Member postings for Rick Hann

Ah! One must first determine what "the job" is! The desired result is a smooth moving piston with minimal friction that seals. To do that you must know what ACTUAL dimensions you are dealing with. I.E. ACTUAL bore diameter, ACTUAL O-ring X-section diameter, and desired O-ring compression I have found that 5% compression is the upper limit of compression. If it were me, I would shoot for a for no more than .005" total compression. For example: Assume a nominal bore diameter of .750". Assume actual bore diameter = .753". Assume nominal 3/4" x 1/16" (.0625" 0-ring will be used. Actual measured x-section = .071". Desired 0-ring groove diameter would be .753" - 2x.071" + .005" = .616". If you noticed, There is no need to know the piston diameter as it obviously must move freely. The o-ring groove depth has no meaningful relation ship to the piston diameter. Groove width is not so critical. It needs a bit of side clearance. Using published O-ring compression numbers will most likely result in far too much drag. Rick

My post was not meant to dispute your numbers. I have built quite a few engines and because I am not an expert machinist, often times I have ended up with cylinder bores that are not "spot on". A few thousandths over or under planned dimensions will make a difference on the groove dimension, especially on a small bore cylinder. Another variable to consider is the actual diameter of the o-ring cross section. Rick

Scott, You must calculate the depth of the groove based upon the cylinder bore diameter. You should not use published o-ring compression recommendations. I would shoot for no more than 5% compression of the o-ring. It should be a easy fit in the cylinder. Rick

Looks a lot like my 8mm Boley.

Rick

I bought mine years ago from McMaster-Carr. There was a discussion a while back and if I remember correctly, it was hard to find in Europe and expensive. Probably not worth it for one or two jobs. I have built numerous engines over the years and I would not be without it. Still have 50% of it left. A Google search should turn something up if you are still interested. Rick

Timesaver Sampler Pack. 8 different grades. 4 each for ferrous metals and 4 each non-ferrous metals. Non embeding! I have used it for more than 25 years. Rick

David, It seems that your best option for propane firing is the Marty Burner. You do need a large enough firebox to be able to install the burners without too much flame overlap. If you are so inclined to play around with Btu outputs versus orifice size, gas pressure and other variables, I found the following site to be helpful. Rick

ronreil.abana/BTU-Caculator.xls

David,

I think it would be possible for you to fire your sweet William with propane. I don't know what scale you are working with, but I successfully fired a 3-1/2" Gauge Rob Roy with propane ceramic burner (firebox approximately 3"x2". Burner output approximately 18,000 BTU. There is a lot of information on gas firing, but you have to look for it. If you want to see it running, just google Utube (Rick's Rob Roy). With a small firebox, it is a bit like trying to put 10# in a 5# sack. Good Luck! Rick

In 1960, I worked one summer for a small Iron foundry in Northern Illinois, USA. They would tap the cupola (iron) in the afternoon to pour the days mould production. I was a helper and carried the Iron to the moulder who would pour their own moulds. No safety equipment in those days. There were a couple of "Old hands" who liked to impress anyone new on the floor (salesmen, visitors, etc.) by standing next to the cupola and using their finger to flick beads of molten iron across the floor from the stream of iron flowing from the tapped cupola into the crucible. One would ask the other one if it was hot enough and his answer would be Just a second, I will check it as he flicked the molten iron with his finger. Needless to say, I was impressed! Rick

I don't know the meaning of the word apathy and what's more, I don't care!

Rick

If you decide use bone meal from a garden center, make sure you are well away from civilization. I tried bone meal in a failed attempt at color case hardening. My workshop is in the basement. Before i realized it, the stench was terrible. It took a couple days for the smell to go away and as an aside my wife was pissed. If you use it outside you are likely to hear from the downwind neighbors! Just saying! Rick

Perhaps you are looking at the wrong end of the barrel. Could it possibly be used the thread the inside of a 20 Ga.shotgun to install removable chokes? Hust a thought. Rick

Prime with white lacquer and Bob"s your uncle!

Rick

I recently purchased an HP EliteBook 840 G3. i wanted to plug in my camera chip (SDHC Card) and could not find a slot Lots of other slots and ports on the side. I finally noticed a little plastic cover on the bottom, removed it and there was my missing SDHC card slot. I assume they had to put it underneath because they ran out of room on the side. Just my experience or lack of.. Rick

If you use the smokebox tube for a form, the diameter of the casting will be off by twice the thickness of the sandpaper/emery cloth. I factored that in when I turned the wooden former I used. Might not make much of a difference though. maybe 1/16 inch or so. It is much easier to sand off using longer strokes. The smokebox using the smokebox tube would only allow radial sanding, very little room for longitudinal strokes. Use whatever works best for you. Rick

Bob, I have made several springs like this. Yes you need to heat them red hot to make the bend. You may need to heat it several times to get the 180 deg. bend tight so that there is no hinge type movement at the bend. the power in the spring should come from the spring leaves, not the bend. Do your bending and shaping in a fully annealed state. To temper the spring, heat it until red (non-magnetic) and quench, usually in oil. Then reheat to desired stiffness. I usually shoot for 500-600 deg F. If too soft, reheat, quench and re-temper to a lower temp, or to a higher temp if too hard. There are numerous temp tables on the internet.. Good luck. Rick

When I built my Rob Roy many years ago, I had no way of machining the smokebox radius. My poor boy solution was to turn a piece of wood to the diameter of the smokebox less the thickness of sandpaper, wrapped the wood form with sandpaper and proceeded to sand the radius of the bronze casting. Can't remember how long it took, but probably less time than it would take to set it up for fly cutting. No danger of catching the casting with the cutter. Worked for me. Rick

Hi, I realize this an old thread, but I ran across it when looking for information on this engine. I started this little engine more than 20 years ago when I lived in Germany. I made quite a few of the parts and they languished in my unfinished projects box until the Corona Virus hit and I decided to try and complete it. Has anyone actually finished this little engine? When I got down to actually putting pieces together, I soon found out the their were several dimensional errors that required binning several parts. Not wanting to be accused of being a whinger, I would like to hear from anyone who has built this engine and could give me a heads up on problems they may have encountered. Thanks.

Rick Hann

I placed an order with Macc a couple days ago. Got an email confirming my order the next day and another the following day notifying me that my order had bee shipped. Note that I am in the USA. I have ordered from them before and was satisfied. With the currency exchange rate being what it is plus no VAT and reasonable postage costs, I can buy some things cheaper from them than I can in the USA, especially BA fasteners, taps and dies. I received my last order from them in less than 10 days. Rick, Cape Cod, MA

A method I have used with good success is to turn the mandrel to a slip fit in the flywheel. Mill a flat on the mandrel approximately 10% of the diameter. use a wire or pin, that is slightly less in diameter than the amount milled off the mandrel. slip the wire in the gap, rotate the flywheel in the opposite direction of the rotation and it will lock lock it tight on the mandrel. When finished, reverse the rotation and it will slip right off. a good benefit of this is that you can make the mandrel a bit shorter than the flywheel hub and you will also be able to face off the hub without interfering with a locking bolt. I have also used this method to face the ends of cylinders after boring.

Rick