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| Posted: Thu Apr 26th, 2012 02:13 am |
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61st Post |
| Posted: Thu Apr 26th, 2012 02:43 am |
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62nd Post |
Kurt Heflin
Member
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Hey Eddie,
Whaz up??? I see from the Barnsville photos you were havin all the fun.....you lucky dog!!
I couldn't make it this time. Yet on the good side - I am in MUCH better health ; )
Kurt
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Terry Bentley
Member
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Back with some progress. Got tired of watching the grass grow. I started making the con rod and then stopped because I needed time to think thu how I wanted to proceed, or I just had other things to do. '
This is where we left off on the rod. Doesnt look like anything we could stuff in a motor yet.
This is a rotary table sitting on the mill. It rotates a full 360 degrees and accurate down to 10 seconds of one degree on a vernier scale.
With the rod securely clamped down to rotary table, I can start whittling away at the extra material until I reach the desired shape. First I center the top pin hole to dead center of X and Y axis of piston pin bushing. With a small adapter that fits in center hole of rotary table I can use a piston pin to locate it exactly at center line. Then with a dial indicator I will run it down one side the length of rod until its perfectly straight with table set to zero on dial at hand wheel. Now all I do is offset the cutting tool or end mill half its diameter plus half the width I want the rod to be. In this case I wanted around 0.200" thicker around the ID of pin bushing at top of rod. By offsetting the cutting tool half its diameter I now have the cutting edge directly on centerline of rod. Then move the milling table again, half the width I want rod to measure. This is taken in smaller cuts, not all at one time, until this dimension is reached. From center of piston pin bushing the tool is offset about 0.820" for finish cut on the X axis. Looking at the part where its cutting is on the right side.
When I reach zero on the Y axis, I can then start rotating rotary table around center line of pin bushing.
Swap the toe clamp around and do same to the left side until I reach zero on Y axis, then again rotate table around 90 degrees counter clockwise. Now the upper end of rod is taking a more recognizable shape and getting close to finish size.
You can see the shavings starting to pile up just from the little bit of cutting on rod so far. They are covering the floor completely too.
The top of rod has been cut to about a 0.450" radius from center line of pin bushing. I change the tool out to a small 3/8" ball nose end mill. You can see the rod starting to take shape. Nice clean radius from outer edge of upper rod end blending to center section. All of the material where toe clamp is between upper and lower rod ends will be removed down to the same depth as this radius has been cut, and obviously on both sides. It will make center section of this rod about 0.400" thick and 0.900" wide for now. Possibly remove more as this progresses further. I did not draw up a blueprint with dimensions or even sketch what this is going to look like yet. For the moment I am just winging it and blindly cutting it down the way I want it to look like. Its still a little ways away before the rod is finished and look like a functional part. When I get both sides on top end of rod done the same, then flip it around and do the lower end. Counterbore the holes for rod bolts on cap then finish removing all excess material. It will begin taking shape after a little more machine work. If this is keeping you interested, please stay tuned. More to come shortly.
Last edited on Fri May 4th, 2012 06:47 am by Terry Bentley
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Michael John
Member
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Awesome work Terry! I have been holding on the my Clintons hoping that someone would start making billet connecting rods for them. Please let me know if you are going to start selling them.
Thanks!
Michael
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Terry Bentley
Member
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Got motivated today and wanted to get some progress done. This is taking longer than I was planning. But what doesnt? Decided to go ahead and make the fixture plate. What this does is allows me to remove rod and be able to clamp it back down without having to setup and locate each time. Obviously a must have if planning to make more that one of anything. Does not look complicated, but blindly going at it, made me rethink about everything I was machining on lathe. Fortunately I got lucky and work out any bugs in my head so didnt waste a bunch of material making more mistakes than usable parts.
The plate is nothing more than 1/4" aluminum scrap. The rod measures 3" center to center. Top end is wider than lower. So the plate is stepped for this. At 60 degrees on same 3" center line, the two small mounting holes are drilled. This makes for two equal lateral triangles back to back. So when I flip plate around to machine other end, the mounting holes line up in same location on rotary table T slots. The two large holes are used to align the rod to plate and plate to rotary table. The bushings and pins work for either end in combination with the other.
Now with an easy way to keep rod correctly located, I can set up for one side, cut, flip rod and do same to other side without altering any setup measurements. By recording all of the measurements from digital readout, point to point, I can repeat on the other rod in 1/4 the time its taking to machine this one out. I just start roughing it out and work my way down to finish measurements. Sounds simple enough.
Got some more dead weight removed and with the fixture I can almost eliminate most machining marks. Makes for an easy cleanup with minimum of hand sanding before polish. Here I didnt do anything but hit it on the buffing wheel to see what kind of finish it would have. So far, I am pleased with results.
The rod is not nearly finished yet. Top end of rod is very close to done tho. I still need to recess the rod bolts, then remove all excess material from lower and rod cap. I will likely cut out the center of beam and make it the shape of an "I" to further reduce unnecessary weight. Its come a long way from just a thick piece of scrap plate. Already looks fast enough to start bench racing with...
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| Posted: Thu May 17th, 2012 02:06 am |
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69th Post |
David Luciani
Administrator
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gribit gribit gribit????
is that crickets i hear on this thread got aweful quite lately need my machinists fix.
dave
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| Posted: Thu May 17th, 2012 04:14 am |
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70th Post |
Terry Bentley
Member
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Well Dave...........originally I was waiting for a tutorial to sand cast a manifold, but now just watching grass grow. Actually my allergies are giving me fits. I also made a commitment to finish building up eight AK-47 receivers and assemble them finally after about 5 years. Really getting the rails welded on tonite. I will heat treat them tomorrow and then in the parkerizing tank after the trunions are riveted, barrels pressed, head spaced and pinned. I could add the build of them here to this thread, but might be a little off topic. Hows that garage cleaning of them old chainsaw parts you keep tripping over coming?
Since I have the rotary table still indexed to one of the mills right now, it makes for a quick little project some might like. I am copying a part that I used to be too cheap to buy. Made several of these back in high school for a shop project. I think you will appreciate the effort of machining the particular part, and may find a need for one on your LMR.
Last edited on Thu May 17th, 2012 06:45 am by Terry Bentley
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| Posted: Thu May 17th, 2012 04:28 am |
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71st Post |
| Posted: Thu May 17th, 2012 06:42 am |
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72nd Post |
Terry Bentley
Member
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I would like to do a writeup covering a complete build from start to finish. But not here. May be considered to some way off topic, even if I could relate the machining aspects to some karting relevant components. I would be concerned some here might find offense to any type of firearm exposure. You know how dangerous those darn assault weapons are anyway. Then turns political, a small war starts, I get banned and this fine thread is removed. Would be such a waste.
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| Posted: Thu May 17th, 2012 09:14 am |
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73rd Post |
Sterling Brundick
Member
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Terry - I wish you would. I'd be willing to bet most everyone on this site is pro 2nd Amendment (I think that's the right 1 - right to keep and bear arms). At least put the mags on and see what happens. Go from there. But, I see your point about the subject being way off topic. And, if you start with something off subject, then others will follow suit and this wonderfully educational site is likely to get in trouble.
But, I'm with Dave. Where you been??? I've already painted the house and watched the paint dry waiting on the sand casting thing, which I really wanted to see.
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| Posted: Thu May 17th, 2012 03:04 pm |
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74th Post |
David Luciani
Administrator
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contrary to popular belief i do work sometimes.
between getting my last apartment cleaned up and showing it getting the people lined up for a complete repaint on the duplex unit 1500 s.f. in three days while it's empty and doing 60-65 hr weeks for the union between i find myself very busy.
plus my three favorite swap meets were in there too!!!
i am going to get pix of mold boards with mcculloch manifolds mounted on next week and maybe be firing up the foundry if the insulation is still usable.
was getting thin last year.
otherwise first tutorial will be the stupid reline the furnace thread i'll be doing when the liner fails.
i'd love to see the pix on the gun stuff.
bag any complaints and you getting banned ain't happening.
dave
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| Posted: Fri May 18th, 2012 02:29 am |
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75th Post |
Steve Welte
Member
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Ahhh how pretty. Now if we could get some programmer to write all the CNC info for a full billet Clinton we could all have one. Billet block, rod, crank etc. Oh and I want mine fully polished! Bright red covers on a polished block. Oh wait I want 2 'cause I want to go fast on a dual!
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| Posted: Fri May 18th, 2012 04:02 am |
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76th Post |
Terry Bentley
Member
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Steve Welte wrote: Oh wait I want 2 'cause I want to go fast on a dual!
The only thing two Clintons will do is faster. But that is still by no stretch of the definition fast.
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| Posted: Fri May 18th, 2012 02:48 pm |
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77th Post |
Jack Canaday
Member
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Just got my first Clinton since 1957. Have been watching this for some time now. One requist and one question. Does anyone have a left hand aluminum flywheel they would sell? Would a billit rod need bronse bearing, some of the 4 stroke rods are done without and seem to live. I would be able to make rods on my cnc, if a few wanted them. will also try searching for lnserts first. JAC
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| Posted: Fri May 18th, 2012 05:02 pm |
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78th Post |
Steve Welte
Member
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Ha Ha But I want to go fast on a dual. "Come on Man", my first race in 1959 was on an A 400 dead axle Dart. We did have a dual A 490. Friend had a dual WB 510 and another Homelite 82's. But I want that BILLET Clinton. "Come on Man". I love following this.
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| Posted: Sat May 19th, 2012 04:40 am |
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79th Post |
Terry Bentley
Member
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I heartfully apologize for getting sidetracked and not having anything added specific to the Clinton yet. I am looking forward to having one version of this motor finished soon enough tho. Might not be the removable head with motoplat model, but the other one will do for now. I surely dont want Dave to suffer any withdrawals, not getting his fix either. I hear the pain can be sometimes unbearable. So can at least add some general stuff I was working on tonite and hopefully have more specific to the thread posting not too far down the road. Below is the arbor press I would normally use to press three or multiple piece cranks apart. This may include most foreign kart engines, motorcycle and even Seadoo crank assemblies.
This dog of a press stands nealy seven feet tall. The 1 1/4" diameter cheater bar handle is about six feet in length for some decent leverage and managed to have sliced a hole in ceiling when at rest. This particular model is a ratcheting compound arbor press.
By sliding the pin thru, I can get over 30 tons of leverage to do just about anything. This type of press dwarfs any of the conventional hydraulic presses out there. Doesnt matter how many tons of one it is either. The down side to a hydraulic press is having to build up fluid pressure until it overcomes the resistance its being used for. Can easliy be a lethal weapon in the wrong untrained hands when something decides to let go. Been there done that and gratefully had moved before I became one with nature. Someone up there has always been keeping an eye on me when I have done things. Either press fitting something, crimping, smashing or forcing something that isnt supposed to fit or cutting key slots. Many uses. This press is great in converting pre 1982 pennies into nice thin copper washers or shim stock.
I havent used this much during the past 10 years, so it just sits on floor and collects rust. A simple fixture to press multi three piece crank assemblies apart. In the foreign engine build that will be coming forthwith, I will cover in detail how to press apart, and reassemble the crank, including alignment on centers, not V blocks, with dial indicators.
But the press has so many other uses as well. Here is what I was sidetracked on and finishing up this evening.
The piece of sheet metal at rear is 1mm(0.039") thick 4130 chromoloy. Sells for around $12 as pictured. Originally just a flat stamped piece of sheet metal. Lets call it an "AK flat" just for ease of identification. What I need to do is bend this AK flat up on both sides to form a channel about 1 1/4" across the inside width. This is my version of a first generation jig I built out of improvised scrap laying around, from a picture found on the internet. The original one was just able to fold the AK flat into a channel as we will soon see happen. Early AK flats were as the name implies "flat". The finished product would also need to have both sides to include a small lip folded in on top. We will call these lips the "top rails". I added to the basic setup to be able and do just that after the channel shape was achieved. While still pushed thru, I could swap top plate around then add an arm that would fold the top lip(top rail) as needed. Newer AK flats came with the top rails already folded, making for all of the extra pieces no longer needed. But fixture served its purpose well until the newer AK flats became available. This is the only fixture of type that could also bend the top rails in existence. But now is no longer a needed function. So much for trying to be creative.
By assembling the pieces of stock together we get the general shape of what the AK flat will be patterned after.
First the center section with both side plates attached, then both top and bottom plates bolted. There are two small locating holes on AK flat that line up with pins press fit in bottom of center section. You will notice the AK flat has dimples and holes all over. The side plates are both cut for clearance at each matching location.
Here is everything bolted snugly together. The AK flat can be seen right above bottom plate. Now we get to do some collateral damage.
Moving over to the arbor press. You can see the AK flat better and it bolted to the plates. The large flat topped frame with rectangular hole is what the AK flat is going to get pushed thru. Can be referred to as the press block or die. It is nothing more than 1/4" thick 3" angle iron. Originally part of a torn down steel building. Pieces cut and welded together, then all controlling surfaces machined to exact spec size for part. The jigs and fixtures could have all been cleaned up and painted with red oxide to give them that professional look. But would have served no functioning practical purpose, especially since i dont offer tours in the shop.
The bottom plate is sandwiching the AK flat to center section. It is same outside dimension as finished product, which also serves to give perfect alignment in the press block it is fitted in. The large ram of arbor press is resting on a piece of aluminum scrap cut at same angle as finished part will be shaped. About 2 1/2 degrees of angle, for those inquiring minds.
Now exerting downward pressure on ram the AK flat breaks its flat shape then is forced thru the opening in press block.
Its pushed completely thru. Without the need to bend the top rails anymore this design of fixture is completely obsolete. Otherwise I would be flipping over the top plate and adding a lever to bend the top rails. A newer and so much simpler design is nothing more than a finished sized plate pushing thru a machined channel that breaks both sides of AK flat over to desired finished channel shape.
The AK flat is no longer flat. Once the edges broke, as in bent over, it took little force to push thru.
Being that the top plate of fixure is longer than opening in press block and doesnt fit thru, was removed in order to push this all the way out bottom. Lower plate can now be unbolted and removed. The small black screws at each end are then removed. This allows that center section to slide right out the top between the small top rails that were already prebent. The outer plates can now fall out.
Here is the result of all that work. This is a DIY type of build, not mass production. Fortunately the jigs and fixtures dont take very long to build or would be very time/cost prohibitive to do a small number of build ups of parts such as these. It took 1/4th the time to bend these last two flats I had left over than did to write and upload the pics here on this post. But the AK flat can no longer be called a flat. It is now considered by the BATF a restricted firearm exactly as is pictured, just as you see it. Legal for me to build and 922r compliant, but not legal for me to sell. Go figure. I would enjoy doing a complete writeup on the whole project and will get it all finished. But here is not the place for it to be posted. This is just a small taste of what can be done with a little mechanical ability and basic equipment. Not to mention the world wide web as a 24/7 ready to access library at your fingertips.
NOTE: There are many ways to achieve this task set forth here. At the time I was building a bunch of these without top rails prebent, This was one direction I pursued. Its function was to bend the channel shape and while still pressed in the block, I could add a swing arm that would bend the top rail perfectly square and identical on both sides without changing jig or fixture components already built. in existing setup. It worked well for me and results were precise and exactly as expected. Your results may vary.
Last edited on Sat May 19th, 2012 06:24 am by Terry Bentley
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| Posted: Sun May 20th, 2012 11:59 pm |
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80th Post |
Terry Bentley
Member
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Just a little followup on these receivers for anyone finding it informative.
Here is the before and after. Top is right after the previous post as a bent receiver. Lower is just after plunging. Helping to keep this post on topic, I have included the H-81 motor I will be doing a full build and completely modify. I figure it will stretch out quite a little while. Hopefully everyone will stay interested for the long haul.
This is the test part to confirm correct temp range. First I preheat the old ceramic kiln. Then drop in a test dummy. The pic does not show, but receiver is just starting to glow a dull dark orange. Didnt do ay good to take more pics, just would not show much difference. I drop these in and wait about 5 minutes. Then start checking with a magnetic stick. Just soon as the receiver is no longer attracted to the magnet, its time to remove and plunge directly into a bucket of slightly soapy water at room temp. The result is in first pic above. They will hiss and try to boil off the water for less than 2 seconds. Did I mention how hot my Asbestos gloves get when reaching down in this inferno? Amazing how fast you can rip a glove off that is saturating your fingers with so much heat.
Now its time to draw the temper. I have unplugged the kiln, but it still retains a lot of heat for a while. When the temp dropped to around 800 degrees, I put all of these receivers in. Then with the cover off, the temp slowly drops down to ambient. Cool down time is not critical for this application. Just needed to be brought up to around 800 degrees and a slow a cool down. They are officially heat treated and ready for the next step in assembly. This is a common process, that kart motor cranks are put thru, but a little more control of temp and time of saturation. Since these sheet metal parts are only 1mm(o.039") thick by the time they reach correct temp, complete saturation has already occurred. If this was a crankshaft or connecting rod, the next step would be to straighten, then grind to finish size. There I was able to keep this somewhat on topic. Yea Haw!
OK no more of the AK build here, well, unless its something that may have some significance to vintage stuff.
Sorry for those that are enjoying the fix from this particular post. There are nights I find myself totally absorbed in someone elses build of something, and wonder why I am not spending that same time doing instead of looking. Can anyone relate?
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