My one boss/foreman was a diesel tractor puller and was telling me that he was @100 psi boost on his tractor and some guys were over 100 psi, wow! He also really hated the turbine guys.
Ray
Ray
Small engine dyno
- Thread starter Bentwings
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Bentwings
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I forgot. That’s amazing that those big electrics are sheet metal construction using the term lightly haven’t seen a sheet metal motor since my HS friend had a CRosley. I wonder if the tech could be applied to models. Might make cylinder blocks of v 8 more practical. Bolted and pinned. Oh my gosh time for refill of coffee. LOL. Can’t wait for design thoughts along this line . You will be the starting consultant! I just bough som aluminum bar stock close to $200 worth that I probably can hold in one hand. You won’t believe the price of copper my son is having trouble getting 4130 tubing for the race cars he is building. Suppliers only sell 4’ lengths. 8’ doesn’t exist any more except for one or two suppliers. The shippers don’t want to ship long lengths either.
Byron
solarenergyadventures
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You guys have made some cool dynos! So far, I've found the easiest way to make a dyno is to use an AC induction motor as an eddy current brake. It is literally already made for you, and any AC induction motor will work. You simply feed DC to the windings to increase the braking effect. Here is one I made for testing my automotive air conditioning compressor steam engine. In this vid I'm using it to test another electric motor. I just thought I would share. Cheers all. .
Bentwings
Well-Known Member
That is really cool. When I’m ready for this I’d like to contact you for some help. My system will be slower and smaller but the same target.
Byron
I've been thinking of the same thing. Another project to add to the list! Any plans available or is it something needing some CAD?
The egg-beater I maintained ran 1800 shp @33,000 RPM.
solarenergyadventures
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Thanks, I'm glad you liked it. I will be adding better instrumentation in the future so I can feed the data into a laptop, but right now I've got a big list of other things to do first. I would be happy to help whenever you're ready to build your own. Cheers!
Bentwings
Well-Known Member
Thank you I’ll make the stepper motor conversion to start with and see if the steamer can drive it . Unless I can put a lot of air in to the turbines I don’t think they will do much even coupled together. The first one I ordered is not as nice as the second but I could or another of them and have a three stage turbine even so I’d guess it could take a lot of air compared to the steamer . Mean time I’ll get the boiler done and tested. I don’t want the standard automotive gages as they just take up too much space I’ve searched for the smaller steamer gages and have found pretty much what I need. Not sure about delivery. Some come from Europe so shipping might take longer, but my son has had pretty fast service from Europe and Australia. The boiler will have 1/8” or 1/4” fittings rather than metric pipe as the engine has. I found a tap and die set for the metric pipe threads but it’s over $110 for three taps and one die. fittings one source did that these metric pipe threads can be whittworth. I haven done a whittworth since I was an apprentice. My machinery manual is out at sons shop 65 miles away I don’t get out there regularly so I’ll look them up next time I get out there I did look on the internet but I’d rather have the book right in front of me. They may even need a fiber washer under them as I don’t think they seal like npt does with just a little Teflon tape. It’s surprising how many fittings you can need the boiler is 1/4” wall aluminum tube standard 4” copper water tubing end cap cost almost as much for 1 as my entire order of aluminum I got free shipping too. I can get AN#3 fittings and use 3/16” Teflon flex brake line but it’s going out of favor and being replaced with 1/4” line so I may just go with it as it looks nice as stainless braid covered. My son has the fancy assembly tools too so a tough job will be easy for a change . Well it dinner time nice outside for winter here. 35 deg right now no snow at all.
byron
It's something that would need to be drawn up on CAD. I have all the factory manuals which include all the dimensions. Each cylinder is pretty much a 9" bore x 10" stroke so I was thinking somewhere between 1/6 and 1/10 scale.I've been thinking of the same thing. Another project to add to the list! Any plans available or is it something needing some CAD?
The egg-beater I maintained ran 1800 shp @33,000 RPM.
Ray
solarenergyadventures
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Wow, it sounds like your to do list is as long as mine! I look forward to pictures of what you're up to. I've never tried using stepper motors for dyno brakes, it will be interesting to see how well that works. Do your turbines have proper DeLaval nozzles in them? If so, they may not use much steam/air at all, but they are inherently low torque high rpm devices. Cheers.
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Bentwings
Well-Known Member
Hi I had a stroke of good luck to day I found immersion electric water heaters. There are a few wit 1” npt threads too these are 110 vac however you can get 220 too and higher output . One of these will just fit in the boiler I’m building so I won’t have to use the Rc hot plate except as backup I don’t have enough circuit power I don’t think to run two of these heaters and there is no 220 outlet withou some electrical mods. I really don’t want that .since my boiler is aluminum I’ll wrap it with header insulation under the outside jacket . There is a smaller one so maybe I could add a lower wattage as a booster . I’ll drill and tap the end caps for 1” npt on both ends just in case . According to the charts I found it should only take about 10 minutes to get steam up. That would be nice . These are only $30 each so I might be able to not buy the air compressor but I really could use one anyway . I haven’t received the aluminum materials I ordered yet. I have the boiler tube I may make it an inch longer just for more volume . Also found a shaft driven boiler fill water pump but they are out of stock for now I ma just make a gear pump lik an oil pump instead. I have material and gears already .
byron
I pushed our garage out 12’ at one end and built a heated shop. Unfortunately the big air compressor is in the unheated garage and won’t work well in winter. I have a small pancake compressor for air tools but it is too noisy to use for air in the shop. I would love a quiet compressor if such exists. Which one are you getting?
Bentwings
Well-Known Member
I tell you what the California ultra quiet air compressors are great harbor freight has knock offs that are just as quiet . I’ve had it with noisy compressors.
byron
Bentwings
Well-Known Member
Well I just found out that chilertern has come out with an electric boiler. It’s cheaper than the compressor but very similar to the one I have sketched up. I’ve already got everything I need except gages so I’ll finish mine in parallel as mine is twice the size. Plus twice as thick walled I can use more pressure if needed. Basically the same design but I have a bigger heater.
byron
Bentwings
Well-Known Member
Along the dyno line I had forgotten I used placid industries hysteresis clutches and shaft brakes. These make perfect torque measuring possible the have an arm you can rest on a fixed surface then calibrate the current, force applied and compare to a chart. Simple use standard hp calculations. Many different load catagories are available so essentially no moving parts. They aren’t the cheapest thing around I’ll call as soon as possible and get a quote.
Byron
Hi Byron, I guess you have confirmed the pressure the electric elements can withstand inside the boiler.
Also hoop stress calculations in you boilershell, and boiler end design?
Any chance you can post some drawings so we can see the design? And details of the electric heater units will be interesting! I know a few friends who would like this!
K2
Also hoop stress calculations in you boilershell, and boiler end design?
Any chance you can post some drawings so we can see the design? And details of the electric heater units will be interesting! I know a few friends who would like this!
K2
Greetings,
The low noise air compressors are great for noise, but deliver around 1/2 the CFM of a similarly sized noisy airless. I have a small Rigid that was on sale at Lowes, and it's lovely to not even notice it's cycling if the stereo is on. Beats being startled out of your skin when an airless kicks on during a moment of concentration.
With a 3/8 air hose and a 1/2 inch rapid air ring around the top of the shop (16X20) adding some capacity, my little compressor is good for one good braaap from an impact gun before having to recharge. It won't fill an auto tire from flat to full pressure without recycling several times. Don't think I'm unhappy with it though! It's great for finish nailers, staplers, air guns, and small air brush use, but if you use much air it may not work out so well for you. I'm thinking about getting a larger version of the quiet compressor for the building and putting the little quiet one under the bench where I build models and fool around with smaller stuff.
It might be cheaper for my needs to just get a decent cordless impact gun and ratchet these days, save on the space for a larger compressor AND lose the air hose dragging around behind me
Happy New Year,
Stan
Bentwings
Well-Known Member
My son and grand son have an auto shop they both are snap on devotees. They have gone to all battery powered impact and drivers although they still have air tools. The 1” impact will take about anything off including any part of the operator in the way . They both have so many tools it’s just crazy but newer cars take special tools for almost everything. I’m limited being at home to about the minimum power tools I inherit some of their stuff occasionally. I barely have a small socket set and hand tools usually if I don’t have exactly what I need I just walk up to orients about 3 blocks away. Tech stuff I have them come and get me then I spend the day at the shop. I plan carefully so I get done what I need in one day. This little boiler will probably take a couple days unless I can get them to help out. There is a surprising amount of detail stuff to do. I’m doing the home work now. They just got a new porta power so I can hydraulically test this boiler I know I could blow it up but I’m just going to proof test it. They have a stock tank for tire testing so I’ll make use of that . These little engines only need about 30 psi unless you want broken parts. This one is too expensive for that. I won’t even run the turbines up very fast. I can get ceramic bearings if I need but I’ll see how the stock ones do first. The big issue is they have such small shaft that just find in ding a coupler is hard. I may have to consider installing larger shafts . Model boar couplers aren’t going to last long that’s for sure.Greetings,
The low noise air compressors are great for noise, but deliver around 1/2 the CFM of a similarly sized noisy airless. I have a small Rigid that was on sale at Lowes, and it's lovely to not even notice it's cycling if the stereo is on. Beats being startled out of your skin when an airless kicks on during a moment of concentration.
With a 3/8 air hose and a 1/2 inch rapid air ring around the top of the shop (16X20) adding some capacity, my little compressor is good for one good braaap from an impact gun before having to recharge. It won't fill an auto tire from flat to full pressure without recycling several times. Don't think I'm unhappy with it though! It's great for finish nailers, staplers, air guns, and small air brush use, but if you use much air it may not work out so well for you. I'm thinking about getting a larger version of the quiet compressor for the building and putting the little quiet one under the bench where I build models and fool around with smaller stuff.
It might be cheaper for my needs to just get a decent cordless impact gun and ratchet these days, save on the space for a larger compressor AND lose the air hose dragging around behind me
Happy New Year,
Stan
I absolutely hate drafting and mechanical drawing so I may see if I can get the cad program working. It’s been a while is I’ll need a little learning what I’ve forgotten . I may end up getting Fusion instead. We have been discussing a 3D printer but there are so many local places that it might just not be economically feasible
byron
Bentwings
Well-Known Member
Setback on new boiler. I got email from chilertern . The nice electric boiler they have won’t power the 4 cyl engine. . So I had to write that one off. Then my son called and he cut a 14” piece of 4” aluminum tube but it turns out that it’s tapered inside. I’d guess for vibration control snd it grossly out of round. One end has nearly 1/4” wall but the other is only 3/16” wall . So I’d have to make radically different end caps then because it’s tapered I’d have to make odd size tube holder for the transfer tubes. So I’ll have to order a new tube from the metal supplier. I ordered a second immersion heater in case I need more heat. I looked for a relief valve too but came up empty . I’m still looking for a metric pipe tap and die set . Unfortunately most I’ve seen are not listed correctly . They show as metric but don’t have the right ones listed in the contents . I did find more small gages then I see they aren’t very high quality . I may have to get automotive stuff .
mom goingvto make the base or mounting board like the textile plant floors. Thin strips glued together to look like scale floor then I think I’ll either use casting resin or plain epoxy resin my grand son is body man and he said he can surface it dead flat and glass clear don’t think it will look nice I’ve got a working space all set up so I can begin assembly as soon as it arrives. The boiler is the big headache now. I found an on line hoop stress calculator so I’m ok so far. The heater might be an issue but I suspect that the tube is pretty small and probably thicker than it looks I’ll weigh it then be more able to take a guess at wall thickness. I don’t think it will be an issue as 50 psi is probably as high as I’ll need to go if that . .
byron
Bentwings
Well-Known Member
I have only some sketches as my double vision makes doing much else. I’ll make some cad models and take pictures as I go . I have a bunch of parts coming . I may lay them out and take pictures just to show this is a bigger project than meets the eye. Try reading a micrometer with magnifying glass then seeing two views at the same time. Closing one eye helps sometimes. I’m using a stylus to help typing but I still make mistakes . I think I’m going to use two heaters. I have to check the home circuits to see what I use. I could pull the stove out snd make a y extension cord so I could use 220 but it’s a lot of work. I can use two separate circuits with a bit heavier extension cord. If it doesn’t work I’ll just break down and go with the quiet air compressor. I was already committed when I started the boiler build or I could have just scrapped it. But we’ll see how it turns out. It’s a new hobby for me so plenty of room for mistakes and misdirection. Something I learned in football I think. LOL
Byron
Byron
Here's a "Small Engine Dyno" that I built years ago and is still working - built as a "Rolling Road" braked dyno for testing slotcars and is capable of measuring from 0 to 300W output.
I started with the idea of using a DC motor as a generator and loading its output - using motor parts scavenged from dead cordless tools.
Below the GA for the rolling road - the roller drives a smaller motor as an analogue tacho where Volts equals (calibrated of course) rpm.
And the larger motor is the "generator" to be loaded up by applying increasing loads (multiple 12V x 50W downlighter lamps) such that Amperes equals torque (again obviously calibrated).
Well even dead short it did not produce enough torque to do the job - I nearly wrote the whole thing off as a failure but then I thought - what if you force the brake motor in reverse ? - with nothing to lose I tried it - only now forcing the load via the surge lamps - as in the diagram below.
Using the original drive components out of the donor cordless drill as a power supply
Eureka it worked - Current was still proportional to torque.
Note optional loading of 50W, 100W & 150W - giving a range of 0-300W in 50W steps.
It's only major shortcoming was specifically the problem with slotcar motors is that they cannot output maximum power for more than a few seconds without cooking them so your test has to be done very quickly - this should not be a problem for motors capable of continuous output.
The point I am making here is that you can get a torque reading via the amperes and calibrate it against a torque arm and spring balance - using nothing more than scavenged parts from a cordless drill.
Hope this is of some use to someone.
Regards, Ken
Edit: The DC Wattmeters are an 8 component dead simple (and accurate) idea off the internet if anyone is interested.
I started with the idea of using a DC motor as a generator and loading its output - using motor parts scavenged from dead cordless tools.
Below the GA for the rolling road - the roller drives a smaller motor as an analogue tacho where Volts equals (calibrated of course) rpm.
And the larger motor is the "generator" to be loaded up by applying increasing loads (multiple 12V x 50W downlighter lamps) such that Amperes equals torque (again obviously calibrated).
Well even dead short it did not produce enough torque to do the job - I nearly wrote the whole thing off as a failure but then I thought - what if you force the brake motor in reverse ? - with nothing to lose I tried it - only now forcing the load via the surge lamps - as in the diagram below.
Using the original drive components out of the donor cordless drill as a power supply
Eureka it worked - Current was still proportional to torque.
Note optional loading of 50W, 100W & 150W - giving a range of 0-300W in 50W steps.
It's only major shortcoming was specifically the problem with slotcar motors is that they cannot output maximum power for more than a few seconds without cooking them so your test has to be done very quickly - this should not be a problem for motors capable of continuous output.
The point I am making here is that you can get a torque reading via the amperes and calibrate it against a torque arm and spring balance - using nothing more than scavenged parts from a cordless drill.
Hope this is of some use to someone.
Regards, Ken
Edit: The DC Wattmeters are an 8 component dead simple (and accurate) idea off the internet if anyone is interested.
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