 1/4" dia.), your turning down the diameter to 1" is compatible with the standard headstock 1"x8tpi used on many mini/midi lathes. My Jet 10x14 has about 1" length of threaded 1"x8tpi to the shoulder. This would then accept commonly available face plates, chucks and other accessories. Have you thought about how to achieve variable spindle speeds. Do you have space for stepped pulleys? Another consideration is a spindle lock or means to hold the spindle from turning while installing or removing chucks, etc.

Good luck on your endeavor.

[Tom Dunn AL]

Sounds like an interesting challenge. Based on your description of the spindle size (1 1/4" dia.), your turning down the diameter to 1" is compatible with the standard headstock 1"x8tpi used on many mini/midi lathes. My Jet 10x14 has about 1" length of threaded 1"x8tpi to the shoulder. This would then accept commonly available face plates, chucks and other accessories. Have you thought about how to achieve variable spindle speeds. Do you have space for stepped pulleys? Another consideration is a spindle lock or means to hold the spindle from turning while installing or removing chucks, etc.

Good luck on your endeavor.

Thanks, Thomas! Really good information.

Yep, planning on turning down to 1"x8tpi. Others had suggested that size and thread, too. Am also planning on 1" length with a shoulder. I understand that the shoulder provides a "square" face for the face plate to true against. But, I think I have read about a non-threaded space between the thread and the shoulder. Do I have that right? What would be the function of that non-threaded space? Also, I can't remember what I read about the thread direction. Is right-hand the norm?

I have a dead HF table top drill press that I will adapt for a stepped pulley. Haven't torn it apart far enough to know what would need to be done to use it. I did round up the exploded parts diagram. But, it is not clear as to how the pulleys are mated to the spindle and axle. I think that they are mounted differently. I am also wondering if I might be able to turn down the JT33 chuck taper to 1/2" and mount a plate sander. Any idea about the thread count for that plate?

Oooo... A spindle lock. Great idea! I guess that could be as simple as a hole tapped through the spindle to receive a round bar and a jam hole, or flats cut to receive a wrench. What do you suggest?

[Tom Dunn AL]

Hey, Thomas,
How about this idea... A narrow, flat stock spanner pin wrench for a spindle lock... Situated between the head stock face and the backside of the pulley... Tapping a hole in the spindle would be easier than trying to achieve the needed accuracy of a complete through-tap... And, less manpower than filing flats... I could easily embed a threaded seat into the face of the head stock to receive a removable jam bolt... Suggestions?

Just plan too tired to try to do any assembly, today. Years add wisdom and I am old enough to know better than to try to true up a mold when I am tired... But, soon!

[Tom Dunn AL]

I made a little progress on assembly, today. The pictures tell the story... Please enjoy and comment.


Additional progress has been made in gathering materials. I am helping a friend prep for moving and he blessed me with a blow dryer, a half pail of dry wall mud, and a bag of play sand. I will take the hot wire out of the blow dryer and make a foam cutter. I will use its fan to feed a DIY aluminum forge. I will use the mud to coat lost foam molds. I will use the sand for lost foam casting of the pulleys, face plate, etc.


I have already rounded up some foam from the local appliance dealer... Good source... I guess furniture stores also could be a honey hole for free foam.


To infinity and beyond!


Tom

[Mike Stephens]

Very cool. Keep the updates coming.

[Mike Cruz]

Tom, you're really doing this, aren't you? Gonna enjoy this...

[Doug Herzberg]

I will use the sand for lost foam casting of the pulleys, face plate, etc. Tom

Now that's extreme DIYism. Sounds like fun - no way you can be doing that much work to save $$.

Good luck

[Tom Dunn AL]

Now that's extreme DIYism. Sounds like fun - no way you can be doing that much work to save $$.

Good luck

Thanks guys!

I am already collecting my aluminum. Could have had way more than enough in soda cans, but they are really "dirty." Make lots of slag. Just keeping the pop tops. Yep, I love to DIY!

[Tom Dunn AL]

Here is a reply to a mirror thread question at Alloy Avenue:

"Right-near" 220.37 pounds:D. My brother and I developed a spreadsheet in Open Office that will calculate the weight of an object and select the bag weights to minimize the total cost. I could post it in Excel, if you can tell me how to upload it on this forum.


Yep, putting in lots of screws. And, the pictures show that I am using heavy bracing timbers. I have worked with concrete before. You are exactly right.

[ray hampton]

Thanks guys!

I am already collecting my aluminum. Could have had way more than enough in soda cans, but they are really "dirty." Make lots of slag. Just keeping the pop tops. Yep, I love to DIY!

do you know that the pop cans are painted on the inside of the can ?

[Tom Dunn AL]

Hi, Ray,

Yes, I had read that. So are food cans. Plus, the paint on the outside, too. Hence, my "dirty" observation.

I had a piece of aluminum door threshold slip threw my fingers. It was given to me, but I forgot to take it with me when I left and it was thrown away. Maybe it was not as much of a lose. Some folks are not fans of extruded aluminum for re-casting.

Not much progress, today. Not enough get-up-and-go. Maybe tomorrow, after church.

[Tom Dunn AL]

I am still thinking on how to embed the spindle hub. If I encase the rear bearing housing in the concrete, I get better rigidity. But, if I leave a bit of space around it, I could shim the hub plate for alignment. I will be truing the hub against the head stock face board of the mold. And, I would think for a wood lathe, that the alignment would not be too critical. My tail stock design will allow for adjustment, so I am leaning toward fully embedding the hub. Thoughts/suggestions?

[Mike Cruz]

As long as you will still have access to replace the bearing in the future...

[Tom Dunn AL]

As long as you will still have access to replace the bearing in the future...

Yep, the hub will be coated in petroleum jelly before the pour and I will be able to remove it for maintenance. I am also considering tapping a hole for a zerk fitting and leaving an access port. Maybe even a buddy bearing.

[Tom Dunn AL]

Well, progress on the mold has been slow... I cut the wrong side of the line on a critical cut and thought I was out of materials to remake the piece. But, I remembered that I have another piece, I just need to "fetch" it. A significant advancement is that I have just been given a BBQ grill. That should have enough metal for the pulley and a few other fixtures. Can't remember if I mentioned that I also was given a blow drier. I will harvest the wire for making a foam cutter and the fan for a forge blower. I came across a propane bottle in a trash pile, this morning. For some weird reason, it had two random holes drilled in it. What a shame...

[Mike Cruz]

Tom, hadn't heard much about this lately, and was concerned you gave up! Glad to hear you are still at it, just hit a small hicup.

I had to do a little concrete stuff my self, lately. So, I was thinking about you and your project. I REALLY appreciate what you are going though...

[Mark Norman]

Glad to provide some inspiration. I am truly flattered.


I should stop by the creek more often.


Keep up the good work Tom! I would hope you have made some progress since the last update.