Injection Molder/Research Development - Revision history

4ndy at 16:07, 24 January 2015

2015-01-24T16:07:41Z

← Older revision		Revision as of 16:07, 24 January 2015
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	Afterthought: In order to be used with a leadscrew, perhaps an ACME threaded nut could be welded or clamped onto the side of the shaft of one of these syringes, near the thumb-ring at the top. However, this would leave the driving force offset from the piston's longitudinal axis, and could result in the driving rod being bent through buckling force. Alternatively, a nut could be held inside something that fits into the thumb-ring itself, and the guiding plate left in place at the top.		Afterthought: In order to be used with a leadscrew, perhaps an ACME threaded nut could be welded or clamped onto the side of the shaft of one of these syringes, near the thumb-ring at the top. However, this would leave the driving force offset from the piston's longitudinal axis, and could result in the driving rod being bent through buckling force. Alternatively, a nut could be held inside something that fits into the thumb-ring itself, and the guiding plate left in place at the top.

			===Narrow-barrel design===
			Using a leadscrew to drive the piston in a drill stand/press instead of its leverage allows a longer, narrower barrel to be used, such as a 1" pipe/nipple. It should be feasible to turn a piston to fit the barrel out of aluminium cast into the rough shape needed. A nut holder / guide for the leadscrew could then be bolted onto the piston via some cast shape, holes drilled into the piston, or welded onto a steel rod piston if one could be found that fit the barrel.

	===Mould plates===		===Mould plates===
	Though cylinder pressure is unknown, clamping force for plates in commercial machines [https://en.wikipedia.org/wiki/Injection_moulding#Equipment has been given] (reliable?) as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.		Though cylinder pressure is unknown, clamping force for plates in commercial machines [https://en.wikipedia.org/wiki/Injection_moulding#Equipment has been given] (reliable?) as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.

4ndy: Added notes about leadscrew drives obviating the problem of limited drill press displacement, linked to WP writing about clamping force

2015-01-24T15:26:52Z

Added notes about leadscrew drives obviating the problem of limited drill press displacement, linked to WP writing about clamping force

← Older revision		Revision as of 15:26, 24 January 2015
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	Possible resulting problem: the piston will need a much higher force on it in order to deliver the same pressure out the nozzle, and hoop stress on a pipe used for the barrel may be an issue (need verification from those who have tested this before). Will the 4mmx20mm steel bar lever in this stand provide enough leverage to press such a piston down without warping? Moments: the press-bar mounting point is 80mm from the pivot/fulcrum, the handle extends 260mm beyond that, for a total of up to 340mm leverage distance.		Possible resulting problem: the piston will need a much higher force on it in order to deliver the same pressure out the nozzle, and hoop stress on a pipe used for the barrel may be an issue (need verification from those who have tested this before). Will the 4mmx20mm steel bar lever in this stand provide enough leverage to press such a piston down without warping? Moments: the press-bar mounting point is 80mm from the pivot/fulcrum, the handle extends 260mm beyond that, for a total of up to 340mm leverage distance.

			Alternative solution: instead of using the drill stand's lever, a [https://en.wikipedia.org/wiki/Leadscrew leadscrew] could be mounted in a hammer drill in order to drive a piston into the injection barrel. For instance, [http://www.techkits.com/model_20/home.html LNS Technologies' PIM drill-press accessory] appears to use such a system. This requires an appropriate (e.g. ACME thread) nut to be fastened onto the piston somehow, and for the drill's bearing to be capable of withstanding the corresponding pressure without damage (not to mention that the clamp holding it must not slip). So that the leadscrew does not need to pass through the piston itself, the corresponding nut needs to be fastened well above the piston, ideally to the internal length of the barrel.

	===Wide-barrel design===		===Wide-barrel design===
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	====Reusing Unintended Parts design====		====Reusing Unintended Parts design====
	Just get an [http://www.ebay.co.uk/itm/Vintage-3Ring-Medical-Doctor-Dentist-Vet-Stainless-Steel-Chrome-Brass-Syringe-/161489747182?pt=UK_Collectables_Scientific_MJ&hash=item259989fcee old stainless steel medical syringe] and stick a heat-sink on it. Done. Piston is guaranteed to fit the barrel perfectly.		Just get an [http://www.ebay.co.uk/itm/Vintage-3Ring-Medical-Doctor-Dentist-Vet-Stainless-Steel-Chrome-Brass-Syringe-/161489747182?pt=UK_Collectables_Scientific_MJ&hash=item259989fcee old stainless steel medical syringe] and stick a heat-sink on it. Done. Piston is guaranteed to fit the barrel perfectly. I am seriously considering getting a cheap second-hand one of these right now to start adapting.

	Problem: will the wall thickness be too thin and [https://en.wikipedia.org/wiki/Cylinder_stress cause a split?] We need to know necessary injection pressure for small moulds for this.		Problem: will the wall thickness be too thin and [https://en.wikipedia.org/wiki/Cylinder_stress cause a split?] We need to know necessary injection pressure for small moulds for this.

	~~I am seriously considering getting~~ a ~~cheap second-hand~~ one of these ~~right now to start adapting~~.		Afterthought: In order to be used with a leadscrew, perhaps an ACME threaded nut could be welded or clamped onto the side of the shaft of one of these syringes, near the thumb-ring at the top. However, this would leave the driving force offset from the piston's longitudinal axis, and could result in the driving rod being bent through buckling force. Alternatively, a nut could be held inside something that fits into the thumb-ring itself, and the guiding plate left in place at the top.

	===Mould plates===		===Mould plates===
	Though cylinder pressure is unknown, clamping force for plates in commercial machines ~~is commonly~~ given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.		Though cylinder pressure is unknown, clamping force for plates in commercial machines [https://en.wikipedia.org/wiki/Injection_moulding#Equipment has been given] (reliable?) as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.

4ndy: Altered headings, lobotomised sense of humour that might be lost in translation, and moved integrated design to top

2015-01-24T14:55:48Z

Altered headings, lobotomised sense of humour that might be lost in translation, and moved integrated design to top

← Older revision		Revision as of 14:55, 24 January 2015
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			==Integrated Frame==

			===Narrow Steel Rod, Drilled Aluminium Block design===
			See [http://rick.sparber.org/Articles/gpi.pdf Rick Sparber's modified Gingery] system. Steel rods can easily be salvaged from (sadly abundant) broken-down inkjet printers from scrap yards. If a thick plate/ingot of aluminium cannot be found, a barrel/chamber can be cast out of small scraps of aluminium (pending a 3D-printed form for ideal shape).

			===Thick Steel Rod and Pipe design===
			Dave Hakkens has put together [http://www.preciousplastic.com/machines/injection/ an initial prototype] for an all-steel injection moulder. A solid design using a wide square-tube frame and a long piece of 30mm steel rod for the piston, this thing would not be easy to transport.

	==Drill Stand Accessory==		==Drill Stand Accessory==
	Having recently got hold of a cheap [http://www.ebay.co.uk/sch/i.html?_nkw=power+drill+stand&_sop=15 power drill stand] from LIDL (£13, brand 'Powerfix') that could be used to kickstart development of this, by focusing on designing a modular piston & chamber system that could be mounted in any such [[drill press]], instead of one integrated into a frame like the Gingery design, I have been looking into options: [[User:4ndy\|4ndy]] ([[User talk:4ndy\|talk]]) 21:57, 3 December 2014 (CET)		Having recently got hold of a cheap [http://www.ebay.co.uk/sch/i.html?_nkw=power+drill+stand&_sop=15 power drill stand] from LIDL (£13, brand 'Powerfix') that could be used to kickstart development of this, by focusing on designing a modular piston & chamber system that could be mounted in any such [[drill press]], instead of one integrated into a frame like the Gingery design, I have been looking into options: [[User:4ndy\|4ndy]] ([[User talk:4ndy\|talk]]) 21:57, 3 December 2014 (CET)
Line 6:		Line 14:
	Possible resulting problem: the piston will need a much higher force on it in order to deliver the same pressure out the nozzle, and hoop stress on a pipe used for the barrel may be an issue (need verification from those who have tested this before). Will the 4mmx20mm steel bar lever in this stand provide enough leverage to press such a piston down without warping? Moments: the press-bar mounting point is 80mm from the pivot/fulcrum, the handle extends 260mm beyond that, for a total of up to 340mm leverage distance.		Possible resulting problem: the piston will need a much higher force on it in order to deliver the same pressure out the nozzle, and hoop stress on a pipe used for the barrel may be an issue (need verification from those who have tested this before). Will the 4mmx20mm steel bar lever in this stand provide enough leverage to press such a piston down without warping? Moments: the press-bar mounting point is 80mm from the pivot/fulcrum, the handle extends 260mm beyond that, for a total of up to 340mm leverage distance.

	===Standardised Parts ~~Overkill~~ design===		===Wide-barrel design===

			====Standardised Parts design====
	Drive an [http://www.ebay.co.uk/itm/Piston-Rings-Kit-Assembly-40-mm-fit-for-STIHL-023-MS-230-/191260014091?pt=UK_Home_Garden_GardenPowerTools_CA&hash=item2c87fc360b aluminium compressor piston] down a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½ inch steel pipe], with a bespoke con-rod made out of whatever (a wooden board should do here for compressive strength, but steel plate or rod is preferable), use a [http://www.ebay.co.uk/itm/Male-x-Male-Hex-Nipple-Threaded-Reducer-Pipe-Fitting-Stainless-Steel-304-BSP-/251513956597?pt=UK_DIY_Materials_Plumbing_MJ&var=&hash=item3a8f6668f5 1½" to ½" reducer nipple] and tap a corresponding threaded hole into the mould gate for a perfect seal between nozzle & plates.		Drive an [http://www.ebay.co.uk/itm/Piston-Rings-Kit-Assembly-40-mm-fit-for-STIHL-023-MS-230-/191260014091?pt=UK_Home_Garden_GardenPowerTools_CA&hash=item2c87fc360b aluminium compressor piston] down a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½ inch steel pipe], with a bespoke con-rod made out of whatever (a wooden board should do here for compressive strength, but steel plate or rod is preferable), use a [http://www.ebay.co.uk/itm/Male-x-Male-Hex-Nipple-Threaded-Reducer-Pipe-Fitting-Stainless-Steel-304-BSP-/251513956597?pt=UK_DIY_Materials_Plumbing_MJ&var=&hash=item3a8f6668f5 1½" to ½" reducer nipple] and tap a corresponding threaded hole into the mould gate for a perfect seal between nozzle & plates.

	Problem: a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½" BSP pipe] is supposed to have a 'nominal' diameter of 40mm. Does this mean inside diameter, and how close do they actually come? Will a 40mm piston have a loose fit or interference fit, and so do we need a larger/smaller piston with silicone o-rings to seal it properly? ''Why do we still use imperial pipe sizes when everything else is already metric??~~'' Bloody plumbers...~~		Problem: a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½" BSP pipe] is supposed to have a 'nominal' diameter of 40mm. Does this mean inside diameter, and how close do they actually come? Will a 40mm piston have a loose fit or interference fit, and so do we need a larger/smaller piston with silicone o-rings to seal it properly? Why do we still use imperial pipe sizes when everything else is already metric??

	===Reusing Unintended Parts design===		====Reusing Unintended Parts design====
	Just get an [http://www.ebay.co.uk/itm/Vintage-3Ring-Medical-Doctor-Dentist-Vet-Stainless-Steel-Chrome-Brass-Syringe-/161489747182?pt=UK_Collectables_Scientific_MJ&hash=item259989fcee old stainless steel medical syringe] and stick a heat-sink on it. Done. Piston is guaranteed to fit the barrel perfectly.		Just get an [http://www.ebay.co.uk/itm/Vintage-3Ring-Medical-Doctor-Dentist-Vet-Stainless-Steel-Chrome-Brass-Syringe-/161489747182?pt=UK_Collectables_Scientific_MJ&hash=item259989fcee old stainless steel medical syringe] and stick a heat-sink on it. Done. Piston is guaranteed to fit the barrel perfectly.

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	I am seriously considering getting a cheap second-hand one of these right now to start adapting.		I am seriously considering getting a cheap second-hand one of these right now to start adapting.


	===Mould plates===		===Mould plates===
	Though cylinder pressure is unknown, clamping force for plates in commercial machines is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.		Though cylinder pressure is unknown, clamping force for plates in commercial machines is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.

	~~==Integrated Frame==~~

	~~===Narrow Steel Rod, Drilled Aluminium Block design===~~
	See [http://rick.sparber.org/Articles/gpi.pdf Rick Sparber's modified Gingery] system. Steel rods can easily be salvaged from (sadly abundant) broken-down inkjet printers from scrap yards. If a thick plate/ingot of aluminium cannot be found, a barrel/chamber can be cast out of small scraps of aluminium (pending a 3D-printed form for ideal shape).

	~~===Overkill Steel Rod and Pipe design===~~
	Dave Hakkens has put together [http://www.preciousplastic.com/machines/injection/ an initial prototype] for an all-steel injection moulder. A solid design using a wide square-tube frame and a long piece of 30mm steel rod for the piston, this thing would not be easy to transport.

4ndy: /* Mould plates */ clarification

2014-12-17T18:36:54Z

Mould plates: clarification

← Older revision		Revision as of 18:36, 17 December 2014
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	===Mould plates===		===Mould plates===
	Though cylinder pressure is unknown, clamping force for ~~the~~ plates is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.		Though cylinder pressure is unknown, clamping force for plates in commercial machines is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.


	==Integrated Frame==		==Integrated Frame==

4ndy: Added notes on integrated frame designs.

2014-12-03T22:00:12Z

Added notes on integrated frame designs.

← Older revision		Revision as of 22:00, 3 December 2014
Line 20:		Line 20:

	===Mould plates===		===Mould plates===
	Though cylinder pressure is unknown, clamping force for the plates is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be ~~overkill~~, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.		Though cylinder pressure is unknown, clamping force for the plates is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be unnecessary, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.


			==Integrated Frame==

			===Narrow Steel Rod, Drilled Aluminium Block design===
			See [http://rick.sparber.org/Articles/gpi.pdf Rick Sparber's modified Gingery] system. Steel rods can easily be salvaged from (sadly abundant) broken-down inkjet printers from scrap yards. If a thick plate/ingot of aluminium cannot be found, a barrel/chamber can be cast out of small scraps of aluminium (pending a 3D-printed form for ideal shape).

			===Overkill Steel Rod and Pipe design===
			Dave Hakkens has put together [http://www.preciousplastic.com/machines/injection/ an initial prototype] for an all-steel injection moulder. A solid design using a wide square-tube frame and a long piece of 30mm steel rod for the piston, this thing would not be easy to transport.

4ndy: Creation: added details on drill stand accessory type design. You know you're on Diaspora/Reddit too much when you hit 'show preview' only to find that you used some Markdown links out of habit.

2014-12-03T20:57:16Z

Creation: added details on drill stand accessory type design. You know you're on Diaspora/Reddit too much when you hit 'show preview' only to find that you used some Markdown links out of habit.

New page

==Drill Stand Accessory==
Having recently got hold of a cheap [http://www.ebay.co.uk/sch/i.html?_nkw=power+drill+stand&_sop=15 power drill stand] from LIDL (£13, brand 'Powerfix') that could be used to kickstart development of this, by focusing on designing a modular piston & chamber system that could be mounted in any such [[drill press]], instead of one integrated into a frame like the Gingery design, I have been looking into options: [[User:4ndy|4ndy]] ([[User talk:4ndy|talk]]) 21:57, 3 December 2014 (CET)

'''Limitation''': the drill only traverses up to 60mm vertically when the lever is swung, though the whole carriage can be positioned anywhere on the top half-or-so of a 500mm post. Consequently, the piston should only need to press up to 60mm in order to inject the plastic, so a short & wide barrel is needed, rather than the long, narrow option of Gingery's steel rod in a drilled-out aluminium block.

Possible resulting problem: the piston will need a much higher force on it in order to deliver the same pressure out the nozzle, and hoop stress on a pipe used for the barrel may be an issue (need verification from those who have tested this before). Will the 4mmx20mm steel bar lever in this stand provide enough leverage to press such a piston down without warping? Moments: the press-bar mounting point is 80mm from the pivot/fulcrum, the handle extends 260mm beyond that, for a total of up to 340mm leverage distance.

===Standardised Parts Overkill design===
Drive an [http://www.ebay.co.uk/itm/Piston-Rings-Kit-Assembly-40-mm-fit-for-STIHL-023-MS-230-/191260014091?pt=UK_Home_Garden_GardenPowerTools_CA&hash=item2c87fc360b aluminium compressor piston] down a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½ inch steel pipe], with a bespoke con-rod made out of whatever (a wooden board should do here for compressive strength, but steel plate or rod is preferable), use a [http://www.ebay.co.uk/itm/Male-x-Male-Hex-Nipple-Threaded-Reducer-Pipe-Fitting-Stainless-Steel-304-BSP-/251513956597?pt=UK_DIY_Materials_Plumbing_MJ&var=&hash=item3a8f6668f5 1½" to ½" reducer nipple] and tap a corresponding threaded hole into the mould gate for a perfect seal between nozzle & plates.

Problem: a [https://en.wikipedia.org/wiki/British_Standard_Pipe#Pipe_thread_sizes 1½" BSP pipe] is supposed to have a 'nominal' diameter of 40mm. Does this mean inside diameter, and how close do they actually come? Will a 40mm piston have a loose fit or interference fit, and so do we need a larger/smaller piston with silicone o-rings to seal it properly? ''Why do we still use imperial pipe sizes when everything else is already metric??'' Bloody plumbers...

===Reusing Unintended Parts design===
Just get an [http://www.ebay.co.uk/itm/Vintage-3Ring-Medical-Doctor-Dentist-Vet-Stainless-Steel-Chrome-Brass-Syringe-/161489747182?pt=UK_Collectables_Scientific_MJ&hash=item259989fcee old stainless steel medical syringe] and stick a heat-sink on it. Done. Piston is guaranteed to fit the barrel perfectly.

Problem: will the wall thickness be too thin and [https://en.wikipedia.org/wiki/Cylinder_stress cause a split?] We need to know necessary injection pressure for small moulds for this.

I am seriously considering getting a cheap second-hand one of these right now to start adapting.

===Mould plates===
Though cylinder pressure is unknown, clamping force for the plates is commonly given as requiring a few tons. For lost-PLA cast aluminium plates, the top end of the plates could have smooth/threaded holes through each side to clamp them together with a pair of hexagonal-cap bolts, while the work-piece vice of the drill stand can hold the bottom end. This itself may be overkill, as [https://www.youtube.com/watch?v=uD-kCf8amHk this video] shows a drill stand vice providing sufficient clamping force for small moulds. The bolts would make good locating pins however, making it easier to align the plates.