Tire Hammer Build

[Leeknivek]

Been a while since I've gotten on here. It's been a looooong winter.

I'm in the process of deep-cleaning my shop, which has netted me with an immeasurable amount of hardware, solvents, grinding discs, lubricants, scrap (read: stock) - you name it. 

So I think I'm going to build a tire hammer. I totaled my crappy Hyundai this past November, and steel being $200 a ton here, I haven't scrapped it yet. I have a donut spare with matching hub, ready to use. Lots of aluminum to play with casting later, too. 

Anyways, I have a large majority of parts needed to build a tire hammer. I'm debating between either a DuPont style linkage, or a Beaudry Champion style linkage. Leaning towards Beaudry. I won't be buying Clay Spencer's plans, mostly because I'm using found parts - and I don't wish to get into the politics, either - so I'm looking here for help and documentation of my build. I'm collecting parts right now, as I'm cleaning the shop, and hope to be finished by June or July.

I have a lot of this figured out in my head. I haven't built anything really mechanical, though I understand the principles. This is a list of what I'm stuck on right now, since detailed, documented builds are few and far between:

- ANVIL My local yards usually have large steel drops, but I haven't been out yet this year with the snow. An alternative I *might* be able to use is an old Clark Michigan payloader. The hydraulic pump has been shot for 20+ years and it barely ran up until about 8 years ago, where it's sat in overgrowth since. (not my choice!). The engine is also just about siezed up, so it isn't worth too much more than scrap. I think it has solid steel axles - if I can separate them I might be able to use them. I'd prefer to find something at the yard, though... The nice thing about steel being so cheap is that I'm ready to have a hay-day at the yard!

- DONUT SPARE I'm concerned with welding the rim of the donut spare. From what I understand, the Clay Spencer hammers would have the tire pried away from the rim with shims and jammed full of wet rags. Is this true? Safe? Has anyone tried a bolt-on method of affixing the plate for the eccentric shaft?

- DRIVE WHEEL I don't have a drill press anymore, nor a lathe - has anyone made the drive wheel without these tools? Is there a source (in scrap or new form) of something like this? I think it's a 3-4", usually aluminum wheel with a small I.D. to attach to the hub of the drive motor. 

- BUSHINGS/BEARINGS Using the DuPont-style linkage, are bushings necessary? Are they preferred? I have a lifetime supply of grease and grease nipples (like, 40 gallons). What have some other builds used? I don't have any bushings off-hand, though I do have a number of various roller and ball bearings. I want this to last forever and plan to start a real business after having the economy of a power hammer. 

- MAST Square tubing is first choice, of course, but how is I-beam? I've read about and have seen small plate trusses welded onto the webbing for stability. Anyone have experience with this?

- Guide Tube Again, I have a lot of grease. Is this acceptable?

I know these things are pretty simple, but I don't think it hurts to ask. 

My Budget is about $350. Here's a list of what I still need:

- Anvil
- Hammer
- Mast
- Baseplate
- Drive Wheel
- 1HP motor
- Coil Spring
- Pillow Block(s) - (very easy to find en masse and inexpensively on eBay, I've found) 
- Bushings?

Thanks for reading. Wish me luck!





 

[Frosty]

Okay. . . LUCK!

Anything else? Sorry, couldn't resist. How good are you at mechanical drawing, drafting board and pencil or CADD? The more problems and mistakes you can make on paper the better things turn out.

Did other tires and wheels survive the wreck? If so, don't count one out for the driven wheel it could make getting the speed right easier. It'd also sure be easier to bust the tire loose and weld on the rim if that's really necessary.

You'll want the anvil to be in the 20x the weight of the ram range so thick and solid are preferable.

The frame can surely be boxed in I or wide flange beam will be significantly stronger and more rigid than an equal weight of sq or rectangular tubing. It's also much easier to weld the horizontal top beam, the anvil brace and base plate more solidly. The details of how to can be covered another time. Unless you are a welder fabricator already?

The heavier the base plate the better, it'll not only increase the weight but being more rigid is once again better.

Where are these bearings/bushings you're referring to going? Different places, needs and stresses have different requirements.

What you'll need for a drive wheel will depend on how you plan the thing, that can wait for now.

How you guide the ram is another component with a lot of different approaches.

I should stop or I'll blather on for a long time. You're going to need to start designing what you want on a concept level. Just buy some graph paper and sharpen a pencil. The first step is to make sketches of what you think will work. If you post pics of your drawings we can help.  This is too complex a build to just answer a list of questions and do you any good.

.Frosty The Lucky.

 

[Leeknivek]

I do scale drawings here and there, I find that it isn't so much difficult but rather more tedious, which I have no aversion to. I sketched a scale layout on the shop floor earlier, so that's a start! I'll work on some drafting tomorrow morning. I may have to make some changes due to using found and scrap parts. 

I have three tires that survived, four including the spare. The rims on the others are aluminum alloy, though. I do have an exceptionally large pile of tires and rims (50+) inherited from my grandfather. I can mix and match from there.

Thick and solid is what I'm hoping for. Going to take a trip to one yard before work, see what I can see...

I have dabbled a fair amount in MIG and stick welding, though I know more in the abstract than I have experience. A welding shop was impressed with my work when I applied there, if that says anything. I'm certainly no expert, though. 

I'm hoping for a 30"x40" footprint, the thickest I can reasonably find. 3/4" minimum, I think.

The bearings and bushings I was referring to are the ones located in the linkage, the moving points aside from the pillow block. On the DuPont-style linkage, there are six - two on the eccentric shaft mount/pillow block, two on the tup, and two in the middle. Well, one per each side on all of those. I guess for a 50lb hammer it shouldn't be too big of a deal, but if a couple of dollars and a little extra planning can add reliability, then I may want to pursue that. 

The ram guide seems to be the most complicated part of this build. It might be that I can't fabricate something, since I don't own any machine tools.

Don't be shy about talking too much, either, friend - I can sponge it up all day long!

[Frosty]

I had to look up DuPont linkage but have the picture now. Pretty much the same thing as my 50lb. LG. I'd go bushings, they take the impact shocks much better than roller let alone ball bearings. The increase in friction is negligible in this use. The pins can be 9/16+/- lag bolts, grade 8s are plenty and you can buy bronze bushings to match for a few bucks. You can drill and tap for zerks or just drill for weep oilers, no sweat both are good. This is a pretty straight forward fab job, nothing special needed. You'll want to keep your eyes open for pipe with the same ID as the bushing's OD so they'll slide together. The bushings come in common bold diameters so just pick the bolt size and the rest of the linkage joints derive from THAT dimension.

I'd have to go measure but I THINK the crank arm is only a couple inches off center so there's no need to weld on the rims. You can simply make a crank plate drilled to match the lug pattern and bolt it on with the wheel. EASY PEASY.

No need for a pillow block for the cross head bearing on the crank.(Am I mistaken about this pillow block?) A stout lag bolt, matching bushing and build the cross head to fit. Basic fab work. Moderately precise fab work but not complicated nor difficult.

It just occurred to me, the pillow block you're referring to is maybe the one the tire is mounted on? If so, no pillow block. Use a trailer spindle and trailer wheel hub. Everything is there, all off the shelf and tough as nails. Just buy the trailer hub with the same bolt pattern as the drive wheel. Trailer WELD spindles are made to be welded to trailer axles, you can buy round or square receiver tube. EASY PEASY.

Don't start gathering salvage yet, it's too easy to get yourself committed to something and painting yourself into a corner. There are a few things to keep your eyes open for as ideal finds. The anvil, if you can find a piece of steel shafting around 30" long in the 1,000lb+ range that's a grab it now. If you run across H or Wide flange structural shape . . . CRAP I can't remember the specifics of size but you want heavy and I can't remember the lb/ft. It's measured by flange width x web depth x lbs per foot. For example 10" x 12" x 18lb. I just grabbed those numbers out of the air as an example. That'd be wide flange. 12" x 12" would be H beam and I beam would be 8" x 12". All air numbers for examples. The heavier the better.

I don't think 30" x 40" is enough base plate, you won't have any depth between the center of the dies and the pillar, maybe 8" if you push the pillar and anvil to the edges. It might be okay but I'd have to model it out to guesstimate. I think the plate in the shop is 36" x 48" but I'd have to go measure it. I've been waiting for weather to warm up to get back to work on a tire hammer for a friend so I just HAPPEN to have it's  base.

Where are you going to mount the motor? That will determine the drive and treadle/clutch mechanism.

Yeah, the guides always seem to be tricky to me too but looking at the old hammers they're really simple and kind of sloppy so we just may be imagining tighter specs than necessary. We'll just have to keep our eyes open and see. I know some home builds have way hard to make or inefficient looking guides. I could be wrong of course, I'm not a power hammer officianado guy, I just like to build . . . stuff

Do you have a copy of "The Little Giant Powerhammer," book by, Richard R. Kern? It won't tell you how to build a power hammer but it's all there so a guy can get a handle on the basic mechanical hammer's works. The only real difference is your clutch mechanism, all the rest is basically the same.

.Frosty The Lucky.

 

[jeremy k]

Buying the plans for Clays type hammer will not get you into politics, but it will give you a lots better insight on your build - even with found parts vs. what the plans specify. Parts may not be the same but the concept of its working IS. Plans that anyone can buy are cheap compared to many cut-a-part/re-do sessions of the project not working correctly. Do as you wish  - I am not trying to "sell" Clays plans, but they can only help you - even if you don't build it exactly as he does.  Good Luck

[Frosty]

I second Jeremy. Reinventing the wheel is only desirable as a pastime unless a person has no choice.

Frosty The Lucky.

[Leeknivek]

I'm not trying to reinvent the wheel, by any means. What I'm looking to build, I should have clarified, is in the same working principles of the Clay Spencer tire hammer. Friction drive, same linkage, same general idea. I just think the $30 is a little steep. I'm getting a better and better visual in my head of how to assemble it all as I go. 

"The pins can be 9/16+/- lag bolts" - Do you have a picture of this? I don't understand what you mean, lag bolts with the threads cut off? 
I was thinking just some grade 8's, like you also mentioned. I'll keep an eye out for bushings and see if they aren't for sale in surplus on eBay. 

You're right about the crank arm dimensions, and that's exactly what I was hoping to hear. 

The pillow block I'm referring to is mounted upside down on some plate, the uppermost part of the linkage. It mounts to the eccentric shaft. I was thinking a piece of heavy rod (1"-1 1/2") welded to the crank plate and a hole drilled for a cotter pin on the opposite side. I have some heavy round stock - broken jackhammer bits, giant bolts, etc. - but I'm sure just about any steel would work for the eccentric shaft.

I have the whole car to use, too. So I have two spindles from the rear wheels. Very small (6" or so) brake drums attached. Same lug pattern as my spare. But the trailer spindle is a good idea for the other tires I have, if I end up using those. 

I could do 36x48 - it'll fit on a standard pallet at that point. I'm trying to fit it with the concrete slab I have poured outside behind my shop where my coal forge is. I'll have to take some measurements to make sure I have room.

The motor I think will go in about the same spot as the Clay Spencer hammer would have. I picked up a set of old bed rails to make all of the foot pedal and clutch linkage with. Couple of nice big heavy duty hinges, too. 

For the guides, the simplest I can think is either a cylindrical ram in a matching steel pipe, a bolted-up frame of plate for a square ram, or maybe even a hardwood bearing surface within a steel frame. 

I like to build stuff too!

I don't have a copy of that book, I'll keep an eye out at Goodwill for it. 

 

[jeremy k]

$30 a little steep??? - that will be minor compared to the time and effort involved in building a power hammer that works.

Please keep track and post the total hrs of time scrounging, welding/fabricating ,mat'l costs and other costs involved for this build so we can compare to our own times in building power hammers. Keep us updated.

Myself - Kinyon style power hammer builder of 2, along with a few Little Giant total rebuilds.

[Frosty]

Yeah, $30.00 is pretty cheap, I've already got more than 3 hrs into talking about this and we're not even up to coffee shop napkin sketches level yet.

A lag bolt has an unthreaded section between the head and the threads, this is the lag. The lag is the bearing surface the ID of the bushing rides on. If the lag is a bit longer than the bushing the bolt can be tightened without inhibiting the bushing's movement. Slip the link journal over the lag bolt and screw the bolt into the next piece, say the crank plate and there it is. Crank and cross head on a bronze bearing. A pillow block won't have a suitable bearing, neither roller or ball bearings really like impacts.

Forget trying to cheap some parts, bronze bushings will be available at any decent hardware store, even the Home Depot a few miles from here carries them.

Remember, you are planning on building a power tool with significant capacity to injure and kill people if something fails. Spending $30 on proven plans is pretty cheap. Just because you have a wrecked car doesn't mean you have to build the whole hammer out of it, it'll only have a few pieces that will work.

How serious do you want to get about salvaging materials and spending time? Instead of buying bearings or bushings you could tear the engine apart, strip the rod and main bearings, melt them and pour babbit bearings. Hmmm?

I don't have a copy of Clay Spencer's plans, where is the motor? on the base or on top, above or below the tire? You ALREADY have the bed rails. So you're committed eh? You're painting yourself into corners you don't know exist.

You keep referring to Clay's plans but say you don't have nor are willing to buy a set. Do you feel maybe designing your hammer with his plans is maybe worth giving the man his due?

Frosty The Lucky.

[Leeknivek]

Please keep track and post the total hrs of time scrounging, welding/fabricating ,mat'l costs and other costs involved for this build so we can compare to our own times in building power hammers. Keep us updated.

​Sure. I'd like to document most of this for those that are looking for information.

 

A lag bolt has an unthreaded section between the head and the threads, this is the lag. The lag is the bearing surface the ID of the bushing rides on. If the lag is a bit longer than the bushing the bolt can be tightened without inhibiting the bushing's movement. Slip the link journal over the lag bolt and screw the bolt into the next piece, say the crank plate and there it is. Crank and cross head on a bronze bearing. A pillow block won't have a suitable bearing, neither roller or ball bearings really like impacts.

​Sorry, when I think of lag bolt I usually think exclusively of lag bolts for wood. I understand what you mean now - this is what I was planning on doing. I hope it is clear where my confusion was after saying this....... 

"I second Jeremy. Reinventing the wheel is only desirable as a pastime unless a person has no choice."

"Remember, you are planning on building a power tool with significant capacity to injure and kill people if something fails. Spending $30 on proven plans is pretty cheap. Just because you have a wrecked car doesn't mean you have to build the whole hammer out of it, it'll only have a few pieces that will work.

How serious do you want to get about salvaging materials and spending time? Instead of buying bearings or bushings you could tear the engine apart, strip the rod and main bearings, melt them and pour babbit bearings. Hmmm?

I don't have a copy of Clay Spencer's plans, where is the motor? on the base or on top, above or below the tire? You ALREADY have the bed rails. So you're committed eh? You're painting yourself into corners you don't know exist.

You keep referring to Clay's plans but say you don't have nor are willing to buy a set. Do you feel maybe designing your hammer with his plans is maybe worth giving the man his due?

Frosty The Lucky."

​Please don't be trite and captious. This is the sort of politic that I was referring to. I do not mean to impose or to offend, but I have seen a lot of condescending talk from many users on this forum. I don't think it's very encouraging, to say the least, and certainly I can't imagine that it's very well appreciated by those on the receiving end.

Now. Back to business. 

I have looked into buying Clay Spencer's plans, however, there is only a printed copy available and no .PDF version that I could find. I do not have checks. If I could pay through PayPal and receive a .PDF document, that would be a little more practical for me. I suppose I should email him. 

(PS - I work for $9.59 an hour - so that's more than three hours of my time right there. Even without the gouging taxes one has to pay.)

I don't have a copy of Clay Spencer's plans, where is the motor?
on the base or on top, above or below the tire? You ALREADY have the bed rails. So you're committed eh? You're painting yourself into corners you don't know exist.

​I mentioned that this would be a friction drive in a previous post, so the motor will be towards the top able to come into contact with the drive wheel (spare). 

Yes, I am committed to using fully-capable owned material on a non-structural and non-critical part. I do understand what you mean, though, but I will be working with salvaged materials. I acknowledge that this comes with restrictions. On the other hand, these are literally called "Junkyard Hammers".



***DISCLAIMER - for the sake of my integrity, no sarcasm was meant in any word or phrase in this post and my words were placed carefully. I am remaining neutral and keeping my patience. 

[KRS]

Patience is something you will need, it took me a few nights drawing and calculating as I have build mine without bought plans.

I think I did the bare minimum of planning and drawing with very little changes in the shop.

Hardwood bearings will work if done correct and can always be change to PTFE or better, UHMWPE

 

 

  

[Leeknivek]

Yes, I've got it just about figured out enough to sketch it up in scale. I just need to figure out the ratios in which the linkage arms would have to be. Is there a resource for this anywhere? 

The hardwood bearings I meant for the ram guide - still debating it but ideally, like you mentioned, it needs to be something that can be replaced. I think that really only implies that it's bolted on to the frame rather than welded, which isn't that big a deal.

I'm off to the scrapyard tomorrow. I spotted a piece of I-beam there yesterday. I think, based on pictures I've seen, if the anvil is 36" tall, the mast will need to be 72" tall - twice the height - to allow a decent stroke. 

I did read, also, in my copy of "The Complete Modern Blacksmith", if it's of any news to anyone, that tightening or loosening the coil spring on LG, Fairbanks or Clay Spencer type linkages will adjust the stroke and force. 

[KRS]

It´s no rocket science and I am not trying to discourage you making your own plans,

but if you really don´t want to purchase plans you have to have a few fix points to build around.

In no particular order:

-Ram weight and geometry, slim Ram is taller, if you use round stock how do you prevent it from rotating

-Cam, crank distance to centre, variable?

-Stroke, distance between the dies- idle/max rpm, variable?

-RPM, diameter of the motor wheel, and the tire- if you go too fast with a dupont linkage it will do....     nothing.

-Spring, this depends on position, RPM at the crankshaft, length of the crank, weight of the Ram

-how much Spring tension in idle/ Top/Bottom dead centre, how to adjust the tension.

-changeable dies? do you want to use tools with the hammer?

-optional: safety?

I think you need to make final decisions for at least 3 points from the list before you go on

[swedefiddle]

Good Morning, Lee

I don't see anything Trite or Captious in Frosty's suggestions. What I see is Frosty asking you to slow down your thinking, BEFORE you make a grave mistake.

Knowledge from someone who has taken the time to write a set of blueprints, is gold!! Then you can read between the lines and do your own adjustments as per what inventory you have scrounged. You don't have to purchase as set of drawings, BUT, sometimes you might glean a thought for a potential problem. In the bigger picture of your Life-Time, a few weeks is not a hurdle, compared to costly mistakes. It's sometimes VERY HARD to be humble.

I am not interested in what you call politics, I am interested in people not getting HURT. Please stay SAFE.

just my $.02

Neil

[Leeknivek]

I don't have the means to purchase plans unless they're available in .PDF format. 

From what I've imagined in ram geometry, the ram will be in some way leveled by the linkage in two axis, X and Y, if Z is vertical stroke. This would, however, put more lateral stresses on the linkage members and not allow a completely square ram. In using a DuPont style linkage, the ram is attached at two points and the rotation of the ram would be dependent on how loose the linkage is. More loose of a linkage means an easier movement in stroke, more powerful stroke while creating potentially more wear on moving parts - and vice versa, more stiff linkage means more effort required to move the ram and less powerful stroke, but likely even more wear on parts however the ram should be more centered and less prone to lateral movement. This is the basis for a guide - to not only center the ram but to also remove points of stress from the linkage due to lateral movement. 

I don't claim this to be entirely true, of course, this is just how I understand it. Feel free to correct me, I'm only assuming based on reasoning. 

I am, right now, undecided on how my ram will be guided because that will be left to what I am able to find. The only thing I will be buying new in this project is hardware - new steel is incredulously more expensive than scrap. 

I have found a few options - 

Using a square ram, which will be inherently shorter than cylindrical rams of the same weight: 

1. Wide Roller Bearings set in heavy (3"x1/4") angle iron. I have read that this design is relatively simple to construct, so long as care is taken to make all the holes square, and has the benefit of little drag and little maintenance, as opposed to other fully enclosed designs.

2. The "traditional" square tubing. Easier to assemble, so long as care is taken in squareness, but with the trade-off of more maintenance compared to option 1.

3. An alternative V-ways that I've come up with myself, in which the flange of railroad track or i-beam is used as the negative, with an enclosed, bolted on guide of plate. This would require some squaring up of the flange, but I think a grinder, a level, and a good eye is sufficient. A light oil or heavy grease should work fair enough. 


Using a cylindrical ram:

1. Wide Roller Bearings, as above, but ideally with a radius to fit the cylinder. 

2. Thick-walled pipe. Same merits as option 2. above. 

----------This is all using a DuPont style linkage. A Beaudry-style linkage can only work with V-ways, and I am still considering that route. In videos I have seen, Beaudry linkages seem to have more snap. More velocity = more force, the main difference between a drop hammer and a power hammer. 

What I end up doing is entirely dependent on what I can find. I think all options will work well, but option 1 - using roller bearings - has the most merit, I think, in that it is simple yet reliable. 


The stroke and all that follows is also going to be dependent on what is used for a ram. 

The drive system is comprised of the following:

>Electric motor with 2.5" diameter drive wheel
>Spare tire donut, 19.5" diameter crank
>Crank plate, on the center of crank
>Eccentric shaft, final drive point of the drive system.

There is a great resource for computing pulley ratios and RPM's, among other things, on a website called Blocklayer.com. Using this resource, I have found the following:

With the sizes listed above, an input RPM from the 2.5"d drive wheel of 1750 (common on most motors) will net an RPM of 225 on the 19.5"d spare tire crank. 225 RPM on a 50lb tup should be fair, so long as I'm not overworking, under-maintaining or otherwise abusing the machine. 

I have considered also using 3/4" drive sockets. I recently came across an old set while cleaning. A 3/4" drive socket wrench will typically be a 3/4" drive machined into a larger cylinder, mounted onto a steel shaft. Using this, it offers the option of changing drive wheel diameters. 3/4" sockets surely aren't cheap, but since I have an entire set with no use, it may be worth experimenting with. 



Most of your points, KRS, are dependent on me having at least a ram first. I hope the above illustrates that I am taking this seriously and planning out what I can. 


For the dies I will be using the top bit on pieces of rail track, welded to plate, bolted into the ram and anvil. I'll tap the holes with the biggest size tap that I own - probably 1/2" or 5/8". If that turns out to be too small, I can always go larger. 

As far as safety, surely I have no incentive to kill or maim my person. I don't think blacksmithing is the epitome of safety to begin with, never mind mechanical power hammers (homemade or commercial). 

I have a large grille of steel, meant to cover the rear window on a pickup, that I will probably form around the linkage to form a protective shroud. I will also be using some sort of lockout device - maybe even a vehicle ignition - so that the hammer requires a key to be powered on. Just so that it doesn't accidentally get turned on. 


I appreciate all the feedback, really. This is helping me along a great amount. Thank you. 
 

[Charles R. Stevens]

The flywheel/drive plate will have to be welded to the wheel as you can't bolt threw a tubeless rim. If you don't seperate the tire from the wheel, the rubber will not like the welding heat. It doesn't need to be fully welded. I suggest having holes bored to accomidate the lug nuts or it will make wheel bearings impossible to service. A hole close to the rim (2 for balance) is useful for re driving the inevitable dropped lug nut. Multiple holes drilled and taped for the drive rod will make it easier to dial in the onset you need to drive the hammer.

as to bolt grades, grase 8 bolts have higher tensile strength, and there for can be torcd tighter, but they don't do so well in shear, use a larger size or a grade 5 for pivot pins (larger size is good as grade 8 bolts are harder and will last longer) for most applications grade 5 bolts are what hold your car to gether and should be sufficient. If you have an application where maximum clamping force is needed, use grade 8 studs, with grade 8 nuts and washers. SAE corse thread is usualy sufficient but again in a high clamping force application use fine thread ( not recommended in aluminum with out inserts or exposed to heat, IE exhaust manifolds)

I was a mechanic in another life, so the scrounged up car parts are something I know all to well.

i myself am looking at a helve style lineage, it has a larger foot print but the leaf spring over the top makes it usable as either a treadle hammer or adapted to power. Not to mention easer to build the lincage. 

 

[arftist]

Charles why couldn't the drive plate or whatever be bolted on to the wheel using the lug stud holes? Obviously the mounting studs would need to be longer.  

Also I have to politely disagree about bolts, grade 5 are used for automotive work because they are strong enough, and cheaper. Winches wouldn't be mounted with grade 8s if 5's were stronger. I am afraid this is a myth. 

[Charles R. Stevens]

The issue with using longer studs is, 

1. Long metric or standard fine thread, 

2. The center hub pilot and/or the acorn nuts (lug nuts) center the wheel on the hub assembly. It can be done, but I think it's more work. Depending on the crank offset one might get away with just cutting out the cente of the plate.

3. One must use something to prevent the center from bending in, such as pipe spacers. 

As to grade 8 bolts, I may have been misinformed in trade school and by GM engineers. It is my understanding that in applications where placed in shear, the greater potential for clamping force should be taken advantage of so friction between the two components will take most of the load, such as winch mounts and truck drawbars. I prime example is the steering gear box and cracked frames on late 70-80's 4wheel drive Chevy trucks. Using grade 8 bolts in place of the original grade 5's especially with out the funky crush leave backspaces will lead to bolt failure and frame cracks. The use of the factory bolts and spacers works very well, but a frame plate must be used with grade 8 faceners alog with higher torc. The grade 8 faceners indeed has higher tensile strength, but is some what more britle. There for it is recommended that it not be used in shear, or it should be used in a larger size than a grade 5. 

[Leeknivek]

Grade 5 vs. Grade 8 bolts:

Grade 5 (sized 1/4"-1")

Yield Strength: 92,000 psi
Tensile Strength: 120,000 psi


Grade 8 (sized 1/4"-1 1/2")

Yield Strength: 130,000 psi
Tensile Strength: 150,000 psi


There are more sources out there, I'm certain, but the numbers say grade 8 is far superior to grade 5 in terms of tensile strength and shear rating. They have to be in order to be classified as such. 

That being said, considering that mild steel "has a minimum yield strength of 36,000 psi and ultimate tensile strength of 58,000–80,000 psi"​, and most weld filler materials have a tensile strength of around 70,000+ psi, I think grade 5 will do fine for a power hammer. Grade 8's, as Charles mentioned, should inevitably last longer. 

__________________________

Based on what you've said, Charles, it does seem like using the studs is more trouble than it's worth. I'll just have to remove the tire and run a few beads. If I make my own crank plate, I can give extra space on the opposite side for a counterweight if I need it.


I think I'm going to use 5/8"ID x 3/4"OD x 1" OAL bronze bushings, inserted into 3/4"ID x 1 1/16"OD black steel pipe. This allows me to use 5/8" or 3/4" threaded rod for the spring. I still don't have a ram or coil spring and am having trouble calculating how long the toggle arms and toggle links should be. I guess it's probably not very important, but I think it will determine how hard my ram will hit and how long my stroke will be. This is important for planning the guide. 

 

Edited March 28, 2015 by Leeknivek

[Leeknivek]

Here's a quick and dirty .gif I made, also, from an image I found on Google. Just for fun.

 

[Charles R. Stevens]

Don't over look some of the easily obtained specialty hard ware, such as spring shackle bolts,

[dragon]

Just to toss it out there, Clay does accept paypal for his plans. I think he charges $2 more if paying by paypal to cover the fee.  Just send him an email asking about it.   I purchased a set of his plans that way, myself.

[KRS]

On topic of welding the flywheel to the tire, I think a rear mounted drive wheel has enough advantages to consider it.

It makes it easy to change the tire, you don´t have to weld anything to the tire. The part where the motor wheel and the tire connects is further away from the user.

It allows a versatile build and is not more complex then a front wheel drive. And obviously for drifting you need a rear wheel drive

Edit: Lee, in the animated image the motor is wrong mounted, it should climb the wheel for a better control.

Edited March 29, 2015 by KRS

[arftist]

On topic of welding the flywheel to the tire, I think a rear mounted drive wheel has enough advantages to consider it.

It makes it easy to change the tire, you don´t have to weld anything to the tire. The part where the motor wheel and the tire connects is further away from the user.

It allows a versatile build and is not more complex then a front wheel drive. And obviously for drifting you need a rear wheel drive

Edit: Lee, in the animated image the motor is wrong mounted, it should climb the wheel for a better control.

​That makes a lot of sense to me. Move a lot of the rotating stuff away from your face especially the intersection of the tire and drive wheel. 

 

To the OP; Please use grade 8s only. Not sure why you think a powerhammer doesn't suffer much stress, in reality the shock created by the hammer blows means a powerhammer has much more strains to bear than most other machines. The strength of steel has nothing to do with it whatsoever. 

One other thing; the geometry of the toggle arm assembly is beyond critical. This is the main reason I would buy a set of plans, and is evidence by the difference between a true Dupont linkage (not fussy, works smooth and easy) and the modified version found on a Little Giant (must be tuned well for satisfactory performance). 

One additional thing; glad you chose to use bushings however the I.D. of 3/4 pipe is not remotely close enough to 3/4" to use drive in bushings. Schedule 80 is slightly smaller, perhaps it could be reamed to 3/4". 

[Leeknivek]

finally got to see what the scrapyard has. Found an i-beam mast, a huge structural i-beam for the base, and I have two options for the anvil.

option 1 - about 8"Dx30-36"H. Looks to be a large ram of some sort, has a cast in loop with steel wire running through it on one side. Only problem - it might be cast iron. This is the better of the two choices, aside from the cast iron possibility. Is it worth trying to weld? (my stick welder goes up to 400amps, 220v). It may just be hardened, hard to tell with the few minutes i had. There was a thin section where the cast-in loop is, chipped right off with no effort. Hit it with a junk hammer I found. This piece would be my preference.

I guess I could bolt it in, also.

 

Option 2 - an industrial roller for a printing press or something to that effect. About 4-5" in diameter but 7' long. Steel.

 

 

both have machined surfaces. Both are probably about the same weight. One is fat and short, one is skinny and long. I could even cut a hole in the base to plant the long one in the ground however long I need it to be, setting this up outside.

 

opinions?? Price is $0.25/pound

Edited April 6, 2015 by Leeknivek