Member postings for Jeff Dayman

Top notch work Richard!

It's usually a good idea to grind off any slag on the edges of plasma or flame cut or laser cut steel disks before trying to turn them on a lathe. Even if the slag is not too hard, the interrupted cut along the rough serrated edges is hard on the lathe.

The hardness of the slag depends on the carbon content of the steel. Plain carbon or high carbon steels can have very hard slag, ie 60 Rc or higher. Mild steel (low carbon steel) slag is usually only a little harder than the parent steel as it is not hardenable except by case hardening.

Cheers John, good luck with your model. Do keep us posted on the progress!

Hi John, Do you have access to an outdoor space where you could do your own casting in aluminum? If so you can achieve good castings at home, yourself. It can be done with a charcoal fire contained in a firebrick box strapped together with hose clamps, blown with a hair dryer or hand bellows. ( Lump charcoal, not briquets, briquets do not burn as hot, they are fine for BBQ but not casting! ) An ordinary steel soup can can be used as a crucible for aluminum, handled with long handled water pump pliers. For small work, a couple of cigar boxes or similar wood boxes could be used to hold the sand moulds. Play sand with some crushed kitty litter bentonite clay mixed in works fine for basic small castings. I have done many small castings exactly this way. Just food for thought. If you don't have access to a space to do this, there are lots in ME forum who do, so if you posted a thread asking for assistance you may find someone nearby. If you were near me here in Canada you would be welcome to have a go here. By the way, for the aluminum, I find that scrapped aluminum car wheels (from being in collisions or just bad curb impact damage) are readily available cheaply at garages and yield LOTS of high quality aluminum alloy that was designed for casting.

Hi John, You don't mention what scale car you are planning, or if it will be used outdoors. If it is going to be large, or highly stressed, or used in the rain, PLA parts might not stand up well. They are about 50% the strength of moulded ABS for example, and some brands of PLA degrade fast if wet.

However, you could get or borrow a 3D printer and 3D print an excellent pattern to use for sand casting aluminum parts. If you do this, don't forget to make the 3D printed pattern scaled up oversize to account for the shrinkage of the aluminum. You can do the scaling in CAD or in the Cura slicer when you make your stl file. (if you use Cura slicer)

Hi Neil, about 3D printing by FDM and heat resistant materials: for several years Stratasys and other firms have offered service bureau printing of both Ultem PEI and PEEK polymers. I had some valve parts for a steam sterilizer made in 2011 in Ultem in my day job, and they withstood the heat OK but were a bit porous. A recent article about the various machines is below. The technology exists and is actively being developed.

https://www.3dnatives.com/en/ranking-3d-printers-peek-ultem020520184/#!

Parts FDM'd in both these resins can operate at over 100 deg C. The nozzle temps on some machines reach 470 deg C for PEEK.Just to be clear, these are multi million dollar commercial machines, and 3D printed parts in these materials are far more expensive than regular service polymers like PLA,ABS,etc. As far as I know no one is offering a home type low cost machine to 3D print Ultem or PEEK in the home shop. They may, someday.

Edited By Jeff Dayman on 14/12/2020 12:31:05

Rod, can you do the following:

1. download a pre-designed file set from Thingiverse.com, (file is in stl format)

2. load a slicer program like Cura to your PC (Cura comes free with the printer if you buy a Creality one like Ender 3, not sure if other makers give out a free slicer)

3. follow the online tutorial for the slicer, or a yout ube video on how to use it and open the stl file, position it in Cura, and slice it, generating a g-code the printer can read

4. put the g-code file made by the slicer program on a micro SD memory card

5. Load the memory card to the slot on the Ender 3 controller

6. Select the file with the controller, push start.

If you can do these things and do basic allen wrench assembly on the machine itself, you can run an Ender 3 3D printer.

Myfordboy has some great videos on yout ube also, for both Ender 3 printer and Elegoo resin printers, and others.

Edited By Jeff Dayman on 11/12/2020 17:30:14

Great engine Keith! well done.

Hi Thomas, plenty of great how to 3D print video on Yout Ube. Michael on Teaching Tech channel in Australia has some excellent ones. Link below.

https://www.youtube.com/channel/UCbgBDBrwsikmtoLqtpc59Bw

Same as me Pete, the only thing on my Ender 3 that I keep reasonably clean is the glass bed. Quick alcohol wipe for that, quick brush off of the way surfaces the carriage wheels roll on, and away it goes. Certainly NOT a super clean environment, and plenty of great parts off the Ender 3. Drop of iso 32 oil once in a while on the Z axis screw.

Edited By Jeff Dayman on 11/12/2020 17:14:14

Sorry re my brain fade / typo hot end vs cold end, of course OP did mention cold end was where he was working. I still think a water jacket where you want to transfer heat will be much more efficient than coils wound around. I agree with others who suggested soldering the coils or using heat transfer compounds would help if coil must be used, but a jacket and liquid or gaseous cooling media is a better method to move heat.

Has the boiler had a hydrostatic test with water only, to twice working pressure? If not do not apply air pressure at all.

Be VERY careful pressurising a boiler with air, would suggest no more than 20 psi for a boiler with working pressure of 90-100 psi.

Is the regulator open? Does the motion rotate smoothly by hand? Are the valves adjusted correctly?

Hi Bo'sun, by using a pipe applied to the hot end, you introduce a barrier to heat conduction at the interface of the pipe to the hot end part. Every such barrier will seriously reduce heat transfer from a hot item to a cooler item. If you can fit a water jacket around the hot end and transfer heat directly from the hot end to the cooling media the heat transfer will be far better. This method is used in the majority of liquid cooled IC engines in the world, for good reason. Only mentioning it as food for thought, and may save some cost and time straightening copper pipe.

If you only have number stamps and no letter stamps, 710 will also work.

signed I.N. Verse

For John Rutzen - you have a private message.

There was an article in MEW ages ago about a guy who made a gear type oil pump with an extra long shaft, with a motor well above fluid level driving it. This was intended for suds coolant on a mill or lathe as I recall but likely would be fine for parts washer use - IF it had a large area filter like a car oil filter on the inlet. This type of gear pump would not need rubber seals if the shaft bushing was a close fit on the shaft. The rubber seals and impeller parts inside pumps is what get attacked and ruined by solvents in parts washers usually. The motor for the gear type pump could mounted well above the parts washer, high and dry. A cheap DC gearhead one from China with a 200-500 rpm output would likely be fine. Most cars from 1930's to early 1960's had gear type oil pumps, with two gears in a close fitting housing, one of them driven.

Hope this idea helps.

Looking great Mal! fully boxed frames - long before the hot rodders got onto the idea.....Cheers

"

It really is "Pays yer money etc" the main thing is just to get on with the job

Regards - Ramon"

My sentiments exactly. Most things I build do not need accuracy anywhere near the capability of Haier centre finding, and most times a cigarette paper between tool and work is plenty accurate for the job at hand. Zig Zag white ones are still available locally. Apparently popular too with the local hemp head practitioners. Never lit one on fire on purpose here in my shop though, just use 'em for setup.

For round work in a vise, picking up the vise jaw (by any method) is so much easier than using a wobbler on the round bit, and is pretty foolproof, so I have no idea why anyone would bother fooling with a wobbler on the round bit. It just adds locational uncertainty, it does not improve any skill in particular.

To the OP, again, Just make stuff, don't stress on the details for the last thou. The more you do the better and more accurate you will get. To quote Stewart Hart "a little clearance never got in the road."

Too much time, unlimited money, one pointless project after the other. Amurkan dream.

Don't worry about metric William, just make a photocopy of the plans for the simple oscillator and mark it up with the mm dimensions converted to inches with a calculator - just divide mm by 25.4 to get decimal inches. Example - you might not have a 6 mm dia drill for a cylinder bore but you may have a 6.35 mm one (1/4" )   This is very close to the metric size. If you adjust the piston size to suit a 1/4" bore rather than 6 mm it will likely work fine.

If you have a smartphone it likely has a good calculator app already. There are many calculator apps online. You don't need a handheld calculator anymore.

A handy tool set for any shop is a full 128 piece set of twist drills with fractional, number, and letter drills included, from #60 to 1/2". You will find sizes very close to many nominal metric dimensions in these sets. The 128 pc sets don't cost much from China now, and some are very good quality drills.

Edited By Jeff Dayman on 30/11/2020 02:20:58