Large HPR Rail Base Build

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DRAGON64

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Based on the brilliant ProRail Base (now referred to as Rail Launch Pad Base) built by John Coker

Many years ago, Inspired by John Coker's launch pad design, I built my own variant Rail Base for HPR use. My variant is designed around 2" square tube material, and handles anything that can launch using buttons for the standard 1010 8020 rail (F thru J impulse). My variant was completely assembled using stainless nuts and bolts, as I did not have access (or funding) to weld capabilities. The pad has served me well:

IMG_2103.jpg


Now I have a need to build another pad, this time in support of much larger projects that will handle L, M & N impulse, utilizing the 1515 8020 rail, and supporting rockets weighing 45 to 100 pounds. This variant is a complete upscale of my original build, and will be based on 3" square Aluminum tube.

For the original pad I built, I sourced the raw material from OnlineMetals.com. The cost of raw material from Online Metals for this new build was a bit staggering, at $400+ I did a little consumer research shopping and stumbled across Mid West Steel & Aluminum; even with $51 shipping included, the cost for raw material was a comfortable $235!

My wife said that the UPS guy was not happy dragging this box off the truck, but stated he was glad it was off the truck...

IMG_0617.jpg


To my surprise, based the condition of the box, no parts material was lost in transit...

IMG_0619.jpg


Once unboxed, the parts looked a little like overkill, especially considering the material alone weighs 61lbs without the rail, or any connecting nuts, bolt and washers... You can smell the cutting oil on this material... luv it!

Before I get to full design and assembly, deburring the material is first and foremost the most important first task...

IMG_0622.jpg
 

tfish

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looks good!

yes...Cokers design is pretty cool..I have 8 "Coker style" pads in the shop waiting for their 1515 rails.

On some of the pads I put 1010 rails on one side of the Boom and 1515 rails on the other side. Then you just have to flip the Boom to the size you need.

Tony
 

DRAGON64

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Dual purposing the boom with both 101 & 1515 rails is a great idea! Question; are/did you Tig welding or bolt your pads together? I am considering getting a quote to get some of the key plates welded to save on stainless steel hardware weight.
 

tfish

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My pads are highly modified "Coker" style pads... this thread sort of shows the progression of the pads https://www.rocketryforum.com/threads/modified-john-coker-pads.138634/

They are both bolted and welded. I use a MIG with a spool gun.
Yep stainless hardware can add up fast. I use galvanized hardware on some price sensitive projects.

Feel free to PM me any questions...I don't want to bomb your pad thread

Tony
 

DRAGON64

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Nice work on those pads, far more modified than what my mission plan is, hats off man!
 

DRAGON64

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I have modeled the pad in SolidWorks, currently without hardware installed. Hardware installation in SolidWorks will highlight minor shifts in leg hole mounts, otherwise the pad is close to going into production.

Shown here with a single 6' piece of 1515 rail. I have two 6' lengths that I will link for the total working length of 12'

RAIL BASE 01.jpg


RAIL BASE 02.jpg


RAIL BASE 03.jpg
 

DRAGON64

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This pad, like my original pad, will allow for 5° of adjustment from vertical, away from the flight line.
 

DRAGON64

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A quick minor update; it looks like I will have a path to getting this pad welded together instead of using a nut and bolt assembly process. Now working on a drawing package to send to the welder so that I can get a quote... cost should come in under the cost of stainless steel hardware.
 

DRAGON64

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So the components are going to a local shop today to get welded up! This will save a bit of cash on hardware, not having to buy a lot of stainless steel, and they will even drill and cut the parts that I need to bring it all together. Total cost will not to exceed $100. I will post pics of the welded assembly(s) when I get them back home.
 

DRAGON64

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I had hopes to get the welded assembly back from Engineering Management Services today, but they had a little back log of other welding projects done, so they could not fit mine in by close of business this past Friday. Hopefully I will get the parts back by Wednesday, Friday at the latest.
 

DRAGON64

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Finally, the welding is complete, and the pad components are back in my shop. I can now start final assembly with stainless hardware, and marrying up the 1515 rail.

IMG_2095.jpg


IMG_2094.jpg


This pad is huge!
 

DRAGON64

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So my coin has equalized enough for me to place an order to McMaster-Carr for stainless steel hardware to finish assembly of my launch pad. Where applicable, I ordered 316 stainless for its corrosive resistance, and 18-8 on components not available in 316.

Total cost not including 1515 rail:

Raw material was: $235
Welding was: $100
Stainless hardware: $133 delivered

I left off the 1515 rail in the pricing, as I have owned these parts for nearly 15-years, and that money is long since spent and forgotten. However todays pricing from McMaster-Carr is $68.39 per 6' section, plus shipping... which can be costly, 15 years ago I do remember paying upwards of $30 for shipping!! Shop around, or put together a group order to save money.

As for a blast deflector; I have an un-used DirecTV dish that will work perfectly!

Once assembled, I will get a weight on this pad, as this pad will need to be drug 500+ft into the field, and it may be a cardio experience for some.
 

mtnmanak

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For anyone needing the rails, you can get 1515 rail from 80/20 at $0.48 per inch (current pricing). Last time I bought rails from them (a little over a year ago), I bought 4 x 6' sections and paid $27 in shipping. I will save you the math - that came out to about $42 a rail, including shipping. Their 1010 rails are currently selling at $0.26 an inch.

 
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DRAGON64

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Definitely shop around, as better pricing can be had for those long rail components. One consideration, which goes without mentioning, but I digress, consider how you will store, and transport your rail. In my case I opted for 2-pieces at 6ft; enough for length when assembled for safe launch of larger and heavier vehicles, but also logistically manageable in a car or truck.

I am still waiting on the bolts to come in from McMaster-Carr, and then I can assemble the pad; pics are coming!
 

mtnmanak

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Grainger also carries 80/20 rails. I bought some 1010 from them and didn't have to deal with shipping since they have a local branch.
Awesome, I didn't realize Grainger sold them. I get a bunch of stuff through Grainger to avoid shipping costs (like compressor oil. Why is it so hard to get good compressor oil?). Going through the Grainger catalog is like a kid going through the toy store catalog at Christmas...

Definitely shop around, as better pricing can be had for those long rail components. One consideration, which goes without mentioning, but I digress, consider how you will store, and transport your rail. In my case I opted for 2-pieces at 6ft; enough for length when assembled for safe launch of larger and heavier vehicles, but also logistically manageable in a car or truck.

I am still waiting on the bolts to come in from McMaster-Carr, and then I can assemble the pad; pics are coming!
Definitely agree with using multiple shorter sections. Clubs that store their rails onsite can get away with longer pieces, but for a mobile solution, multiple sections is the way to go.

Looking forward to seeing your new pads! May be time for me to move past my Jaw Stand pad!
 

DRAGON64

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I considered the Jaw Stand pad as a suitable replacement for my PVC mid power pad, but as I moved further and further away from mid power rocketry, I decided against it. My other rail base pad pulls double duty, as long as I build all my rockets with rail buttons, so when I do, I fly both HPR and MPR from the rail base.

IMG_2103.jpg
 

DRAGON64

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I have some minor fitment items (grinding some fat welds), otherwise the pad went right together.

IMG_2127.jpg


Here the new pad is compared to my original HPR pad.

IMG_2128.jpg
 
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